Figure 1. RORγt⁺ ILCs regulate adaptive immune cell responses to commensal bacteria and are enriched in MHCII-associated genes.

a–d, Defined age- and sex-matched mouse strains were examined for the frequency of splenic Ki-67⁺ CD4⁺ T cells (top) and CD44^high CD62L^low CD4⁺ T cells (bottom) (a), spleen size (b), spleen weight (c) and relative optical density (OD) values of serum IgG specific to commensal bacteria (d). Antibiotics (ABX) were administered in the drinking water from weaning until 6–8 weeks of age. Scale bar represents 0.5 cm (b). Flow cytometry plots are gated on live CD4⁺ CD3⁺ T cells (a). e, f, DAVID pathway analysis of GO terms enriched in the transcriptional profiles of naïve CD4⁺ T cells and group 3 RORγt⁺ ILCs (e) and heat map of selected lymphoid-associated and MHCII-associated gene transcripts (f). g, h, Gating strategy for ILCs and expression of RORγt and MHCII in ILCs from the mesenteric lymph node of naïve RORγt-eGFP reporter mice (g) and the small intestine of healthy humans (h). Blue line = ILCs, Grey fill = negative control population. Data are representative of 3 independent experiments containing 3–5 mice per group or 4 human donors. Results are shown as the means ± s.e.m. ** p < 0.01, *** p < 0.001 (two-tailed students t-test).