Klebsiella pneumoniae surface antigen

Klebsiella pneumoniae surface antigens are a collection of immunogenic molecules located on the bacterial exterior, primarily consisting of the capsular polysaccharide (K antigen), lipopolysaccharide (O antigen), and various outer membrane proteins (OMPs) (Podschun & Ullmann, 1998). These components are essential for the pathogen's survival and virulence within the host; the capsule acts as a protective shield against phagocytosis and complement-mediated lysis, while the O-antigen provides resistance to the bactericidal activity of serum (Bengoechea & Sa Pessoa, 2019). As therapeutic targets, these antigens are the focus of vaccine development and monoclonal antibody therapies designed to treat infections caused by multi-drug resistant (MDR) strains (Choi et al., 2020). For example, the monoclonal antibody AR-401 targets the O-antigen to promote opsonophagocytic killing by host immune cells (Aridis Pharmaceuticals). A significant challenge in targeting these antigens is their high structural diversity, particularly the existence of over 77 distinct K-serotypes, which requires the use of multivalent or broadly cross-reactive therapeutic agents (Vaxcyte, 2023).

Other names

Klebsiella pneumoniae antigensCapsular polysaccharide (K antigen)Lipopolysaccharide (O antigen)Outer membrane proteins (OMPs)K. pneumoniae surface components

Enhancement of opsonophagocytosis and neutralization of bacterial virulence factors