FIG. 1.

C. pneumoniae increases the sensitivity of monocytes to MMP-1 and MMP-9 induction by TNF-α and GM-CSF. Monocytes were incubated with the IFU for 6 h, washed, and cultured in the presence or absence of TNF-α (50 ng/ml) and GM-CSF (50 ng/ml) for an additional 48 h. Supernatants were harvested at 48 h and were assayed for MMP-1 and MMP-9 by Western blotting. Panel A represents a dose response of IFU of live C. pneumoniae, whereas panel B compares IFU of live C. pneumoniae to the equivalent IFU of C. pneumoniae following heating at 90°C for 15 min.