[Experimental study on preventive effects of lung metastases using LAK cells induced from various lymphocytes--special references to enhancement of lung metastasis after laparotomy stress].

In 5 week-old female SD rats, ether anesthesia or laparotomy for 30 minutes was done, followed by iv inoculation of 1 x 10(6) MRMT-1 cells. On day 14, number of lung metastatic nodules was examined. Preventive effect of LAK cells on lung metastases was also observed. LAK cells were induced from regional lymph node lymphocytes (LN), thymus cells (TC) and spleen cells (SC) of the rats on day 7 after tumor inoculation by incubation with 1 micrograms/ml of R-IL2 (TGP-3) for 4 days. 1) Lung metastases were noted in 100% after MRMT-1 intravenous inoculation, while number of lung metastatic nodules was reduced after iv administration of LAK cells. 2) When MRMT-1 cells were inoculated intravenously after laparotomy stress for 30 minutes, number of lung metastatic nodules was significantly increased and LAK cells reduced it significantly. 3) When R-IL2 sc administration for 4 days was accompanied, number of lung metastatic nodules was less than that of without R-IL2 substitution. 4) The antitumor effect of LAK cells was the strongest in LN-LAK, while it was the weakest in SC-LAK. In conclusion, usefulness of LAK cells for preventing lung metastases by surgical stress was indicated. This fact suggested that possibility of adoptive immunotherapy using LAK cells might be useful for prevention of lung metastases after laparotomy.