FIG. 4.

The R71T variation in Nef does not attenuate HIV-1 replication and CD4⁺ T-cell depletion in HLT. (A) Cummulative p24 production over 15 days of HLT infection with the indicated X4-tropic HIV-1 NL4-3 Nef variants. Infections were performed without adding exogenous IL-2 with virus stocks containing 10 ng of p24 antigen and cummulative virus production was monitored at 3, 6, 9, 12 and 15 days postinfection. u, uninfected tissue. (B) Frequency of HIV-1 infected p24⁺ cells and (C) CD4⁺/CD8⁺ T-cell ration in the tissue blocks (black bars) and cells that migrated in the gel foams (grey bars) at the end of culture at 15 days postinfection. Tissue culture, infections and FACS analysis were performed as described previously (9, 10). Similar results were obtained in two independent experiments using tissues derived from different donors.