Division of Pulmonary and Critical Care Medicine, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA.
Division of Gastroenterology, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA.
Trends Microbiol. 2022 Apr;30(4):390-402. doi: 10.1016/j.tim.2021.09.002. Epub 2021 Sep 29.
The complement system has historically been entertained as a fluid-phase, hepatically derived system which protects the intravascular space from encapsulated bacteria. However, there has been an increasing appreciation for its role in protection against non-encapsulated pathogens. Specifically, we have an improved understanding of how pathogens are recognized by specific complement proteins, as well as how they trigger and evade them. Additionally, we have an improved understanding of locally derived complement proteins, many of which promote host defense. Moreover, intracellular complement proteins have been identified that facilitate local protection and barrier function despite pathogen invasion. Our review aims to summarize these advances in the field as well as provide an insight into the pathophysiological changes occurring when the system is dysregulated in infection.
补体系统一直被认为是一种液相关的、肝脏来源的系统，它可以保护血管内空间免受囊膜细菌的侵害。然而，人们对它在抵抗非囊膜病原体中的作用的认识也在不断提高。具体来说，我们对病原体如何被特定的补体蛋白识别，以及它们如何触发和逃避这些蛋白有了更好的理解。此外，我们对局部产生的补体蛋白也有了更好的理解，其中许多蛋白促进宿主防御。此外，已经鉴定出细胞内补体蛋白，它们可以在病原体入侵的情况下促进局部保护和屏障功能。我们的综述旨在总结这一领域的这些进展，并深入了解当该系统在感染中失调时发生的病理生理变化。
