Division of Rheumatology, Immunology, and Allergy, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA.
J Immunol. 2013 Apr 15;190(8):4196-204. doi: 10.4049/jimmunol.1202688. Epub 2013 Mar 13.
In vivo control of Mycobacterium tuberculosis reflects the balance between host immunity and bacterial evasion strategies. Effector Th1 cells that mediate protective immunity by depriving the bacterium of its intracellular niche are regulated to prevent overexuberant inflammation. One key immunoregulatory molecule is Tim3. Although Tim3 is generally recognized to downregulate Th1 responses, we recently described that its interaction with Galectin-9 expressed by M. tuberculosis-infected macrophages stimulates IL-1β secretion, which is essential for survival in the mouse model. Why IL-1β is required for host resistance to M. tuberculosis infection is unknown. In this article, we show that IL-1β directly kills M. tuberculosis in murine and human macrophages and does so through the recruitment of other antimicrobial effector molecules. IL-1β directly augments TNF signaling in macrophages through the upregulation of TNF secretion and TNFR1 cell surface expression, and results in activation of caspase-3. Thus, IL-1β and downstream TNF production lead to caspase-dependent restriction of intracellular M. tuberculosis growth.
结核分枝杆菌体内控制反映了宿主免疫与细菌逃避策略之间的平衡。通过剥夺细菌细胞内龛位来介导保护性免疫的效应 Th1 细胞受到调节,以防止过度的炎症反应。一个关键的免疫调节分子是 Tim3。虽然 Tim3 通常被认为下调 Th1 反应,但我们最近发现,它与结核分枝杆菌感染的巨噬细胞表达的半乳糖凝集素-9 相互作用,刺激 IL-1β 的分泌,这对于在小鼠模型中生存是必不可少的。为什么 IL-1β 是宿主抵抗结核分枝杆菌感染所必需的,目前尚不清楚。在本文中,我们表明,IL-1β 通过招募其他抗菌效应分子,直接杀死鼠类和人类巨噬细胞中的结核分枝杆菌。IL-1β 通过上调 TNF 分泌和 TNFR1 细胞表面表达,直接增强巨噬细胞中的 TNF 信号,导致 caspase-3 的激活。因此,IL-1β 和下游 TNF 的产生导致细胞凋亡依赖性限制细胞内结核分枝杆菌的生长。