IN-VITRO INFECTION OF SMOOTH-MUSCLE CELLS BY CHLAMYDIA-PNEUMONIAE

Recent observations have shown that both Chlamydia pneumoniae antigens and DNA may be found within atherosclerotic lesions. In this study, w e evaluated the ability of C. pneumoniae to infect cells that make up atherosclerotic lesions, including endothelial cells, smooth muscle ce lls, and cholesterol loaded smooth muscle cells. The organism readily infected rabbit, bovine, and human aortic smooth muscle cells, Cholest erol-loaded smooth muscle cells were even more susceptible to C. pneum oniae infection, Chlamydia trachomatis inefficiently infected smooth m uscle cells, demonstrating that this is not a characteristic of all me mbers of the genus Chlamydia, C. pneumoniae infected bovine endothelia l cells poorly. This study demonstrates that C. pneumoniae readily inf ects one of the important types of cells found within atherosclerotic lesions, i.e., smooth muscle cells with and without cholesterol loadin g.