Abstract
The distribution of lymphocyte populations in peripheral blood and lymphoid tissue in ruminants was examined using a panel of monoclonal antibodies, flow cytometry, and immunohisto-chemistry. In ruminants, the continuous Peyer's patch was proposed as a primary lymphatic organ, with a function similar to that of the bursa of Fabricius in birds. Our findings suggested that the arthritis caused by caprine arthritis-encephalitis virus is due to a hyperresponsive cellular immunity of the cytotoxic and suppressor T cells in the synovial fluid, and N cells in the peripheral blood lymphocytes are a major component of the immune system in this arthritis. The CD8+ T cells may play an effector role in suppressing bovine leukemia virus growth in recombinant vaccinia virus-vaccinated animals. Lymphomas of enzootic bovine leukosis were demonstrated as tumors of mature B cells with common characteristics.
