Fig. 5.

IFN-γ does not prevent HIV entry into monocytic cells. (a) Purified monocytes (1 × 10⁴/ml) obtained from HIV-negative individuals were incubated with a dual-tropic HIV clinical isolate no. 204 with a MOI of 0·1 for the indicated periods of time. DNA extracted at these times was subjected to PCR analysis for HIV gag; β-actin was used as an internal control. Amplified products were electrophoresed and analysed by densitometry. (b) Purified monocytes (1 × 10⁴/ml) from five HIV-negative individuals were cultured for 48 h with 1 ng/ml of IFN-γ or IL-2 followed by infection with a dual tropic HIV clinical isolate no. 204 at a MOI of 0·1 for 8 h. The DNA was extracted and subjected to PCR analysis for gag amplification as described above. One representative sample is shown. The average ratio of HIV-gag to β-actin calculated from the results obtained from five different individuals is also shown. UC, uninfected controls.