FIG. 2.

Infection with CNS-derived HIV and FIV strains increases MMP expression in primary macrophages. MMP-2 and -9 protein (A, C) and RNA (B, D) levels were assessed by gelatin zymography and semiquantitative RT-PCR at days 0, 1, 3, 5, and 7 postinfection using conditioned media from uninfected and JRCSF-infected human macrophages (A, B) and uninfected and V₁CSF-infected feline macrophages (C, D). Infection with either virus induced concurrent increases in MMP-2 and -9 protein and mRNA expression that increased with viral replication. Viral replication was measured by RT-PCR amplification of the HIV-1 gag gene or the FIV pol gene using RNA from human and feline PBMC infected with HIV or FIV as positive controls (+). Conditioned medium and RNA from stimulated human macrophages served as controls for detection of MMP expression (+). Amplification of GAPDH was used to ensure equal template loading.