Fig. 5: The bystander T cells inhibit ILC2 activation in the MLN through SFRs.

a The tSNE analysis was performed on SFR-positive cells gated by flow cytometry from the MLN of WT mice at day 6 following three consecutive days of papain treatment (top and middle panels). The bottom panel displays the average proportion of SFR-positive cells. 1 × 10⁴ WT (b) or SFR-deficient (c) ILC2s were stimulated with or without 1 × 10⁵ WT or SFR-deficient T- or B-cells in the presence of IL-7 plus IL-33 for 48 h. Following a 3-h restimulation with PMA plus ionomycin, the expression of IL-5 and IL-13 by ILC2s was analyzed using intracellular staining. n = 5, 4, 4, 4, 3 (b) and n = 6, 6, 4, 5, 3 (c) mice in groups shown from left to right. d, e After a 3-h PMA plus ionomycin restimulation on day 6, the intracellular staining was performed to detect the expression of IL-13 in MLN CD45.1^-CD45.2⁺DsRed^- ILC2s from the mice (as illustrated in Supplementary Fig. 5g) following papain (d) or IL-33 (e) treatment (i.n., day 0, 1 and 2). n = 4, 5 mice (left to right groups, d); n = 3 mice per group (e). f Representative immunofluorescence staining (left) and quantitation (right) of MLN ILC2s in mice on day 6 after papain treatment (i.n., day 0, 1 and 2). Green: CD3, representing T zone; Red: B220, representing B zone; Sky blue sphere: KLRG1-positive and CD3-negative, representing ILC2s. n(WT) = 74 and n(SFR^−/−) = 78 field per group. g After a 3-hour PMA plus ionomycin restimulation on day 6, the intracellular staining was performed to detect the expression of IL-5 and IL-13 in MLN ILC2s from mice following IL-33 treatment (i.n., day 0, 1 and 2). n = 11, 9, 7, 11, 7 mice (left to right groups). The data represent at least two independent experiments with similar results. All data are represented as means ± SEM, and statistical analysis was conducted using one-way ANOVA (f, g) or two-tailed Student’s t test (b–e). ns, not significant. Please refer to Supplementary Fig. 5 for further details.