Research progress on the interactions between Treponema pallidum adhesion proteins and host cells

Treponema pallidum (Tp) has an outer membrane that encircles the periplasmic space, the peptidoglycan, cytoplasmic membrane, and protoplasmic components. The low abundance of lipopolysaccharides and transmembrane proteins enable it to conceal itself and to exert robust capabilities for tissue invasion and immune escape. Adhesion-mediated colonization plays a significant role in the pathogenesis of syphilis caused by Tp. In vitro studies have shown that Tp can adhere to cells of humans and other mammals, with a preference for interacting with specific molecules on certain cell surfaces, thereby influencing the invasion, pathogenicity and immune escape of Tp. This review summarizes how adhesion proteins of Tp interact with various host cells to trigger invasion and infection, and overviews their role in syphilis pathogenesis, aiming to offer significant insights for research into etiology, vaccine development, and the discovery of novel therapeutic agents for syphilis.