FIG. 4.

Loss and gain of function of CD8⁺ cell anti-HIV activity. (A) Shown are representative anti-HIV activity levels of CD8⁺-cell-conditioned media from 6 different donors (S1–S6) and HLI upon treatment with normal rabbit serum (light bars) or rabbit serum containing anti-human IFN antibodies (dark bars). (B) The effects of increasing amounts of anti-IFN receptor antibody (anti-IFNAR2) on the anti-HIV activity of CD8⁺-cell-conditioned media from 2 different donors (S1 and S2). (C) Shown are the HIV replication levels (RT activity) in cultures containing acutely infected CD4⁺ cells alone (circles), cocultured with untreated CD8⁺ cells from a HIV-negative donor (squares), or cocultured with CD8⁺ cells from the same donor that were transfected in vitro with an IFN expression vector (triangles).