Martin Schwemmle: Decoding Pandemic Influenza Viruses

Decoding Pandemic Influenza Viruses

Influenza A viruses (IAVs) primarily circulate in wild waterfowl but can occasionally spread to other species, including humans. Although most zoonotic IAV infections in humans are limited to individuals, pandemics can occur when zoonotic viruses acquire adaptations that enable them to overcome human-specific host barriers. A major barrier for zoonotic IAVs is the interferon-induced innate immune factor Mx1 (MxA in humans). Notably, IAV can escape MxA restriction through adaptive amino acids in the viral nucleoprotein. Martin Schwemmle will present findings that recapitulate the evolutionary adaptation processes by which the 1918 and 2009 pandemic viruses overcame the antiviral activity of MxA. He will also shed light on the strategies employed by pre-pandemic influenza A viruses (IAVs) to suppress the innate immune response required to achieve MxA resistance. Finally, he will demonstrate that IAV host species expressing antivirally active Mx1 proteins, such as bats, exert strong selective pressure on circulating viruses, driving their evolution toward partial or even complete MxA resistance in NP. Together, these insights provide a framework for assessing the zoonotic risk posed by newly emerging IAVs.