分枝杆菌细胞壁脂质PDIM致病机制研究进展

 结核分枝杆菌(Mycobacterium Tuberculosis,MTB)是导致人和动物结核病的病原体。MTB细胞壁成分复杂,功能多样,不但帮助分枝杆菌抵御外界不良的生活环境,同时在细菌逃逸宿主免疫攻击和致病过程中也发挥重要作用。脂质占细胞壁干重的60%以上,其高含量与细菌毒力密切相关。MTB不含内毒素,也不产生外毒素和侵袭性酶类,其致病性主要与占细胞壁干重60%以上的脂质成分密切相关。PDIM(phthiocerol dimycocerosate)作为细胞壁组分中独特而重要的结构,在维持细菌正常结构上发挥重要作用。由于PDIM在细胞壁分布的广泛性,研究发现PDIM在病原体-宿主的相互作用过程中也扮演重要角色,尤其是在细菌的早期侵染及进入巨噬细胞环节中发挥积极作用。对PDIM重要致病和毒力损伤机制研究,不仅加深对病原体-宿主互作网络中的理解,还有望为结核病的治疗带来新的希望与突破。

Research Advances in the Pathogenesis of Mycobacterial Cell Wall Lipids PDIM

Mycobacterium Tuberculosis (MTB) is the pathogen that could induce severe contagious disease. The cell wall of MTB is complexed and composed of complicated components, such as lipids. The envelope of MTB is the high content of lipid, constituting up to 60% of the dry weight of mycobacteria. It has been demonstrated that the prominent role is played by mycobacterial lipids in pathogenesis, notably in tuberculosis. The most lipids are phthiocerol dimycocerosate (PDIM), which is an important cell wall lipid of pathogenic mycobacterium and it has been intensively studied since being shown to promote MTB virulence. Recent studies have suggested that PDIM play a role in cell wall permeability, modulating the early immune responses of murine macrophages, participating in both the receptor-dependent phagocytosis of Mtb and the prevention of phagosomal acidification. However, its cellular and molecular mechanisms of action still remain unknown. Thus, research on the pathogenicity of PDIM not only is helpful to understand the interaction between bacterium and host cell, but also brings a new hope and a breakthrough for the TB treatment.