Anyone who has overcome a bout of the flu or received a vaccination can appreciate the essential, protective role of the immune system. Yet, the simple idea of an individual’s ability to protect itself from foreign agents becomes exponentially more complex when studied at a cellular and molecular level. MMI immunology faculty are no strangers to the labyrinthine world of cells, molecules, and signaling pathways that act in our defense. Some of our faculty focus on broadly applicable immunological phenomena such as the contribution of NKT cell autoreactivity to tolerance, the regulatory role of gamma delta T cells, or mechanisms of leukocyte migration. Other MMI immunology faculty study host-pathogen relationships, often in the context of reliably adapted animal models. The development and efficacy of Blastomyces dermatitidis and Borrelia burgdorferi vaccines, the contribution of innate and adaptive cellular responses to resistance in African trypanosomiasis, and the manipulation of innate immune cells by Toxoplasma gondii constitute a few of the research foci within the context of specific infectious diseases.