Various measurable functions of the immune system show progressive dysfunction with advancing age. Increased vulnerability to infections is one aspect of this process. Experimental murine listeriosis will be employed as a model to investigate the effect of aging on the host capacity to acquire anti-microbial immunity. A systematic analysis of the age effect on the events in induction and expression of anti-microbial immunity will be performed. Host capacity to generate immunological specific memory as a function of age at the time of primary immunization and the rate at which it decays will be investigated. The effect of thymic function on the process of immunological aging will also be studied.
