APOPTOSIS OF MURINE MACROPHAGE CELL LINE INFECTED WITH ORIENTIA TSUTSUGAMUSHI.

초록

Shigella flexneri induce apoptosis, which specifically kills cultuered macrophages but not epithelial cells and this induction of apoptosis may be an important step in the pathogenesis of Shigella as it breaches the gastrointestinal barrier. Thereafter many papers described the apoptosis of cells infected with various bacteria especially in macrophage. Recently Kasuya et. al. reported apoptosis of lymphocytes in mice infected with O.tsutsugamushi. We also obeserved the apoptosis induced in murine macroghage cell line, J774,infected with Boryong strain isolated in Korea which cause leathal mouse infection. The J774 cells change their morphology which was seemed to be activated, and detatched off from the culture plate. We examined the induction of DNA fragmentation of J774 cells and a nucleosome pattern of DNA degradation was observed after 24h infection. DNA fragmentation was also detected by terminal D-transferase-mediated dUTP-biotin end labeling(TUNEL) method. We also examined the cytokine secretion pattern of J774 cells during the rickettsia infection. Some of mechanism of induction of apoptosis will be discussed.