Photo Credit: iStock.com/Mohammed Haneefa Nizamudeen

Interleukin 15 (IL-15) represents a potential target for severe asthma, according to a study that examined whether specific T cell subsets impact asthma symptom duration. Richard Ramonell, MD, and colleagues published the findings in JCI Insight. They found a significant association between airway CD8+ effector memory T cells re-expressing CD45RA (TEMRAs) and asthma duration in severe asthma (SA), but not mild to moderate asthma (MMA). This association was not seen for CD8+ CD45RO+ or tissue-resident memory T cells. Higher frequencies of IFN-γ+ CD8+ TEMRAs compared with IFN-γ+ CD45RO+ T cells were observed in SA airways. Further, airway IL15 expression was higher in SA compared with MMA, “prompted by the transcriptomic profile of SA CD8+ TEMRAs and proliferative response to IL-15,” the researchers noted. IL15 expression in asthmatic airways negatively correlated with lung function. “Our findings add a new dimension to understanding asthma heterogeneity, identifying IL-15 as a potential target for treatment,” Dr. Ramonell and colleagues wrote.