The human immune response has two general features: a fast-acting, innate immune system, and a slower, but more specific, adaptive immune system. Recent work by Dr. Cooper has indicated that a major cell of the innate response, the natural killer cell, has the ability to exhibit a form of immunologic “memory.” Immunologic memory means that a cell works better in the present if it was activated in the past; this memory is the basis for the long-term protection provided by vaccinations. It was once thought that immunologic memory was strictly limited to the adaptive immune system. Now, however, the discovery of memory in natural killer cells indicates its role in the innate immune system as well. Natural killer cells are vitally important components of immunity in children and adults. They help to control viral and bacterial infections and they may also play a role in protecting against the development of autoimmune diseases like juvenile rheumatoid arthritis (JRA). As a Faculty Scholar, Dr. Cooper will explore the properties of natural killer cells' memory response, and determine the mechanisms by which this response can be enhanced. Her long-term goals are to develop a better understanding of this critical component of the immune system, potentially leading to improved treatment strategies for children with immune disorders. For example, Dr. Cooper’s research may suggest ways to enhance natural killer cell memory responses—and so strengthen the immune system—in children with HIV-infection, premature infants, or pediatric patients with JRA and other chronic autoimmune diseases.