Protective colonic iNKT cells are expanded by Goblet cell-associated antigen passages in CD1d-dependent manner in adults

Abstract

Abstract Invariant natural killer T (iNKT) cells are unique innate immune cell which secrete cytokines and immune mediators. These cells recognize self or microbial glycolipids presented in the context of CD1d. iNKT cells can contribute to host protection or pathogenesis during intestinal inflammation. Colonic iNKT cells are established under the influence of the microbiota in early life and the current understanding is that colonic iNKT cells are fixed and not manipulable in later life. Goblet cells (GCs) or/and goblet cell associated passages (GAPs) deliver luminal antigens and maintain peripheral T regulatory cells in the steady state. However, GAPs in the colon are absent in adult mice due to GCs microbial sensing. We found that the glycolipids can be delivered through GAPs and that inducing GAPs in the colon in adult mice resulted in significant iNKT cell expansion. Deletion of GCs or deletion of CD1d on GCs prevented iNKT cell expansion suggesting a role for colonic GCs in presenting glycolipids to iNKT cells. Single cell RNA sequencing of colonic-iNKT cells showed significantly increased iNKT2 and iNKT1 subsets after colonic GAP induction. Proteomic analysis of these iNKT cells further confirmed the characteristics of expanded iNKT subsets. Moreover, iNKT cells expanding after colonic GAP induction persisted and were protective in DSS-induced colitis. Adoptive transfer of the expanded colonic iNKT cells protected in the DSS-induced colitis model, indicating that expanded colonic iNKT cells were sufficient for protection in this model. These findings indicate that colonic iNKT cells are not fixed during early life but can be expanded in a GAP dependent and GC CD1d dependent manner and can be protective in some models of colitis. Crohn's and Colitis Foundation