A predisposing effect of HLA class II genes in celiac disease by skewing the naive CD4+ T-cell receptor repertoire
Polymorphisms of human leukocyte antigen (HLA) genes confer risks for many human diseases. For predisposing effects relating to T-cell receptor (TCR) recognition of peptide-HLA, the effect can be both selection of the TCR repertoire and preferential presentation of disease-driving epitopes. In celiac disease (CeD) HLA-DQ2.5 predisposes by presenting deamidated gluten peptides to CD4+ T cells that typically employ stereotyped TCRs. Here we analyzed whether genetic variants within the HLA and TR loci shape the naive TCR repertoire. We sequenced the {beta} TCR repertoires of naive CD4+ T cells of 103 CeD subjects and 103 controls and performed gene usage quantitative trait loci analyses. The naive CD4+ TCR repertoire was significantly affected by HLA and TRA and TRB polymorphisms. Individuals carrying the HLA-DQ2.5 allotype exhibited increased frequencies of TCR genes involved in stereotyped recognition of gluten epitopes thus demonstrating a disease-predisposing effect of HLA by selection of a disease-relevant TCR repertoire.