Alveolar macrophage cell line MH-S is valuable as an in vitro model for Legionella pneumophila infection
Alveolar macrophage cell line MH-S is valuable as an in vitro model for Legionella pneumophila infection
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DOI：
10.1165/ajrcmb.24.3.4359
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发表时间：
2001-03-01
影响因子：
6.4
通讯作者：
Yamamoto, Y
中科院分区：
文献类型：
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作者：
Matsunaga, K;Klein, TW;Yamamoto, Y
肺泡巨噬细胞是嗜肺军团菌在感染过程中的优势生长部位。然而，由于可获得的原代肺泡巨噬细胞的限制，肺泡巨噬细胞中LP感染的研究是困难的。在本研究中，我们使用一种命名为MH-S的小鼠肺泡巨噬细胞系建立了体外肺泡巨噬细胞LP感染模型。用强毒嗜肺乳杆菌(Lp-V)感染MH-S细胞和肺泡灌洗法获得的原代小鼠肺泡巨噬细胞，均显示细菌生长旺盛，而用强毒嗜肺乳杆菌(Lp-Av)感染则只有极少量的生长。MH-S细胞感染后的细胞因子信息表达检测显示，LP-V对IL-6、IL-10和肿瘤坏死因子-α有较强的诱导作用，而LP-Av感染对这些细胞因子的诱导作用较弱。此外，还分析了IL-1α蛋白分泌和IL-1α的消息水平，发现感染LP-V后两种巨噬细胞均能显著诱导IL-1α的产生。用逆转录/聚合酶链式反应分析两种巨噬细胞对LP-V感染的IL-12p40反应，发现诱导的消息水平增加，但显著水平的诱导只是缓慢的。用Lp-V或Lp-Av感染两种类型的巨噬细胞的培养上清液，用酶联免疫吸附试验检测IL-12蛋白的分泌，只显示最低的产量。因此，MH-S肺泡巨噬细胞对LP感染的反应与原代肺泡巨噬细胞相似，可作为研究LP感染的体外模型系统。本研究还发现LP感染对肺泡巨噬细胞分泌IL-12蛋白有抑制作用。
Alveolar macrophages are the preferential site for growth of Legionella pneumophila (Lp) during infection. However, the study of Lp infection in alveolar macrophages is difficult due to the limitation of available primary alveolar macrophages. In the present study, we established an in vitro Lp infection model in alveolar macrophages using a continuous cell line of murine alveolar macrophages designated MH-S. Infection of both MH-S cells and primary mouse alveolar macrophages obtained by alveolar lavage with virulent L. pneumophila (Lp-V) showed vigorous growth of the bacteria, but infection with avirulent L. pneumophila (Lp-Av) resulted in only minimum growth. Cytokine message expression determination in the MH-S cells after infection showed strong induction of interleukin (IL)-6, IL-10, and tumor necrosis factor-alpha messages induced by Lp-V but minimal induction of these cytokines by Lp-Av infection. IL-1 alpha protein secretion and the message levels for IL-1 alpha were also analyzed, and remarkable induction of IL-1 alpha was evident in both macrophage types when infected with Lp-V. Analysis of IL-12 p40 responses of both macrophage types to Lp-V infection assessed by reverse transcriptase/polymerase chain reaction revealed induction of increased message levels, but significant levels were induced only slowly. Determination of IL-12 protein secretion by enzyme-linked immunosorbent assay of culture supernatants from both macrophage types infected with either Lp-V or Lp-Av showed only minimum production. Thus, MH-S alveolar macrophages showed a similar response to Lp infection compared with primary alveolar macrophages and can be a useful in vitro model system to study Lp infection. The study also revealed the restricted IL-12 protein secretion of alveolar macrophages by Lp infection.