Abstract

Invariant natural killer T (iNKT) cells are a rare, heterogeneous T-cell subset with cytotoxic and immunomodulatory properties. During thymic development, murine iNKT cells go through different maturation stages differentiating into distinct sublineages, namely iNKT1, iNKT2, and iNKT17 cells. Recent reports indicate that iNKT2 cells display immature properties and give rise to other subsets, whereas iNKT1 cells seem to be terminally differentiated. Whether human iNKT cells follow a similar differentiation model is still unknown. To define the maturation stages and assess the sublineage commitment of human iNKT cells during thymic development, in this study we performed scRNAseq analysis on human Va24+ Vß11?+?iNKT cells isolated from thymocytes. We show that these iNKT cells displayed heterogeneity and our unsupervised analysis identified five clusters representing different maturation stages, from an immature profile with high expression of genes important for iNKT cell development and proliferation to a mature, fully differentiated profile with high levels of cytotoxic effector molecules. Evaluation of expression of sublineage-defining gene sets revealed mainly cells with an iNKT2 signature in the most immature cluster, whereas the more differentiated ones displayed an iNKT1 signature. Combined analysis with a publicly available scRNAseq dataset of human iNKT cells from peripheral blood suggested that the two main subsets exist both in thymus and in the periphery, while a third more immature one was restricted to the thymus. Our data point to the existence of different maturation stages of human thymic iNKT cells and provide evidence for sublineage commitment of iNKT cells in the human thymus.

View details for DOI 10.1093/jleuko/qiad113

View details for PubMedID 37742056