title: Conversion of specific to nonspecific cytotoxic T lymphocytes.
abstract: The type of cytotoxic T lymphocyte (CTL) generated during a mixed leukocyte culture has been shown to depend on the purity of interleukin 2 (IL 2) used to stimulate growth. Antigen-specific CTL requiring both antigen and IL 2 to proliferate or express cytotoxicity (designated Type I in this work) are generated and maintained with highly purified IL 2. In the presence of IL 2 alone, they persist in a quiescent, noncytotoxic state, and on its removal they rapidly die. A second type of CTL (Type II), of nonspecific cytotoxicity, and dependent only on IL 2 for growth, is generated by exposure to an impure lymphokine preparation containing IL 2. Type I cells are T lymphocytes which are nongranular and nonadherent, whereas Type II cells are larger, adhere to plastic, and contain many granules. Cloned Type I cells are converted to Type II under three conditions: by low levels of IL 2 in the presence of a crude lymphokine preparation; by high levels of IL 2 in the presence of antigen; or by high levels of IL 2 in the presence of the phorbol diester PMA. Conversion results from an effect of the growth conditions on individual cells, and not from selection of a minor population.
mesh_terms: D000818:Animals; D002455:Cell Division / Q000187:drug effects; D003602:Cytotoxicity, Immunologic / Q000187:drug effects; D004357:Drug Synergism; D006801:Humans; D007376:Interleukin-2 / Q000494:pharmacology; D007519:Isoantigens / Q000276:immunology; D007959:Lymphocyte Culture Test, Mixed; D051379:Mice; D008815:Mice, Inbred Strains; D011994:Recombinant Proteins / Q000494:pharmacology; D013602:T-Lymphocytes, Cytotoxic / Q000166:cytology* / Q000187:drug effects / Q000276:immunology; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
chemical_list: D007376:Interleukin-2; D007519:Isoantigens; D011994:Recombinant Proteins; D013755:Tetradecanoylphorbol Acetate