Thymopoietic effects of IL-7 are abrogated by GVHD.

B6/Ly 5.1 and B6C3F1 hosts (n = 5-8 per group) were lethally irradiated and received 10 × 10⁶ cells of a 50:50 mixture of TCD B6/Ly5.2 and HY-TCR Tg⁺ BM. Treated animals received IL-7, 5 μg/d on day 1 to day 28 after BMT with analysis performed between 28 and 35 days after BMT. Each subset was defined as delineated in “Materials and methods” using 4-color flow cytometry. In the top panel, differences with P < .05 are noted by an * for CD4⁺ and by a § for CD8⁺ T cells. In the middle and lower panels, * denotes differences with P < .05.