This course investigates the immunological mechanisms that enable vertebrates to respond to foreign substances, and examines the experimental observations upon which current concepts are based. The underlying course theme is understanding interactions between pathogens and host immune responses, and the continuing evolution of this competition that leads to health or disease. The course provides a thorough treatment of the molecular and cellular aspects of both innate and adaptive systems. The course concludes with discussion of the physiological consequences of an immune response, certain clinical manifestations of immune reactivity, and how our understanding of immune mechanisms has been applied to clinical and public health problems. 3 class hours and 3 laboratory hours a week for one semester. In addition to quizzes and examinations, presentations of assignments and of a recent research paper that deals with a topic of current interest are required. (Offered every Spring.) Prerequisites: BIOL 3413 and either one additional area B course or CHEM 3330.