title: Functionally distinct human T cell clones that produce lymphokines with IL-2-like activity.
abstract: Various functionally distinct human T cell clones derived from in vitro mixed leukocyte cultures are found to secrete lymphokines with detectable Interleukin-2 (IL-2)-like activity upon antigenic stimulation. These lymphokine producing clones are not only dependent on exogenous growth factors provided in the form of crude phytohemagglutinin (PHA)-induced spleen conditioned medium for growth but can themselves be driven to proliferate by their own lymphokines. The induction of lymphokine production appears to be antigen-specific and the lymphokines secreted are believed to contain nonantigen and nonspecies specific IL-2-like activity. We show here that IL-2-like lymphokines are produced by a subset of T lymphocyte clones, i.e., the help-independent cytotoxic T cells clones that have the capacity to proliferate to, as well as to lyse, the original sensitizing cells. In addition, other T cell clones capable of producing active lymphocytes include those clones that have the T helper cell characteristics, i.e., can undergo antigen-induced proliferation but are not cytotoxic; in the presence of lectin (PHA), however, some helper T cells (Th) but not others, can express lectin-dependent cell-mediated lysis. Finally, yet another subset of T lymphocytes, the help-dependent cytotoxic T cell clones that cannot proliferate to antigenic stimulation, was found to produce no detectable IL-2-like activity.
mesh_terms: D002999:Clone Cells / Q000276:immunology; D003602:Cytotoxicity, Immunologic; D000939:Epitopes; D006801:Humans; D007376:Interleukin-2 / Q000096:biosynthesis* / Q000502:physiology; D007519:Isoantigens / Q000276:immunology; D037102:Lectins / Q000494:pharmacology; D008213:Lymphocyte Activation; D007959:Lymphocyte Culture Test, Mixed; D013601:T-Lymphocytes / Q000276:immunology*; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology
chemical_list: D000939:Epitopes; D007376:Interleukin-2; D007519:Isoantigens; D037102:Lectins