title: Human T cell hybridomas producing cytotoxic lymphokines: induction of lymphotoxin release and killer cell activity by anti-CD3 monoclonal antibody or lectins and phorbol ester.
abstract: Human T cell hybrids were constructed between lectin-activated peripheral blood lymphocytes and CEM.TET1, a variant of the CEM T lymphoblastoid cell line. Hybrids were screened for their ability to produce cytotoxic lymphokines and interleukin-2 (IL-2) following lectin activation. Five hybrids were identified that released significant levels (greater than 75 units/ml) of cytotoxic activity that was detected on the murine L929 target cells; three hybrids were identified that produced IL-2. Cell surface phenotype of the T cell hybrids did not correlate with their ability to produce these lymphokines. The II-23 hybrid (CD3+;4+) produced an inducible cytotoxic activity that was fully neutralized by anti-lymphotoxin antibodies. The release of lymphotoxin (LT) rapidly attained maximum levels 12 hrs to 24 hrs after lectin activation; IL-2 production was maximum at 48 hrs. The induction of LT and IL-2 release required similar membrane stimulating agents. The phorbol ester, phorbol 12-myristate 13-acetate (PMA) in combination with phytohemagglutinin or concanavalin A, were required for maximal release of LT and IL-2. Anti-CD3 monoclonal antibodies coupled to agarose, but not anti-T200-agarose, induced the release of high levels of LT and IL-2. Soluble anti-CD3 was not sufficient to induce IL-2 or LT release from the II-23 hybrid; however, soluble anti-CD3 combined with PMA was a strong stimulus for lymphotoxin and IL-2 release. The II-23 hybrid also functioned as a cytotoxic T cell line in a 51Chromium release assay. Induction of killer cell function required similar perturbation of Ti/CD3 complex. This human T cell hybrid line offers an inducible model system for the simultaneous study of the molecular events regulating the production of growth inhibitory/cytotoxic (LT) and growth promoting (IL-2) lymphokines and cytotoxic T cell function.
mesh_terms: D000911:Antibodies, Monoclonal / Q000276:immunology; D000920:Antibody-Dependent Cell Cytotoxicity; D000945:Antigens, Differentiation, T-Lymphocyte; D000954:Antigens, Surface / Q000276:immunology; D006801:Humans; D006825:Hybridomas / Q000276:immunology; D037102:Lectins / Q000494:pharmacology; D008233:Lymphotoxin-alpha / Q000378:metabolism*; D013601:T-Lymphocytes / Q000276:immunology; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
chemical_list: D000911:Antibodies, Monoclonal; D000945:Antigens, Differentiation, T-Lymphocyte; D000954:Antigens, Surface; D037102:Lectins; D008233:Lymphotoxin-alpha; D013755:Tetradecanoylphorbol Acetate