Dataset Information

MHC Class II Risk Alleles and Amino Acid Residues in Idiopathic Membranous Nephropathy.

ABSTRACT: Epitopes of phospholipase A2 receptor (PLA2R), the target antigen in idiopathic membranous nephropathy (iMN), must be presented by the HLA-encoded MHC class II molecules to stimulate autoantibody production. A genome-wide association study identified risk alleles at HLA and PLA2R loci, with the top variant rs2187668 within HLA-DQA1 showing a risk effect greater than that of the top variant rs4664308 within PLA2R1. How the HLA risk alleles affect epitope presentation by MHC class II molecules in iMN is unknown. Here, we genotyped 261 patients with iMN and 599 healthy controls at the HLA-DRB1, HLA-DQA1, HLA-DQB1, and HLA-DPB1 loci with four-digit resolution and extracted the encoded amino acid sequences from the IMGT/HLA database. We predicted T cell epitopes of PLA2R and constructed MHC-DR molecule-PLA2R peptide-T cell receptor structures using Modeler. We identified DRB1*1501 (odds ratio, 4.65; 95% confidence interval [95% CI], 3.39 to 6.41; P<0.001) and DRB1*0301 (odds ratio, 3.96; 95% CI, 2.61 to 6.05; P<0.001) as independent risk alleles for iMN and associated with circulating anti-PLA2R antibodies. Strong gene-gene interaction was noted between rs4664308(AA) and HLA-DRB1*1501/DRB1*0301. Amino acid positions 13 (P<0.001) and 71 (P<0.001) in the MHC-DR?1 chain independently associated with iMN. Structural models showed that arginine13 and alanine71, encoded by DRB1*1501, and lysine71, encoded by DRB1*0301, facilitate interactions with T cell epitopes of PLA2R. In conclusion, we identified two risk alleles of HLA class II genes and three amino acid residues on positions 13 and 71 of the MHC-DR?1 chain that may confer susceptibility to iMN by presenting T cell epitopes on PLA2R.

SUBMITTER: Cui Z

PROVIDER: S-EPMC5407714 | biostudies-literature | 2017 May

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

MHC Class II Risk Alleles and Amino Acid Residues in Idiopathic Membranous Nephropathy.

Cui Zhao Z Xie Li-Jun LJ Chen Fang-Jin FJ Pei Zhi-Yong ZY Zhang Li-Jie LJ Qu Zhen Z Huang Jing J Gu Qiu-Hua QH Zhang Yi-Miao YM Wang Xin X Wang Fang F Meng Li-Qiang LQ Liu Gang G Zhou Xu-Jie XJ Zhu Li L Lv Ji-Cheng JC Liu Fan F Zhang Hong H Liao Yun-Hua YH Lai Lu-Hua LH Ronco Pierre P Zhao Ming-Hui MH

Journal of the American Society of Nephrology : JASN 20161116 5

Epitopes of phospholipase A2 receptor (PLA2R), the target antigen in idiopathic membranous nephropathy (iMN), must be presented by the HLA-encoded MHC class II molecules to stimulate autoantibody production. A genome-wide association study identified risk alleles at HLA and PLA2R loci, with the top variant rs2187668 within HLA-DQA1 showing a risk effect greater than that of the top variant rs4664308 within PLA2R1. How the HLA risk alleles affect epitope presentation by MHC class II molecules in ...[more]

PMID: 27852637

Similar Datasets

Project description:The coexistence of immunoglobulin A nephropathy (IgAN) and idiopathic membranous nephropathy (IMN) in a few cases suggested that there could be existed a similar mechanism in pathogenesis of these two types of primary glomerulonephritis. In order to verify this hypothesis, a total of 23 reported IgAN-associated SNPs were genotyped in a cohort of 485 IMN patients and 569 healthy controls with Chinese Han origin. After Cochran-Armitage test for trend analysis, seven IgAN-associated SNPs located in the major histocompatibility complex (MHC) region were found to be significantly associated with the susceptibility of IMN, with rs9275596 as the top one (p = 1.97E-43, OR = 3.977). It was worth mentioning that the minor alleles of the SNPs conferred completely opposite effects on the pathogenesis of IMN and IgAN, suggesting quite different roles played by these SNPs for these two kinds of primary glomerulonephritis. Conditional logistic regression analysis displayed that SNPs protective from IMN (odds ratio < 1.00) were still significantly associated with IMN (p = 3.67E-4 for rs660895 and p = 1.26E-4 for rs9275224) with the most significant SNP rs9275596 as a covariate. Haplotype-based analysis showed that the seven SNPs were mapped to independent linkage disequilibrium (LD) blocks. Moreover, three out of these seven SNPs, including rs9275224, rs660895, and rs9357155, were found to be potential expression quantitative trait loci (eQTLs) for HLA-DQ molecules. Out of the purpose of identifying the causal variants for IMN within the MHC region, imputation analysis was performed using genotype data of Chinese Han released by the 1000 Genome Project and identified hundreds of SNPs potentially associated with the disease. In brief, our analysis revealed a significant association with the susceptibility of idiopathic membranous nephropathy for the IgAN-correlated SNPs. These SNPs conferred a completely different role for the pathogenesis of these two kinds of diseases.

Project description:Introduction: Minimal change disease (MCD) is a major cause of nephrotic syndrome. With a substantial number of patients requiring long-term immunosuppression leading to significant morbidity, the study aim was to determine MCD glomerular transcriptome to serve as a basis for biomarker discovery and novel drug target identification. Animal work showed podocyte injury induced by IL-7/IL-7R signaling (Zhai S, BBRC, 2018). Methods: Renal biopsies from adult patients representing the following groups were selected from the Norwegian Kidney Biopsy Registry: MCD (n=14), as well as normal tissue (n=8) and primary membranous nephropathy (MN; n=12) as the two reference groups. RNA for 75 base-pair paired-end RNASeq was obtained by dissecting glomeruli via laser capture microdissection (LCM) from FFPE cross-sections. Systematic delineation of condition-specific alteration in transcriptional landscapes was achieved by combining pathway-centered analyses with methodologies derived from network science and integrating multiple bioinformatics resources. Results: Compared to normal glomeruli, glomeuli from MCD displayed an inflammatory signature that appeared to be predominantly governed by the IL1 and IL7 systems. While enrichment of IL1 production and secretion was a shared feature of MCD and MN compared to normal tissue, responses involving IL7 pathway activation were unique to MCD. Indeed, IL7R expressed by glomeruli was the most up-regulated gene of to the interleukin-family in MCD vs normal controls. IL7 pathway activation was paralleled by significant enrichment in adaptive immune system processes and transcriptional regulation and depletion in pathways related to energy metabolism and transcription. Downregulation of these organ function-related themes again occurred predominately in MDC and were significantly less pronounced in MN. Conclusion: Our results demonstrate that archival FFPE-biopsies can be used to generate glomeruli-specific gene expression profiles suitable for systematic delineation of kidney-associated diseases. Here the latter provides a data-driven rationale to experimentally address these MCD-specific features as biomarkers and as novel drug targets. In this context inhibiting activation of the IL7 pathway may be particularly promising.

Dataset Information

MHC Class II Risk Alleles and Amino Acid Residues in Idiopathic Membranous Nephropathy.

Publications

MHC Class II Risk Alleles and Amino Acid Residues in Idiopathic Membranous Nephropathy.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets