A collaborative study has found a new way to selectively block the ability of white blood cells to 'crawl' toward the sites of injury and infection when such mobility drives disease.
According to researchers, the findings suggest a new treatment approach for autoimmune diseases like rheumatoid arthritis, lupus and multiple sclerosis, and for conditions made worse by misplaced inflammation, like atherosclerosis, stroke and transplant rejection.
Human cells migrate as part of complex bodily functions like immunity. For instance, disease fighting cells for instance move toward bacteria and cells infected with viruses, which they target for destruction.
Unfortunately, the same cells can mistakenly attack the body's own cells or drive inflammation too far, worsening the problem they rushed in to solve.
Researchers at the University of Rochester Medical Center have been studying proteins called integrins that enable T cells, a major subset of immune cells, to migrate.
The integrin-related mechanisms suggest a way to shut down only those T cells currently in the act of disease-related migration, while leaving in place reserves needed in the likely event that another infection occurs during treatment.
Making the mechanistic discoveries possible was a successful effort by the researchers to capture on video the first detailed images of fast-migrating T cells and the behaviour of key proteins related to migration, which had been tagged with fluorescence.
"There are many cases where it would be incredibly useful to precisely block integrin activation, and thus T cell migration," said Minsoo Kim, Ph.D., assistant professor of Microbiology and Immunology within the David H. Smith Center for Vaccine Biology and Immunology at the Medical Center, and lead author of the article.
There are two mechanisms that make cell migration, or programmed directional movement, possible.
The first migratory mechanism is chemotaxis, which tells the T cells, named after the thymus (T) where they mature, which direction to move in.
The second is propulsion. In between infections and injuries, inactive T cells ride along with the bloodstream. T cells 'realize' when they pass by part of a blood vessel wall close to the site of an injury or infection.
The study is published in The Journal of Experimental Medicine.