TNFα/TNFR2 disruption using anti-TNFR2 blocking mAb abolishes protective effect of Treg after allo-HCT. (A-B) [B6 x C3H]F1 female mice underwent total body irradiation (TBI) followed by transplantation with B6 BM cells plus T cells or with B6 BM cells plus T cells supplemented with HY-Tregs. HY peptide was administered at day 0, 1, 3, and 6, and mice were treated or not with anti-TNFR2 administered at day 0, 2, and 4. The experiment was performed twice, 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 treated or not with anti-TNFR2 administered at day 0, 2, and 4. 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. ns, nonsignificant. *P < .05; **P < .01; ***P < .001.