Involvement of matrix metalloproteinases in human immunodeficiency virus type I-induced replication by clinical Mycobacterium avium isolates

The role of Mycobacterium avium isolates in modulating human immunodeficien cy virus type 1 (HIV-1) replication was examined by use of an in vitro, res ting T cell system. Two human clinical isolates (serotypes 1 and 4) but not an environmental M. avium isolate (serotype 2) enhanced HIV-1 replication. The M. avium-induced HIV-1 replication was not associated with cell activa tion or differential cytokine production or utilization. Addition of matrix metalloproteinase (MMP) inhibitors and their in vivo regulators, tissue in hibitors of metalloproteinases-1 and -2, abrogated M. avium-induced HIV-1 r eplication 80%-95%. The MMP inhibitors did not have any effect on the HIV-1 protease activity, suggesting that they may affect cellular processes. Fur thermore, MMP-9 protein was differentially expressed after infection with c linical M. avium isolates and paralleled HIV-1 p24 production. Collectively , these data suggest that M. avium-induced HIV-1 replication is mediated, i n part, through the induction of MMP-9.