Bacterial O-antigen-specific antibody (None commonly used)

A **bacterial O-antigen-specific antibody** is an antibody—often developed as a recombinant monoclonal antibody—that binds to the O-antigen, a highly variable polysaccharide chain forming part of the lipopolysaccharide (LPS) molecule on the outer membrane of Gram-negative bacteria. O-antigen-specific antibodies recognize and attach to the unique carbohydrate moieties at the cell surface, enabling immune mechanisms such as opsonization, complement activation, and enhanced phagocytosis, all of which can result in clearance or killing of the bacteria. Antibodies targeting bacterial O-antigens are of particular therapeutic interest in the fight against multidrug-resistant infections due to their pathogen specificity and the ability, in some cases, to circumvent bacterial evasion of small-molecule antibiotics. However, wide diversity of O-antigens between and within bacterial species presents challenges for universal application and underlines the need for careful validation and patient stratification in clinical settings.

Other names

O-antigen-targeting antibodyAnti-O-antigen antibodyO-PS-specific antibody

Binding to bacterial surface O-antigen (O-polysaccharide of LPS), promoting opsonization and phagocytic clearance\nComplement activation and bactericidal activity\nEnhanced antibody-dependent cellular phagocytosis and serum sensitivity\nBlocking cell-surface interactions that mediate infection or immune evasion