FIG. 3.

Structure of the CD4C/HIV transgenes expressing various Nef alleles. Nef allele fragments Nef^AD-93, Nef^032an, Nef^039nm, Nef^JR-CSF, Nef^SF2, and Nef^YU10x, as well as the mutant Nef^NL4-3(T71R) were inserted within the same CD4C/HIV^MutG backbone sequences replacing Nef^NL4-3(WT). The transgenes were constructed as described in Materials and Methods. Abbreviations: mCD4enh, mouse CD4 enhancer; hCD4 prom, human CD4 promoter; SV40, polyadenylation sequences from simian virus 40; Ex1, CD4 gene exon 1; X, interruption of the ORF of the indicated HIV-1 genes; LTR, long terminal repeat; A, restriction site AatII; Bs, restriction site BssHII; S, restriction site SstI.