Trained Lung Cells Show Promise in Reducing Inflammation and Preventing Acute Lung Injury
Excessive inflammation in the lungs can be fatal, and many COVID-19 deaths have been attributed to this complication. However, a team of researchers from the University of Illinois Chicago has made a groundbreaking discovery that could help combat this issue. Their study reveals that certain lung cells can be trained to reduce inflammation and prevent acute lung injury, offering hope for future treatments.
The researchers focused their investigation on lung immune cells called alveolar macrophages. These cells have the ability to remove cellular debris, ingest harmful bacteria, and release anti-inflammatory proteins, effectively counterbalancing inflammation in the lungs. Remarkably, these cells can be trained by an initial infection to become even more efficient in handling subsequent infections.
To test their theory, the scientists injected these trained cells into mice and observed the results after an infection with pneumonia. The findings were remarkable – the trained cells helped the mice survive the infection by reducing inflammation. This suggests that these trained cells could potentially be used in cell therapy to prevent excessive inflammation in humans as well. The study has been published in the Journal of Experimental Medicine.
The researchers discovered that after the initial exposure to a bacterial toxin, the alveolar macrophages were able to mitigate the severity of inflammation caused by a second exposure to the toxin one week later. Interestingly, this beneficial effect was still evident even when the second exposure occurred a month later. Dr. Jalees Rehman, the senior author of the study and head of the UIC Department of Biochemistry and Molecular Genetics, explained that this memory or training phenomenon exhibited by the cells is a key factor in their ability to reduce acute lung injury.
One of the notable abilities of these trained cells is their effectiveness in removing post-infection debris, such as cellular debris from immune cells and damaged tissue. Dr. Rehman emphasized the importance of clearing out this debris, as its persistence can trigger the immune system to continue reacting, leading to increased inflammation. Moreover, since this debris is not specific to a particular type of infection, the trained macrophages could potentially reduce the risk of acute lung injury from different diseases.
Alveolar macrophages are unique cells that are present in our lungs from birth and persist into adulthood. While they die during infections, they can regenerate from surviving alveolar macrophages. Additionally, they pass on epigenetic information to their cellular progeny, allowing new macrophages to retain a memory of previous infections. This combined ability makes them highly effective in mitigating acute lung injury.
The researchers also noted the potential of training macrophages in other organs or directly increasing the levels of molecules involved in debris removal. This could open up avenues for further study and potential therapies. Dr. Rehman, who is also a member of the University of Illinois Cancer Center, emphasized the need for future research to explore these possibilities.
Although this study focused on mice, the implications for human health are significant. The discovery of these trained lung cells offers hope for the development of therapies that can reduce inflammation and prevent acute lung injury in patients. As more research is conducted in this area, it is expected to have a profound impact on our ability to combat the devastating effects of excessive inflammation in the lungs.
