Chronic IL-21 Exposure Reshapes Pulmonary Environment, Elevating Risk Of Respiratory Diseases
Our lungs are constantly working, and their internal environment, or “pulmonary environment,” is crucial for keeping us healthy. This research sheds light on how a specific immune signaling molecule, called Interleukin-21 (IL-21), can significantly impact lung health over time.
The study found that when the lungs are exposed to high levels of IL-21 for extended periods, it triggers a cascade of changes. It creates a “pro-inflammatory state,” meaning there’s an increase in inflammation, driven by various signaling molecules like TNF-α and IL-6. This chronic inflammation can be damaging to lung tissues.
Furthermore, this prolonged IL-21 exposure leads to “cellular senescence,” which is essentially cells getting old and dysfunctional prematurely. It also alters the behavior of important immune cells called macrophages, which are responsible for cleaning up debris and fighting infections. These macrophages start accumulating fats, and their ability to respond effectively is compromised.
Perhaps most concerning, the research shows that chronic IL-21 exposure weakens the lung’s “antiviral responses,” making it harder for the body to fight off viral infections. This is because key components for recognizing and combating viruses, like MHC-II expression and IFN-α production, are reduced.
These findings are particularly significant because the changes observed in the lungs due to IL-21 exposure closely resemble those seen in naturally aging lungs and in individuals suffering from a severe and progressive lung disease known as Idiopathic Pulmonary Fibrosis. This suggests that elevated IL-21 levels might be a key factor driving lung dysfunction in older individuals and contributing to serious respiratory conditions.
Source: link to paper