Single cell RNA-seq of metabolite specific T-cells (MR1-restricted) from adult mouse thymus.

Mucosal-Associated Invariant T cells have a unique specificity for the microbial metabolite 5-OP-RU presented by the non-classical presentation molecule MR1. Upon activation, they release cytotoxic mediators and engage an antimicrobial activity. As a subset of T lymphocytes, MAIT development occurs in the thymus where they acquire their effector phenotype under the control of the key transcription factor ZBTB16. This particular maturation process is in contrast with conventional T cells that egress the thymus with a naive phenotype before populating the secondary lymphoid organs, and the molecular events driving the MAIT lineage decision are poorly known. In the present work, we evaluated the transcriptional events and the role of the slam-SAP pathway on the lineage decision of MR1-restricted T cells by single cell RNAseq. MAIT cells undergoing positive selection were FACS-sorted with a MR1:5-OP-RU labeled tetramer, from thymus of wild-type and sapKO mice. Their transcriptomes were captured using a 10x chromium system.