FIG 3.

Neutralization and binding studies of CD4-Ig variants with the Envs of SIVmac316 and SIVmac239 variants. (A) IC₅₀s were determined with experiments similar to those of Fig. 1 except that pseudoviruses expressing the Env proteins of SIVmac239, SIVmac239 G382R, SIVmac239 H442Y, or SIVmac239 G382R/H442Y were preincubated with various concentrations of the indicated CD4-Ig variants. IC₅₀s are the means ± SEM from two or three independent experiments. (B to D) 293T cells were transfected to express envelope glycoproteins of SIVmac239 (B), SIVmac316 (C), or SIVmac239 G382/H442Y (D). Cells were preincubated with the indicated concentrations of CD4-Ig variants, washed, incubated with APC-conjugated anti-human antibody, and analyzed by flow cytometry. Mean fluorescence intensities (MFI) ± SEM from three replicate samples are indicated. Experimental results depicted are representative of two experiments with similar results.