Restoration of β2AR expression in β2ARKO BM reverses immune dysfunction following MI. (A) Representative CD68, tryptase, and MPO staining for the infarct zone of hearts from WT C57BL/6 mice receiving β2ARKO BM with GFP, WT β2AR, β2ARTYY, or β2ARGRK− transduced before transplantation that underwent MI surgery. Arrowheads indicate positive staining. Insets show higher magnification at 250×. (B–D) Quantification of CD68 (B), tryptase (C), and MPO (D) staining for the infarct zone of 4-d post-MI hearts from GFP, WT β2AR, β2ARTYY, or β2ARGRK− BMT mice. n = 4–8; one-way ANOVA, *P < 0.05, †P < 0.01, ‡P < 0.001 vs. β2ARKO + β2AR BMT. Data are expressed as mean ± SEM.