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Friday, December 29, 2017
This Months Highlights
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Thoughts on Turning 29
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Glomerular Disease Pathology in the Era of Proteomics: From Pattern to Pathogenesis
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Renal Dendritic Cells: The Long and Winding Road
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Mesenchymal Stromal Cells for AKI after Cardiac Surgery
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Clusters Not Classifications: Making Sense of Complement-Mediated Kidney Injury
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Genetic Complexity of Autosomal Dominant Polycystic Kidney and Liver Diseases
Data indicate significant phenotypic and genotypic overlap, plus a common pathogenesis, between two groups of inherited disorders, autosomal dominant polycystic kidney diseases (ADPKD), a significant cause of ESRD, and autosomal dominant polycystic liver diseases (ADPLD), which result in significant PLD with minimal PKD. Eight genes have been associated with ADPKD (PKD1 and PKD2), ADPLD (PRKCSH, SEC63, LRP5, ALG8, and SEC61B), or both (GANAB). Although genetics is only infrequently used for diagnosing these diseases and prognosing the associated outcomes, its value is beginning to be appreciated, and the genomics revolution promises more reliable and less expensive molecular diagnostic tools for these diseases. We therefore propose categorization of patients with a phenotypic and genotypic descriptor that will clarify etiology, provide prognostic information, and better describe atypical cases. In genetically defined cases, the designation would include the disease and gene names, with allelic (truncating/nontruncating) information included for PKD1. Recent data have shown that biallelic disease including at least one weak ADPKD allele is a significant cause of symptomatic, very early onset ADPKD. Including a genic (and allelic) descriptor with the disease name will provide outcome clues, guide treatment, and aid prevalence estimates.
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Precision Transplant Medicine: Biomarkers to the Rescue
The concept that individuals with the same disease and a similar clinical presentation may have very different outcomes and need very different therapies is not novel. With the development of many innovative tools derived from the omics technologies, transplant medicine is slowly entering the era of precision medicine. Biomarkers are the cornerstone of precision medicine, which aims to integrate biomarkers with traditional clinical information and tailor medical care to achieve the best outcome for an individual patient. Here, we discuss the basic concepts of precision medicine and biomarkers, with a specific focus on progress in renal transplantation. We delineate the different types of biomarkers and provide a general assessment of the current applications and shortcomings of previously proposed biomarkers. We also outline the potential of precision medicine in transplantation. Moving toward precision medicine in the field of transplantation will require transplant physicians to embrace the increased complexity and expanded decision algorithms and therapeutic options that are associated with improved disease nosology.
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Novel Insights into the Pathogenesis of Monogenic Congenital Anomalies of the Kidney and Urinary Tract
Congenital anomalies of the kidneys and urinary tract (CAKUT) comprise a large spectrum of congenital malformations ranging from severe manifestations, such as renal agenesis, to potentially milder conditions, such as vesicoureteral reflux. CAKUT causes approximately 40% of ESRD that manifests within the first three decades of life. Several lines of evidence indicate that CAKUT is often caused by recessive or dominant mutations in single (monogenic) genes. To date, approximately 40 monogenic genes are known to cause CAKUT if mutated, explaining 5%–20% of patients. However, hundreds of different monogenic CAKUT genes probably exist. The discovery of novel CAKUT-causing genes remains challenging because of this pronounced heterogeneity, variable expressivity, and incomplete penetrance. We here give an overview of known genetic causes for human CAKUT and shed light on distinct renal morphogenetic pathways that were identified as relevant for CAKUT in mice and humans.
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DnaJ Heat Shock Protein Family B Member 9 Is a Novel Biomarker for Fibrillary GN
Fibrillary GN (FGN) is a rare primary glomerular disease. Histologic and histochemical features of FGN overlap with those of other glomerular diseases, and no unique histologic biomarkers for diagnosing FGN have been identified. We analyzed the proteomic content of glomeruli in patient biopsy specimens and detected DnaJ heat shock protein family (Hsp40) member B9 (DNAJB9) as the fourth most abundant protein in FGN glomeruli. Compared with amyloidosis glomeruli, FGN glomeruli exhibited a >6-fold overexpression of DNAJB9 protein. Sanger sequencing and protein sequence coverage maps showed that the DNAJB9 protein deposited in FGN glomeruli did not have any major sequence or structural alterations. Notably, we detected DNAJB9 in all patients with FGN but not in healthy glomeruli or in 19 types of non-FGN glomerular diseases. We also observed the codeposition of DNAJB9 and Ig-. Overall, these findings indicate that DNAJB9 is an FGN marker with 100% sensitivity and 100% specificity. The magnitude and specificity of DNAJB9 overabundance in FGN also suggests that this protein has a role in FGN pathogenesis. With this evidence, we propose that DNAJB9 is a strong biomarker for rapid diagnosis of FGN in renal biopsy specimens.
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Aldosterone Is Essential for Angiotensin II-Induced Upregulation of Pendrin
The renin-angiotensin-aldosterone system has an important role in the control of fluid homeostasis and BP during volume depletion. Dietary salt restriction elevates circulating angiotensin II (AngII) and aldosterone levels, increasing levels of the Cl–/HCO3– exchanger pendrin in β-intercalated cells and the Na+-Cl– cotransporter (NCC) in distal convoluted tubules. However, the independent roles of AngII and aldosterone in regulating these levels remain unclear. In C57BL/6J mice receiving a low-salt diet or AngII infusion, we evaluated the membrane protein abundance of pendrin and NCC; assessed the phosphorylation of the mineralocorticoid receptor, which selectively inhibits aldosterone binding in intercalated cells; and measured BP by radiotelemetry in pendrin-knockout and wild-type mice. A low-salt diet or AngII infusion upregulated NCC and pendrin levels, decreased the phosphorylation of mineralocorticoid receptor in β-intercalated cells, and increased plasma aldosterone levels. Notably, a low-salt diet did not alter BP in wild-type mice, but significantly decreased BP in pendrin-knockout mice. To dissect the roles of AngII and aldosterone, we performed adrenalectomies in mice to remove aldosterone from the circulation. In adrenalectomized mice, AngII infusion again upregulated NCC expression, but did not affect pendrin expression despite the decreased phosphorylation of mineralocorticoid receptor. By contrast, AngII and aldosterone coadministration markedly elevated pendrin levels in adrenalectomized mice. Our results indicate that aldosterone is necessary for AngII-induced pendrin upregulation, and suggest that pendrin contributes to the maintenance of normal BP in cooperation with NCC during activation of the renin-angiotensin-aldosterone system by dietary salt restriction.
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Cardiovascular Effects of Renal Distal Tubule Deletion of the FGF Receptor 1 Gene
The bone-derived hormone fibroblast growth factor–23 (FGF-23) activates complexes composed of FGF receptors (FGFRs), including FGFR1, and α-Klotho in the kidney distal tubule (DT), leading to increased sodium retention and hypertension. However, the role of FGFR1 in regulating renal processes linked to hypertension is unclear. Here, we investigated the effects of selective FGFR1 loss in the DT. Conditional knockout (cKO) of FGFR1 in the DT (FGFR1DT-cKO mice) resulted in left ventricular hypertrophy (LVH) and decreased kidney expression of α-Klotho in association with enhanced BP, decreased expression of angiotensin converting enzyme 2, and increased expression of the Na+-K+-2Cl– cotransporter. Notably, recombinant FGF-23 administration similarly decreased the kidney expression of α-Klotho and induced LVH in mice. Pharmacologic activation of FGFR1 with a monoclonal anti-FGFR1 antibody (R1MAb1) normalized BP and significantly attenuated LVH in the Hyp mouse model of excess FGF-23, but did not induce a response in FGFR1DT-cKO mice. The hearts of FGFR1DT-cKO mice showed increased expression of the transient receptor potential cation channel, subfamily C, member 6 (TRPC6), consistent with cardiac effects of soluble Klotho deficiency. Moreover, administration of recombinant soluble Klotho lowered BP in the Hyp mice. Thus, FGFR1 in the DT regulates systemic hemodynamic responses opposite to those predicted by the actions of FGF-23. These cardiovascular effects appear to be mediated by paracrine FGF control of kidney FGFR1 and subsequent regulation of soluble Klotho and TRPC6. FGFR1 in the kidney may provide a new molecular target for treating hypertension.
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Kidney Proximal Tubule Lipoapoptosis Is Regulated by Fatty Acid Transporter-2 (FATP2)
Albuminuria and tubular atrophy are among the highest risks for CKD progression to ESRD. A parsimonious mechanism involves leakage of albumin-bound nonesterified fatty acids (NEFAs) across the damaged glomerular filtration barrier and subsequent reabsorption by the downstream proximal tubule, causing lipoapoptosis. We sought to identify the apical proximal tubule transporter that mediates NEFA uptake and cytotoxicity. We observed transporter-mediated uptake of fluorescently labeled NEFA in cultured proximal tubule cells and microperfused rat proximal tubules, with greater uptake from the apical surface than from the basolateral surface. Protein and mRNA expression analyses revealed that kidney proximal tubules express transmembrane fatty acid transporter-2 (FATP2), encoded by Slc27a2, but not the other candidate transporters CD36 and free fatty acid receptor 1. Kidney FATP2 localized exclusively to proximal tubule epithelial cells along the apical but not the basolateral membrane. Treatment of mice with lipidated albumin to induce proteinuria caused a decrease in the proportion of tubular epithelial cells and an increase in the proportion of interstitial space in kidneys from wild-type but not Slc27a2–/–mice. Ex vivo microperfusion and in vitro experiments with NEFA-bound albumin at concentrations that mimic apical proximal tubule exposure during glomerular injury revealed significantly reduced NEFA uptake and palmitate-induced apoptosis in microperfused Slc27a2–/– proximal tubules and Slc27a2–/– or FATP2 shRNA-treated proximal tubule cell lines compared with wild-type or scrambled oligonucleotide–treated cells, respectively. We conclude that FATP2 is a major apical proximal tubule NEFA transporter that regulates lipoapoptosis and may be an amenable target for the prevention of CKD progression.
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ShcA Adaptor Protein Promotes Nephrin Endocytosis and Is Upregulated in Proteinuric Nephropathies
Nephrin is a key structural component of the podocyte slit diaphragm, and proper expression of nephrin on the cell surface is critical to ensure integrity of the blood filtration barrier. Maintenance of nephrin within this unique cell junction has been proposed to require dynamic phosphorylation events and endocytic recycling, although the molecular mechanisms that control this interplay are poorly understood. Here, we investigated the possibility that the phosphotyrosine adaptor protein ShcA regulates nephrin turnover. Western blotting and immunostaining analysis confirmed that ShcA is expressed in podocytes. In immunoprecipitation and pulldown assays, ShcA, via its SH2 domain, was associated with several phosphorylated tyrosine residues on nephrin. Overexpression of ShcA promoted nephrin tyrosine phosphorylation and reduced nephrin signaling and cell surface expression in vitro. In a rat model of reversible podocyte injury and proteinuria, phosphorylated nephrin temporally colocalized with endocytic structures coincident with upregulation of ShcA expression. In vivo biotinylation assays confirmed that nephrin expression decreased at the cell surface and correspondingly increased in the cytosol during the injury time course. Finally, immunostaining in kidney biopsy specimens demonstrated overexpression of ShcA in several human proteinuric kidney diseases compared with normal conditions. Our results suggest that increases in ShcA perturb nephrin phosphosignaling dynamics, leading to aberrant nephrin turnover and slit diaphragm disassembly.
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Endotoxin Preconditioning Reprograms S1 Tubules and Macrophages to Protect the Kidney
Preconditioning with a low dose of endotoxin confers unparalleled protection against otherwise lethal models of sepsis. The mechanisms of preconditioning have been investigated extensively in isolated immune cells such as macrophages. However, the role of tissue in mediating the protective response generated by preconditioning remains unknown. Here, using the kidney as a model organ, we investigated cell type–specific responses to preconditioning. Compared with preadministration of vehicle, endotoxin preconditioning in the cecal ligation and puncture mouse model of sepsis led to significantly enhanced survival and reduced bacterial load in several organs. Furthermore, endotoxin preconditioning reduced serum levels of proinflammatory cytokines, upregulated molecular pathways involved in phagocytosis, and prevented the renal function decline and injury induced in mice by a toxic dose of endotoxin. The protective phenotype involved the clustering of macrophages around S1 segments of proximal tubules, and full renal protection required both macrophages and renal tubular cells. Using unbiased S1 transcriptomic and tissue metabolomic approaches, we identified multiple protective molecules that were operative in preconditioned animals, including molecules involved in antibacterial defense, redox balance, and tissue healing. We conclude that preconditioning reprograms macrophages and tubules to generate a protective environment, in which tissue health is preserved and immunity is controlled yet effective. Endotoxin preconditioning can thus be used as a discovery platform, and understanding the role and participation of both tissue and macrophages will help refine targeted therapies for sepsis.
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FXR/TGR5 Dual Agonist Prevents Progression of Nephropathy in Diabetes and Obesity
Bile acids are ligands for the nuclear hormone receptor farnesoid X receptor (FXR) and the G protein–coupled receptor TGR5. We have shown that FXR and TGR5 have renoprotective roles in diabetes- and obesity-related kidney disease. Here, we determined whether these effects are mediated through differential or synergistic signaling pathways. We administered the FXR/TGR5 dual agonist INT-767 to DBA/2J mice with streptozotocin-induced diabetes, db/db mice with type 2 diabetes, and C57BL/6J mice with high-fat diet-induced obesity. We also examined the individual effects of the selective FXR agonist obeticholic acid (OCA) and the TGR5 agonist INT-777 in diabetic mice. The FXR agonist OCA and the TGR5 agonist INT-777 modulated distinct renal signaling pathways involved in the pathogenesis and treatment of diabetic nephropathy. Treatment of diabetic DBA/2J and db/db mice with the dual FXR/TGR5 agonist INT-767 improved proteinuria and prevented podocyte injury, mesangial expansion, and tubulointerstitial fibrosis. INT-767 exerted coordinated effects on multiple pathways, including stimulation of a signaling cascade involving AMP-activated protein kinase, sirtuin 1, PGC-1α, sirtuin 3, estrogen-related receptor-α, and Nrf-1; inhibition of endoplasmic reticulum stress; and inhibition of enhanced renal fatty acid and cholesterol metabolism. Additionally, in mice with diet-induced obesity, INT-767 prevented mitochondrial dysfunction and oxidative stress determined by fluorescence lifetime imaging of NADH and kidney fibrosis determined by second harmonic imaging microscopy. These results identify the renal signaling pathways regulated by FXR and TGR5, which may be promising targets for the treatment of nephropathy in diabetes and obesity.
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Opposing Roles of Dendritic Cell Subsets in Experimental GN
Dendritic cells (DCs) are thought to form a dendritic network across barrier surfaces and throughout organs, including the kidney, to perform an important sentinel function. However, previous studies of DC function used markers, such as CD11c or CX3CR1, that are not unique to DCs. Here, we evaluated the role of DCs in renal inflammation using a CD11c reporter mouse line and two mouse lines with DC-specific reporters, Zbtb46-GFP and Snx22-GFP. Multiphoton microscopy of kidney sections confirmed that most of the dendritically shaped CD11c+ cells forming a network throughout the renal interstitium expressed macrophage-specific markers. In contrast, DCs marked by Zbtb46-GFP or Snx22-GFP were less abundant, concentrated around blood vessels, and round in shape. We confirmed this pattern of localization using imaging mass cytometry. Motility measurements showed that resident macrophages were sessile, whereas DCs were motile before and after inflammation. Although uninflamed glomeruli rarely contained DCs, injury with nephrotoxic antibodies resulted in accumulation of ZBTB46+ cells in the periglomerular region. ZBTB46 identifies all classic DCs, which can be categorized into two functional subsets that express either CD103 or CD11b. Depletion of ZBTB46+ cells attenuated the antibody-induced kidney injury, whereas deficiency of the CD103+ subset accelerated injury through a mechanism that involved increased neutrophil infiltration. RNA sequencing 7 days after nephrotoxic antibody injection showed that CD11b+ DCs expressed the neutrophil-attracting cytokine CXCL2, whereas CD103+ DCs expressed high levels of several anti-inflammatory genes. These results provide new insights into the distinct functions of the two major DC subsets in glomerular inflammation.
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MYH9 E1841K Mutation Augments Proteinuria and Podocyte Injury and Migration
Intronic variants of the MYH9 gene that encodes the nonmuscle myosin heavy chain IIA are associated with diabetic nephropathy in European Americans and with sickle cell disease–associated nephropathy. However, the causal functional variants of MYH9 have remained elusive. Rare missense mutations in MYH9 cause macrothrombocytopenia and are occasionally associated with development of nephropathy. The E1841K mutation is among the common MYH9 missense mutations and has been associated with nephropathy in some carriers. To determine the contribution of the E1841K mutation in kidney disease, we studied the effects of the E1841K mutation in mice subjected to high salt or angiotensin II (Ang II) as models of hypertension and in mice subjected to renal mass reduction as a model of CKD. Despite similar levels of BP among wild-type (MYH9+/+) mice and mice heterozygous (MYH9+/E1841K) and homozygous (MYH9E1841K/E1841K) for the mutation in each model, MYH9E1841K/E1841K mice exhibited mildly increased albuminuria in response to high salt; severe albuminuria, nephrinuria, FSGS, and podocyte foot effacement in Ang II–induced hypertension; and early mortality in the renal mass reduction model. Treatment with candesartan during Ang II–induced hypertension attenuated kidney disease development in MYH9E1841K/E1841K mice. In vitro, isolated primary podocytes from MYH9E1841K/E1841K mice exhibited increased lamellipodia formation and reorganization of F-actin stress fibers. Wound healing assays revealed that MYH9+/+ podocytes had the lowest migration rate, followed by MYH9+/E1841K then MYH9E1841K/E1841K podocytes. In conclusion, the MYH9 E1841K variant alters podocyte cytoskeletal structure and renders podocytes more susceptible to injury after a damaging stimulus.
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Collectin-11 Promotes the Development of Renal Tubulointerstitial Fibrosis
Collectin-11 is a recently described soluble C-type lectin, a pattern recognition molecule of the innate immune system that has distinct roles in host defense, embryonic development, and acute inflammation. However, little is known regarding the role of collectin-11 in tissue fibrosis. Here, we investigated collectin-11 in the context of renal ischemia-reperfusion injury. Compared with wild-type littermate controls, Collec11 deficient (CL-11–/–) mice had significantly reduced renal functional impairment, tubular injury, renal leukocyte infiltration, renal tissue inflammation/fibrogenesis, and collagen deposition in the kidneys after renal ischemia-reperfusion injury. In vitro, recombinant collectin-11 potently promoted leukocyte migration and renal fibroblast proliferation in a carbohydrate-dependent manner. Additionally, compared with wild-type kidney grafts, CL-11–/– mice kidney grafts displayed significantly reduced tubular injury and collagen deposition after syngeneic kidney transplant. Our findings demonstrate a pathogenic role for collectin-11 in the development of tubulointerstitial fibrosis and suggest that local collectin-11 promotes this fibrosis through effects on leukocyte chemotaxis and renal fibroblast proliferation. This insight into the pathogenesis of tubulointerstitial fibrosis may have implications for CKD mediated by other causes as well.
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Wnt/{beta}-Catenin-Promoted Macrophage Alternative Activation Contributes to Kidney Fibrosis
The Wnt/β-catenin pathway is crucial in normal development and throughout life, but aberrant activation of this pathway has been linked to kidney fibrosis, although the mechanisms involved remain incompletely determined. Here, we investigated the role of Wnt/β-catenin in regulating macrophage activation and the contribution thereof to kidney fibrosis. Treatment of macrophages with Wnt3a exacerbated IL-4– or TGFβ1-induced macrophage alternative (M2) polarization and the phosphorylation and nuclear translocation of STAT3 in vitro. Conversely, inhibition of Wnt/β-catenin signaling prevented these IL-4– or TGFβ1-induced processes. In a mouse model, induced deletion of β-catenin in macrophages attenuated the fibrosis, macrophage accumulation, and M2 polarization observed in the kidneys of wild-type littermates after unilateral ureter obstruction. This study shows that activation of Wnt/β-catenin signaling promotes kidney fibrosis by stimulating macrophage M2 polarization.
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Dynamin-Related Protein 1 Deficiency Promotes Recovery from AKI
The proximal tubule epithelium relies on mitochondrial function for energy, rendering the kidney highly susceptible to ischemic AKI. Dynamin-related protein 1 (DRP1), a mediator of mitochondrial fission, regulates mitochondrial function; however, the cell-specific and temporal role of DRP1 in AKI in vivo is unknown. Using genetic murine models, we found that proximal tubule–specific deletion of Drp1 prevented the renal ischemia-reperfusion–induced kidney injury, inflammation, and programmed cell death observed in wild-type mice and promoted epithelial recovery, which associated with activation of the renoprotective β-hydroxybutyrate signaling pathway. Loss of DRP1 preserved mitochondrial structure and reduced oxidative stress in injured kidneys. Lastly, proximal tubule deletion of DRP1 after ischemia-reperfusion injury attenuated progressive kidney injury and fibrosis. These results implicate DRP1 and mitochondrial dynamics as an important mediator of AKI and progression to fibrosis and suggest that DRP1 may serve as a therapeutic target for AKI.
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Incident CKD after Radical or Partial Nephrectomy
The comparative effectiveness of partial nephrectomy versus radical nephrectomy to preserve kidney function has not been well established. We determined the risk of clinically significant (stage 4 and higher) CKD after radical or partial nephrectomy among veterans treated for kidney cancer in the Veterans Health Administration (2001–2013). Among patients with preoperative eGFR≥30 ml/min per 1.73 m2, the incidence of CKD stage 4 or higher after radical (n=9759) or partial nephrectomy (n=4370) was 7.9% overall. The median time to stage 4 or higher CKD after surgery was 5 months, after which few patients progressed. In propensity score–matched cohorts, partial nephrectomy associated with a significantly lower relative risk of incident CKD stage 4 or higher (hazard ratio, 0.34; 95% confidence interval [95% CI], 0.26 to 0.43, versus radical nephrectomy). In a parallel analysis of patients with normal or near-normal preoperative kidney function (eGFR≥60 ml/min per 1.73 m2), partial nephrectomy was also associated with a significantly lower relative risk of incident CKD stage 3b or higher (hazard ratio, 0.15; 95% CI, 0.11 to 0.19, versus radical nephrectomy) in propensity score–matched cohorts. Competing risk regression models produced consistent results. Finally, patients treated with a partial nephrectomy had reduced risk of mortality (hazard ratio, 0.55; 95% CI, 0.49 to 0.62). In conclusion, compared with radical nephrectomy, partial nephrectomy was associated with a marked reduction in the incidence of clinically significant CKD and with enhanced survival. Postoperative decline in kidney function occurred mainly in the first year after surgery and appeared stable over time.
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Particulate Matter Air Pollution and the Risk of Incident CKD and Progression to ESRD
Elevated levels of fine particulate matter <2.5 µm in aerodynamic diameter (PM2.5) are associated with increased risk of cardiovascular outcomes and death, but their association with risk of CKD and ESRD is unknown. We linked the Environmental Protection Agency and the Department of Veterans Affairs databases to build an observational cohort of 2,482,737 United States veterans, and used survival models to evaluate the association of PM2.5 concentrations and risk of incident eGFR <60 ml/min per 1.73 m2, incident CKD, eGFR decline ≥30%, and ESRD over a median follow-up of 8.52 years. County-level exposure was defined at baseline as the annual average PM2.5 concentrations in 2004, and separately as time-varying where it was updated annually and as cohort participants moved. In analyses of baseline exposure (median, 11.8 [interquartile range, 10.1–13.7] µg/m3), a 10-µg/m3 increase in PM2.5 concentration was associated with increased risk of eGFR<60 ml/min per 1.73 m2 (hazard ratio [HR], 1.21; 95% confidence interval [95% CI], 1.14 to 1.29), CKD (HR, 1.27; 95% CI, 1.17 to 1.38), eGFR decline ≥30% (HR, 1.28; 95% CI, 1.18 to 1.39), and ESRD (HR, 1.26; 95% CI, 1.17 to 1.35). In time-varying analyses, a 10-µg/m3 increase in PM2.5 concentration was associated with similarly increased risk of eGFR<60 ml/min per 1.73 m2, CKD, eGFR decline ≥30%, and ESRD. Spline analyses showed a linear relationship between PM2.5 concentrations and risk of kidney outcomes. Exposure estimates derived from National Aeronautics and Space Administration satellite data yielded consistent results. Our findings demonstrate a significant association between exposure to PM2.5 and risk of incident CKD, eGFR decline, and ESRD.
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DnaJ Homolog Subfamily B Member 9 Is a Putative Autoantigen in Fibrillary GN
Fibrillary GN is a rare form of GN of uncertain pathogenesis that is characterized by the glomerular accumulation of randomly arranged, nonbranching fibrils (12–24 nm) composed of Ig and complement proteins. In this study, we used mass spectrometry to comprehensively define the glomerular proteome in fibrillary GN compared with that in controls and nonfibrillary GN renal diseases. We isolated glomeruli from formalin-fixed and paraffin-embedded biopsy specimens using laser capture microdissection and analyzed them with liquid chromatography and data-dependent tandem mass spectrometry. These studies identified DnaJ homolog subfamily B member 9 (DNAJB9) as a highly sampled protein detected only in fibrillary GN cases. The glomerular proteome of fibrillary GN cases also contained IgG1 as the dominant Ig and proteins of the classic complement pathway. In fibrillary GN specimens only, immunofluorescence and immunohistochemistry with an anti-DNAJB9 antibody showed strong and specific staining of the glomerular tufts in a distribution that mimicked that of the immune deposits. Our results identify DNAJB9 as a putative autoantigen in fibrillary GN and suggest IgG1 and classic complement effector pathways as likely mediators of the destructive glomerular injury in this disease.
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Factor H Competitor Generated by Gene Conversion Events Associates with Atypical Hemolytic Uremic Syndrome
Atypical hemolytic uremic syndrome (aHUS), a rare form of thrombotic microangiopathy caused by complement pathogenic variants, mainly affects the kidney microvasculature. A retrospective genetic analysis in our aHUS cohort (n=513) using multiple ligation probe amplification uncovered nine unrelated patients carrying a genetic abnormality in the complement factor H related 1 gene (CFHR1) that originates by recurrent gene conversion events between the CFH and CFHR1 genes. The novel CFHR1 mutants encode an FHR-1 protein with two amino acid substitutions, L290S and A296V, converting the FHR-1 C terminus into that of factor H (FH). Next-generation massive-parallel DNA sequencing (NGS) analysis did not detect these genetic abnormalities. In addition to the CFHR1 mutant, six patients carried the previously uncharacterized CFH-411T variant. In functional analyses, the mutant FHR-1 protein strongly competed the binding of FH to cell surfaces, impairing complement regulation, whereas the CFH-411T polymorphism lacked functional consequences. Carriers of the CFHR1 mutation presented with severe aHUS during adulthood; 57% of affected women in this cohort presented during the postpartum period. Analyses in patients and unaffected carriers showed that FH plasma levels determined by the nonmutated chromosome modulate disease penetrance. Crucially, in the activated endothelial (HMEC-1) cell assay, reduced FH plasma levels produced by the nonmutated chromosome correlated inversely with impairment of complement regulation, measured as C5b-9 deposition. Our data advance understanding of the genetic complexities underlying aHUS, illustrate the importance of performing functional analysis, and support the use of complementary assays to disclose genetic abnormalities not revealed by current NGS analysis.
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Metabolic Effects of Diet and Exercise in Patients with Moderate to Severe CKD: A Randomized Clinical Trial
CKD is steadily increasing along with obesity worldwide. Furthermore, obesity is a proinflammatory risk factor for progression of CKD and cardiovascular disease. We tested the hypothesis that implementation of caloric restriction and aerobic exercise is feasible and can improve the proinflammatory metabolic milieu in patients with moderate to severe CKD through a pilot, randomized, 2x2 factorial design trial. Of 122 participants consented, 111 were randomized to receive caloric restriction and aerobic exercise, caloric restriction alone, aerobic exercise alone, or usual care. Of those randomized, 42% were women, 25% were diabetic, and 91% were hypertensive; 104 started intervention, and 92 completed the 4-month study. Primary outcomes were a change from baseline in absolute fat mass, body weight, plasma F2-isoprostane concentrations, and peak oxygen uptake (VO2 peak). Compared with usual care, the combined intervention led to statistically significant decreases in body weight and body fat percentage. Caloric restriction alone also led to significant decreases in these measures, but aerobic exercise alone did not. The combined intervention and each independent intervention also led to significant decreases in F2-isoprostane and IL-6 concentrations. No intervention produced significant changes in VO2 peak, kidney function, or urine albumin-to-creatinine ratio. In conclusion, 4-month dietary calorie restriction and aerobic exercise had significant, albeit clinically modest, benefits on body weight, fat mass, and markers of oxidative stress and inflammatory response in patients with moderate to severe CKD. These results suggest healthy lifestyle interventions as a nonpharmacologic strategy to improve markers of metabolic health in these patients.
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Allogeneic Mesenchymal Stem Cells for Treatment of AKI after Cardiac Surgery
AKI after cardiac surgery remains strongly associated with mortality and lacks effective treatment or prevention. Preclinical studies suggest that cell-based interventions may influence functional recovery. We conducted a phase 2, randomized, double-blind, placebo-controlled trial in 27 centers across North America to determine the safety and efficacy of allogeneic human mesenchymal stem cells (MSCs) in reducing the time to recovery from AKI after cardiac surgery. We randomized 156 adult subjects undergoing cardiac surgery with evidence of early AKI to receive intra-aortic MSCs (AC607; n=67) or placebo (n=68). The primary outcome was the time to recovery of kidney function defined as return of postintervention creatinine level to baseline. The median time to recovery of kidney function was 15 days with AC607 and 12 days with placebo (25th, 75th percentile range, 10–29 versus 6–21, respectively; hazard ratio, 0.81; 95% confidence interval, 0.53 to 1.24; P=0.32). We did not detect a significant difference between groups in 30-day all-cause mortality (16.7% with AC607; 11.8% with placebo) or dialysis (10.6% with AC607; 7.4% with placebo). At follow-up, 12 patients who received AC607 and six patients who received placebo had died. Rates of other adverse events did not differ between groups. In these patients with AKI after cardiac surgery, administration of allogeneic MSCs did not decrease the time to recovery of kidney function. Our results contrast with those in preclinical studies and provide important information regarding the potential effects of MSCs in this setting.
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Complement Activation in Peritoneal Dialysis-Induced Arteriolopathy
Cardiovascular disease (CVD) is the leading cause of increased mortality in patients with CKD and is further aggravated by peritoneal dialysis (PD). Children are devoid of preexisting CVD and provide unique insight into specific uremia- and PD-induced pathomechanisms of CVD. We obtained peritoneal specimens from children with stage 5 CKD at time of PD catheter insertion (CKD5 group), children with established PD (PD group), and age-matched nonuremic controls (n=6/group). We microdissected omental arterioles from tissue layers not directly exposed to PD fluid and used adjacent sections of four arterioles per patient for transcriptomic and proteomic analyses. Findings were validated in omental and parietal arterioles from independent pediatric control (n=5), CKD5 (n=15), and PD (n=15) cohorts. Transcriptomic analysis revealed differential gene expression in control versus CKD5 arterioles and in CKD5 versus PD arterioles. Gene ontology analyses revealed activation of metabolic processes in CKD5 arterioles and of inflammatory, immunologic, and stress-response cascades in PD arterioles. PD arterioles exhibited particular upregulation of the complement system and respective regulatory pathways, with concordant findings at the proteomic level. In the validation cohorts, PD specimens had the highest abundance of omental and parietal arteriolar C1q, C3d, terminal complement complex, and phosphorylated SMAD2/3, a downstream effector of TGF-β. Furthermore, in the PD parietal arterioles, C1q and terminal complement complex abundance correlated with the level of dialytic glucose exposure, abundance of phosphorylated SMAD2/3, and degree of vasculopathy. We conclude that PD fluids activate arteriolar complement and TGF-β signaling, which quantitatively correlate with the severity of arteriolar vasculopathy.
from Journal of the American Society of Nephrology current issue http://ift.tt/2lqAPr4
Cluster Analysis Identifies Distinct Pathogenetic Patterns in C3 Glomerulopathies/Immune Complex-Mediated Membranoproliferative GN
Membranoproliferative GN (MPGN) was recently reclassified as alternative pathway complement–mediated C3 glomerulopathy (C3G) and immune complex–mediated membranoproliferative GN (IC-MPGN). However, genetic and acquired alternative pathway abnormalities are also observed in IC-MPGN. Here, we explored the presence of distinct disease entities characterized by specific pathophysiologic mechanisms. We performed unsupervised hierarchical clustering, a data-driven statistical approach, on histologic, genetic, and clinical data and data regarding serum/plasma complement parameters from 173 patients with C3G/IC-MPGN. This approach divided patients into four clusters, indicating the existence of four different pathogenetic patterns. Specifically, this analysis separated patients with fluid-phase complement activation (clusters 1–3) who had low serum C3 levels and a high prevalence of genetic and acquired alternative pathway abnormalities from patients with solid-phase complement activation (cluster 4) who had normal or mildly altered serum C3, late disease onset, and poor renal survival. In patients with fluid-phase complement activation, those in clusters 1 and 2 had massive activation of the alternative pathway, including activation of the terminal pathway, and the highest prevalence of subendothelial deposits, but those in cluster 2 had additional activation of the classic pathway and the highest prevalence of nephrotic syndrome at disease onset. Patients in cluster 3 had prevalent activation of C3 convertase and highly electron-dense intramembranous deposits. In addition, we provide a simple algorithm to assign patients with C3G/IC-MPGN to specific clusters. These distinct clusters may facilitate clarification of disease etiology, improve risk assessment for ESRD, and pave the way for personalized treatment.
from Journal of the American Society of Nephrology current issue http://ift.tt/2ljWT7E
Impaired {beta}-Oxidation and Altered Complex Lipid Fatty Acid Partitioning with Advancing CKD
Studies of lipids in CKD, including ESRD, have been limited to measures of conventional lipid profiles. We aimed to systematically identify 17 different lipid classes and associate the abundance thereof with alterations in acylcarnitines, a metric of β-oxidation, across stages of CKD. From the Clinical Phenotyping Resource and Biobank Core (CPROBE) cohort of 1235 adults, we selected a panel of 214 participants: 36 with stage 1 or 2 CKD, 99 with stage 3 CKD, 61 with stage 4 CKD, and 18 with stage 5 CKD. Among participants, 110 were men (51.4%), 64 were black (29.9%), and 150 were white (70.1%), and the mean (SD) age was 60 (16) years old. We measured plasma lipids and acylcarnitines using liquid chromatography-mass spectrometry. Overall, we identified 330 different lipids across 17 different classes. Compared with earlier stages, stage 5 CKD associated with a higher abundance of saturated C16–C20 free fatty acids (FFAs) and long polyunsaturated complex lipids. Long-chain–to–intermediate-chain acylcarnitine ratio, a marker of efficiency of β-oxidation, exhibited a graded decrease from stage 2 to 5 CKD (P<0.001). Additionally, multiple linear regression revealed that the long-chain–to–intermediate-chain acylcarnitine ratio inversely associated with polyunsaturated long complex lipid subclasses and the C16–C20 FFAs but directly associated with short complex lipids with fewer double bonds. We conclude that increased abundance of saturated C16–C20 FFAs coupled with impaired β-oxidation of FFAs and inverse partitioning into complex lipids may be mechanisms underpinning lipid metabolism changes that typify advancing CKD.
from Journal of the American Society of Nephrology current issue http://ift.tt/2lso6nJ
FOX NEWS: Flu outbreak already reported in 36 states, CDC says
Flu outbreak already reported in 36 states, CDC says
The early start of the outbreaks, which usually see a peak in February, has to do with the low efficacy of the vaccine and possibly the cold temperatures gripping much of the country.
FOX NEWS: Woman sues hospital over nude photo taken of her on operating table
Woman sues hospital over nude photo taken of her on operating table
A woman has sued the Pennsylvania hospital where she once worked over nude photos taken of her while she was on the operating table.
FOX NEWS: Frostbite: Know the signs and symptoms
Frostbite: Know the signs and symptoms
When old man winter comes to town, it's important to make sure you and your family are ready for more than just a heavy snow fall.
FOX NEWS: Cashier, butcher help deliver baby at California market
Cashier, butcher help deliver baby at California market
“So many emotions in one," said the store owner. "I’m still in shock yet very happy.”
FOX NEWS: OB-GYN delivers patient's twins 14 hours after giving birth to her own daughter
OB-GYN delivers patient's twins 14 hours after giving birth to her own daughter
An OB-GYN who was determined not to miss the birth of her patient’s twins swooped in to deliver the two babies just 14 hours after she gave birth herself.
Thursday, December 28, 2017
FOX NEWS: Family praises 'miracle surgeon' after daughter's emergency surgery
Family praises 'miracle surgeon' after daughter's emergency surgery
The family of a 4-year-old brain tumor patient are praising the “miracle surgeon” who unexpectedly gave them hope after their daughter’s operation, Fox 35 reported.
Do Australians Need a Sugar Intervention?
By KASSIE BRACKEN, JONAH M. KESSEL and TAIGE JENSEN from NYT Health http://ift.tt/2CiWV72
FOX NEWS: WHO considers adding 'gaming disorder' to list of mental diseases
WHO considers adding 'gaming disorder' to list of mental diseases
The WHO guidelines are the international standard for reporting health conditions.
Wednesday, December 27, 2017
F.D.A. Leaves Tainted Foods on Shelves Too Long, Report Finds
By SHEILA KAPLAN from NYT Health http://ift.tt/2Cfau7z
FOX NEWS: China clones first gene-edited dog, sentencing him to possible early death
China clones first gene-edited dog, sentencing him to possible early death
The dog's genome was edited so it would develop atherosclerosis and scientists could further advance the battle against the disease in humans.
FOX NEWS: China clones first gene-edited dog, but it's sentenced to die of heart disease
China clones first gene-edited dog, but it's sentenced to die of heart disease
The dog's genome was edited so it would develop atherosclerosis and scientists could further advance the battle against the disease in humans.
FOX NEWS: Marijuana use increases among pregnant women in California, study says
Marijuana use increases among pregnant women in California, study says
A study by scientists in Northern California found smoking marijuana is on the rise among pregnant women in the U.S.
Tuesday, December 26, 2017
Measles Deaths Fall to a Record Low Worldwide
By DONALD G. McNEIL Jr. from NYT Health http://ift.tt/2BSwFDF
Monday, December 25, 2017
One Man’s Stand Against Junk Food as Diabetes Climbs Across India
By GEETA ANAND from NYT Health http://ift.tt/2BBxRHg
Sunday, December 24, 2017
FOX NEWS: American expat fights for his life after falling off roof in Bali while chasing monkey who stole his Pittsburgh Steelers cap
American expat fights for his life after falling off roof in Bali while chasing monkey who stole his Pittsburgh Steelers cap
A Florida man living in Indonesia is fighting for his life after he plunged 33 feet off a rooftop while chasing a monkey that had snatched his favorite Pittsburgh Steelers cap.
Saturday, December 23, 2017
FOX NEWS: Utah dad prepared to take out loan after porch pirates steal pricey meds from ill son
Utah dad prepared to take out loan after porch pirates steal pricey meds from ill son
A single father from Riverdale, Utah, was prepared to take out a loan after porch pirates stole $5K worth of medication his sick son desperately needs.
In Asia’s Fattest Country, Nutritionists Take Money From Food Giants
By THOMAS FULLER, ANAHAD O’CONNOR and MATT RICHTEL from NYT Health http://ift.tt/2l0ULAF
Friday, December 22, 2017
FOX NEWS: 86-year-old woman with dementia warms up to Santa ─ and makes him cry
86-year-old woman with dementia warms up to Santa ─ and makes him cry
Karen Rangel was diagnosed with Alzheimer’s in 2014 and was recently put on hospice care.
FOX NEWS: War Horses for Veterans helps returning soldiers in innovative way
War Horses for Veterans helps returning soldiers in innovative way
War Horses for Veterans offers a three-day equine and networking experience where they bond with horses, as well as each other.
FOX NEWS: Eating fish weekly raises IQ by almost 5 points in children, study finds
Eating fish weekly raises IQ by almost 5 points in children, study finds
The study was conducted last month among 541 Chinese children between the ages of 9 and 11.
Greater Access to Donated Livers Promised to Transplant Patients
By TED ALCORN from NYT Health http://ift.tt/2ByxzVH
Thursday, December 21, 2017
FOX NEWS: Could ‘Christmas tree syndrome’ ruin your holidays?
Could ‘Christmas tree syndrome’ ruin your holidays?
Could "Christmas tree syndrome” wreak havoc on your holidays? Inside the holiday health risk that could make you sick.
FOX NEWS: Why ‘bad’ foods aren't really bad for you
Why ‘bad’ foods aren't really bad for you
Nutritional studies can be confusing. One week coffee is good for you, and the next week it’s bad for you. Fox News’ Dr. Manny Alvarez sits down with Dr. Aaron Carroll, author of "The Bad Food Bible” to discuss which controversial foods aren’t really bad for you after all.
FOX NEWS: Could early retirement shorten your life?
Could early retirement shorten your life?
A new study from Cornell University finds that people who call it quits at 62 and start collecting Social Security don't live as long as those who wait.
FOX NEWS: Dr. Siegel offers insight on treating Amtrak crash victims
Dr. Siegel offers insight on treating Amtrak crash victims
The Fox News Medial A-Team member details the types of injuries caused by a derailment and the needs of local hospitals.
FOX NEWS: Experts warn cold, flu season will peak Christmas week
Experts warn cold, flu season will peak Christmas week
The regions that could be hit the hardest are mid-Atlantic states and the southern half of the country.
FOX NEWS: US life expectancy decreases for second straight year as overdose deaths soar
US life expectancy decreases for second straight year as overdose deaths soar
U.S. deaths from drug overdoses skyrocketed 21 percent last year, and for the second straight year dragged down how long Americans are expected to live.
FOX NEWS: Woman says she is her own twin sister due to rare genetic condition
Woman says she is her own twin sister due to rare genetic condition
Muhl, a singer and entertainer from California, has been diagnosed with rare genetic condition called chimerism.
Wednesday, December 20, 2017
FOX NEWS: Michigan cities, counties' opioid lawsuit targets drug companies, pharmacies
Michigan cities, counties' opioid lawsuit targets drug companies, pharmacies
Nine cities and counties in Michigan have filed a lawsuit against 21 drug companies, distributors and pharmacies, accusing them of helping fuel the national opioid epidemic -- and costing taxpayers money.
Tuesday, December 19, 2017
E.P.A. Delays Bans on Uses of Hazardous Chemicals
By SHEILA KAPLAN from NYT Health http://ift.tt/2D70sp8
FOX NEWS: Tennessee woman gives birth to baby who was frozen as embryo for 24 years
Tennessee woman gives birth to baby who was frozen as embryo for 24 years
A Tennessee woman gave birth to Emma, a baby who was frozen in an embryo for 24 years.
A Federal Ban on Making Lethal Viruses Is Lifted
By DONALD G. McNEIL Jr. from NYT Health http://ift.tt/2oK6WHf
Monday, December 18, 2017
A Beginners Guide to Analyzing and Visualizing Mass Cytometry Data [IMMUNOLOGY NOTES AND RESOURCES]
Mass cytometry has revolutionized the study of cellular and phenotypic diversity, significantly expanding the number of phenotypic and functional characteristics that can be measured at the single-cell level. This high-dimensional analysis platform has necessitated the development of new data analysis approaches. Many of these algorithms circumvent traditional approaches used in flow cytometric analysis, fundamentally changing the way these data are analyzed and interpreted. For the beginner, however, the large number of algorithms that have been developed, as well as the lack of consensus on best practices for analyzing these data, raise multiple questions: Which algorithm is the best for analyzing a dataset? How do different algorithms compare? How can one move beyond data visualization to gain new biological insights? In this article, we describe our experiences as recent adopters of mass cytometry. By analyzing a single dataset using five cytometry by time-of-flight analysis platforms (viSNE, SPADE, X-shift, PhenoGraph, and Citrus), we identify important considerations and challenges that users should be aware of when using these different methods and common and unique insights that can be revealed by these different methods. By providing annotated workflow and figures, these analyses present a practical guide for investigators analyzing high-dimensional datasets. In total, these analyses emphasize the benefits of integrating multiple cytometry by time-of-flight analysis algorithms to gain complementary insights into these high-dimensional datasets.
from The Journal of Immunology current issue http://ift.tt/2yTzopW
The Reign of Antibodies: A Celebration of and Tribute to Michael Potter and His Homogeneous Immunoglobulin Workshops [PILLARS OF IMMUNOLOGY]
from The Journal of Immunology current issue http://ift.tt/2BaxsiP
Pillars Article: Evidence for Amino Acid Sequence Differences among Proteins Resembling the L-chain Subunits of Immunoglobulins. J. Mol. Biol. 1965. 12: 81-87 [PILLARS OF IMMUNOLOGY]
from The Journal of Immunology current issue http://ift.tt/2yUt8hD
Salmonella Vaccines: Conduits for Protective Antigens [BRIEF REVIEWS]
Vaccines afford a better and more cost-effective approach to combatting infectious diseases than continued reliance on antibiotics or antiviral or antiparasite drugs in the current era of increasing incidences of diseases caused by drug-resistant pathogens. Recombinant attenuated Salmonella vaccines (RASVs) have been significantly improved to exhibit the same or better attributes than wild-type parental strains to colonize internal lymphoid tissues and persist there to serve as factories to continuously synthesize and deliver rAgs. Encoded by codon-optimized pathogen genes, Ags are selected to induce protective immunity to infection by that pathogen. After immunization through a mucosal surface, the RASV attributes maximize their abilities to elicit mucosal and systemic Ab responses and cell-mediated immune responses. This article summarizes many of the numerous innovative technologies and discoveries that have resulted in RASV platforms that will enable development of safe efficacious RASVs to protect animals and humans against a diversity of infectious disease agents.
from The Journal of Immunology current issue http://ift.tt/2BaxrLN
The Role of MHC-E in T Cell Immunity Is Conserved among Humans, Rhesus Macaques, and Cynomolgus Macaques [ANTIGEN RECOGNITION AND RESPONSES]
MHC-E is a highly conserved nonclassical MHC class Ib molecule that predominantly binds and presents MHC class Ia leader sequence-derived peptides for NK cell regulation. However, MHC-E also binds pathogen-derived peptide Ags for presentation to CD8+ T cells. Given this role in adaptive immunity and its highly monomorphic nature in the human population, HLA-E is an attractive target for novel vaccine and immunotherapeutic modalities. Development of HLA-E–targeted therapies will require a physiologically relevant animal model that recapitulates HLA-E–restricted T cell biology. In this study, we investigated MHC-E immunobiology in two common nonhuman primate species, Indian-origin rhesus macaques (RM) and Mauritian-origin cynomolgus macaques (MCM). Compared to humans and MCM, RM expressed a greater number of MHC-E alleles at both the population and individual level. Despite this difference, human, RM, and MCM MHC-E molecules were expressed at similar levels across immune cell subsets, equivalently upregulated by viral pathogens, and bound and presented identical peptides to CD8+ T cells. Indeed, SIV-specific, Mamu-E–restricted CD8+ T cells from RM recognized antigenic peptides presented by all MHC-E molecules tested, including cross-species recognition of human and MCM SIV-infected CD4+ T cells. Thus, MHC-E is functionally conserved among humans, RM, and MCM, and both RM and MCM represent physiologically relevant animal models of HLA-E–restricted T cell immunobiology.
from The Journal of Immunology current issue http://ift.tt/2yTkn7s
Superoxide Production by NADPH Oxidase Intensifies Macrophage Antiviral Responses during Diabetogenic Coxsackievirus Infection [AUTOIMMUNITY]
Coxsackievirus B infections are suspected environmental triggers of type 1 diabetes (T1D) and macrophage antiviral responses may provide a link to virus-induced T1D. We previously demonstrated an important role for NADPH oxidase (NOX)–derived superoxide production during T1D pathogenesis, as NOX-deficient NOD mice (NOD.Ncf1m1J) were protected against T1D due, in part, to impaired proinflammatory TLR signaling in NOD.Ncf1m1J macrophages. Therefore, we hypothesized that loss of NOX-derived superoxide would dampen diabetogenic antiviral macrophage responses and protect from virus-induced diabetes. Upon infection with a suspected diabetogenic virus, Coxsackievirus B3 (CB3), NOD.Ncf1m1J mice remained resistant to virus-induced autoimmune diabetes. A concomitant decrease in circulating inflammatory chemokines, blunted antiviral gene signature within the pancreas, and reduced proinflammatory M1 macrophage responses were observed. Importantly, exogenous superoxide addition to CB3-infected NOD.Ncf1m1J bone marrow–derived macrophages rescued the inflammatory antiviral M1 macrophage response, revealing reduction-oxidation–dependent mechanisms of signal transducer and activator of transcription 1 signaling and dsRNA viral sensors in macrophages. We report that superoxide production following CB3 infection may exacerbate pancreatic β cell destruction in T1D by influencing proinflammatory M1 macrophage responses, and mechanistically linking oxidative stress, inflammation, and diabetogenic virus infections.
from The Journal of Immunology current issue http://ift.tt/2Ba8r7w
Essential Role of CARD14 in Murine Experimental Psoriasis [AUTOIMMUNITY]
Caspase recruitment domain family member 14 (CARD14) was recently identified as a psoriasis-susceptibility gene, but its immunological role in the pathogenesis of psoriasis in vivo remains unclear. In this study, we examined the role of CARD14 in murine experimental models of psoriasis induced by either imiquimod (IMQ) cream or recombinant IL-23 injection. In all models tested, the psoriasiform skin inflammation was abrogated in Card14–/– mice. Comparison of the early gene signature of the skin between IMQ-cream–treated Card14–/– mice and Tlr7–/–Tlr9–/– mice revealed not only their similarity, but also distinct gene sets targeted by IL-23. Cell type–specific analysis of these mice identified skin Langerinhigh Langerhans cells as a potent producer of IL-23, which was dependent on both TLR7 and TLR9 but independent of CARD14, suggesting that CARD14 is acting downstream of IL-23, not TLR7 or TLR9. Instead, a bone marrow chimera study suggested that CARD14 in radio-sensitive hematopoietic cells was required for IMQ-induced psoriasiform skin inflammation, controlling the number of V4+ T cells producing IL-17 or IL-22 infiltrating through the dermis to the inflamed epidermis. These data indicate that CARD14 is essential and a potential therapeutic target for psoriasis.
from The Journal of Immunology current issue http://ift.tt/2ySF7w1
The Loss of TET2 Promotes CD8+ T Cell Memory Differentiation [IMMUNE REGULATION]
T cell differentiation requires appropriate regulation of DNA methylation. In this article, we demonstrate that the methylcytosine dioxygenase ten-eleven translocation (TET)2 regulates CD8+ T cell differentiation. In a murine model of acute viral infection, TET2 loss promotes early acquisition of a memory CD8+ T cell fate in a cell-intrinsic manner without disrupting Ag-driven cell expansion or effector function. Upon secondary recall, TET2-deficient memory CD8+ T cells demonstrate superior pathogen control. Genome-wide methylation analysis identified a number of differentially methylated regions in TET2-deficient versus wild-type CD8+ T cells. These differentially methylated regions did not occur at the loci of differentially expressed memory markers; rather, several hypermethylated regions were identified in known transcriptional regulators of CD8+ T cell memory fate. Together, these data demonstrate that TET2 is an important regulator of CD8+ T cell fate decisions.
from The Journal of Immunology current issue http://ift.tt/2BaxmHZ
Downregulation of NFAT3 Due to Lack of T-Box Transcription Factor TBX5 Is Crucial for Cytokine Expression in T Cells [IMMUNE REGULATION]
The NFAT family transcription factors play crucial roles in immunological and other biological activities. NFAT3 is rarely expressed in T cells, and the mechanisms and significance of the specific NFAT3 downregulation in T cells have been unknown. In human CD4+ T cells, overexpression of NFAT1 and NFAT3 enhanced and suppressed IL-2 expression, respectively. NFAT3 downregulation in Jurkat cells using RNA interference technology augmented IL-2 expression, whereas a knockdown of NFAT1, NFAT2, and NFAT4 suppressed it. The promoter/enhancer activity of the NFAT-binding site in the IL-2 gene was upregulated and downregulated by NFAT1 and NFAT3, respectively. A study employing NFAT1/NFAT3 chimeric molecules revealed that the region in NFAT3 responsible for NFAT promoter activity inhibition was located within its N-terminal transactivation domain, Ca2+-regulatory domain, and DNA-binding domain. Downregulation of NFAT3 expression in T cells is mediated by lower chromatin accessibility and enhancer activity in its promoter in comparison with aortic smooth muscle cells expressing endogenous NFAT3. The binding sites of T-box transcription factor TBX5 and NK-2 transcription factor–related locus 5 Nkx2.5, which were expressed at higher levels in aortic smooth muscle cells than in T cells, were located within the –387 to +97 NFAT3 promoter region, exhibiting the maximum enhancer activity. Mutating the binding site of TBX5 but not Nkx2.5 diminished the NFAT3 promoter activity, whereas the overexpression of TBX5 enhanced it. Introduction of TBX5 into CD4+ T cells enhanced the expression of NFAT3 and suppressed that of IL-2. TBX5 deficiency-mediated downregulation of NFAT3 is crucial for the high cytokine-producing activity of T cells.
from The Journal of Immunology current issue http://ift.tt/2yUmA2l
Route of Antigen Presentation Can Determine the Selection of Foxp3-Dependent or Foxp3-Independent Dominant Immune Tolerance [IMMUNE REGULATION]
It has been shown that dominant tolerance, namely in transplantation, requires Foxp3+ regulatory T cells. Although most tolerance-inducing regimens rely on regulatory T cells, we found that induction of tolerance to proteins in aluminum hydroxide can be achieved in Foxp3-deficient mice using nondepleting anti-CD4 Abs. This type of tolerance is Ag specific, and tolerant mice retain immune competence to respond to unrelated Ags. We demonstrated with chicken OVA–specific TCR-transgenic mice that the same tolerizing protocol (CD4 blockade) and the same target Ag (OVA) achieves Foxp3-dependent transplantation tolerance to OVA-expressing skin grafts, but Foxp3-independent tolerance when the Ag is provided as OVA–aluminum hydroxide. In the latter case, we found that tolerance induction triggered recessive mechanisms leading to elimination of effector cells and, simultaneously, a dominant mechanism associated with the emergence of an anergic and regulatory CTLA-4+IL-2lowFoxp3– T cell population, where the tolerance state is IL-10 dependent. Such Foxp3-independent mechanisms can improve the efficacy of tolerance-inducing protocols.
from The Journal of Immunology current issue http://ift.tt/2Baib1p
STAT5B: A Differential Regulator of the Life and Death of CD4+ Effector Memory T Cells [IMMUNE REGULATION]
Understanding the control of Ag restimulation-induced T cell death (RICD), especially in cancer immunotherapy, where highly proliferating T cells will encounter potentially large amounts of tumor Ags, is important now more than ever. It has been known that growth cytokines make T cells susceptible to RICD, but the precise molecular mediators that govern this in T cell subsets is unknown until now. STAT proteins are a family of transcription factors that regulate gene expression programs underlying key immunological processes. In particular, STAT5 is known to favor the generation and survival of memory T cells. In this study, we report an unexpected role for STAT5 signaling in the death of effector memory T (TEM) cells in mice and humans. TEM cell death was prevented with neutralizing anti–IL-2 Ab or STAT5/JAK3 inhibitors, indicating that STAT5 signaling drives RICD in TEM cells. Moreover, we identified a unique patient with a heterozygous missense mutation in the coiled-coil domain of STAT5B that presented with autoimmune lymphoproliferative syndrome–like features. Similar to Stat5b–/– mice, this patient exhibited increased CD4+ TEM cells in the peripheral blood. The mutant STAT5B protein dominantly interfered with STAT5-driven transcriptional activity, leading to global downregulation of STAT5-regulated genes in patient T cells upon IL-2 stimulation. Notably, CD4+ TEM cells from the patient were strikingly resistant to cell death by in vitro TCR restimulation, a finding that was recapitulated in Stat5b–/– mice. Hence, STAT5B is a crucial regulator of RICD in memory T cells in mice and humans.
from The Journal of Immunology current issue http://ift.tt/2yTQcNC
Ultraviolet B-Induced Maturation of CD11b-Type Langerin- Dendritic Cells Controls the Expansion of Foxp3+ Regulatory T Cells in the Skin [IMMUNE REGULATION]
Skin dendritic cells (DCs) are divided into several subsets with distinctive functions. This study shows a previously unappreciated role of dermal CD11b-type Langerin– DCs in maintaining immunological self-tolerance after UVB exposure. After UVB exposure, dermal CD11b-type Langerin– DCs upregulated surface CD86 expression, induced proliferation of Foxp3+ regulatory T (Treg) cells without exogenous Ags, and upregulated a set of genes associated with immunological tolerance. This Treg-expansion activity was significantly hampered by CD80/CD86 blockade in vivo. These results indicate that CD11b-type Langerin– DCs from the UVB-exposed skin are specialized to expand Treg cells in the skin, which suppress autoimmunity.
from The Journal of Immunology current issue http://ift.tt/2B8azMO
The Role of Macrophages in the Response to TNF Inhibition in Experimental Arthritis [IMMUNE SYSTEM DEVELOPMENT]
The reduction of synovial tissue macrophages is a reliable biomarker for clinical improvement in patients with rheumatoid arthritis (RA), and macrophages are reduced in synovial tissue shortly after initiation of TNF inhibitors. The mechanism for this initial response is unclear. These studies were performed to identify the mechanisms responsible for the initial reduction of macrophages following TNF inhibition, positing that efflux to draining lymph nodes was involved. RA synovial tissue and synovial fluid macrophages expressed CCR7, which was increased in control macrophages following incubation with TNF-α. Human TNF transgenic (hTNF-Tg) mice were treated with infliximab after development of arthritis. Ankles were harvested and examined by histology, immunohistochemistry, quantitative RT-PCR, ELISA, and flow cytometry. hTNF-Tg mice treated with infliximab demonstrated significant clinical and histologic improvement 3 d after the initiation of therapy, at which time Ly6C+ macrophages were significantly reduced in the ankles. However, no evidence was identified to support a role of macrophage efflux to draining lymph nodes following treatment with infliximab. In contrast, apoptosis of Ly6C+ macrophages in the ankles and popliteal lymph nodes, decreased migration of monocytes into the ankles, and a reduction of CCL2 were identified following the initiation of infliximab. These observations demonstrate that Ly6C+ macrophage apoptosis and decreased ingress of circulating monocytes into the joint are responsible for the initial reduction of macrophages following infliximab treatment in hTNF-Tg mice.
from The Journal of Immunology current issue http://ift.tt/2yU4uh5
CXCR3/CXCL10 Axis Shapes Tissue Distribution of Memory Phenotype CD8+ T Cells in Nonimmunized Mice [IMMUNE SYSTEM DEVELOPMENT]
The preimmune repertoire consists of mature T lymphocytes that have not yet been stimulated in the periphery. Memory phenotype (MP) cells have been reported as part of the preimmune repertoire (i.e., T cells bearing memory markers despite lack of engagement with cognate Ag); however, little is known about their trafficking and function. In this study, we hypothesized that MP cells, naive to TCR stimulation, constitute a transient population that traffics to tissues during development. Using mutant and transgenic animals with a monospecific TCR, we discovered increased numbers of MP CD8+ T cells circulating in nonimmunized Cxcr3–/– and Cxcl10–/– mice compared with wild-type animals. Phenotypic differences included decreased numbers of preimmune MP Ag-specific T cells in the skin and thymus and a distinct pattern of activation upon TCR engagement. Our results show for the first time, to our knowledge, an important role for CXCR3 and CXCL10 in the tissue distribution of preimmune MP cells.
from The Journal of Immunology current issue http://ift.tt/2B8azwi
A Novel Pkhd1 Mutation Interacts with the Nonobese Diabetic Genetic Background To Cause Autoimmune Cholangitis [IMMUNOGENETICS]
We previously reported that NOD.c3c4 mice develop spontaneous autoimmune biliary disease (ABD) with anti-mitochondrial Abs, histopathological lesions, and autoimmune T lymphocytes similar to human primary biliary cholangitis. In this article, we demonstrate that ABD in NOD.c3c4 and related NOD ABD strains is caused by a chromosome 1 region that includes a novel mutation in polycystic kidney and hepatic disease 1 (Pkhd1). We show that a long terminal repeat element inserted into intron 35 exposes an alternative polyadenylation site, resulting in a truncated Pkhd1 transcript. A novel NOD congenic mouse expressing aberrant Pkhd1, but lacking the c3 and c4 chromosomal regions (NOD.Abd3), reproduces the immunopathological features of NOD ABD. RNA sequencing of NOD.Abd3 common bile duct early in disease demonstrates upregulation of genes involved in cholangiocyte injury/morphology and downregulation of immunoregulatory genes. Consistent with this, bone marrow chimera studies show that aberrant Pkhd1 must be expressed in the target tissue (cholangiocytes) and the immune system (bone marrow). Mutations of Pkhd1 produce biliary abnormalities in mice but have not been previously associated with autoimmunity. In this study, we eliminate clinical biliary disease by backcrossing this Pkhd1 mutation onto the C57BL/6 genetic background; thus, the NOD genetic background (which promotes autoimmunity) is essential for disease. We propose that loss of functional Pkhd1 on the NOD background produces early bile duct abnormalities, initiating a break in tolerance that leads to autoimmune cholangitis in NOD.Abd3 congenic mice. This model is important for understanding loss of tolerance to cholangiocytes and is relevant to the pathogenesis of several human cholangiopathies.
from The Journal of Immunology current issue http://ift.tt/2yTEpyz
Live Attenuated Leishmania donovani Centrin Gene-Deleted Parasites Induce IL-23-Dependent IL-17-Protective Immune Response against Visceral Leishmaniasis in a Murine Model [IMMUNOTHERAPY AND VACCINES]
No vaccine exists against visceral leishmaniasis. To develop effective vaccines, we have previously reported protective role of live attenuated centrin gene–deleted Leishmania donovani (LdCen–/–) parasites through induction of Th1 type immune response in mice, hamsters, and dogs. In this study, we specifically explored the role of Th17 cells in LdCen–/–-induced host protection in mice. Our results showed that compared with wild-type L. donovani infection, LdCen–/– parasites induce significantly higher expression of Th17 differentiation cytokines in splenic dendritic cells. There was also induction of IL-17 and its promoting cytokines in total splenocytes and in both CD4 and CD8 T cells following immunization with LdCen–/–. Upon challenge with wild-type parasites, IL-17 and its differentiating cytokines were significantly higher in LdCen–/–-immunized mice compared with nonimmunized mice that resulted in parasite control. Alongside IL-17 induction, we observed induction of IFN-–producing Th1 cells as reported earlier. However, Th17 cells are generated before Th1 cells. Neutralization of either IL-17 or IFN- abrogated LdCen–/–-induced host protection further confirming the essential role of Th17 along with Th1 cytokines in host protection. Treatment with recombinant IL-23, which is required for stabilization and maintenance of IL-17, heightened Th17, and Tc17 responses in immunized mice splenocytes. In contrast, Th17 response was absent in immunized IL-23R–/– mice that failed to induce protection upon virulent Leishmania challenge suggesting that IL-23 plays an essential role in IL-17–mediated protection by LdCen–/– parasites. This study unveiled the role of IL-23–dependent IL-17 induction in LdCen–/– parasite-induced immunity and subsequent protection against visceral leishmaniasis.
from The Journal of Immunology current issue http://ift.tt/2Baxbwj
Amplifying IFN-{gamma} Signaling in Dendritic Cells by CD11c-Specific Loss of SOCS1 Increases Innate Immunity to Infection while Decreasing Adaptive Immunity [INFECTIOUS DISEASE AND HOST RESPONSE]
Although prophylactic vaccines provide protective humoral immunity against infectious agents, vaccines that elicit potent CD8 T cell responses are valuable tools to shape and drive cellular immunity against cancer and intracellular infection. In particular, IFN-–polarized cytotoxic CD8 T cell immunity is considered optimal for protective immunity against intracellular Ags. Suppressor of cytokine signaling (SOCS)1 is a cross-functional negative regulator of TLR and cytokine receptor signaling via degradation of the receptor–signaling complex. We hypothesized that loss of SOCS1 in dendritic cells (DCs) would improve T cell responses by accentuating IFN-–directed immune responses. We tested this hypothesis using a recombinant Listeria monocytogenes vaccine platform that targets CD11c+ DCs in mice in which SOCS1 is selectively deleted in all CD11c+ cells. Unexpectedly, in mice lacking SOCS1 expression in CD11c+ cells, we observed a decrease in CD8+ T cell response to the L. monocytogenes vaccine. NK cell responses were also decreased in mice lacking SOCS1 expression in CD11c+ cells but did not explain the defect in CD8+ T cell immunity. We found that DCs lacking SOCS1 expression were functional in driving Ag-specific CD8+ T cell expansion in vitro but that this process was defective following infection in vivo. Instead, monocyte-derived innate TNF-α and inducible NO synthase–producing DCs dominated the antibacterial response. Thus, loss of SOCS1 in CD11c+ cells skewed the balance of immune response to infection by increasing innate responses while decreasing Ag-specific adaptive responses to infectious Ags.
from The Journal of Immunology current issue http://ift.tt/2yTznCo
Toxoplasma gondii Inactivates Human Plasmacytoid Dendritic Cells by Functional Mimicry of IL-10 [INFECTIOUS DISEASE AND HOST RESPONSE]
Plasmacytoid dendritic cells (pDCs) are the major producers of IFN-α, an antiviral cytokine involved in immunomodulation and control of HIV type 1 replication, whereas Toxoplasma gondii is a life-threatening opportunistic infection in AIDS patients. During infection with HIV type 1, human pDCs decrease in circulation and remaining pDC produce lower amounts of IFN-α in response to viral stimulation. In this study, we investigated the impact of coinfection with T. gondii on the innate virus-directed responses of human pDCs. Using intracellular flow cytometry and fluorescence microscopy, we determined that T. gondii invaded but did not induce IFN-α or TNF-α in human pDC. However, T. gondii inhibited IFN-α and TNF-α produced in response to HSV and HIV, thus functionally inactivating pDC. IFN-α production was inhibited only in cells infected by T. gondii, which inhibited neither uptake of GFP-HSV nor localization of TLR9 in CD71+ endosomes, directing us to investigate downstream events. Using imaging flow cytometry, we found that both T. gondii and IL-10 inhibited virus-induced nuclear translocation, but not phosphorylation, of IFN response factor 7. Blockade of IFN response factor 7 nuclear translocation and inhibition of the IFN-α response was partially reversed by a deficiency in the T. gondii–derived ROP16 kinase, known to directly phosphorylate STAT3, a critical mediator of IL-10’s anti-inflammatory effects. Taken together, our results indicate that T. gondii suppresses pDC activation by mimicking IL-10’s regulatory effects through an ROP16 kinase-dependent mechanism. Our findings further imply a convergent mechanism of inhibition of TLR signaling by T. gondii and IL-10 and suggest potential negative consequences of HIV/T. gondii coinfection.
from The Journal of Immunology current issue http://ift.tt/2Bax8k7
NOX2-Derived Reactive Oxygen Species Control Inflammation during Leishmania amazonensis Infection by Mediating Infection-Induced Neutrophil Apoptosis [INFECTIOUS DISEASE AND HOST RESPONSE]
Reactive oxygen species (ROS) produced by NADPH phagocyte oxidase isoform (NOX2) are critical for the elimination of intracellular pathogens in many infections. Despite their importance, the role of ROS following infection with the eukaryotic pathogen Leishmania has not been fully elucidated. We addressed the role of ROS in C57BL/6 mice following intradermal infection with Leishmania amazonensis. Despite equivalent parasite loads compared with wild-type (WT) mice, mice deficient in ROS production by NOX2 due to the absence of the gp91 subunit (gp91phox–/–) had significantly more severe pathology in the later stages of infection. Pathology in gp91phox–/– mice was not associated with alterations in CD4+ T cell–mediated immunity but was preceded by enhanced neutrophil accumulation at the dermal infection site. Ex vivo analysis of infected versus uninfected neutrophils revealed a deficiency in infection-driven apoptosis in gp91phox–/– mice versus WT mice. gp91phox–/– mice presented with higher percentages of healthy or necrotic neutrophils but lower percentages of apoptotic neutrophils at early and chronic time points. In vitro infection of gp91phox–/– versus WT neutrophils also revealed reduced apoptosis and CD95 expression but increased necrosis in infected cells at 10 h postinfection. Provision of exogenous ROS in the form of H2O2 reversed the necrotic phenotype and restored CD95 expression on infected gp91phox–/– neutrophils. Although ROS production is typically viewed as a proinflammatory event, our observations identify the importance of ROS in mediating appropriate neutrophil apoptosis and the importance of apoptosis in inflammation and pathology during chronic infection.
from The Journal of Immunology current issue http://ift.tt/2yVdF0Y
The IFN Response in Bats Displays Distinctive IFN-Stimulated Gene Expression Kinetics with Atypical RNASEL Induction [INFECTIOUS DISEASE AND HOST RESPONSE]
Bats host a large number of zoonotic viruses, including several viruses that are highly pathogenic to other mammals. The mechanisms underlying this rich viral diversity are unknown, but they may be linked to unique immunological features that allow bats to act as asymptomatic viral reservoirs. Vertebrates respond to viral infection by inducing IFNs, which trigger antiviral defenses through IFN-stimulated gene (ISG) expression. Although the IFN system of several bats is characterized at the genomic level, less is known about bat IFN-mediated transcriptional responses. In this article, we show that IFN signaling in bat cells from the black flying fox (Pteropus alecto) consists of conserved and unique ISG expression profiles. In IFN-stimulated cells, bat ISGs comprise two unique temporal subclusters with similar early induction kinetics but distinct late-phase declines. In contrast, human ISGs lack this decline phase and remained elevated for longer periods. Notably, in unstimulated cells, bat ISGs were expressed more highly than their human counterparts. We also found that the antiviral effector 2-5A–dependent endoribonuclease, which is not an ISG in humans, is highly IFN inducible in black flying fox cells and contributes to cell-intrinsic control of viral infection. These studies reveal distinctive innate immune features that may underlie a unique virus–host relationship in bats.
from The Journal of Immunology current issue http://ift.tt/2B97Ti9
IL-1{beta} Induces Pathologically Activated Osteoclasts Bearing Extremely High Levels of Resorbing Activity: A Possible Pathological Subpopulation of Osteoclasts, Accompanied by Suppressed Expression of Kindlin-3 and Talin-1 [INNATE IMMUNITY AND INFLAMMATION]
As osteoclasts have the central roles in normal bone remodeling, it is ideal to regulate only the osteoclasts performing pathological bone destruction without affecting normal osteoclasts. Based on a hypothesis that pathological osteoclasts form under the pathological microenvironment of the bone tissues, we here set up optimum culture conditions to examine the entity of pathologically activated osteoclasts (PAOCs). Through searching various inflammatory cytokines and their combinations, we found the highest resorbing activity of osteoclasts when osteoclasts were formed in the presence of M-CSF, receptor activator of NF-B ligand, and IL-1β. We have postulated that these osteoclasts are PAOCs. Analysis using confocal laser microscopy revealed that PAOCs showed extremely high proton secretion detected by the acid-sensitive fluorescence probe Rh-PM and bone resorption activity compared with normal osteoclasts. PAOCs showed unique morphology bearing high thickness and high motility with motile cellular processes in comparison with normal osteoclasts. We further examined the expression of Kindlin-3 and Talin-1, essential molecules for activating integrin β-chains. Although normal osteoclasts express high levels of Kindlin-3 and Talin-1, expression of these molecules was markedly suppressed in PAOCs, suggesting the abnormality in the adhesion property. When whole membrane surface of mature osteoclasts was biotinylated and analyzed, the IL-1β–induced cell surface protein was detected. PAOCs could form a subpopulation of osteoclasts possibly different from normal osteoclasts. PAOC-specific molecules could be an ideal target for regulating pathological bone destruction.
from The Journal of Immunology current issue http://ift.tt/2yTk10P
IL-33-Responsive Group 2 Innate Lymphoid Cells Are Regulated by Female Sex Hormones in the Uterus [INNATE IMMUNITY AND INFLAMMATION]
Group 2 innate lymphoid cells (ILC2s) reside in multiple organs in the body, where they play roles in immunity, tissue homeostasis, and metabolic regulation. However, little is known about the regulatory mechanisms of ILC2s in different organs. Here, we identified ILC2s in the mouse uterus and found that they express cell surface molecules, including the IL-33 receptor, ST2, that are roughly comparable to those expressed by lung ILC2s. Both in vivo and in vitro treatment with IL-33 induced type 2 cytokine production in uterine ILC2s, suggesting that they respond to IL-33 in a manner similar to ILC2s in other organs. Importantly, uterine ILC2s were nearly absent in ovariectomized mice and were increased in wild-type mice by estrogen administration, whereas lung ILC2s were unaffected by both ovariectomy and estrogen administration. Likewise, a marked reduction in uterine ILC2s was observed in mice deficient in estrogen receptor α or estrogen receptor β. Furthermore, uterine ILC2s highly expressed estrogen receptor α, and in vitro culture of isolated uterine ILC2s with 17β-estradiol modified expression of a number of genes. Finally, an increased prevalence in neonatal mortality was observed in litters from dams lacking the IL-33 receptor, ST2. Taken together, our findings indicate that unlike lung IL2Cs, uterine ILC2s are regulated by female sex hormones, which may specialize them for specific physiological functions.
from The Journal of Immunology current issue http://ift.tt/2Bawx1V
Identification of IFN-{gamma} and IL-27 as Critical Regulators of Respiratory Syncytial Virus-Induced Exacerbation of Allergic Airways Disease in a Mouse Model [INNATE IMMUNITY AND INFLAMMATION]
Respiratory syncytial virus (RSV) infection induces asthma exacerbations, which leads to worsening of clinical symptoms and may result in a sustained decline in lung function. Exacerbations are the main cause of morbidity and mortality associated with asthma, and significantly contribute to asthma-associated healthcare costs. Although glucocorticoids are used to manage exacerbations, some patients respond to them poorly. The underlying mechanisms associated with steroid-resistant exacerbations remain largely unknown. We have previously established a mouse model of RSV-induced exacerbation of allergic airways disease, which mimics hallmark clinical features of asthma. In this study, we have identified key roles for macrophage IFN- and IL-27 in the regulation of RSV-induced exacerbation of allergic airways disease. Production of IFN- and IL-27 was steroid-resistant, and neutralization of IFN- or IL-27 significantly suppressed RSV-induced steroid-resistant airway hyperresponsiveness and airway inflammation. We have previously implicated activation of pulmonary macrophage by TNF-α and/or MCP-1 in the mechanisms of RSV-induced exacerbation. Stimulation of pulmonary macrophages with TNF-α and/or MCP-1 induced expression of both IFN- and IL-27. Our findings highlight critical roles for IFN- and IL-27, downstream of TNF-α and MCP-1, in the mechanism of RSV-induced exacerbation. Thus, targeting the pathways that these factors activate may be a potential therapeutic approach for virus-induced asthma exacerbations.
from The Journal of Immunology current issue http://ift.tt/2yTPRKQ
The Activation of Human Dermal Microvascular Cells by Poly(I:C), Lipopolysaccharide, Imiquimod, and ODN2395 Is Mediated by the Fli1/FOXO3A Pathway [INNATE IMMUNITY AND INFLAMMATION]
Endothelial cell (EC) dysfunction has been associated with inflammatory and autoimmune diseases; however, the factors contributing to this dysfunction have not been fully explored. Because activation of TLRs has been implicated in autoimmune diseases, the goal of this study was to determine the effects of TLR ligands on EC function. Human dermal microvascular ECs (HDMECs) treated with TLR3 [Poly(I:C)], TLR4 (LPS), and TLR7 (imiquimod) agonists showed decreased proliferation and a reduced total number of branching tubules in three-dimensional human dermal organoid ex vivo culture. In contrast, the TLR9 ligand class C, ODN2395, increased angiogenesis. The antiproliferative effects of TLR3, TLR4, and TLR7 ligands correlated with significant downregulation of a key regulator of vascular homeostasis, Fli1, whereas TLR9 increased Fli1 levels. Furthermore, Poly(I:C) and LPS induced endothelial to mesenchymal transition that was reversed by the pretreatment with TGF-β neutralizing Ab or re-expression of Fli1. We showed that Fli1 was required for the HDMEC proliferation by transcriptionally repressing FOXO3A. In contrast to TLR9, which suppressed activation of the FOXO3A pathway, TLR3, TLR4, and TLR7 ligands activated FOXO3A as indicated by decreased phosphorylation and increased nuclear accumulation. The inverse correlation between Fli1 and FOXO3A was also observed in the vasculature of scleroderma patients. This work revealed opposing effects of TLR9 and TLR3, TLR4, and TLR7 on the key angiogenic pathways, Fli1 and FOXO3A. Our results provide a mechanistic insight into the regulation of angiogenesis by TLRs and confirm a central role of Fli1 in regulating vascular homeostasis.
from The Journal of Immunology current issue http://ift.tt/2BaxOpF
Reticulon-1 and Reduced Migration toward Chemoattractants by Macrophages Differentiated from the Bone Marrow of Ultraviolet-Irradiated and Ultraviolet-Chimeric Mice [INNATE IMMUNITY AND INFLAMMATION]
The ability of macrophages to respond to chemoattractants and inflammatory signals is important for their migration to sites of inflammation and immune activity and for host responses to infection. Macrophages differentiated from the bone marrow (BM) of UV-irradiated mice, even after activation with LPS, migrated inefficiently toward CSF-1 and CCL2. When BM cells were harvested from UV-irradiated mice and transplanted into naive mice, the recipient mice (UV-chimeric) had reduced accumulation of elicited monocytes/macrophages in the peritoneal cavity in response to inflammatory thioglycollate or alum. Macrophages differentiating from the BM of UV-chimeric mice also had an inherent reduced ability to migrate toward chemoattractants in vitro, even after LPS activation. Microarray analysis identified reduced reticulon-1 mRNA expressed in macrophages differentiated from the BM of UV-chimeric mice. By using an anti-reticulon-1 Ab, a role for reticulon-1 in macrophage migration toward both CSF-1 and CCL2 was confirmed. Reticulon-1 subcellular localization to the periphery after exposure to CSF-1 for 2.5 min was shown by immunofluorescence microscopy. The proposal that reduced reticulon-1 is responsible for the poor inherent ability of macrophages to respond to chemokine gradients was supported by Western blotting. In summary, skin exposure to erythemal UV radiation can modulate macrophage progenitors in the BM such that their differentiated progeny respond inefficiently to signals to accumulate at sites of inflammation and immunity.
from The Journal of Immunology current issue http://ift.tt/2yVdEKs
Embryonic Lethality and Host Immunity of RelA-Deficient Mice Are Mediated by Both Apoptosis and Necroptosis [INNATE IMMUNITY AND INFLAMMATION]
In mammalian cells, signaling pathways triggered by TNF can be switched from NF-B activation to apoptosis and/or necroptosis. The in vivo mechanisms underlying the mutual regulation of these three signaling pathways are poorly understood. In this article, we report that the embryonic lethality of RelA-deficient mice is partially prevented by the deletion of Rip3 or Mlkl, but it is fully rescued by the combined ablation of Fadd and Rip3 or Mlkl or by blocking RIP1 kinase activity (RIP1K45A). RelA–/–Fadd–/–Rip3–/– triple-knockout (TKO) and RelA–/–Rip1K45A/K45A mice displayed bacterial pneumonia leading to death ~2 wk after birth. Moreover, RelA–/–Rip1K45A/K45A mice, but not TKO mice, developed severe inflammation associated with inflammatory skin lesion. Antibiotic treatment improved bacterial pneumonia, extended the lifespan of TKO and RelA–/–Rip1K45A/K45A mice, and alleviated skin inflammation in RelA–/–Rip1K45A/K45A mice. These results show the mechanisms underlying the in vivo mutual regulation between NF-B activation and the cell death pathway and provide new insights into this interplay in embryonic development and host immune homeostasis.
from The Journal of Immunology current issue http://ift.tt/2BaAsLW
Rhesus Macaque Myeloid-Derived Suppressor Cells Demonstrate T Cell Inhibitory Functions and Are Transiently Increased after Vaccination [INNATE IMMUNITY AND INFLAMMATION]
Myeloid-derived suppressor cells (MDSCs) are major regulators of T cell responses in several pathological conditions. Whether MDSCs increase and influence T cell responses in temporary inflammation, such as after vaccine administration, is unknown. Using the rhesus macaque model, which is critical for late-stage vaccine testing, we demonstrate that monocytic (M)-MDSCs and polymorphonuclear (PMN)-MDSCs can be detected using several of the markers used in humans. However, whereas rhesus M-MDSCs lacked expression of CD33, PMN-MDSCs were identified as CD33+ low-density neutrophils. Importantly, both M-MDSCs and PMN-MDSCs showed suppression of T cell proliferation in vitro. The frequency of circulating MDSCs rapidly and transiently increased 24 h after vaccine administration. M-MDSCs infiltrated the vaccine injection site, but not vaccine-draining lymph nodes. This was accompanied by upregulation of genes relevant to MDSCs such as arginase-1, IDO1, PDL1, and IL-10 at the injection site. MDSCs may therefore play a role in locally maintaining immune balance during vaccine-induced inflammation.
from The Journal of Immunology current issue http://ift.tt/2yTPK1S
Granzyme A in Human Platelets Regulates the Synthesis of Proinflammatory Cytokines by Monocytes in Aging [INNATE IMMUNITY AND INFLAMMATION]
Dysregulated inflammation is implicated in the pathobiology of aging, yet platelet–leukocyte interactions and downstream cytokine synthesis in aging remains poorly understood. Platelets and monocytes were isolated from healthy younger (age <45, n = 37) and older (age ≥65, n = 30) adults and incubated together under autologous and nonautologous conditions. Synthesis of inflammatory cytokines by monocytes, alone or in the presence of platelets, was examined. Next-generation RNA-sequencing allowed for unbiased profiling of the platelet transcriptome in aging. Basal IL-8 and MCP-1 synthesis by monocytes alone did not differ between older and younger adults. However, in the presence of autologous platelets, monocytes from older adults synthesized greater IL-8 (41 ± 5 versus 9 ± 2 ng/ml, p < 0.0001) and MCP-1 (867 ± 150 versus 216 ± 36 ng/ml, p < 0.0001) than younger adults. Platelets from older adults were sufficient for upregulating the synthesis of inflammatory cytokines by monocytes. Using RNA-sequencing of platelets followed by validation via RT-PCR and immunoblot, we discovered that granzyme A (GrmA), a serine protease not previously identified in human platelets, increases with aging (~9-fold versus younger adults, p < 0.05) and governs increased IL-8 and MCP-1 synthesis through TLR4 and caspase-1. Inhibiting GrmA reduced excessive IL-8 and MCP-1 synthesis in aging to levels similar to younger adults. In summary, human aging is associated with changes in the platelet transcriptome and proteome. GrmA is present and bioactive in human platelets, is higher in older adults, and controls the synthesis of inflammatory cytokines by monocytes. Alterations in the platelet molecular signature and signaling to monocytes may contribute to dysregulated inflammatory syndromes in older adults.
from The Journal of Immunology current issue http://ift.tt/2B97SuB
NFAT5-Regulated Macrophage Polarization Supports the Proinflammatory Function of Macrophages and T Lymphocytes [INNATE IMMUNITY AND INFLAMMATION]
Macrophages are exquisite sensors of tissue homeostasis that can rapidly switch between pro- and anti-inflammatory or regulatory modes to respond to perturbations in their microenvironment. This functional plasticity involves a precise orchestration of gene expression patterns whose transcriptional regulators have not been fully characterized. We had previously identified the transcription factor NFAT5 as an activator of TLR-induced responses, and in this study we explore its contribution to macrophage functions in different polarization settings. We found that both in classically and alternatively polarized macrophages, NFAT5 enhanced functions associated with a proinflammatory profile such as bactericidal capacity and the ability to promote Th1 polarization over Th2 responses. In this regard, NFAT5 upregulated the Th1-stimulatory cytokine IL-12 in classically activated macrophages, whereas in alternatively polarized ones it enhanced the expression of the pro-Th1 mediators Fizz-1 and arginase 1, indicating that it could promote proinflammatory readiness by regulating independent genes in differently polarized macrophages. Finally, adoptive transfer assays in vivo revealed a reduced antitumor capacity in NFAT5-deficient macrophages against syngeneic Lewis lung carcinoma and ID8 ovarian carcinoma cells, a defect that in the ID8 model was associated with a reduced accumulation of effector CD8 T cells at the tumor site. Altogether, detailed analysis of the effect of NFAT5 in pro- and anti-inflammatory macrophages uncovered its ability to regulate distinct genes under both polarization modes and revealed its predominant role in promoting proinflammatory macrophage functions.
from The Journal of Immunology current issue http://ift.tt/2yUESR6
Hospital Giants Vie for Patients in Effort to Fend Off New Rivals
By REED ABELSON from NYT Health http://ift.tt/2B9vKxZ
FOX NEWS: Woman develops rare c-section scar condition 5 times
Woman develops rare c-section scar condition 5 times
In a rare occurrence, a pregnant woman's gestational sac — the small vessel that holds the developing embryo — attached not to the lining of her womb but instead to a scar left over from a previous C-section.
FOX NEWS: Seasonal affective disorder: It's more than the winter blues
Seasonal affective disorder: It's more than the winter blues
Why are you feeling so blah?
FOX NEWS: 7 harmful houseplants that are a danger in disguise
7 harmful houseplants that are a danger in disguise
You might like to brighten up your home office or window sills with colorful flowers and hardy, inspiring greenery.
FOX NEWS: Pediatrician meets teen organ donor's family in emotional union
Pediatrician meets teen organ donor's family in emotional union
A Texas pediatrician connected with a grieving grandmother on Sunday to celebrate the 15-year-old teen who saved her life through organ donation.
FOX NEWS: Opioid epidemic burdening grandparents, foster care
Opioid epidemic burdening grandparents, foster care
As the opioid epidemic pushes children out of their parents’ custody, grandparents and other relatives are forced to step up.
FOX NEWS: US health officials to target high-risk alternative remedies
US health officials to target high-risk alternative remedies
U.S. health officials plan to crack down on a growing number of unproven alternative remedies, focusing on those containing dangerous ingredients that have occasionally been linked to serious injury and death.
FOX NEWS: Bears' Zach Miller shares video of first steps following gruesome leg injury
Bears' Zach Miller shares video of first steps following gruesome leg injury
Chicago Bears tight end Zach Miller posted a 17-second video to Instagram on Sunday that showed him slowly taking steps without the assistance of crutches, just weeks after he underwent emergency surgery to repair a torn artery that could have cost him his leg.
FOX NEWS: 5 warning signs your appendix might burst
5 warning signs your appendix might burst
These symptoms may warrant a call to your doctor or a trip to the emergency room.
FOX NEWS: Company recalls salami, prosciutto over possible salmonella contamination
Company recalls salami, prosciutto over possible salmonella contamination
A Canadian-based manufacturer is recalling ready-to-eat salami and speck products that are sold and distributed in the U.S. over concerns of possible salmonella contamination.
Sunday, December 17, 2017
Drug Company Under Fire After Revealing Dengue Vaccine May Harm Some
By DENISE GRADY and KATIE THOMAS from NYT Health http://ift.tt/2AM16a0
Saturday, December 16, 2017
In Opioid Battle, Cherokee Want Their Day in Tribal Court
By JAN HOFFMAN from NYT Health http://ift.tt/2AZiGLF
Uproar Over Purported Ban at C.D.C. of Words Like ‘Fetus’
By SHEILA KAPLAN and DONALD G. McNEIL Jr. from NYT Health http://ift.tt/2kAH5Mt
Friday, December 15, 2017
Six Lessons in Helping African Women Avoid H.I.V.
By DONALD G. McNEIL Jr. from NYT Health http://ift.tt/2oiUlKH
A Last Push for Obamacare Sign-ups — and Worries About Who Got Hurt
By KATE ZERNIKE and ROBERT PEAR from NYT Health http://ift.tt/2Cj7zcE
FOX NEWS: Mom of 5 who lost home in Hurricane Harvey learns she's expecting quadruplets
Mom of 5 who lost home in Hurricane Harvey learns she's expecting quadruplets
A Hurricane Harvey survivor who lost her home in the devastating floodwaters was shocked to learn that she is expecting naturally conceived quadruplets.
FOX NEWS: Mom claims Hatchimals bath bomb gave daughter chemical burns
Mom claims Hatchimals bath bomb gave daughter chemical burns
A mother is sounding the alarm over one of the season’s hottest toys after she claims it left her daughter with chemical burns.
