Turco J, Winkler H H
Infect Immun. 1984 Aug;45(2):303-8. doi: 10.1128/iai.45.2.303-308.1984.
We studied the effects of crude mouse lymphokines and cloned mouse interferon-gamma on the interaction of Rickettsia prowazekii with mouse macrophage-like RAW264.7 cells. Treatment of RAW264.7 cells with lymphokines before infection, after infection, or both before and after infection with R. prowazekii led to killing of a substantial proportion of the RAW264.7 cells. Such cytotoxicity required both lymphokines and viable R. prowazekii and did not occur in mouse fibroblastic L929 cells. Untreated cultures of RAW264.7 cells supported good growth of the Breinl strain of R. prowazekii, but in lymphokine-treated cultures, little or no rickettsial growth occurred in the cells that survived the cytotoxic reaction. In addition, treatment of RAW264.7 cells with lymphokines before rickettsial infection was associated with suppression of the initial infection. The effects of cloned mouse interferon-gamma were similar to the effects of crude mouse lymphokines. Assessment of cytotoxicity, inhibition of the initial infection, and inhibition of rickettsial growth in RAW264.7 cells pretreated with various concentrations of interferon-gamma indicated that the effects of the lymphokines could be explained by the interferon-gamma that was present in these preparations. Treatment of RAW264.7 cells with interferon-gamma makes them unsuitable host cells for R. prowazekii.
我们研究了粗制小鼠淋巴因子和克隆的小鼠γ干扰素对普氏立克次体与小鼠巨噬细胞样RAW264.7细胞相互作用的影响。在用普氏立克次体感染RAW264.7细胞之前、之后或感染前后用淋巴因子处理，都会导致相当比例的RAW264.7细胞死亡。这种细胞毒性既需要淋巴因子，也需要活的普氏立克次体，在小鼠成纤维细胞L929中不会发生。未经处理的RAW264.7细胞培养物能支持普氏立克次体布雷因尔菌株的良好生长，但在经淋巴因子处理的培养物中，在细胞毒性反应中存活下来的细胞中几乎没有立克次体生长。此外，在立克次体感染前用淋巴因子处理RAW264.7细胞与抑制初始感染有关。克隆的小鼠γ干扰素的作用与粗制小鼠淋巴因子的作用相似。对用不同浓度γ干扰素预处理的RAW264.7细胞的细胞毒性、初始感染抑制和立克次体生长抑制进行评估表明，淋巴因子的作用可以用这些制剂中存在的γ干扰素来解释。用γ干扰素处理RAW264.7细胞会使其成为不适宜普氏立克次体寄生的宿主细胞。
