Figure 4.

Inhibition of pseudoviral and viral infection. (A) U87-CD4⁺-CXCR4⁺ cells were infected with pNL43-Luc-R⁻E⁻ pseudovirions encapsidated with either HIV-1 Env_HXB2 (filled symbols) or MuLV Env (open symbols) for 48 h in the presence of various concentrations of 5-Helix or 5-Helix-PE. Luciferase activity was measured and normalized to 100% for no added protein. (B) CEM cells infected with HIV-1_NL4-3 were incubated with 5-Helix or 5-Helix-PE for 5–6 days before p24 antigen levels in the viral supernatants were measured by ELISA. The data are normalized to 100% for no added protein and represent the mean ± SEM of three experiments.