Protective Protein Prevents Immune System from Ravaging Joints and Bones
Researchers at Northwestern University Feinberg School of Medicine have discovered why the immune cells of people with rheumatoid arthritis become hyperactive and attack the joints and bones. The immune cells have lost their bouncer, the burly protein that keeps them in line the same way a bouncer in a nightclub controls rowdy patrons.
The Feinberg School team has identified this bouncer, a protein called P21, which prevents immune cells from launching into their destructive rampage through the cartilage and bone. When the scientists developed and injected an imitation of the protein into an animal model of rheumatoid arthritis, the disease process was halted.
“The bouncer molecule stopped the immune cells from going crazy,” said lead author Harris Perlman, associate professor of rheumatology at Northwestern’s Feinberg School. “Imagine destructive customers in a bar, and the bouncer says, ‘You are going to behave!’ That’s P21. This discovery opens up a new avenue for future therapies, which are greatly needed for rheumatoid arthritis.”
Previous research by the Feinberg team showed people with rheumatoid arthritis were low in P21, but the protein’s role was unknown. The new study, which will be published in the journal Arthritis & Rheumatism, reveals the protein’s vital role in keeping the immune cells in check.
Currently, there is no effective, nontoxic way to stop the hyperactive immune cells, Perlman said.
