title: Inhibitory and stimulatory effect of spleen cells from tumour bearing animals on the growth of syngeneic tumour cells.
abstract: When spleen cells from C3H mice inoculated with a primary spontaneously arisen C3H mammary carcinoma were added to tumour target cells of the same type in vitro, both an inhibitory and a stimulatory effect on target cell growth were seen, when compared with the effect of adding normal syngeneic spleen cells. The inhibitory effect was seen regularly when high concentrations of spleen cells were added, while there was a stimulatory effect when low concentrations were added to the tumour target cells. When transferring spleen cells from tumour bearing mice together with a tumour inoculum to groups of normal syngeneic recipients, the resultant tumour growth was enhanced, as compared with recipients given tumour plus normal spleen cells and those given tumour cells only. It was found that the spleen cells which caused the greastest enhancement in vitro caused the greatest inhibition in vitro. This relationship could be explained by assuming the occurrence in spleens of tumour bearers of a population of reactive cells which when added in high concentrations to tumour target cells in vitro cause inhibition, while they cause stimulation of tumour growth in vivo because of being transferred to recipients in relatively low concentrations.
mesh_terms: D000818:Animals; D002455:Cell Division; D003602:Cytotoxicity, Immunologic; D007700:Kinetics; D008214:Lymphocytes / Q000276:immunology*; D008325:Mammary Neoplasms, Experimental / Q000276:immunology* / Q000473:pathology; D051379:Mice; D013154:Spleen / Q000166:cytology