Figure 4

Spread of cell-associated virus. U87.CD4.CCR5 cells were inoculated with VSV G-pseudotyped HIV-1 particles [50,000 (A) or 20,000 (B) cpm of RT activity per inoculum] and then trypsinized 24-h later to remove residual adsorbed virus. The cells were then replated and cultured for a further 10 days. The results shown represent the mean RT activity ± standard deviation of triplicate samples. (C) As for B except that 1 μM C34 peptide was maintained in the culture following the trypsinization step. Effects of D674E and D674N mutations on viral spread initiated by cell-free (D) and cell-associated (E) virus in 10-day U87.CD4.CCR5 cultures. The results shown represent the mean p24 content ± standard deviation of duplicate samples obtained from the cultures.