[Radiation effect on anti-tumor activity of C3H mouse spleen cells to MH134 hepatoma cells].
Tumor-specific immunity was induced in C3H mice by immunizing with syngeneic MH134 hepatoma cells. The radiation sensitivity of tumor-specific effector cells in the immunized spleen cells and that of non-specific effector cells in normal spleen cells were compared. The spleen cells, both immunized and normal, were irradiated in vitro, then mixed with the tumor cells. The anti-tumor activity of the cells was measured by Winn assay and by a cytostatic test in vivo with diffusion chambers, on the basis of growth inhibition of tumor cells. The growth of tumor cells was inhibited by immune spleen cells more effectively than by normal spleen cells. The anti-tumor activity of immunized and normal spleen cells decreased dose-dependently in the respective ranges of 2.5-20 Gy and 2.5-10 Gy irradiation. In the normal spleen cells, anti-tumor activity was mainly detected in the fraction of non-adherent cells, not in adherent cells. The anti-tumor activity of non-adherent cells was diminished with 2.5 Gy irradiation. These results indicated that the radio-resistance of anti-tumor effector cells in C3H mice was increased by immunization with syngeneic MH134 hepatoma cells. Based on these and other findings in this experimental system, we concluded that tumor-specific effector cells that were radiosensitive at 10-20 Gy might involve delayed-type hypersensitivity (DTH) effector cells (macrophages) and that non-specific effector cells that were radiosensitive at 2.5-10 Gy might involve natural killer cells and lymphokine-activated killer cells.
Nobusawa
H
H
Department of Radiology, School of Medicine, Showa University.
Hachisu
R
R
D000818:Animals; D016219:Immunotherapy, Adoptive; D015979:Killer Cells, Lymphokine-Activated / Q000276:immunology; D007694:Killer Cells, Natural / Q000276:immunology; D008114:Liver Neoplasms, Experimental / Q000276:immunology / Q000473:pathology* / Q000628:therapy; D008297:Male; D051379:Mice; D011836:Radiation Tolerance; D013154:Spleen / Q000166:cytology / Q000528:radiation effects*