A Genetic Disposition for Autoimmune Encephalitis: Searching for Human Leukocyte Antigen (HLA) Complex Subtypes.
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ABSTRACT:
SUBMITTER: Jobst BC
PROVIDER: S-EPMC5716492 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:ObjectiveWhile immune checkpoint inhibitors are increasingly used for various cancers, unpredictable immune-related adverse events (irAEs) such as autoimmune encephalitis is life-threatening. Here, we report an association between human leukocyte antigen (HLA) and atezolizumab-induced encephalitis.MethodsFrom an institutional prospective cohort for encephalitis, we identified patients with autoimmune encephalitis after the use of atezolizumab, a PD-L1 (programmed death-ligand 1) inhibitor, from August 2016 to September 2019 and analyzed their HLA genotypes.ResultsA total of 290 patients received atezolizumab, and seven patients developed autoimmune encephalitis, and five of whom were enrolled for the analysis. The patients presented altered mentality, seizures, or myelitis. Three patients had the HLA-B*27:05 genotype in common (60%), which is significantly frequent given its low frequency in the general population (2.5%). After Bonferroni correction, HLA-B*27:05 was significantly associated with autoimmune encephalitis by atezolizumab (corrected P < 0.001, odds ratio 59, 95% CI = 9.0 ~ 386.9).InterpretationHere we found that three in five patients with autoimmune encephalitis associated with atezolizumab had the rare HLA-B*27:05 genotype. Further systematic analyses in larger cohorts are necessary to investigate the value of HLA screening to prevent the life-threatening adverse events.
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Project description:ObjectiveThe swine leukocyte antigen (SLA) gene group, which is closely linked and highly polymorphic, has important biomedical significance in the protection and utilization of germplasm resources. However, genetic polymorphism analyses of SLA microsatellite markers in Chinese miniature pigs are limited.MethodsEighteen pairs of microsatellite primers were used to amplify the SLA regions of seven miniature pig breeds and three wild boar breeds (n = 346) from different regions of China. The indexes of genetic polymorphism, including expected heterozygosity (He), polymorphic information content (PIC), and haplotype, were analyzed. The genetic differentiation coefficient (Fst) and neighbor-joining methods were used for cluster analysis of the breeds.ResultsIn miniature pigs, the SLA I region had the highest numbers of polymorphisms, followed by the SLA II and SLA III regions; the region near the centromere had the lowest number of polymorphisms. Among the seven miniature pig breeds, Diannan small-ear pigs had the highest genetic diversity (PIC value = 0.6396), whereas the genetic diversity of the Hebao pig was the lowest (PIC value = 0.4330). The Fst values in the Mingguang small-ear, Diannan small-ear, and Yunnan wild boars were less than 0.05. According to phylogenetic cluster analysis, the South-China-type miniature pigs clustered into one group, among which Mingguang small-ear pigs clustered with Diannan small-ear pigs. Haplotype analysis revealed that the SLA I, II, and III regions could be constructed into 13, 7, and 11 common haplotypes, respectively.ConclusionThis study validates the high genetic diversity of the Chinese miniature pig. Mingguang small-ear pigs have close kinship with Diannan small-ear pigs, implying that they may have similar genetic backgrounds and originate from the same population. This study also provides a foundation for genetic breeding, genetic resource protection, and classification of Chinese miniature pigs.
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Project description:Background:Preeclampsia is a condition associated with systemic disorders in the mother and the fetus. However, the exact causes of preeclampsia are unknown, but several genetics and environmental factors play role in development of this disease. Major histocompatibility complex role is very important during pregnancy through which the fetus is not rejected by mother's immune system. Objective:In this study, we investigated the relationship of the human leukocyte antigen (HLA)-DQA1*0102/HLA-DQB1*0602 polymorphism with preeclampsia. Materials and Methods:Genomic DNA of 181 pregnant women with a history of preeclampsia as the case group and 228 pregnant women with no history of preeclampsia as the controls were extracted. The HLA-DQA1*0102/HLA-DQB1*0602 polymorphisms of all DNA samples were identified by the SSP-PCR method. Frequencies difference of variables between case and control groups were calculated by Chi-square test. The ethnic origin of the participants in this study was extracted from their medical records. Results:There was a significant association between preeclampsia and Sistani ethnic group (p=0.031). Moreover, there was a significant association between preeclampsia and frequencies of allele HLA-DQB1*0602 (p<0.001), and genotypes of heterozygote (+0102/-0602) (p<0.001) and negative homozygote (-0102/-0602) (p=0.005). There also was an association between allele HLA-DQB1*0602 and preeclampsia in Fars ethnic group (p=0.028). Conclusion:It seems that immune incompatibility may have an important role in preeclampsia predisposition. According to our results, the lack of locus HLA-DQB1*0602 may be a risk factor for preeclampsia.
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Project description:Major histocompatibility complex class I (MHCI) glycoproteins present cytosolic peptides to CD8+ T cells and regulate NK cell activity. Their heavy chains (HC) are expressed from up to three MHC gene loci (human leukocyte antigen [HLA]-A, -B, and -C in humans), whose extensive polymorphism maps predominantly to the antigen-binding groove, diversifying the bound peptide repertoire. Codominant expression of MHCI alleles is thus functionally critical, but how it is regulated is not fully understood. Here, we have examined the effect of polymorphism on the turnover rates of MHCI molecules in cell lines with functional MHCI peptide loading pathways and in monocyte-derived dendritic cells (MoDCs). Proteins were labeled biosynthetically with heavy water (2H2O), folded MHCI molecules immunoprecipitated, and tryptic digests analysed by mass spectrometry. MHCI-derived peptides were assigned to specific alleles and isotypes, and turnover rates quantified by 2H incorporation, after correcting for cell growth. MHCI turnover half-lives ranged from undetectable to a few hours, depending on cell type, activation state, donor, and MHCI isotype. However, in all settings, the turnover half-lives of alleles of the same isotype were similar. Thus, MHCI protein turnover rates appear to be allele-independent in normal human cells. We propose that this is an important feature enabling the normal function and codominant expression of MHCI alleles.
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Project description:Sudan is located in the heart of Africa and surrounded by eight countries with people of different ethnic origins. Historical records show that the population of the Sudan is a mixture of Arabic, West Asian Arabic and sub-Saharan African elements. The present survey provides data on allele lineages, and haplotype frequencies of Human Leukocyte Antigen (HLA) class I (HLA-A and HLA-B) and class II (HLA-DR and -HLA-DQ) loci in 11 Sudanese populations. The sampled individuals are all local transplant donors who provided informed consent for HLA analyses on their blood samples and were registered at National Cancer Institute, University of Gezira, Wad Medani. The HLA class I and II data reported here can be subjected for future analyses of genetic structure and health in Sudan. These include as reference datasets for identifying the association between HLA and diseases and for designing donor recruitment strategies.
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Project description:Human leukocyte antigen (HLA)-DR15 is a haplotype associated with multiple sclerosis. It contains the two DRB* genes DRB1*1501 (DR2b) and DRB5*0101 (DR2a). The reported anchor motif of the corresponding HLA-DR molecules was determined in 1994 based on a small number of peptide ligands and binding assays. DR2a could display a set of peptides complementary to that presented by DR2b or, alternatively, a similar peptide repertoire but recognized in a different manner by T cells. It is known that DR2a and DR2b share some peptide ligands, although the degree of similarity of their associated peptidomes remains unclear. In addition, the contribution of each molecule to the global peptide repertoire presented by the HLA-DR15 haplotype has not been evaluated. We used mass spectrometry to analyze the peptide pools bound to DR2a and DR2b, identifying 169 and 555 unique peptide ligands of DR2a and DR2b, respectively. The analysis of these sets of peptides allowed the refinement of the corresponding binding motifs revealing novel anchor residues that had been overlooked in previous analyses. Moreover, the number of shared ligands between both molecules was low, indicating that DR2a and DR2b present complementary peptide repertoires to T cells. Finally, our analysis suggests that, quantitatively, both molecules contribute to the peptide repertoire presented by cells expressing the HLA-DR15 haplotype.
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Project description:Human leukocyte antigen (HLA)-F has been involved in immune regulation of infectious diseases. However, the role of HLA-F polymorphisms in hepatitis B infection outcomes remains unclear. Here, we aimed to determine HLA-F polymorphism implication in chronic HBV. Genotype analysis was performed for three single nucleotide polymorphisms (SNPs) of HLA-F and one SNP of HLA-E using PCR-SSP, in 252 Tunisian patients with chronic HBV infection stratified according to their HBV DNA levels (140 patients with low HBV DNA levels < 2000 IU/mL and 112 patients with high HBV DNA levels ? 2000 IU/mL) and 240 healthy controls (CTRL). The three HLA-F SNPs (HLA-F*01:02, -F*01:03 and -F*01:04) have the same allelic and genotypic frequencies in patients and in CTRL. We reported a low HLA-F*01:02 and F*01:04 allelic frequencies in the Tunisian population; however, high HLA-F*01:03 allele frequencies were observed (17%). A significant association was found between the HLA-F*01:03 allele and decreased level of HBV DNA (P = 0.02 OR 0.56, 95% CI 0.35-0.92). No significant differences were observed in haplotype distribution between patients and CTRL. A significant association of HLA-F*01:03 with the level of HBV DNA suggests an important role of HLA-F in HBV replication control.
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Project description:IntroductionIdiopathic pulmonary fibrosis (IPF) is a chronic interstitial pneumonia marked by progressive lung fibrosis and a poor prognosis. Recent studies have highlighted the potential role of infection in the pathogenesis of IPF and a prior association of the HLA-DQB1 gene with idiopathic fibrotic interstitial pneumonia (including IPF) has been reported. Due to the important role that the Human Leukocyte Antigen (HLA) region plays in the immune response, here we evaluated if HLA genetic variation was associated specifically with IPF risk.MethodsWe performed a meta-analysis of associations of the HLA region with IPF risk in individuals of European ancestry from seven independent case-control studies of IPF (comprising a total of 5,159 cases and 27,459 controls, including the prior study of fibrotic interstitial pneumonia). Single nucleotide polymorphisms, classical HLA alleles and amino acids were analysed and signals meeting a region-wide association threshold p<4.5×10-4 and a posterior probability of replication >90% were considered significant. We sought to replicate the previously reported HLA-DQB1 association in the subset of studies independent of the original report.ResultsThe meta-analysis of all seven studies identified four significant independent single nucleotide polymorphisms associated with IPF risk. However, none met the posterior probability for replication criterion. The HLA-DQB1 association was not replicated in the independent IPF studies.ConclusionVariation in the HLA region was not consistently associated with risk in studies of IPF. However, this does not preclude the possibility that other genomic regions linked to the immune response may be involved in the aetiology of IPF.
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Project description:Abacavir, a nucleoside reverse-transcriptase inhibitor used for the treatment of human immunodeficiency virus (HIV) infection, develops hypersensitivity in patients carrying HLA-B*57:01 allele through drug antigen presentation. We found that abacavir exposure induced HLA allotype-specific innate immune response in keratinocyte derived from HLA-B*57:01 transgenic mice. Therefore, the mechanism of the novel response was analyzed comprehensively.
2018-03-01 | GSE110394 | GEO