CD4+ tissue-resident memory T cells may trigger severe, and potentially fatal, asthma attacks in men aged 40 years and older.
Results from the WATCH study that analyzed the symptoms and immune cell activity of patients with asthma uncovered a group of immune cells called cytotoxic CD4+ tissue-resident memory T cells that gather in the lungs and may trigger severe asthma. Men who develop asthma later in life were shown to have an overwhelming amount of these cells in their lungs, with more than 65% found to be harmful cells.
"If you are male and you develop asthma after age 40, there's a high chance this T cell population is in your lungs," said study co-leader Gregory Seumois, PhD, research assistant for LJI, in a press release.
These cytotoxic CD4+ tissue-resident memory T cells react to molecules that the body previously fights off; however, these specialized T cells also view harmless molecules as dangerous, producing an inflammatory response. Patients with asthma who have these cells may be more likely to have hard-to-treat asthma attacks due to the general therapies that dampen immune response being ineffective on these cells, potentially leading to fatal asthma attacks.
"Once you understand the role of cells like these T cells better, you can start to develop treatments that target those cells," said WATCH study director Ramesh Kurukulaaratchy, MD, associate professor at the University of Southampton and researcher at the National Institute for Health Research (NIHR), Southampton Biomedical Research Centre, in the press release.
Single-cell RNA sequencing have helped provide a biomarker to detect cytotoxic CD4+ tissue-resident memory T cells in more patients in the future. In addition to the 2 subgroups, T2 high and T2 low, prior research showed the importance of identifying more subgroups in patients with asthma to aid in biomarker detection. Going forward, the researchers note that they want to begin using sequencing tools as well as other techniques to discover additional biomarkers and asthma patient subtypes.
“We have to think of severe asthma as having different subtypes, and the treatment has to be tailored according to these subtypes because one size does not fit all,” study co-author Hasan Arshad, MBBS, DM, FRCO, chair in Allergy and Clinical Immunology at the University of Southampton, researcher at NIHR Southampton Biomedical Research Centre, and director of The David Hide Asthma and Allergy Research Centre, Isle of Wight, said in the press release.
University of Southampton. Specialized T cells may trigger severe asthma attacks in older men. News release. October 23, 2023. Accessed November 8, 2023. https://www.eurekalert.org/news-releases/1005555