Figure 2. LRF is required for IELp immune regulatory functions.

(a) Gating strategy for analysis of thymic IELp. Cyan and red color represent CD44⁺ cells and IELp respectively.

(b) Flow cytometry analysis of IELp from Ctrl and LRF KO mice (n = 7 per group). Representative contour plots (left) show expression of CD44 vs. PD-1 on CD4⁻ CD8α⁻ TCRβ⁺ CD5⁺ H-2K^b+ CD122⁺ cells in the thymus from Ctrl and LRF KO mice. Graphs show the percentage (middle) of IELp (CD44⁻ PD-1⁺ cells) among CD4⁻CD8⁻ TCRβ⁺ CD5⁺ H-2K^b+ CD122⁺ thymocytes and the absolute number (right, each symbol represents one mouse) of IELp. Data pooled from five independent experiments.

(c) Schematic of adoptive transfer colitis experiments in Rag2^–/–Il2rg^-–/– mice. K indicates 1000 cells.

(d, e) Rag2^–/–Il2rg^-–/– mice were adoptively transferred with TCRβ⁺ CD4⁺ CD25⁻CD45RB^hi splenocytes from C57BL/6 mice 3 weeks after receiving either PBS, Ctrl IELp or LRF KO IELp at time 0, as schematized in (c)(n=5 per group). Graphs show changes in body weight (d) and colitis scores (e) post CD4⁺ T cell transfer. Data are from one experiment representative of two (n=5 per group in each experiment).

Error bars indicate standard error of the mean (SEM). P values are from two-tailed unpaired t-test (b) or two-way ANOVA (d, e).