Escherichia coli O2 O-antigen (E. coli O2 O-antigen)

The Escherichia coli O2 O-antigen is a surface-exposed polysaccharide component of the lipopolysaccharide (LPS) molecule found on the outer membrane of specific E. coli serotypes (Poolman & Wacker, 2016). It is a critical member of the Extra-intestinal Pathogenic E. coli (ExPEC) group, which is frequently associated with severe infections such as urinary tract infections (UTIs), urosepsis, and neonatal meningitis (Frenck et al., 2019). The O-antigen acts as a major virulence factor by providing a physical barrier that protects the bacterium from host immune defenses, including complement-mediated killing and phagocytosis (Huttner et al., 2017). Due to its high prevalence in clinical isolates and its accessibility on the bacterial surface, the O2 O-antigen is a primary target for prophylactic vaccines, such as the multi-valent ExPEC conjugate vaccines like ExPEC9V (JNJ-64400141), and experimental monoclonal antibodies (Janssen, 2023). These therapeutic strategies aim to elicit or provide opsonophagocytic antibodies that facilitate the clearance of the pathogen by the host's immune system. Targeting this specific antigen allows for a precision medicine approach to preventing invasive E. coli disease caused by one of the most common serotypes globally.

Other names

O2 antigenE. coli O2 LPSO2-specific polysaccharideEscherichia coli serogroup O2 O-antigen

Active immunization to induce opsonophagocytic antibodies (OPAs) that bind the O2 antigen, facilitating phagocytosis and killing by neutrophils (Frenck et al., 2019).