The role of Arginase 1 in alphavirus-induced arthritis, tenosynovitis, and myositis

An estimated 46 million people in the United States suffer from rheumatic diseases. These diseases are caused by combinations of a variety of genetic and environmental factors, including some viruses and other microbes. Although rheumatic diseases have different causes, they can all lead to painful and sometimes incapacitating inflammation of joints, muscles, and bones. In order to develop new treatment strategies, we need to learn how inflammation causes the symptoms of rheumatic diseases.

Chikungunya virus and Ross River virus are transmitted to humans by infected mosquitoes and cause fever and painful inflammation of joints, bones, and muscles that may last for months to years. These viruses can cause large epidemics of rheumatic disease and spread to new regions of the world. Dr. Morrison’s lab has developed novel mouse models to study the inflammatory disease caused by these viruses and he will use these models to learn how inflammation leads to damage of joints, muscles, and bones. In addition, these models will be used to test drugs that may treat these painful symptoms.

An important component in inflammation is the activation of cells of the immune system called macrophages. While certain types of activated macrophages may be good for some diseases, other types of activated macrophages can be harmful. Dr. Morrison will study how specific functions of macrophages are regulated during inflammation and how macrophage activation contributes to inflammatory arthritis. Because macrophages play a central role in inflammation, this research on virus-induced arthritis may lead to new ways to treat a wide range of human rheumatic diseases.