Localized reactive oxygen and nitrogen intermediates inhibit escape of Listeria monocytogenes from vacuoles in activated macrophages
Localized reactive oxygen and nitrogen intermediates inhibit escape of Listeria monocytogenes from vacuoles in activated macrophages
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DOI：
10.4049/jimmunol.171.10.5447
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发表时间：
2003-11-15
影响因子：
4.4
通讯作者：
Swanson, JA
中科院分区：
文献类型：
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作者：
Myers, JT;Tsang, AW;Swanson, JA
单核细胞增生李斯特氏菌 (Lm) 在被巨噬细胞吞噬后，通过从液泡逃入细胞质来逃避被杀死。活化的巨噬细胞具有杀灭李斯特菌的作用，部分原因是它们可以将 Lm 保留在液泡中。本研究考察了活性氧中间体 (1101) 和活性氮中间体 (RNI) 对抑制 Lm 从液泡逃逸的贡献。 Lm 在感染后 30 分钟内从未激活的巨噬细胞的液泡中逃逸。用 IFN-γ、LPS、IL-6 和针对 IL-10 的中和抗体激活的巨噬细胞将 Lm 保留在液泡内，ROI 和 RNI 的抑制剂在不同程度上阻断了对液泡逃逸的抑制。对 gp91(phox-/-) 和 NO 合酶 2(-/-) 小鼠巨噬细胞中 Lm 逃逸的测量表明，液泡保留需要 ROI，并通过 RNI 增强。使用与 BSA (DHFF-BSA) 偶联的荧光探针二氢-2',4,5,6,7,7'-六氟荧光素 (DHFF-BSA) 进行的活细胞成像表明氧化化学物质快速产生并定位于 Lm 液泡。氧化 DHFF-BSA 的化学反应与在吞噬体中保留 Lm 的化学反应相似。 DHFF-BSA 的荧光转换在较小的液泡中更有效地发生，表明在更有限的体积中产生更高浓度的 ROI 或 RNI。因此，活化的巨噬细胞通过将 ROI 和 RNI 定位到液泡，并通过它们在小空间中的联合作用，将 Lm 保留在吞噬体内。
Listeria monocytogenes (Lm) evades being killed after phagocytosis by macrophages by escaping from vacuoles into cytoplasm. Activated macrophages are listericidal, in part because they can retain Lm in vacuoles. This study examined the contribution of reactive oxygen intermediates (1101) and reactive nitrogen intermediates (RNI) to the inhibition of Lm escape from vacuoles. Lm escaped from vacuoles of nonactivated macrophages within 30 min of infection. Macrophages activated with IFN-gamma, LPS, IL-6, and a neutralizing Ab against IL-10 retained Lm within the vacuoles, and inhibitors of ROI and RNI blocked inhibition of vacuolar escape to varying degrees. Measurements of Lm escape in macrophages from gp91(phox-/-) and NO synthase 2(-/-) mice showed that vacuolar retention required ROI and was augmented by RNI. Live cell imaging with the fluorogenic probe dihydro-2',4,5,6,7,7'-hexalluorofluorescein coupled to BSA (DHFF-BSA) indicated that oxidative chemistries were generated rapidly and were localized to Lm vacuoles. Chemistries that oxidized DHFF-BSA were similar to those that retained Lm in phagosomes. Fluorescent conversion of DHFF-BSA occurred more efficiently in smaller vacuoles, indicating that higher concentrations of ROI or RNI were generated in more confining volumes. Thus, activated macrophages retained Lm within phagosomes by the localization of ROI and RNI to vacuoles, and by their combined actions in a small space.