Pluto Bioinformatics

GSE72909: Complementarity and redundancy of IL-22-producing innate lymphoid cells

Bulk RNA sequencing

Homeostasis of the gut microbiota is pivotal to the survival of the host. Intestinal T cells and Innate Lymphoid cells (ILCs) control the composition of the microbiota and respond to its perturbations. Interleukin 22 (IL-22) plays a pivotal role in the immune control of gut commensal and pathogenic bacteria and is secreted by a heterogeneous population of intestinal T cells, NCR- ILC3 and NCR+ILC3. Expression of NCR by ILC3 is believed to define an irreversible effector ILC3 end-state fate in which these cells are key to control of bacterial infection via their production of IL-22. Here we identify the core transcriptional signature that drives the differentiation of NCR- ILC3 into NCR+ ILC3 and reveal that NCR+ILC3 exhibit more plasticity than originally thought, as NCR+ ILC3 can revert to NCR- ILC3. Contrary to the prevailing understanding of NCR+ ILC3 genesis and function, in vivo analyses of mice conditionally deleted of the key ILC3 genes Stat3, Il22, Tbet and Mcl1 demonstrated that NCR+ ILC3 were not essential for the control of colonic infections in the presence of T cells. However, NCR+ ILC3 were mandatory for homeostasis of the caecum. Our data identify that the interplay of intestinal T cells and ILC3 results in robust complementary fail-safe mechanisms that ensure gut homeostasis. SOURCE: Wei Shi (shi@wehi.edu.au) - The Walter and Eliza Hall Institute of Medical Research