This Is MS Multiple Sclerosis Community: Knowledge & Support

HONG KONG, Aug 3 (Reuters) - Scientists have identified a class of immune cells that floods the brain soon after a stroke, causing inflammation and more neurological damage.

In their experiment, Yoshimura and his colleagues induced a stroke in several groups of mice and observed how the subsequent flood of immune cells caused inflammation and more damage.

One of the first groups of immune cells to enter the brain is called interleukin-23 (IL-23).

"IL-23 itself is not harmful, but it activates other immune cells like T-cells and macrophages and these attack the brain. This same sort of activation occurs when the body is invaded by microbes and during any sort of injury," Yoshimura said.

The mice that suffered the least brain damage were those genetically engineered to be deficient in IL-23.

"IL-23 operates immediately after stroke or one day later ... so the sooner the intervention (blocking of IL-23) happens, the more protective it is for the brain," he said.

The experts hope to apply the findings of the study, published in Nature Medicine, on people.