Researchers are looking for the best ways to improve current therapies and advance research on ischemic stroke. Ischemic stroke occurs when a blood clot blocks or narrows an artery to the brain. A new study in mice by the University of Pittsburgh (Pitt) shows that a unique subset of white blood cells provides rapid-acting and lasting protection against ischemic stroke in mice.
Their findings are reported in the Clinical Research Journal in a newspaper titled “Neuroprotection against ischemic stroke requires a specific class of early responder T cells in mice.”
“Immunomodulation holds therapeutic promise against brain injury, but using this approach requires an accurate understanding of mechanisms,” the researchers wrote. “We report that CD8+CD122+CD49dlo T-regulatory-like cells (CD8+ TRLs) are among the earliest lymphocytes to infiltrate mouse brain after ischemic stroke and moderate inflammation; they also confer neuroprotection.”
“The great thing about CD8+TRLs is their quick response. They provide very powerful protection to the brain, which can last a long time,” said co-corresponding author Xiaoming Hu, MD, PhD, an associate professor of neurology at Pitt and a researcher with the U.S. Department of Veterans Affairs (VA). is that these cells are easily accessible because they circulate in the blood before entering the injured brain.”
“Creating shelf-stable and ready-to-use CD8+TRLs or developing a cocktail of neuroprotective signaling molecules that are released by those cells once they reach the brain could provide effective future therapies against stroke and offer hope to hundreds of thousands of ineligible patients.” for treatments currently available to them,” said co-senior author Jun Chen, MD, PhD, a professor of neurology at Pitt and a US Department of VA investigator.
The researchers showed for the first time that the CD8+TRLs enter the brain much faster than all other regulatory immune cells. Within 24 hours of researchers clearing these special CD8+TRLs from the bloodstream of stroke mice, the size of the ischemia-affected brain area increased by 50% compared to animals whose CD8+TRL levels remained intact.
The researchers also noted that mice that received a transfusion of purified CD8+TRLs prepared in the lab did better and recovered more quickly than those left untreated for more than five weeks.
“Despite the efforts of thousands of people dedicating their careers to finding treatments that could benefit stroke patients, the therapy options are minimal,” Chen said. “I’ve been working in this field for over 30 years, and this is the first time I feel like I’m seeing the light at the end of the tunnel, a promising future clinical translation that will benefit patients.”