Deficiency of both perforin and FasL in donor CD8⁺T cells cause prolonged expansion after BMT. (A) Mice underwent transplantation as in Figure 1. Splenocytes were harvested 10, 20, and 30 days (n = 3 mice/group) after BMT and analyzed by fluorescence-activated cell sorter (FACS). wt B6 → bm1 (•), pfp^–/–→ bm1 (□), gld → bm1 (⋄), and cdd → bm1 (▴). wt B6 → bm1 versus cdd → bm1, *P < .05 by Mann-Whitney U test. (B) TNF α and IFN γ production by donor CD8⁺ T cells was determined by intracytoplasmic staining. *P < .05 by Mann-Whitney U test. (C) Overall pathologic damage of liver specimens correlated to the intensity of cell infiltration in portal triads, bile ducts/ductules, vascular, and hepatocellular areas. P < .01 by linear regression analysis. Symbols are same as in 3A. Error bars indicate mean ± SD.