Yamamoto Y, Klein T W, Newton C A, Widen R, Friedman H
Infect Immun. 1987 Jun;55(6):1369-74. doi: 10.1128/iai.55.6.1369-1374.1987.
Legionella pneumophila is a facultative intracellular bacterium which replicated well in inbred guinea pig strain 2 peritoneal macrophages at a low infectivity ratio. In contrast, the growth of this organism was markedly restricted in mouse (BDF1) peritoneal macrophages, even at a relatively high infectivity ratio. The initial uptake of L. pneumophila organisms by macrophages was similar in both animal species, and both groups of macrophages supported the growth of Listeria monocytogenes. Treatment of L. pneumophila with immune guinea pig serum did not result in restriction of bacterial growth in macrophages, but guinea pig macrophages were readily induced to suppress the growth of L. pneumophila by preincubation with supernatants obtained from mitogen-activated normal guinea pig splenocyte cultures. Thus, lymphokines generated from mitogen-stimulated guinea pig lymphocytes induced a restriction of growth of these organisms similar to that observed naturally with macrophages from mice, which are considered highly resistant to these bacteria. Although guinea pigs are considered highly susceptible to L. pneumophila infections and mice are considered relatively resistant, the mechanism of this difference is not clear. The results of the present study suggest that the restriction of L. pneumophila growth by macrophages relates to host susceptibility to infection and that cell populations permissive for L. pneumophila can be transformed to nonpermissive by products from stimulated lymphocytes but not by opsonization with immune serum.
嗜肺军团菌是一种兼性胞内细菌，它在低感染率的情况下能在近交系豚鼠2型腹膜巨噬细胞中良好复制。相比之下，即使在相对高的感染率下，这种微生物在小鼠（BDF1）腹膜巨噬细胞中的生长也受到显著限制。巨噬细胞对嗜肺军团菌的初始摄取在这两种动物中相似，并且两组巨噬细胞都支持单核细胞增生李斯特菌的生长。用免疫豚鼠血清处理嗜肺军团菌并不会导致其在巨噬细胞中的生长受限，但通过与从丝裂原激活的正常豚鼠脾细胞培养物中获得的上清液预孵育，豚鼠巨噬细胞很容易被诱导抑制嗜肺军团菌的生长。因此，丝裂原刺激的豚鼠淋巴细胞产生的淋巴因子诱导这些微生物的生长受限，类似于在对这些细菌具有高度抗性的小鼠巨噬细胞中自然观察到的情况。尽管豚鼠被认为对嗜肺军团菌感染高度易感，而小鼠被认为相对抗性较强，但这种差异的机制尚不清楚。本研究结果表明，巨噬细胞对嗜肺军团菌生长的限制与宿主对感染的易感性有关，并且允许嗜肺军团菌生长的细胞群体可以被刺激淋巴细胞产生的产物转化为不允许生长的状态，而不是通过免疫血清的调理作用。
