Recent research published in the Proceedings of the National Academy of Sciences (PNAS) has shed light on why older adults are more susceptible to severe influenza infections. The study identifies a glycosylated protein known as apolipoprotein D (ApoD), which is produced at significantly higher levels in older individuals compared to their younger counterparts. This protein plays a role in lipid metabolism and inflammation, and its elevated presence has been linked to a diminished ability to fend off viral infections, leading to worse health outcomes.
The research team, comprising scientists from multiple institutions including China Agricultural University and the University of Nottingham, discovered that increased levels of ApoD in the lungs of older adults result in substantial tissue damage during influenza infections. This damage hampers the body’s antiviral response, particularly the production of type I interferons, which are crucial for fighting off viruses.
The study utilized an aging-mouse model and human tissue samples to explore the biological mechanisms contributing to the heightened severity of influenza in older patients. It was found that ApoD disrupts mitochondrial function—essential for energy production and immune response—by promoting mitophagy, thereby increasing viral replication and lung injury.
Given the global trend of an aging population, understanding these mechanisms is critical for healthcare strategies. The findings suggest that targeting ApoD could offer a therapeutic avenue to mitigate the severity of influenza infections among the elderly, potentially reducing related morbidity and mortality rates. Professor Kin-Chow Chang from the University of Nottingham emphasized the significance of this research, highlighting the opportunity to improve health outcomes for older adults facing influenza virus challenges.