FIG. 7.

Cell-to-cell HIV transfer. Cell-to-cell viral transfer was measured by a flow cytometry-based assay. Primary CD4⁺ T lymphocytes (A and B) or MT4R5 cells (C and D) were infected with VSV-G-pseudotyped HIV-1 particles carrying different combinations of matrix and Env. The cells were then cocultured with CFSE-labeled target cells, such that targets could be distinguished from donors. The appearance of Gag⁺ target cells was followed over time (A and C). The efficiency of transmission (B and D) was measured by calculating the area under the curve in three independent experiments, with values for the NL(AD8) clone being defined as 100%. Means and standard deviations are shown.