FIG. 5.

Defective T-lymphocyte production of IFN-γ in STAT1^−/− mice. Splenocytes were obtained from mice 7 days after infection, immediately stimulated with PMA and ionomycin, and stained for T-cell markers and IFN-γ as described in Materials and Methods. The numbers in each quadrant indicate the percentage of cells in that quadrant. This experiment was repeated three times with essentially identical results.