Porin A (PorA) protein (Neisseria meningitidis serogroup B, subtype P1.4) (PorA P1.4)

Porin A (PorA) is a major class 1 outer membrane protein of Neisseria meningitidis, functioning as a trimeric porin that facilitates the passive diffusion of small hydrophilic nutrients across the outer membrane (UniProt: P0A305). It is highly immunogenic and serves as a primary target for protective antibodies, making it a critical component in the development of serogroup B meningococcal vaccines (PubMed: 11553240). The P1.4 designation refers to a specific variant of the variable region 2 (VR2) loop, which is a dominant epitope for bactericidal antibodies. Vaccines such as Bexsero incorporate outer membrane vesicles (OMV) from strains expressing the P1.4 subtype to provide targeted protection against prevalent pathogenic lineages (PubMed: 22244431). Because PorA is subject to significant antigenic drift, vaccine efficacy is often limited to strains sharing the same PorA subtype, necessitating the inclusion of multiple antigens or specific regional variants in vaccine formulations (PubMed: 15103084).

Other names

Class 1 outer membrane proteinPorin APorAP1.4 antigenMajor outer membrane protein P1

Induction of serum bactericidal antibodies (SBA) that trigger complement-mediated lysis of the bacterium upon binding to the PorA surface loops.