title: In vivo activity of spleen cells from untreated syngeneic mice against Ehrlich ascites carcinoma.
abstract: Inbred CFW/L1 or BALB/c male mice were injected intraperitoneally with 1 X 10(5) EAC cells. They died in 98.6 or 100%, respectively, within 100 days of observation. Intraperitoneal injection of 6 X 10(7) syngeneic spleen cells from 6--9-week-old CFW/L1 or BALB/c donors 2.5--4 h after tumour inoculation significantly prolonged MST and 16.7 or 23.5% of mice, respectively, survived for 100 days. Smaller amounts of spleen cells, thymus cells, mixed spleen and thymus cells, or spleen cells from older donors did not show this effect. Homogenized spleen cells were also inactive. Antitumour activity of spleen cells was still evident when they were isolated from irradiated (2 000R) donors or were given 24 h after tumour inoculation. Spleen cells used for in vivo studies showed spontaneous cytotoxic activity in vitro against EAC cells in the 51Cr-release cell-mediated cytotoxicity test. The possible participation of NK cells in the observed in vivo antitumour activity of normal spleen cells is discussed.
mesh_terms: D000818:Animals; D002286:Carcinoma, Ehrlich Tumor / Q000276:immunology* / Q000401:mortality; D003602:Cytotoxicity, Immunologic; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D013154:Spleen / Q000276:immunology* / Q000528:radiation effects; D013950:Thymus Gland / Q000276:immunology