FIG. 3.

(A) Frequency of memory (CD95⁺) CD4⁺ and (B) CD8⁺ T cells producing interferon (IFN)-γ, (C, D) interleukin (IL)-2, and (E, F) tumor necrosis factor (TNF)-α after in vitro stimulation with SIV-gag and env overlapping peptides of cells isolated from peripheral lymph nodes collected at 2 weeks after infection. Values obtained from unstimulated cells are subtracted. (G) Levels of IFN-γ RNA and (H) tumor growth factor (TGF)-β RNA in rectal mucosa intact tissue collected 2 weeks after the challenge time.