The overall objective is to utilize chronic lymphatic drainage to investigate the kinetics of cell-mediated and humoral mechanisms of immunological reactions which play a role in host-virus interactions at the level of the local lymph node. Work will be primarily on determining the kinetics and magnitude of antibody-mediated resistance in the local lymph following an inoculation of parapox virus and determining the nature, kinetics, and magnitude of cell-mediated resistance in the local lymph following viral inoculation. The specificity of antibody responses and general changes in the numbers and morphology of cells leaving the responding lymph node during an immune response will be tested with related parapox viruses (Milker's nodule virus and bovine papular stomatitis). Vaccinia virus has been used in studies in other species and therefore will be included for the sake of comparison. The refinement of cell-mediated cytotoxicity assays will continue and comparisons will be made between activity in peripheral blood leukocytes and efferent lymph lymphocytes from a responding lymph node.