National Clinical Research Center for Infectious Diseases, Shenzhen Third People's Hospital, Shenzhen, Guangdong, China.
Front Immunol. 2024 May 30;15:1402024. doi: 10.3389/fimmu.2024.1402024. eCollection 2024.
Mycobacterium tuberculosis (Mtb) is an intracellular pathogen capable of adapting and surviving within macrophages, utilizing host nutrients for its growth and replication. Cholesterol is the main carbon source during the infection process of Mtb. Cholesterol metabolism in macrophages is tightly associated with cell functions such as phagocytosis of pathogens, antigen presentation, inflammatory responses, and tissue repair. Research has shown that Mtb infection increases the uptake of low-density lipoprotein (LDL) and cholesterol by macrophages, and enhances cholesterol synthesis in macrophages. Excessive cholesterol is converted into cholesterol esters, while the degradation of cholesterol esters in macrophages is inhibited by Mtb. Furthermore, Mtb infection suppresses the expression of ATP-binding cassette (ABC) transporters in macrophages, impeding cholesterol efflux. These alterations result in the massive accumulation of cholesterol in macrophages, promoting the formation of lipid droplets and foam cells, which ultimately facilitates the persistent survival of Mtb and the progression of tuberculosis (TB), including granuloma formation, tissue cavitation, and systemic dissemination. Mtb infection may also promote the conversion of cholesterol into oxidized cholesterol within macrophages, with the oxidized cholesterol exhibiting anti-Mtb activity. Recent drug development has discovered that reducing cholesterol levels in macrophages can inhibit the invasion of Mtb into macrophages and increase the permeability of anti-tuberculosis drugs. The development of drugs targeting cholesterol metabolic pathways in macrophages, as well as the modification of existing drugs, holds promise for the development of more efficient anti-tuberculosis medications.
结核分枝杆菌(Mtb)是一种能够在巨噬细胞内适应和生存的细胞内病原体,利用宿主营养物质进行生长和复制。胆固醇是 Mtb 感染过程中的主要碳源。巨噬细胞中的胆固醇代谢与细胞功能密切相关,如病原体吞噬、抗原呈递、炎症反应和组织修复。研究表明,Mtb 感染增加了巨噬细胞对低密度脂蛋白(LDL)和胆固醇的摄取,并增强了巨噬细胞中的胆固醇合成。过量的胆固醇被转化为胆固醇酯,而 Mtb 抑制了巨噬细胞中胆固醇酯的降解。此外,Mtb 感染抑制了巨噬细胞中 ATP 结合盒(ABC)转运蛋白的表达,阻碍了胆固醇的外排。这些改变导致胆固醇在巨噬细胞中大量积累,促进了脂质滴和泡沫细胞的形成,从而有利于 Mtb 的持续生存和结核病(TB)的进展,包括肉芽肿形成、组织空洞和全身播散。Mtb 感染还可能促进巨噬细胞内胆固醇向氧化胆固醇的转化,而氧化胆固醇具有抗 Mtb 活性。最近的药物开发发现,降低巨噬细胞中的胆固醇水平可以抑制 Mtb 侵入巨噬细胞,并增加抗结核药物的通透性。针对巨噬细胞胆固醇代谢途径的药物开发以及现有药物的修饰为开发更有效的抗结核药物提供了希望。