INTRACELLULAR LOCALIZATION OF MTB IN MACROPHAGES: TUBERCLE BACILLI

MTB 在巨噬细胞中的细胞内定位：结核杆菌

• 批准号: 6280690
• 负责人: KATHLEEN H MCDONOUGH
• 金额: $ 0.27万
• 依托单位: WADSWORTH CENTER
• 依托单位国家: 美国
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-01-01 至 1998-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6280690
• 关键词: Mammalia; bacteria; biomedical resource; health care; human tissue; infection; microscopy

(Supported in part by NIH AI 36982-01 to K. McDonough) We are studying the intracellular localization of tubercle bacilli (Mtb) within macrophages. We previously reported (McDonough, et al. (1993) Infec. Immun. 612763) that virulent tubercle bacilli escaped from phagolysosomes into nonfused vesicles or the cytoplasm at several days post-infection. Our recent studies show that these "extraphagosomal" bacteria appear sooner (by 4th day post infection) and in higher numbers when virulent Mtb bacteria are pre-grown within macrophages. These findings are significant because the immune response required to control bacteria with unrestricted access to the host cell's cytoplasm is vastly different from that needed to eradicate a bacterium sequestered within a phagolysosome. It has been difficult to unambiguously differentiate, using traditional TEM techniques, between bacteria that are truly free in the cytoplasm and those that may be encased within a very tightly associated vacuolar membrane. Our approach has been criticized (see Xu, et al. (1994) J. Immunol. 153:2568) by others using cryo electron microscopy. The increased sample size and depth of field provided by HVEM, as well as the ability to perform 3-D image reconstructions should help us to better define the nature of the membranes (if any) that surround these tubercle bacilli. We have been comparing HVEM stereo pairs of macrophage lysates containing virulent tubercle bacteria with those containing avirulent tubuercle bacteria to determine the nature of the vacuoles surrounding these bacteria. A virulent bacillis calmette guerin (BGC) bacteria are often found enclosed within well-preserved contiguous membrane sacs, whereas virulent M. tuberculosis bacteria are more often found within disrupted membranes. These differences are currently being quantified and analyzed. Reconstructions from Sterecon tracings of 0.75lm thick sections photographed in the HVEM were made for poster presentation. Two posters were presented: K.A. McDonough, M. Florczyk, Y. Kress, J. Turner and B.R. Bloom 1997 Passage within macrophages affects the intracellular localization of virulent tubercle bacilli upon reinfection, Proc. ASM Conference on Tuberculosis. M. A. Florczyk, James N. Turner, Karolyn F. Buttle and Kathleen A. McDonough 1997 High Voltage Electron Microscopic Analysis of the Intracellular Localization of Mycobacterium Tuberculosis within Macrophages, Porc. Microbial Infectious Disease in Host Response, Cold Spring Harbor.

（部分由 NIH AI 36982-01 支持，K. McDonough） 研究结核杆菌 (Mtb) 的细胞内定位 巨噬细胞内。 我们之前报道过（McDonough 等人（1993） 感染。 免疫。 612763）致命的结核杆菌从 几天后将溶酶体吞噬到未融合的囊泡或细胞质中 感染后。 我们最近的研究表明，这些“吞噬体外” 细菌出现得更早（感染后第 4 天）且数量更高 当剧毒结核分枝杆菌在巨噬细胞内预生长时的数量。 这些发现很重要，因为免疫反应需要 控制细菌不受限制地进入宿主细胞的细胞质 与根除细菌所需的有很大不同 隔离在吞噬溶酶体内。 已经很难 使用传统 TEM 技术明确区分 真正游离于细胞质中的细菌和那些可能游离于细胞质中的细菌 包裹在紧密相连的液泡膜内。 我们的 该方法受到了批评（参见 Xu 等人（1994）J.Immunol。 153:2568）其他人使用冷冻电子显微镜。 增加的 HVEM 提供的样本大小和景深，以及 执行 3D 图像重建的能力应该可以帮助我们更好地 定义这些周围的膜（如果有的话）的性质 结核杆菌。 我们一直在比较 HVEM 立体声对 含有毒力结核菌的巨噬​​细胞裂解物 含有无毒力的结核菌以确定其性质 这些细菌周围有液泡。 强毒卡美特杆菌 盖林 (BGC) 细菌通常被发现封闭在保存完好的内部 连续的膜囊，而有毒力的结核分枝杆菌 更常见于破裂的膜内。 这些差异 目前正在量化和分析。 重建自 在 HVEM 中拍摄的 0.75 微米厚切片的立体追踪 是为海报展示而制作的。 展示了两张海报：K.A. McDonough、M. Florczyk、Y. Kress、J. Turner 和 B.R.绽放 1997 巨噬细胞内的通过影响细胞内定位 再次感染时有毒力的结核杆菌，Proc。 ASM 会议 结核。 M. A. Florczyk、James N. Turner、Karolyn F. Buttle 和 Kathleen A. McDonough 1997 高压电子显微镜分析 结核分枝杆菌的细胞内定位 巨噬细胞，猪肉。 宿主反应中的微生物传染病， 冷泉港。