Lewis b histo-blood group antigen (Le(b))

The Lewis b histo-blood group antigen (Le(b)) is a complex carbohydrate structure found on the surface of epithelial cells, particularly in the gastric mucosa, and in secretions like saliva [Marionneau S, et al., 2001, PMID: 12084972]. It is synthesized through the sequential action of fucosyltransferases, specifically the products of the FUT2 (Secretor) and FUT3 (Lewis) genes [IUPAC-IUB Joint Commission on Biochemical Nomenclature]. Biologically, Le(b) serves as a critical attachment site for various pathogens, most notably Helicobacter pylori, which utilizes its BabA adhesin to bind specifically to the Le(b) motif [Borén T, et al., 1993, PMID: 8259514]. This interaction is a primary factor in the colonization of the human stomach, leading to chronic inflammation, peptic ulcers, and an increased risk of gastric adenocarcinoma [Aspholm-Hurtig M, et al., 2004, PMID: 15273394]. Beyond H. pylori, Le(b) also acts as a receptor for certain strains of Norovirus and Rotavirus [Tan M, Jiang X., 2005, PMID: 15935300]. Therapeutic strategies targeting Le(b) focus on anti-adhesion molecules, such as glycomimetics or decoy oligosaccharides, which aim to block pathogen binding and facilitate clearance. Because Le(b) expression depends on an individual's genetic 'secretor' status, it also serves as a significant biomarker for susceptibility to specific gastrointestinal infections.

Other names

Lewis b antigenLe(b) antigenBlood group Lewis bFuc-alpha-1,2-Gal-beta-1,3-(Fuc-alpha-1,4)-GlcNAc

Competitive inhibition of pathogen adhesins, specifically the BabA protein of Helicobacter pylori, to prevent bacterial attachment to the gastric mucosa.