FIG. 4.

IFN-γ, TNF-α, and IL-2 production by virus-specific CD8 and CD4 T cells. Splenocytes collected from BALB/c mice on day 7 after VV infection (A) or on day 8 after LCMV infection (B) were stimulated with the corresponding virus-infected A-20 cells for 5 h in vitro. Cell surfaces were stained with anti-CD8α or anti-CD4, and then cells were intracellularly stained with anti-IFN-γ, anti-TNF-α, or anti-IL-2. The percentages of CD8 or CD4 T cells producing each cytokine are indicated in the upper right corners of the corresponding panels.