Fig. 8.

Response of infected cells to CD28-stimulation is altered in the presence of Nef or Vpu. Purified CD4⁺ T cells were infected with VSV-G pseudotyped NL4.3 encoding Nef and Vpu (NL4.3, red), lacking Nef (dNef, blue) or Vpu (dVpu, orange), or lacking both Nef and Vpu (dVpu dNef, green). Twenty-four hours post-infection cells were activated with anti-CD3/anti-CD28 for 24 h. Cells were then incubated with Brefeldin A for 12 h and stained for intracellular IL-2 prior to analysis by flow cytometry. a Representative dot plots illustrating intracellular IL-2 (APC) and infection (GFP) levels. Quadrants were selected based on the IL-2 isotype antibody control and uninfected controls. The percentage of infected cells that are IL-2 positive is indicated (red). The percentage of cells making up the uninfected and IL-2 negative population (Q4) are as follows: uninfected unstimulated: 99.8%, isotype control: 99.7%, uninfected stimulated: 93.8%, NL4.3: 91.3, dNef: 95.5%, dVpu: 90.1, dVpu dNef: 89.3%. b Mean (± SE) percentage of infected cells that are IL-2 positive (n ≥ 6). The means were obtained by analysis of infected cells from two healthy donors. (SE: standard error; *p ≤ 0.05)