TNFα/TNFR2 disruption using TNFα-KO donor T cells abolishes protective effect of Treg after allo-HCT. (A-B) [B6 x C3H]F1 female mice underwent TBI followed by transplantation with B6 BM cells plus T cells or with B6 BM cells plus T cells supplemented with HY-Tregs or B6 BM cells plus T cells collected from TNFα-deficient mice instead of WT B6 mice and supplemented with HY-Tregs. HY peptide was administered at day 0, 1, 3, and 6. The experiment was performed 4 times, and the resulting survival (A) and clinical score (B) data were pooled and compared among the 3 groups of mice. (C-D) Experimental groups were constituted of mice grafted with B6 BM cells plus T cells or T cells collected from TNFα-deficient mice instead of WT B6 mice. The experiment was performed twice, and the resulting survival (C) and clinical score (D) data were pooled. Mice were euthanized in case of weight loss >30% of initial weight or maximal clinical grade (ie, 5/5). Kaplan-Meier survival curves were compared using log-rank test. For analysis of GVHD clinical grading curves, AUC was calculated for each mouse, and then Student t test or 1-way ANOVA with post hoc analysis was performed depending on number of comparatives. *P < .05; **P < .01; ***P < .001.