Studies of the mechanisms for the induction of in vivo tumor immunity. VI. Induction of specific and nonspecific cell-mediated immunity in tumor-bearing hosts and its correlation with transplantation tumor immunity
Ting, C.C.; Rodrigues, D.; Nordan, R.
Cellular Immunology 66(1): 45-58
1982
ISSN/ISBN: 0008-8749 PMID: 6177420 DOI: 10.1016/0008-8749(82)90156-3
Accession: 068629153
Cell-mediated cytotoxic response at tumor site was studied in C57BL/6 mice bearing progressively growing [mouse] FBL-3 ascites leukemia. The effectors isolated from tumor ascites are highly cytotoxic for leukemia target cells. The levels of cytotoxicity obtained with effectors isolated from the tumor site are generally higher than those obtained with immune mice. This cytotoxicity is both specific and nonspecific. The specific cytotoxicity against tumor-associated antigen is mainly mediated by T cells and the nonspecific cytotoxicity against unrelated tumor cells is mediated largely by macrophages. The T cell-enriched preparation did not give significant natural killer activity. When testing the ability of these effectors to produce in vivo immunity against the challenge of FBL-3, only T cells could confer the transplantation-type immunity, but the immunity was transient. The macrophage-enriched preparation isolated from tumor ascites failed to give in vivo protection. In an FBL-3 system, mice with progressively growing tumors apparently are able to develop immune response against tumor cells. This immunity is probably interfered with by a suppressor factor(s) or suppressor cells which restrict their activity to eliminate the tumor cells effectively.