Dr. J. Nikolich-Zugich’s laboratory is interested mainly in two lines of research: 1) investigations on the biology of cytotoxic T-lymphocytes and their role in the normal organism, during aging and infectious process, and 2) investigations on immunosenescence and development of methods of its correction. J. Nikolich-Zugich’s laboratory studies caloric restriction as a way to improve T-cell functioning during an immune response in long-lived animals. Research on long-lived primates showed that the number of naive T-cells and the diversity of their receptors increased in animals put on caloric restriction diet. Moreover, decreased production of inflammatory cytokines indicated that the number of old memory T-cell also went down. Thus, caloric restriction can rejuvenate senescent immune system of primates leading to decrease in the number of memory T-cells in the common pool.