FIGURE 6.

Ubiquitin does not affect HIV-1 infection. Effects of CXCR4 ligands on X4 tropic HIV-1 R9 (A) and R5 tropic HIV-1 R9BaL (B) infection in P4.R5 MAGI cells (n = 3). One h before infection with 0.5 multiplicity of infection of virus, P4.R5 MAGI cells were treated with the indicated concentrations of CXCR4 ligands. Thirty-six hours postinfection cells were assayed for β-galactosidase expression. Experiments with lower multiplicity of infection (0.25 and 0.125) and X4 and R5 tropic pseudotyped virions showed identical results (not shown). *, p < 0.05 versus cells cultured in the absence of CXCR4 ligands.