CD4+ mucosal-associated invariant T cells express highly diverse T cell receptors. (PubMed, J Immunol)
To specifically characterize this TCR repertoire, we analyzed VDJ sequences across 2 datasets and identified distinct TCR usage among CD4+ MAIT cells including TRAV21, TRAV8 (TRAV8-1, TRAV8-2, TRAV8-3), and TRAV12 families (TRAV12-2, TRAV12-3), as well as more variable J segment, CDR3α, and TRBV sequences. TRAV1-2- MAIT cell TCRs were also enriched after in vitro culture with interleukin-2 and Mycobacterium tuberculosis. These results indicate that mature human CD4+ MAIT cells adopt distinct TCR usage from the canonical TRAV1-2+ CD8+ subset and suggest that alternative MR1 ligands in addition to riboflavin intermediates may select for them.