ＢＣＧ経口投与によるがん免疫療法の実験的研究

Abstract

Among a variety of immunotherapeutic agents, BCG has been employed most popularl yagainst human cancer, and numerous therapeutic experiences have been accumulated, althoughgeneral conclusion is difficult to be reached regarding the therapeutic effects of BCG.The author, in cooperation with Dr. T. Tokunaga (N.I.H., Japan), attempted immunotherap ywith oral BCG against mouse and guinea pig tumors.Animals: dd Y, C57B L /6J and SWM/Ms, and Hartley/F and Strain 2 guinea pigs. Tumors: Ehrlich ascites tumor of dd Y, melanoma B 16 of C57 B L /6 J, fibrosarcoma H9A of Hartley/F, liposarcoma H10 of Hartley/F and Line-10 hepatocarcinoma of Strain 2. BCG (lyophilized;Japan BCG Lab) was administered once or twice a week at 80mg/guinea pig and 5mg/mouse, usually.1) Delayed type skin reaction or footpad reaction were measured with PPD at intervalsafter oral BCG. As controls, animals given single subcutaneous injection with BCG were tested.PPD reactions in animals given oral BCG were much weaker than parenteral BCG. 2) After oral BCG, viable BCG were isolated from Peyer's patch and mesenteric nodes in oral group. Onthe other hand, BCG were isolated from spleen and liver but not mesenteric nodes and Peyer'spatch in parenteral BCG group. 3) Some of Ehrlich tumors regressed spontaneousely when 10cells were inoculated intradermally (18.8%).The tumors in mice given oral BCG regressed athigher rate (54.5%). 4) No effect of oral BCG was shown against melanoma B 16, and hepatoma Line-10. 5) Some of liposarcoma H10 were not taken by Hartley/F, when inoculatedintradermally. However the rate of taking was much lower in guinea pigs given oral BCG.Mean survival length of the BCG group was longer than non-treated control. 6) Thirty threepercent of H9A tumor regressed in guinea pigs given oral BCG, while all grew progressivelyin non-treated control.As shown in reults, some therapeutic effects of oral BCG were indicated in some tumors, such as Ehrlich and H9A, but not in others, such as B16 and Line-10. Dissemination of viable BCG was limitted within Peyer's patch and mesenteric nodes. Obviously oral route is muchsafer than dermal route in terms of BCG infection. Pathologic exa mination of Peyer's patchafter oral BCG revealed that proliferation of both T and B cells and infiltration of macrophagesare remarkable in these areas. We may expect that oral BCG can augment some immunologic Mean survival length of the BCG group was longer than non-treated control.( 6) Thirty threepercent of H9A tumor regressed in guinea pigs given oral BCG, while all grew progressivelyin non-treated control.As shown in results, some therapeutic effects of oral BCG were indicated in some tumors, such as Ehrlich and H9A, but not in others, such as B 16 and Line-10. Dissemination of viable BCG was limitted within Peyer's patch and mesenteric nodes. Obviously oral route is muchsafer than dermal route in terms of BCG infection. Pathologic examination of Peyer's patchafter oral BCG revealed that proliferation of both T and B cells and infiltration of macrophagesare remarkable in these areas. We may expect that oral BCG can augment some immunologic tumor growths.