FIG. 9.

Inefficient translation but correct processing of HIV-1 structural proteins by astrocytes. HeLa (A) and U251MG (C) cells were pulse-labelled with [³⁵S]methionine for 1 h at 48 h (HeLa) or 72 h (U251MG) after cotransfection with pEGFP-N1 alone (mock) or together with 20 μg of HIV-1 proviral plasmid pNL4-3 (pulse). Labelled cells were then incubated at 37°C for 1, 2, 3, 4, and 6 h in complete medium, and HIV-1 proteins were detected by immunoprecipitation from cell lysate volumes (standardized by total TCA-precipitable ³⁵S-labelled proteins) with pooled HIV-1 immune serum (BB10). Virions pelleted from the supernatant of HeLa (B) or U251MG (D) transfections were lysed and subjected to immunoprecipitation for analysis of HIV-1 structural proteins.