Human T cell hybridomas secreting immune interferon.

Human T-cell hybridomas were established by hybridization of concanavalin A-stimulated human peripheral blood lymphocytes with a 6-thioguanine-resistant mutant cell line, designated SH9, derived by irradiation from a cloned human cutaneous T lymphoma line, Hut102-B2. High levels of interferon (IFN) were demonstrated in the supernatants of hybridoma L265 and its subclones. Whereas no IFN was detected in SH9 cell cultures, up to 1,330 units of IFN per ml were produced spontaneously by the hybrids. On induction with 12-omicron-tetradecanoylphorbol 13-acetate, IFN synthesis in hybridoma cultures was enhanced 8- to 16-fold. Neutralization with specific antisera and determination of antiviral activities in human and bovine cells showed that the IFN secreted by the hybridomas was immune IFN (IFN-gamma). Analysis of DNA content, karyotype, and cell surface phenotype, including T cell specific antigens and receptors, confirmed the T cell hybrid nature of L265 clones. No correlation was found in the hybridomas between IFN production and the expression of HTLV, a retrovirus released by Hut102-B2 and SH9 cells.