Matrix protein 2 ectodomain (M2e) (M2e)

The Matrix protein 2 ectodomain (M2e) is the highly conserved 24-amino acid N-terminal portion of the Influenza A virus M2 ion channel protein (UniProt P06821). While the full M2 protein is essential for viral uncoating and assembly by facilitating proton transport into the virion, the M2e region is exposed on the surface of the virus and infected cells (PubMed: 10523637). Because M2e remains remarkably stable across different human and avian influenza strains, it is a primary candidate for universal influenza vaccines and therapeutic antibodies (PubMed: 24503459). Therapeutic strategies targeting M2e, such as the monoclonal antibody TCN-032, primarily rely on Fc-mediated effector functions like antibody-dependent cellular cytotoxicity (ADCC) and phagocytosis to clear infected cells rather than direct neutralization (PubMed: 21441449). This target is particularly valuable for providing broad protection against seasonal and pandemic influenza outbreaks where traditional vaccines might fail due to antigenic drift or shift in hemagglutinin (PubMed: 19710353). Furthermore, M2e-based interventions are often designed as fusion proteins or conjugate vaccines to overcome the peptide's low natural immunogenicity (PubMed: 22235239).

Other names

M2eInfluenza A virus M2 protein ectodomainMatrix protein 2 extracellular domainM2 ectodomain peptide

Monoclonal antibodies and vaccine-induced antibodies targeting M2e primarily function through Fc-mediated effector mechanisms, including antibody-dependent cellular cytotoxicity (ADCC) and antibody-dependent cellular phagocytosis (ADCP), to eliminate virus-infected cells (PubMed: 21441449). Unlike antibodies against hemagglutinin, M2e-specific antibodies generally do not neutralize the virus directly but limit viral replication and spread by clearing the factories of viral production (PubMed: 19710353).