title: A cytotoxic substance (CTS-51) produced by human buffy coat cultures stimulated by staphylococcal enterotoxin B: specificity to malignant cells and kinetics of action.
abstract: A unique cytotoxic substance (CTS-51), which is rather specific to malignant cell cultures in vitro, was found to be produced together with human immune interferon and interleukin-2 in buffy coat cultures stimulated with staphylococcal enterotoxin B. CTS-51, which is stable at 100 degrees and has a molecular weight of 8,000-10,000, was found to have biological properties distinct from those of known cytotoxic cytokines. CTS-51 was able to kill four human malignant cell lines at concentrations that did not affect normal or non-malignant cell lines. The mode of CTS-51 action was found to be cytotoxic rather than cytostatic. Several kinetic studies showed that the cell killing activity seemed to be dose-dependent, and the appearance of the activity required about 24 hr. The minimum effective exposure time of the target cells to CTS-51 also seemed to be dose-dependent.
mesh_terms: D002453:Cell Cycle; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects*; D002478:Cells, Cultured; D003603:Cytotoxins / Q000494:pharmacology*; D004768:Enterotoxins / Q000494:pharmacology*; D005347:Fibroblasts / Q000166:cytology; D006801:Humans; D007370:Interferon Type I / Q000494:pharmacology; D009369:Neoplasms / Q000473:pathology
chemical_list: D003603:Cytotoxins; D004768:Enterotoxins; D007370:Interferon Type I; C031818:enterotoxin B, staphylococcal