Figure 1. Expression of β2-ARs on T cells controls the severity and fatality of acute GvHD after allo-HCT.

(A) β2-AR expression in WT or β2-AR^–/– CD4⁺ T cells harvested from spleen and liver on day 14 after allogenic T cell infusion. CD4⁺ T cells were gated from single live H-2^b+H-2^d–CD45⁺CD3⁺ cells, demonstrating an increase in β2-AR expression in the allo CD4⁺ T cells. All recipients received 3.5 × 10⁶ WT C57BL/6 TCD-BM with or without T cells. (B) Body weight and survival of lethally irradiated BALB/c mice after allo-HCT BM alone or with 0.7 × 10⁶ WT C57BL/6 or β2-AR^–/– pan–T cells. (C) Body weight and survival of lethally irradiated C3H/SW mice after allo-HCT with BM alone or with 1.5 × 10⁶ WT C57BL/6 or β2-AR^–/– pan–T cells. (D) Body weight and survival of lethally irradiated BALB/c mice after allo-HCT with BM alone or with 0.2 × 10⁶ WT C57BL/6 or β2-AR^–/– CD4⁺ T cells. All experiments demonstrated increased GvHD severity and mortality in the absence of the β2-AR on T cells. Data pooled from 2 individual experiments, each with n = 6-8 per group to obtain total of n = 12–16 per group in B–D. For comparison of survival curves, a log-rank (Mantel-Cox) test was used in B–D. Two-way ANOVA with Tukey’s multiple comparisons test was used for body weight difference in B–D. *P < 0.05, **P < 0.01. Body weight and survival data are shown as means ± SEM. Other data are presented as median ± min to max.