Genetic determinants of Nef-mediated CD4 and HLA class I down-regulation differences between HIV-1 subtypes B and C

Background HIV-1 subtype C Nef sequences have a significantly lower ability overall to down-regulate CD4 and HLA-I than subtype B Nef sequences. Here we investigated whether Nef amino acids differing in frequency between HIV-1 subtypes B and C explain lower CD4 and HLA-I down-regulation ability of subtype C.