The influence of antiviral therapy and HIV / HCV proteins on matrix metalloproteinase and cytokine production : an in vitro and in vivo study

Abstract

The effect of antiviral therapy on MMP/TIMP expression in THP-1 and LX-2 cells and in HIV/HCV co-infected patients: MMP-9 activity was measured by gelatin zymography, MMP-9 mRNA expression by real-time RT PCR, and MMP-9, MMP-2, and TIMP-1 protein expression by ELISA. Cells were treated for 48 hr unless otherwise stated. In THP-1 cells, interferon-a2a (IFN-a2a) dose-dependently decreased MMP-9 activity relative to PMA (50 ng/ml) controls (P<0.05). IFN-a2a (250 IU/ml) alone, or in combination with ribavirin (RBV; 10 μM), decreased MMP-9 activity compared to PMA (44±4.2 and 60±1.4 versus 100±3.1 AU; P<0.05) while RBV increased MMP-9 activity by ~50 % (P<0.05). At the mRNA level, RBV alone and in combination with IFN-a2a increased MMP-9 expression by ~2.5 fold compared to PMA controls (771 ±116, 772±42 versus 488±45, P<0.05), while IFN-a2a had no effect. Investigating this disparity between extracellular MMP-9 activity and intracellular MMP-9 mRNA it was found that RBV caused a robust increase in intracellular MMP-9 protein levels, while IFN-a2a had no effect. However, in combination with RBV, IFN-a2a reduced the RBV-mediated increases from 5.5±0.4 to 3.3±0.4 ng/ml (P<0.05). Co-treatment of THP-1 cells with the proteasome inhibitor MG 132 (200 nM) increased (P<0.05) MMP-9 activity compared to PMA alone (178±23 versus 100±6.1 AU). However, it did not alter the effect of IFN-a2a on RBV- mediated increased MMP-9 activity in THP-1 cells. However, assessment of the temporal effects of IFN-a2a on MMP-9 mRNA expression revealed an -65 % reduction (P<0.05) at 24 hr compared to PMA controls, while no effect at 48 and 72 hr were recorded. RBV, IFN-a2a, and the combination of both drugs, did not affect cell viability, or the process of differentiation from monocytes to macrophages, at the concentrations used in this study.