Influenza A virus particles strategically adapt their shape—to become either spheres or larger filaments—to favor their ability to infect cells depending on environmental conditions, according to a new study from National Institutes of Health (NIH) scientists. This previously unrecognized response could help explain how influenza A and other viruses persist in populations, evade immune responses, and acquire adaptive mutations, the researchers explain in a new study published in Nature Microbiology.
The study, led by intramural researchers at NIH’s National Institute of Allergy and Infectious Diseases (NIAID), was designed to determine why many influenza A virus particles exist as filaments. The filament shape requires more energy to form than a sphere, they state, and its abundance has been previously unexplained. To find the answer, they developed a way to observe and measure real-time influenza A virus structure during formation.