Joanne Turner, PhD

One-third of the world's population is infected with M. tuberculosis, the germ that causes tuberculosis. However, only a small portion of those individuals will actually develop active infectious disease. This discrepancy is due to the ability of M. tuberculosis to persist within the body for many years in a form often referred to as latency.

In some people this persistent infection is followed by a period of active bacterial growth that produces symptoms of disease and the ability to transmit M. tuberculosis to others. This form of infection is called reactivation. The ability to predict those people who will reactivate their infection would provide a valuable tool that could lead to early detection and treatment of TB, before the onset of symptoms and transmissible infection.

Dr. Turner used an American Lung Association Career Investigator Award to identify immunological markers that change before TB is reactivated. She compared two strains of mice: one susceptible to TB reactivation, and one resistant. Both strains were infected with M. tuberculosis. She found a specific marker in the blood that is indicative of poor disease outcome, and also reflects what is happening in the TB-infected lung. She is continuing this research to identify markers in the blood that not only identify who is likely to reactivate their infection, but can be used to determine when they will reactivate.

One such immune marker is a protein called IL-10.She is studying the role of IL-10 in TB disease progression, to identify the way in which the protein influences the immune response during infection. The ultimate goal is to identify pathways that can be manipulated to prevent reactivation of M. tuberculosis infection, thus reducing transmission.

Dr. Turner's American Lung Association-funded research led to a larger grant from the National Institutes of Health that allowed her to continue and expand her research. Her goal is to use the data she has gathered from mouse studies to transition into research on M. tuberculosis infection in humans. She hopes to be able to develop new diagnostic tests that will indicate a person's risk for reactivation of TB.