title: Enhancement of natural killer cell activity in mice by treatment with a thymic factor.
abstract: The administration of a thymic factor, thymostimulin (TP-1), to mice resulted in considerable augmentation of natural killer (NK) cell activity as measured in a short-term assay against 51Cr-labeled YAC-1 target cells. Conditions suitable for detection of the thymostimulin-induced boosting of NK included multiple daily exposures to TP-1 (50 micrograms/kg), and peak levels of reactivity were observed at 2-4 days after discontinuation of treatment. A strict age-dependency of the effect was also observed, with optimal augmentation of NK-cell activity when TP-1 was administered to mice at 4-6 weeks of age. The effect was not limited to TP-1 treatment but was also observed on administration of another thymic factor (thymosin alpha 1). The activated cells responsible for the increased natural cell-mediated cytotoxicity appeared to be typical murine NK cells, judging by both functional and antigenic criteria.
mesh_terms: D000367:Age Factors; D000818:Animals; D003165:Complement System Proteins / Q000494:pharmacology; D007106:Immune Sera / Q000494:pharmacology; D007694:Killer Cells, Natural / Q000276:immunology*; D008264:Macrophages / Q000276:immunology; D008297:Male; D051379:Mice; D009374:Neoplasms, Experimental / Q000276:immunology*; D010586:Phagocytes / Q000276:immunology; D000077596:Thymalfasin; D013947:Thymosin / Q000031:analogs & derivatives / Q000494:pharmacology; D013949:Thymus Extracts / Q000494:pharmacology*
chemical_list: D007106:Immune Sera; D013949:Thymus Extracts; C031407:thymostimulin; D013947:Thymosin; D003165:Complement System Proteins; D000077596:Thymalfasin