Immunoglobulin gene polymorphisms shape the naïve B-cell receptor repertoire; relevance to celiac disease.

Genetic variation in the loci encoding immunoglobulin genes (IGH, IGK and IGL) affects the repertoire of B-cell receptors (BCRs). Such effects were previously demonstrated for total peripheral blood B cells, but so far have not been investigated at scale for isolated naïve B cells. As B cells are implicated in the pathogenesis of autoimmune diseases, genetically encoded features of the naïve BCR repertoire may affect disease risk, for instance in celiac disease (CeD) which is hallmarked by stereotyped disease-specific antibodies that recognize antigen in their germline configuration. Here we have characterized the BCR repertoire of naïve B cells in 102 individuals with CeD and 102 control subjects by undertaking gene usage quantitative trait loci analyses based on repertoire sequencing and single nucleotide polymorphism genotyping. Variants within each of the loci had significant effects on the naïve BCR repertoires, with the usage of 80% of IGH genes, 54% of IGK genes and 84% of IGL genes being significantly affected by gene polymorphisms. Effects of genetic polymorphisms on BCR usage were observed for genes implicated in stereotypic responses previously associated with CeD, yet no strong evidence for CeD predisposing effects of polymorphisms within the IGH, IGK and IGL loci was uncovered.