FIG 5.

Lower infectivity of partially eCD4-Ig-resistant Env variants. A luciferase-encoding HIV-1 pseudovirus pseudotyped with Env of the SHIV-SF162P3 reference sequence or the same Env modified to include the indicated eCD4-Ig-selected substitutions was incubated at the indicated p24 amounts with either HOS.CCR5 or Cf2Th-CCR5 cells stably expressing human CD4. Luciferase activity was measured 36 to 48 h postinfection. Error bars represent SEM, and the results are representative of two independent experiments. Note that variants bearing the Q428K substitution were markedly less infective than the reference SHIV-SF162p3 Env sequence or other Env variants.