Poxvirus MC148 inhibits CCL1-induced MMP-2 production in VSMCs. VSMCs were preincubated with DMEM or with poxvirus MC148 chemokine (100 ng/mL) for 30 minutes at 37°C. After washing, DMEM or CCL1 (100 ng/mL) with or without MC148 was incubated with the VSMCs for 3 hours at 37°C in 5% CO₂. The supernatants were collected and analyzed by gelatinolytic zymography. Gelatinolytic zymograms were quantified using the NIH Image 1.62f program. CCL1 increased VSMC gelatinolytic activity by 234% over the control. In the presence of MC148 chemokine, however, production of MMP-2 was substantially inhibited. Inc. indicates increase.