Lytic function of bovine lymphokine-activated killer cells from a normal and a malignant catarrhal fever virus-infected animal.

Lymphokine-supplemented long-term cultured bovine lymph node lymphocytes were characterized functionally and phenotypically. Lymphocytes from a normal and a malignant catarrhal fever (MCF) virus-infected animal were maintained without the addition of antigen or feeder cells. Lymphocyte cell lines obtained from both animals: (i) killed allogeneic fibroblasts and allogeneic and xenogeneic cultured tumor cell lines as measured in a 4-h 51Cr release assay, (ii) expressed the same T cell subset marker based on flow cytometry using monoclonal antibodies, and (iii) produced a lytic factor upon stimulation. In contrast, only cells from the MCF virus-infected animal could be maintained for more than 5 months supplemented with 2% Con A-generated lymphokine-containing supernatant. These results suggest that herpesvirus infection enhanced the proliferative capabilities of the cultured lymphocytes from the infected animal. Considering the proliferative and cytotoxic activity together with the T cell phenotype, these data indicated that effector cells are lymphokine-activated killer cells.