## What is the danger of the over-activity of white blood cells? During pneumonia caused by a bacterial infection, cells of the immune system — [white blood cells](https://ul.orna.me/KOge/librarybiomarker?id=166) — migrate to the lungs and fight off pathogens. To enhance this process, the patient receives antibiotics. But in some cases, the body is immune to them, and then the [lymphocytes](https://ul.orna.me/KOge/librarybiomarker?id=135) cause "concomitant damage" in the lung tissue, attacking the body's own cells. If this process doesn’t stop in time, it can lead to chronic pneumonia and partial or complete loss of a person's ability to breathe on their own. ## The findings It is widely known that at the very beginning of the inflammatory response in the lungs, as in the case of other organs, [platelets](https://ul.orna.me/KOge/librarybiomarker?id=83) work together with neutrophilic granulocytes, a subset of white blood cells that specialize in fighting pathogens. However, for the first time, a team of scientists has proven that as inflammation progresses, platelets bind to T cells and migrate with them to the site of inflammation. Upon arrival, they work together to release anti-inflammatory substances. Then the white blood cells stop attacking the body, which helps reduce inflammation and prevents further tissue damage. ## Evidence base The study found that the interaction between platelets and white blood cells — regulatory T cells — plays a significant role in resolving inflammation. And if you act on these connections, enhancing and accelerating their formation, it is possible to stop inflammation — even with a low response of the body to an antibiotic. Since the study was experimental, it was carried out in mice, and only after the recognition of the results by the scientific community will it be possible to conduct clinical trials in humans. However, scientists are confident that this will happen in the near future. “When treating patients with acute pulmonary disease, we are very limited in the measures we can take to support lung function. Basically, it all comes down to fighting off pathogens with antibiotics,” explains Ian Rossite. These recent studies have laid the foundation for a new approach to treating pneumonia. __Sources__: Jan Rossaint et al, Platelets orchestrate the resolution of pulmonary inflammation in mice by T reg cell repositioning and macrophage education, Journal of Experimental Medicine (2021). DOI: 10.1084 / jem.20201353