Parallel T-cell cloning and deep sequencing of the transcripts of human MAIT cells reveal stable oligoclonal TCRß repertoire

Mucosal-associated invariant T (MAIT) cells are abundant in humans and recognize conserved bacterial antigens derived from riboflavin precursors, presented by the non-polymorphic MHC class I-like molecule MR1. Here, we show via transcriptomic analysis that human MAIT cells are remarkably oligoclonal in both blood and liver, display high inter-individual homology, and exhibit a restricted length CDR3ß domain of the TCRVß chain. We extend this analysis to a second sub-population of MAIT cells expressing a semi-invariant TCR conserved between individuals. Overall design: Study of CDR3 regions of TCRalpha and beta sequences