Fig 6.

Pooled SIV⁺ plasma neutralizes CD4-independent Envs and CD4-triggered CD4-dependent Env. (A) Representative CD4-dependent (Rzu4.d11.2.1) and CD4-independent (Rpe6.42.7.2) Env-pseudotyped viruses were incubated with or without 50 μg/ml sCD4 and then incubated with serial dilutions of SIV⁺ plasma pooled from two chronically SIVmac251-infected macaques (not from this study). Viruses were then used to infect 293T cells transfected with rmCD4 plus rmCCR5. (B) The parental and E84K-plus-D470N mutant forms of a CD4-dependent Env were tested for plasma neutralization. (C) The parental and K84E-plus-N470D mutant forms of a CD4-independent Env were tested for plasma neutralization.