MOESM6 of The HIV-1 accessory proteins Nef and Vpu downregulate total and cell surface CD28 in CD4+ T cells

Additional file 6. Specific motifs in Vpu are critical for downregulation of CD4. Infected CD4+ Sup-T1 cells were stained for CD4 and analyzed by flow cytometry. Mean geometric fluorescence intensities of cells (MFI) were determined after gating on live and infected (Zombie RedTM− and GFP+) cells. Cells infected with VSV-G pseudotyped NL4.3 lacking Nef (dNef, blue) and both Nef and Vpu (dNef dVpu, green) were used as controls. (A) Mean (± SE) relative cell surface CD4 on cells infected with NL4.3 encoding various mutations in vpu (n ≥ 4). (B) Relative mean (± SE) total CD4 within cells infected with NL4.3 encoding various Vpu mutations (n ≥ 5). (SE: standard error; *p ≤ 0.05; **p ≤ 0.01; ***p ≤ 0.001; ****p ≤ 0.0001).