Obesity Alters the Course of Influenza Infections | TS Digest

From aiding in the construction of Fermilab to serving as valuable models of cystic fibrosis, ferrets have been on the frontlines of many scientific endeavors. Now, researchers have turned to ferrets to investigate the impact of obesity on influenza dynamics, both within and between individuals. In a new study in Science Advances, researchers identified differences in symptom severity and lung gene expression between normal weight and obese ferrets, providing clues about the mechanisms by which body composition might influence antiviral responses.¹

“We got interested in this because of the 2009 swine flu pandemic, where we saw for the first time, at least epidemiologically, that people who were overweight or obese were more likely to get severe disease,” said lead author Stacey Schultz-Cherry, who studies host-microbe interactions at St. Jude Children’s Research Hospital.

Schultz-Cherry’s team found that, in accordance with increased H1N1 symptom severity, obese ferrets had significantly higher viral titers in their lungs than their normal weight counterparts. Even before infection, lung tissues from obese animals showed increased expression of genes related to cell death and inflammation. During infection, obese ferrets upregulated some inflammatory factors, including interleukin-1, while downregulating some genes associated with antiviral response and lung tissue repair.  

Understanding how immune responses may be dysregulated in obesity is crucial for developing therapeutics to protect this high-risk group, said Schultz-Cherry. “I think it’s very naive on our part to assume that people are just going lose weight… So how can we do science that is modern, that really reflects our current population?”

“This is a great study,” said Aubree Gordon, an influenza researcher at the University of Michigan who was not involved in the study. “Influenza in obese individuals is a substantial problem…having an obese ferret model is incredibly useful for understanding the mechanisms of what’s happening, and hopefully once we understand the mechanism we can get better treatments.”