Department of Medicine, University of California, San Diego, La Jolla, CA, United States.
Department of Vascular Surgery, Changzheng Hospital, Shanghai, China.
Front Immunol. 2021 Mar 31;12:633639. doi: 10.3389/fimmu.2021.633639. eCollection 2021.
Phagocytes, which include neutrophils, monocytes, macrophages, and dendritic cells, protect the body by removing foreign particles, bacteria, and dead or dying cells. Phagocytic integrins are greatly involved in the recognition of and adhesion to specific antigens on cells and pathogens during phagocytosis as well as the recruitment of immune cells. β2 integrins, including αLβ2, αMβ2, αXβ2, and αDβ2, are the major integrins presented on the phagocyte surface. The activation of β2 integrins is essential to the recruitment and phagocytic function of these phagocytes and is critical for the regulation of inflammation and immune defense. However, aberrant activation of β2 integrins aggravates auto-immune diseases, such as psoriasis, arthritis, and multiple sclerosis, and facilitates tumor metastasis, making them double-edged swords as candidates for therapeutic intervention. Therefore, precise regulation of phagocyte activities by targeting β2 integrins should promote their host defense functions with minimal side effects on other cells. Here, we reviewed advances in the regulatory mechanisms underlying β2 integrin inside-out signaling, as well as the roles of β2 integrin activation in phagocyte functions.
吞噬细胞包括中性粒细胞、单核细胞、巨噬细胞和树突状细胞，通过清除外来颗粒、细菌和死亡或垂死的细胞来保护身体。吞噬细胞整合素在吞噬作用过程中对细胞和病原体上特定抗原的识别和黏附以及免疫细胞的募集起着重要作用。β2 整合素，包括 αLβ2、αMβ2、αXβ2 和 αDβ2，是吞噬细胞表面主要存在的整合素。β2 整合素的激活对于这些吞噬细胞的募集和吞噬功能至关重要，对于炎症和免疫防御的调节也至关重要。然而，β2 整合素的异常激活会加重自身免疫性疾病，如牛皮癣、关节炎和多发性硬化症，并促进肿瘤转移，使其成为治疗干预的双刃剑候选者。因此，通过靶向β2 整合素来精确调节吞噬细胞的活性，应该可以在对其他细胞产生最小副作用的情况下促进其宿主防御功能。在这里，我们综述了 β2 整合素内-外信号转导的调节机制的研究进展，以及 β2 整合素激活在吞噬细胞功能中的作用。
