Influenza virus matrix protein 2 ectodomain (M2e) (M2e)

The Influenza virus matrix protein 2 ectodomain (M2e) is a highly conserved 24-amino acid sequence located at the N-terminus of the M2 ion channel protein of Influenza A viruses (Schotsaert et al., 2016, PMID: 26796310). While the full M2 protein functions as a proton-selective ion channel essential for viral uncoating and assembly, the M2e region is exposed on the viral surface and is expressed at high levels on the surface of infected host cells (Pinto & Lamb, 2006, PMID: 16613775). Because M2e remains nearly unchanged across diverse human, avian, and swine influenza strains, it is a primary target for the development of universal influenza vaccines and broadly reactive monoclonal antibodies (Fiers et al., 2004, PMID: 15288710). Therapeutic strategies targeting M2e do not typically neutralize the virus directly; instead, they rely on Fc-receptor-mediated mechanisms, such as antibody-dependent cellular cytotoxicity (ADCC), to clear infected cells and reduce viral shedding (Simovic et al., 2016, PMID: 27692765). Clinical candidates like the monoclonal antibody TCN-032 have been investigated for their ability to provide broad-spectrum protection and reduce symptom severity during outbreaks (Ramos et al., 2015, PMID: 25336722). Despite its potential, M2e is naturally subdominant and requires conjugation to carrier proteins or potent adjuvants to elicit a robust and protective immune response (Neirynck et al., 1999, PMID: 10545910).

Other names

M2 ectodomainInfluenza A virus M2eMatrix protein 2 extracellular domainM2e antigen

Induction of antibody-dependent cellular cytotoxicity (ADCC) and antibody-dependent cellular phagocytosis (ADCP) to eliminate infected cells expressing M2e (Simovic et al., 2016, PMID: 27692765).