Halting immune response could save brain cells after stroke

March 13, 2014

A new study in animals shows that using a compound to block the body's immune response greatly reduces disability after a stroke.

The study by scientists from the University of Wisconsin School of Medicine and Public Health also showed that particular immune cells – CD4+ T-cells produce a mediator, called interleukin (IL) -21 that can cause further damage in tissue. Moreover, normal mice, ordinarily killed or disabled by an ischemic stroke, were given a shot of a compound that blocks the action of IL-21. Brain scans and brain sections showed that the treated mice suffered little or no .

"This is very exciting because we haven't had a new drug for stroke in decades, and this suggests a target for such a drug," says lead author Dr. Zsuzsanna Fabry, professor of pathology and laboratory medicine.

Stroke is the fourth-leading killer in the world and an important cause of permanent disability. In an , a clot blocks the flow of oxygen-rich blood to the brain. But Fabry explains that much of the damage to brain cells occurs after the clot is removed or dissolved by medicine. Blood rushes back into the brain tissue, bringing with it immune cells called T-cells, which flock to the source of an injury.

The study shows that after a stroke, the injured brain cells provoke the CD4+ T-cells to produce a substance, IL-21, that kills the neurons in the blood-deprived tissue of the brain. The study gave new insight how stroke induces neural injury.

Fabry's co-author Dr. Matyas Sandor, professor of pathology and laboratory medicine, says that the final part of the study looked at from people who had died following ischemic strokes. It found that CD4+ T-cells and their protein, IL-21 are in high concentration in areas of the damaged by the stroke.

Sandor says the similarity suggests that the protein that blocks IL-21 could become a treatment for stroke, and would likely be administered at the same time as the current blood-clot dissolving drugs.

"We don't have proof that it will work in humans," he says, "but similar accumulation of IL-21 producing suggests that it might."

Graduate student Benjamin S. D. Clarkson and scientist Changying Ling were key members of the UW research team, as was Dr. Dandan Sun, formerly of the UW neurosurgery department and now at the University of Pittsburgh, and Dr. Vijay Kuchroo, of the Harvard Medical School.

The paper was published this week in the Journal of Experimental Medicine.

Explore further: New stroke treatments becoming a reality

More information: jem.rupress.org/content/early/2014/03/03/jem.20131377.full

Related Stories

New stroke treatments becoming a reality

July 26, 2012

Scientists led by the President of The University of Manchester have demonstrated a drug which can dramatically limit the amount of brain damage in stroke patients.

Peritoneal dialysis as an intervention for stroke patients

September 3, 2013

Ischemic stroke is characterized by an interruption of the blood supply to the brain, which can lead to brain damage and even death. Excess amounts of the excitatory neurotransmitter glutamate are released during stroke events ...

Slowing down the immune system when in overdrive

February 10, 2014

Many people suffer from chronic inflammation because their immune systems overreact to 'self' tissue. Sydney scientists believe that a small molecule known as Interleukin 21 is a promising therapeutic target in such cases.

Recommended for you

Researchers grow retinal nerve cells in the lab

November 30, 2015

Johns Hopkins researchers have developed a method to efficiently turn human stem cells into retinal ganglion cells, the type of nerve cells located within the retina that transmit visual signals from the eye to the brain. ...

Shining light on microbial growth and death inside our guts

November 30, 2015

For the first time, scientists can accurately measure population growth rates of the microbes that live inside mammalian gastrointestinal tracts, according to a new method reported in Nature Communications by a team at the ...

Functional human liver cells grown in the lab

November 26, 2015

In new research appearing in the prestigious journal Nature Biotechnology, an international research team led by The Hebrew University of Jerusalem describes a new technique for growing human hepatocytes in the laboratory. ...

Gut microbes signal to the brain when they are full

November 24, 2015

Don't have room for dessert? The bacteria in your gut may be telling you something. Twenty minutes after a meal, gut microbes produce proteins that can suppress food intake in animals, reports a study published November 24 ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.