Neisseria meningitidis outer membrane protein PorA and associated surface proteins (PorA)

Neisseria meningitidis outer membrane protein PorA (Porin A) is a major class 1 surface protein that functions as a cation-selective porin, facilitating the diffusion of small hydrophilic solutes across the outer membrane (UniProt: P0A316). It is a primary target for the host immune system and serves as the foundational component of outer membrane vesicle (OMV) vaccines, which are particularly vital for preventing Serogroup B meningococcal disease where the polysaccharide capsule is poorly immunogenic (PubMed: 19471315). Because PorA is highly antigenically variable, modern vaccine strategies often combine OMV-derived PorA with other conserved surface proteins, such as Factor H binding protein (fHbp), Neisserial adhesin A (NadA), and Neisserial Heparin Binding Antigen (NHBA), to ensure broader strain coverage (PubMed: 22939021). These associated proteins play critical roles in bacterial survival by mediating adhesion to host cells and inhibiting the alternative complement pathway (PubMed: 21239671). Therapeutic intervention via OMV-based vaccines aims to elicit high titers of serum bactericidal antibodies that trigger complement-mediated killing and opsonophagocytosis of the pathogen (EMA: Bexsero Assessment Report).

Other names

Porin AClass 1 outer membrane proteinOMP PorAMeningococcal PorAOuter membrane vesicle antigens4CMenB antigens

Induction of serum bactericidal antibodies that facilitate complement-mediated lysis and opsonophagocytosis of Neisseria meningitidis.