FIG. 3.

IFN in a CD8⁺ cell-conditioned medium is directly correlated with the anti-HIV activity. (A) Anti-HIV activity (percent suppression, left axis) and IFN-α levels (right axis) of fluids collected from a single-CD8⁺-cell culture over the course of 10 days. (B) Shown are the anti-HIV activities (left axis) and IFN levels (right axis) of CD8⁺ cell fluids from 6 different donors (S1–S6) collected at different days. Symbols differentiate the measurements of IFN-α (circles), IFN-β (diamonds), and IFN-ω (squares). (C) IFN-α levels were measured in 109 separate CD8⁺ cell fluids that were predetermined to exhibit low (<50%) or high (>50%) anti-HIV activity. (D) A receiver operator curve showing the predictive value of IFN-α levels as related to the anti-HIV activity of CD8⁺ cell fluids. (E) Effect of decreasing concentrations of human leukocyte interferon (HLI) on HIV replication (bars, left axis) in primary CD4⁺ cells. IFN-α levels (circles, right axis) in the various HLI dilutions were measured by enzyme-linked immunosorbent assay (ELISA).