Figure 2. Adoptive transfer of CD4⁺CD25⁻Nrp1⁺ T cells synergize with Rapamycin to prevent allograft rejection.

Heterotopic heart grafts were transplanted from BALB/c mice into C57BL/6 recipients. The recipients received a sub-therapeutic regimen of 1 mg/kg/day i.p. Rapamycin for 10 consecutive days (days 0-9), and/or two dose of freshly isolated Nrp1⁺ T cell on day 0 and day 7 (2×10⁶). Rejection was defined as cessation of a palpable impulse. (A) Survival rates were compared using log-rank test. (B) Hematoxylin and eosin staining of representative heart allografts harvested at 7d post transplantation. (C) Quantitative histological evaluation of allografts harvested on 7d post transplantation. SC, syngeneic control, Nrp1⁺ T = neuropilin-1-positive T cells, HPF = high power field, rapa = Rapamycin, NS = not significant. Results are presented as mean ± SD. *P<0.05, **P<0.01, ***P<0.001.