CD147 regulates an early step of HIV-1 infection.
(A) The effect of anti-CD147 mAb on HIV-1 RT. Duplicate
PBMC cultures were inoculated with HIV-1LAV, incubated at
37°C for 1.5 h, and then trypsinized to remove unfused virus.
Analysis of HIV-1 RT was performed at indicated times after inoculation
by using primers long terminal repeat R/U5 specific for the early RT
products (29). Anti-CD147 mAb (50 μg/ml), anti-CD4 mAb (2
μg/ml), or isotype-matched control mAb (50 μg/ml) was added to
cells 2 h before infection. Dilutions of 8E5/LAV cells
containing one HIV-1 genome per cell (44) were used as PCR standards.
The data are representative of three experiments. (B)
The effect of anti-CD147 mAb on subcellular distribution of HIV-1
proteins. MT-4 cells were inoculated at 4°C with HIV-1LAV
in the presence of 50 μg/ml of anti-CD147 mAb (Ancell) or
isotype-matched control mAb (PharMingen). After 30 min, an aliquot
(1 × 106) was withdrawn for protein analysis (0 h
postinfection time point), while the inoculated cultures were
transferred to 37°C and incubated for 1.5 h or 3.5 h.
Subcellular fractionation was performed as described in
Materials and Methods, and proteins in cytosolic (C),
membrane (M), and cytoskeleton (CS) fractions were revealed by Western
blot and enhanced chemiluminescence by using mAbs to actin, CA, and
MA.