Establishment of a cell line from leucocytes of a cow with chronic lymphocytic leukemia

A cell line was established from blood leucocytes of a cow with chronic lymphocytic leukemia. The leucocytes were cultured with conditioned medium (culture fluid of mouse cell line L). In vitro cell transformation was demonstrated by adaptation to permanent growth, modification of cell morphology, the alteration of cell surface phenotype, kinetic behaviour and the loss of the euploid stability of the cell karyotype. Ultrastructural studies showed rather a uniform cell pattern in a culture population heterogeneous for degree of cell vacuolization. A wide variation in the expression of surface markers in cells was demonstrated by E-, EA- and EAC-rosetting. In suspension culture the cell population was found to be sIg negative. Expression of leukemia-associated antigens by a fraction of the cultured cells was evidenced by a cytotoxic technique using complement and heterologous antisera against bovine leukemic lymphocytes, absorbed with normal lymphoid cells. Virus-like particles and BLV antigens were not identified. Culture cells failed to show spontaneous or antibody-dependent killer cytotoxicity. Comparison with blood lymphocytes of healthy and leukemic cattle was done. The established culture should be useful as a model for experimental immunology and oncology.