Influenza A virus matrix protein 2 extracellular domain (M2e)

The Matrix protein 2 extracellular domain (M2e) is a highly conserved 24-amino acid sequence located at the N-terminus of the Influenza A virus M2 protein. While the full-length M2 protein functions as a pH-activated ion channel essential for viral uncoating within host endosomes and the subsequent release of the viral genome, the M2e domain is exposed on the surface of both the virion and infected host cells (UniProt P06821; PubMed: 29315353). Because M2e has remained nearly invariant across diverse Influenza A strains for decades, it is a premier target for the development of 'universal' influenza vaccines and broad-spectrum monoclonal antibodies (PubMed: 30733301). Unlike traditional flu vaccines that target the rapidly mutating head of the hemagglutinin protein, M2e-targeted therapies aim to provide cross-protection against multiple subtypes, including seasonal and pandemic strains, by inducing immune-mediated destruction of infected cells through mechanisms like antibody-dependent cellular cytotoxicity (PubMed: 25479008).

Other names

M2 extracellular domainM2e peptideMatrix protein 2 N-terminal domainInfluenza A M2e

Antibodies targeting M2e primarily act through antibody-dependent cellular cytotoxicity (ADCC) and antibody-dependent cellular phagocytosis (ADCP) to eliminate infected cells; small molecule inhibitors like amantadine block the M2 proton channel pore to prevent viral uncoating.