Neisseria meningitidis Porin A (PorA)

Neisseria meningitidis Porin A (PorA) is a major class 1 outer membrane protein that functions as a cation-selective channel, facilitating the transport of small hydrophilic molecules across the bacterial membrane (UniProt: P0A316). It is a primary target for vaccine development, particularly against serogroup B meningococci, which lack a protective polysaccharide capsule suitable for vaccination (PubMed: 22939900). PorA is highly immunogenic and induces the production of bactericidal antibodies that provide protective immunity through complement-mediated killing (PubMed: 11514318). In clinical practice, PorA is often delivered via outer membrane vesicles (OMVs), which serve as both the antigen carrier and a natural adjuvant, as seen in the Bexsero vaccine (FDA: Bexsero Label). However, the high degree of sequence variation in the surface-exposed loops of PorA (VR1 and VR2) necessitates the use of specific serosubtypes in regional vaccines to ensure coverage against local circulating strains (PubMed: 15106084). The efficacy of PorA-targeting vaccines is typically measured using the serum bactericidal activity (SBA) assay, which correlates with clinical protection (PubMed: 12117948). Despite its effectiveness, the strain-specific nature of PorA-induced immunity remains a significant challenge for global vaccine design (PubMed: 18410492).

Other names

Class 1 outer membrane proteinMeningococcal Porin APorA proteinnmpA

Active immunization inducing the production of bactericidal antibodies that target PorA variable regions, leading to complement-mediated lysis of Neisseria meningitidis.