Herpesvirus saimiri immortalized gamma delta T cell line activated by IL-12

IL-12 is a novel heterodimeric cytokine important for the regulation and differentiation of lymphocytes and NK cells. Like other cytokines, IL-12 mediates its biologic activity through high-affinity receptors expressed on responsive cells. To date, a large number of receptors for IL-12 have been found only on PBMC following activation with PHA or IL-2. To gain further knowledge of the IL-12R complex and the IL-12 signal transduction pathway in cytotoxic T cells, we studied a number of human T cell lines that had been transformed to permanent growth with Herpesvirus saimiri, an oncogenic virus of nonhuman primates. This paper reports the expression of IL-12R on a human gamma delta T cell line that responds to IL-12 with enhanced cytolytic activity and increased expression of cytolytic effector molecules granzyme B and perforin. Using these T cells as a model of IL-12 signal transduction, we confirmed that these events involve members of the Janus kinase family of nonreceptor tyrosine kinases JAK2, TYK2, and signal transducer and activator of transcription 4.