Influenza A virus nucleoprotein (NP) and matrix protein 1 (M1) (NP/M1)

Influenza A virus nucleoprotein (NP) and matrix protein 1 (M1) are highly conserved internal structural proteins essential for the viral life cycle. NP is a major component of the viral ribonucleoprotein (vRNP) complex, responsible for encapsidating the viral RNA and facilitating replication and transcription (UniProt P03466). M1 acts as a scaffold, linking the vRNP to the viral envelope and playing a critical role in viral assembly, budding, and the nuclear export of genetic material (UniProt P03485). Unlike the surface proteins hemagglutinin and neuraminidase, which undergo frequent antigenic drift, NP and M1 exhibit high sequence conservation across different influenza A subtypes. This conservation makes them primary targets for “universal” influenza vaccines, such as OVX313 and FLU-v, which aim to induce cross-reactive T-cell mediated immunity (PubMed: 30733131). While small molecule inhibitors like Nucleozin have been explored to disrupt NP oligomerization, the most prominent clinical focus remains on utilizing these proteins as antigens to provide broad-spectrum protection against diverse influenza strains.

Other names

Nucleocapsid proteinMatrix protein M1Influenza A NPInfluenza A M1vRNP components

Induction of cross-reactive T-cell mediated immunity against conserved internal viral proteins and inhibition of viral ribonucleoprotein assembly or nuclear export.