T and B lymphocytes in persistent lymphocytic and leukemic cattle.

The frequencies of T and B lymphocytes were studied in 15 cattle with enzootic bovine leukosis (EBL), four with persistent lymphocytosis (PL) and two with sporadic bovine leukosis (SPL) of thymic lymphosarcoma (TLS). T lymphocytes were identified by the indirect immunofluorescent antibody technique using rabbit anti-bovine thymocyte serum and B lymphocytes by the surface immunoglobulin immunofluorescence assay. There were 70.5-76.7% B lymphocytes included in the tumor, peripheral blood lymphocytes(PBL), lymph nodes and spleen of EBL cattle; T lymphocytes were in the range of 14.4-21.2%. The PBL in PL cattle showed much higher frequencies of B lymphocytes than normal cattle as in the case of EBL cattle. In TLS cattle, T lymphocytes accounted for 79.0-97.6% of the cells in the tumor, PBL, lymph nodes and spleen and the B lymphocytes for 2.6-15.8%. These results suggest that the tumor cells of EBL originate from B lymphocytes, and those of TLS from T lymphocytes, respectively.