GSE210956
Single-cell Transcriptomics Reveal Different Maturation Stages and Sublineages Commitment of Human Thymic Invariant Natural Killer T Cells
Invariant natural killer T (iNKT) cells are a rare but heterogenous T-cell subset with potent cytotoxic and immunomodulatory properties. During thymic development, murine iNKT cells go through different maturation stages and differentiate into distinct sublineages, namely iNKT1, iNKT2, and iNKT17 cells. Recent reports indicate that iNKT2 cells display immature properties and also 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 to assess the sublineage commitment of human iNKT cells during thymic development, in the present study we performed single-cell RNA sequencing analysis on human iNKT cells isolated from thymocytes. We show that human iNKT cells displayed heterogeneity and our unsupervised analysis identified two clusters: a first cluster expressed an immature profile with high expression of genes that are important for iNKT cell development and proliferation, whereas a second cluster displayed a mature, terminally differentiated profile. Trajectory analysis suggested an ontological relationship between the two clusters. Evaluation of the expression of sublineage-defining gene sets revealed that the first cluster contained mainly cells with an iNKT2 signature, whereas the more differentiated one contained cells that resembled murine iNKT1 cells. 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. Overall design: 3 samples with iNKT cells from human thymus of children between 5 days and 13 months of age.