Dr. Urdahl’s research is focused on understanding immunity against Mycobacterium tuberculosis (Mtb) infection to inform the rational design of an effective vaccine. Working in the mouse model of tuberculosis (TB), his laboratory has recently discovered several barriers that restrict T cell-mediated immunity to Mtb in the lung. These include the inhibition of effector T cell priming by regulatory T cells, the failure of terminally differentiated IFN-?-producing T cells to migrate to the site of infection in the lung, and the functional exhaustion T cells that reside within the lung. Having discovered these barriers, our work now focuses on closing the gaps that limit the translation of this knowledge into an effective TB vaccine. We are working to improve the mouse TB model to better reflect human TB and to exploit this model to gain mechanistic insights and identify correlates of protective immunity. Key findings will be then be tested in the context of human TB.