Respiratory viral infections represent a severe risk of morbidity and mortality to patients with chronic lung conditions, including emphysema and Chronic obstructive pulmonary disease (COPD), resulting in exacerbations that lead to the death of healthy lung tissue and making them one of the most frequent indications for hospital admissions.

According to research, the activation of T cell inflammation, which leads to lung destruction in a COPD exacerbation brought on by viral infection, is surprisingly mediated by lung fibroblasts. They found a fibroblast-secreted factor, HHIP, encoded by the COPD susceptibility gene that inhibits viral inflammation in the lung. Moreover, a T cell subset was discovered that could be targeted for treating COPD flare-ups.

The scientists showed that the absence of HHIP encourages tissue-resident T lymphocytes to multiply and accumulate in the lung, which results in the inflammatory death of resident lung stem cells.

Using high-definition single-cell sequencing of patient samples, the researchers identified a pathogenic T cell subgroup (Tissue Resident Lymphocytes) in human emphysema. In pre-clinical models of emphysema, they found that therapeutic targeting of these harmful T cells improves illness.

These findings provide crucial explanations for why some COPD patients are more prone to experience deteriorating COPD and offer a unique therapeutic strategy to slow COPD progression by restoring tissue components in the lung.

Experts believe that identifying a novel lung stem cell subset in human emphysema lungs vulnerable to these pathogenic T cells would increase the possibility of therapeutic targeting of these pathogenic T cells, ultimately leading to better disease management.

(Source: https://www.news-medical.net/news/20230224/Discovery-of-a-T-cell-subset-points-to-new-treatment-for-COPD-exacerbations.aspx)