Evidence for Tolerance to SV40 Tumor Antigen in Hamsters Bearing Para-Adenovirus 12 Tumor Transplants

[摘要] A study was carried out to determine why hamsters bearing PARA-12 tumor transplants made little or no humoral response to SV40 T antigen known to be present in the tumor cells. Experiments involving localized irradiation, partial surgery, or total excision of the tumor suggested that neither inadequate antigenic stimulation nor binding of antibody by tumor tissue was the explanation for the failure to detect T antibody. It was observed that tumor-bearing hamsters made a depressed antibody response to SV40 T antigen contained in another tumor line. Such animals, however, could make a normal antibody response to sheep red blood cells, indicating that there was no generalized immune depression. The administration of PARA-12 tumor tissue in Freund's complete adjuvant to normal hamsters led to the induction of antibody whereas the same immunization procedure in tumor-bearing animals yielded only a very weak or no response. The results indicate that the PARA-12 tumor-bearing hamsters did not make an immune response because they were tolerant to the SV40 T antigen. This tolerance was apparently dependent on the continued presence of the neoplasm because surgical removal of the tumor followed by appropriate immunization resulted in production of T antibody.

[学科分类] 生物科学（综合）