No group-specific difference of Nef-mediated regulation of surface receptors. (A-F) Quantitative assessment of flow cytometric analysis of Nef-mediated modulation of (A) CD4 and (B) MHC-I in primary CD4+ T cells, (C) CD28 and (D) TCR-CD3 in PBMCs, (E) CD8β in CEM A2-CD8β fusion cells and (F) CD74 (Ii) in THP-1 cells transduced with HIV-1 recombinants expressing eGFP alone (nef-) or together with control or patient-derived nef alleles. A vpu and env defective HIV-1 backbone was used to measure the effect of Nef on CD4 surface expression. Given are n-fold modulation of cell surface expression compared to the nef-defective control HIV-1 construct (average values ± standard errors) derived from three independent experiments. Nef alleles were derived from the HIV-1 NL4-3, NA7 and JR-CSF molecular clones (Co1, black); SIVmac239, HIV-2 BEN, HIV-2 60415 K, SIVsmm FWr1 and FFm1 Nefs (Co2, blue), VNPs (n = 11, green) and Ps (n = 8, red). Co, control; *, p < 0.05; **, p < 0.01; ***, p < 0.001.