Translocated intimin receptor (Tir) (Tir)

The Translocated intimin receptor (Tir) is a pivotal virulence protein utilized by attaching and effacing (A/E) pathogens, most notably Enteropathogenic Escherichia coli (EPEC) and Enterohemorrhagic Escherichia coli (EHEC) (UniProt: P09151). Unlike traditional host receptors, Tir is produced by the bacterium and injected directly into the host intestinal epithelial cell membrane via a type III secretion system (T3SS) (PMID: 9353126). Once integrated into the host membrane, Tir serves as the specific receptor for the bacterial outer membrane protein, intimin (PMID: 11346795). This Tir-intimin interaction triggers a cascade of host signaling events, including the recruitment of actin-modulating proteins that lead to the formation of actin-rich pedestals beneath the adherent bacteria (PMID: 15123611). These pedestals are essential for stable colonization and the effacement of microvilli, leading to severe diarrheal symptoms and, in the case of EHEC, potential systemic complications like hemolytic uremic syndrome (PMID: 25605758). Given its essential role in pathogenesis and its absence in human biology, Tir represents a highly specific target for anti-infective strategies, including vaccines and small-molecule inhibitors designed to disrupt bacterial adhesion (PMID: 21930754).

Other names

TirEspETranslocated intimin receptor protein

Blockade of the interaction between the bacterial intimin protein and the host-integrated Tir receptor to prevent stable attachment and pedestal formation (PMID: 11346795).