Fig. 5

CD4 and HLA-I down-regulation ability of Nefs encoding mutations at codons 8-14. The HLA-I down-regulation ability of the subtype B NL4-3 Nef (panel a) and the subtype C SK68 Nef (panel b) encoding mutations and mutation combinations at codons 8–14 is shown. In addition, panel a shows the HLA-I down-regulation ability of the subtype B B47 Nef which naturally encoded the 8R/11G/14S mutation combination and was subsequently mutated to the consensus residues 8S, 11 V and 14P. Similarly the CD4 down-regulation ability of these mutants is shown in panels c and d. Down-regulation activity is expressed relative to the respective wild-type protein (NL4-3, SK68 or B47), which represents 100 %. The CD4 and HLA-I down-regulation ability expressed relative to SF2 was 97 and 99 % respectively for NL4-3, 89 and 69 % respectively for SK68, and 94 and 92 % respectively for B47. Bars represent the mean of at least 3 replicates, and error bars represent standard deviations from the means. Asterisks indicate mutant clones that were > 10 % different in function from the wild-type and were significantly different from the wild-type as indicated by the Student’s T test (p < 0.05)