Molecular Cues Dictating Positive And Negative Selection In The Thymus

T cells develop in the thymus where CD4+CD8+ double positive (DP) thymocytes undergo positive and negative selection to generate mature CD4+ and CD8+ single positive (SP) T cells. Positive selection allows for the generation of a diverse repertoire of T cells capable of recognizing peptide:MHC (pMHC) complexes, while negative selection ensures that the mature T cell repertoire is self-tolerant. The cell types involved in thymic selection are well understood and recent work has begun to elucidate temporal and spatial aspects involved in selection. However, the intracellular cues regulating development and CD4 vs. CD8 lineage commitment are incompletely understood. Our work focuses on utilizing a single cell RNA sequencing (scRNA-seq) approach to elucidate the molecular cues guiding thymic selection of CD4+ and CD8+ T cells.