Human NKT10 cells are enriched in cord-derived invariant natural killer T cells and mediate immune-regulation in a xenogeneic graft-versus-host disease model.

CD1d-restricted invariant natural killer (iNK) T cells are innate T cells known for their ability to shape adaptive immunity toward inflammation or immune-suppression via the rapid production of Th1-, Th2-, and Th17-type cytokines from corresponding iNKT subsets such as NKT1, NKT2, and NKT17. IL-10-producing invariant NKT cells, termed NKT10 cells, are thought to play an immunoregulatory role, but their potential clinical use remains underexplored. We characterized human NKT10 cells from cord-derived iNKT cells and investigated their therapeutic utility in allogeneic stem cell transplantation. Cord and cord-derived iNKT cells contained a high frequency of CD4+CD25+CD161lowFoxP3+ iNKT cells and showed Th2/Th10-biased cytokine production upon antigenic stimulation. Accordingly, cord-derived iNKT cells displayed a distinct gene expression profile with upregulated genes related to NKT2, NKT10, and regulatory T cells compared with adult donor-derived iNKT cells. Furthermore, single-cell RNA sequencing analysis of cord-derived iNKT cells confirmed the presence of NKT10-like subset that was enriched with multiple immunoregulatory pathways and genes related to immune-checkpoints (NRP1, PD1, CLTA-4, and GITR) and NKT10 (MAF, HIF1A, and FoxP3), whereas the NKT1/17-like subset present in adult donor-derived iNKT cells showed upregulation of genes related to cytotoxicity (GZMA/B, KLRD1, and PRF1), NKR (KLRK1, KLRB1, KLRG1, and NKG7), NKT1 (EOMES and TBX21), and NKT17 (RORC). Lastly, cord-derived iNKT cells suppressed alloreactive T cell proliferation in vitro and ameliorated xenogeneic graft-versus-host disease where the immunodeficient NSG mice received human peripheral blood mononuclear cells supplemented with cord-derived iNKT cells. Thus, NKT10-enriched, cord-derived iNKT cells are candidate cell therapeutics for immune-modulation in allogeneic stem cell transplantation and other autoimmune diseases.