Researchers are looking for the most effective methods to improve current treatments and advance research on ischemic stroke. Ischemic stroke occurs when a blood clot blocks or narrows an artery leading to the brain. A new experiment in mice by the University of Pittsburgh (Pitt) demonstrates that a unique subset of white blood cells provides rapid and lasting protection against ischemic stroke in mice.
In a paper titled, Neuroprotection against ischemic stroke requires a specific class of early responder T cells in mice, the authors are published in the Journal of Clinical Investigation.
Immunomodulation has demonstrated promise for brain injuries, but utilizing it requires a thorough understanding of mechanisms, according to the researchers. CD8+CD122+CD49dlo T regulatory-like cells (CD8+ TRLs) are among the first lymphocytes to infiltrate mouse brains after an ischemic stroke and temper inflammation, and they are also protective against neuroprotection.
The beauty of CD8+TRLs is their quick response. They provide excellent brain protection, which can last a long time, according to Xiaoming Hu, a co-author of the study. Most importantly, these cells are easily accessible because they circulate in the blood before entering the injured brain.
According to co-senior author Jun Chen, MD, PhD, professor of neurology at Pitt University and a VA investigator at the US Department of Veterans Affairs, developing CD8+TRLs that are shelf-stable and ready-to-use might be useful future treatments for stroke or provide hope to hundreds of thousands of patients who are currently ineligible for treatments.
For the first time, the CD8+TRLs penetrate the brain much more rapidly than any other regulatory immune cells. Within 24 hours after researchers eliminated these special CD8+TRLs from stroke mice's bloodstream, the size of the brain region affected by ischemia increased by 50%, compared to animals whose CD8+TRL levels remained constant.
Researchers also found that mice who received a transfusion of purified CD8+TRLs prepared in the lab performed better and recovered faster than mice who were untreated for more than five weeks.
Chen acknowledged that despite tens of thousands of individuals dedicating their careers to finding therapies that would benefit stroke patients, treatment options are limited. This is the first time I have felt that I am seeing the light at the end of the tunnel, promising future clinical translation that will benefit patients.