Type 1 fimbriae D-mannose specific adhesin (FimH) (FimH)

FimH is a critical bacterial adhesin located at the tip of type 1 fimbriae in Escherichia coli, particularly uropathogenic (UPEC) and adherent-invasive (AIEC) strains (UniProt P08191). It functions as a lectin that specifically recognizes and binds to D-mannosylated glycoproteins, such as uroplakin Ia on the bladder epithelium and CEACAM6 in the intestinal mucosa (PMC7058522). This binding is essential for bacterial colonization, invasion, and the formation of intracellular bacterial communities, which contribute to persistent and recurrent infections (MDPI Molecules 2020). FimH is a prominent therapeutic target for urinary tract infections (UTIs) and Crohn's disease, with drug development focusing on small-molecule mannosides like Sibofimloc and GSK3882347 (PMC10664142). These inhibitors act by blocking the mannose-binding pocket, thereby preventing bacterial attachment without necessarily killing the bacteria, which may reduce the selective pressure for antibiotic resistance. Additionally, FimH exhibits a unique catch-bond mechanism where its binding affinity increases under mechanical shear stress, a property that is vital for resisting host clearance mechanisms like urine flow (PMC7058522).

Other names

FimH adhesinProtein FimHType 1 fimbrinMannose-binding lectin FimH

FimH antagonists competitively bind to the mannose-binding lectin domain of the FimH protein, preventing the bacteria from adhering to mannosylated receptors on host epithelial cells, thereby inhibiting colonization and infection.