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 | 2017 Sep-Oct
REPOSITORIES: biostudies-literature
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A Genetic Disposition for Autoimmune Encephalitis: Searching for Human Leukocyte Antigen (HLA) Complex Subtypes.
Epilepsy currents 20170901 5
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Project description:Classical MHC class II (MHCII) proteins present peptides for CD4(+) T-cell surveillance and are by far the most prominent risk factor for a number of autoimmune disorders. To date, many studies have shown that this link between particular MHCII alleles and disease depends on the MHCII's particular ability to bind and present certain peptides in specific physiological contexts. However, less attention has been paid to the non-classical MHCII molecule human leucocyte antigen-DM, which catalyses peptide exchange on classical MHCII proteins acting as a peptide editor. DM function impacts the presentation of both antigenic peptides in the periphery and key self-peptides during T-cell development in the thymus. In this way, DM activity directly influences the response to pathogens, as well as mechanisms of self-tolerance acquisition. While decreased DM editing of particular MHCII proteins has been proposed to be related to autoimmune disorders, no experimental evidence for different DM catalytic properties had been reported until recently. Biochemical and structural investigations, together with new animal models of loss of DM activity, have provided an attractive foundation for identifying different catalytic efficiencies for DM allotypes. Here, we revisit the current knowledge of DM function and discuss how DM function may impart autoimmunity at the organism level.
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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:BackgroundPreeclampsia 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.ObjectiveIn this study, we investigated the relationship of the human leukocyte antigen (HLA)-DQA1*0102/HLA-DQB1*0602 polymorphism with preeclampsia.Materials and methodsGenomic 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.ResultsThere 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).ConclusionIt 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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