Dr. North’s research is directed understanding innate and acquired mechanisms of immunity to tuberculosis and other bacterial infections. Current research emphasizes the use of animal models of tuberculosis to determine the molecular and cellular basis of immunity to this disease on the one hand, and to reveal the mechanisms that enable the tuberculosis bacterium to avoid destruction by this immunity on the other. An understanding of this disease from the point of view of the bacterium, as well as the host, is required for the rational vaccine design.
Recent research has revealed, for example, that although a susceptible host generates immunity against this disease, the tuberculosis bacterium changes its molecular makeup as part of a counter response to neutralize the immunity. Whether the bacterium’s counter response can be overcome by higher levels of immunity is being investigated.
Other TB research is aimed at determining whether one of the key anti-TB drugs depends on host immunity for its sterilizing action. The results obtained thus far show that it does, thus making it likely that the drug is of limited usefulness in treating people whose immune systems are severely compromised by AIDS.