Figure 3

Measurement of viral infectivity and susceptibility to hTRIM5α. The U373-X4-hTRIM5γ and U373-X4-LacZ target cells were pretreated for 20 h with 100 U/ml IFN-α before their infection with 0.2 ng RT of chimeric viruses. The viruses were grouped according to the origin of their CA proteins: laboratory-adapted HIV-2 strains (n=2), HIV-2 clinical isolates from subtype A (n=8) or from subtype B (n=7), CRF01_AB (n=3), synthetic sequences from HIV-2 viruses from non-epidemic subtypes C to H (n=6), synthetic sequences from SIVsmm (n=4) and from SIVmac239, primary HIV-1 CA sequences from patient plasma (n=9). Forty hours after luciferase activity was determined by luminometry. (A) Infectivity values of chimeric viruses measured in the U373-X4 target cells in which hTRIM5α activity had been inhibited by overexpression of hTRIM5γ, which are expressed as RLU/0.2 ng of RT. (B) Susceptibility values of chimeric viruses to hTRIM5α were expressed as a ratio [(RLU for hTRIM5γ cells)/(RLU for LacZ cells)], and normalized to that obtained for NL4-3. The results shown are the mean ± SEM for 3 independent experiments.