Neisseria meningitidis serogroup B outer membrane vesicle proteins (MenB OMV)

Neisseria meningitidis serogroup B outer membrane vesicles (OMVs) are spherical nano-sized structures naturally released from the bacterial surface, containing a mosaic of lipids and outer membrane proteins (OMPs) such as Porin A (PorA). PorA is a major integral membrane protein that acts as a selective channel for nutrient uptake and is a primary target for the host immune system during infection (UniProt: P0A316). Because the serogroup B polysaccharide capsule mimics human antigens and is poorly immunogenic, OMVs are utilized as a vaccine platform to present OMPs in their native conformation to the immune system (PubMed: 24140138). These proteins, particularly PorA, elicit high titers of serum bactericidal antibodies (SBA) which facilitate complement-mediated lysis of the bacteria (PubMed: 15507154). OMV-based vaccines have been successfully deployed to control regional outbreaks, such as the MeNZB vaccine used in New Zealand. Modern formulations like the 4CMenB vaccine (Bexsero) combine OMVs with recombinant proteins to broaden the range of protected strains (FDA: Bexsero). Despite their efficacy, the significant antigenic diversity of PorA across different MenB strains remains a challenge, as antibodies against one PorA subtype may not protect against others. Safety profiles for OMV-containing vaccines generally show higher reactogenicity, including fever and injection site reactions, compared to other vaccine types. Monitoring vaccine effectiveness often involves measuring hSBA titers, which serve as a correlate of protection against invasive disease (CDC: Meningococcal Disease).

Other names

Porin APorAClass 1 outer membrane proteinOuter membrane protein AOMPMenB OMV component

Induction of serum bactericidal antibodies (SBA) that facilitate complement-mediated lysis and opsonophagocytosis of Neisseria meningitidis serogroup B.