Exposure to high levels of IFN-γ and rapid generation of effector CD8 T cells in IFN-γRKO recipients. (A) IFN-γ levels in spleen extracts on days 4 (d4) and 8 (d8) after transplantation. (B) Proportion of IFN-γ-positive CD4 and CD8 T lymphocytes after short in vitro stimulation. (C) Expression of ifngr2 transcripts in CD8 and CD4 T cells from wt and IFN-γRKO recipients. Data are normalized relative to ifngr2 mRNA expression in CD8 and CD4 splenocytes from unmanipulated donor-type (C3H.SW) mice. (A-C) Histograms represent the mean and SD for at least 3 mice per group from experimental triplicates. (D) Percentage of 1B11⁺ CD8 and CD4 donor T cells in the spleen on days 4 and 8 (n ≥ 4/group from 4 different experiments, mean and SD). *P< .05, **P < .01 (A-D). (E) Expression of of VLA-4, LFA-1, and L-PAM on 1B11⁺ and 1B11⁻ CD8 T cells on day 4. (F) Proportion of 1B11⁺ cells among hepatic and intestinal infiltrating CD8 T cells on day 8 after transplantation. (E,F) Results were similar for wt (n = 4) and IFN-γRKO (n = 4) recipients. One data set representative of 4 wt recipients is shown.