Experimental study on active specific immunotherapy utilizing the immune reaction of low-dose irradiated tumor tissue, 7

We have already reported the remarkable effect of the active specific immunotherapy utilizing cryopreserved tumor cells and infiltrating mononuclear cells prepared from a lowdose irradiated tumor tissue after cytoreductive radiotherapy. In the present study, the effect of a biological response modifier, PSK combined with this active specific immunotherapy was investigated. Twelve-week-aged female C3H/He mice transplanted with MM46 tumor cells were received local radiotherapy with the dose of 3,000 rads by high energy electron beam on the fifth day after tumor inoculation. This active specific immunotherapy was performed on the twelveth day, and daily dose of 200 mg/kg of PSK was injected intraperitoneally from the sixth day to the tenth day. The more inhibition of the tumor growth was observed in the group which received this active specific immunotherapy combined with a biological response modifier, PSK compared with that received this active specific immunotherapy alone. (author)