title: The immunization site of cytokine-secreting tumor cell vaccines influences the trafficking of tumor-specific T lymphocytes and antitumor efficacy against regional tumors.
abstract: Tumor cells engineered to secrete cytokines, referred to as tumor cell vaccines, can often generate systemic antitumor immunity and, in many cases, cause tumor regression. We compared the efficacy of s.c. immunization or intrahepatic immunization of GM-CSF-expressing tumor cell vaccines on the growth of s.c. or orthotopic liver tumors. A chemically transformed hepatic epithelial cell line, GP7TB, derived from Fischer 344 rats, was used to generate tumor models and tumor cell vaccines. Our results demonstrated that two s.c. injections of an irradiated tumor cell vaccine significantly controlled the growth of s.c. tumors, but was completely ineffective against orthotopic liver tumors. Effector cell infiltration in liver tumors was markedly reduced compared with s.c. tumors. Enhanced apoptosis of some effector cells was observed in the liver tumors compared with the s.c. tumors. Furthermore, the T cells induced by s.c. immunization preferentially migrated to s.c. tumor sites, as demonstrated by adoptive transfer experiments. In contrast, intrahepatic immunization, using parental tumor cells admixed with adenoviruses carrying the GM-CSF gene, yielded significantly better therapeutic effects on the liver tumors than on the s.c. tumors. Adoptive transfer experiments further confirmed that the T cells induced by liver immunization preferentially migrated to the liver tumor sites. Our results demonstrate that distinct T cell populations are induced by different immunization routes. Thus, the homing behavior of T cells depends on the route of immunization and is an important factor determining the efficacy of immunotherapy for regional tumors.
authors.affiliation: Graduate Institute of Microbiology, National Taiwan University College of Medicine, 7 Chung-Shan South Road, Taipei 10016.
authors.forename: Chun-Jung
authors.initials: CJ
authors.lastname: Chang
authors.forename: Kuo-Feng
authors.initials: KF
authors.lastname: Tai
authors.forename: Steve
authors.initials: S
authors.lastname: Roffler
authors.forename: Lih-Hwa
authors.initials: LH
authors.lastname: Hwang
mesh_terms: D000256:Adenoviridae / Q000235:genetics; D000818:Animals; D017209:Apoptosis / Q000276:immunology; D019496:Cancer Vaccines / Q000008:administration & dosage* / Q000276:immunology / Q000528:radiation effects / Q000627:therapeutic use; D002452:Cell Count; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000528:radiation effects; D016207:Cytokines / Q000378:metabolism*; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000008:administration & dosage / Q000276:immunology; D006131:Growth Inhibitors / Q000008:administration & dosage* / Q000276:immunology / Q000528:radiation effects / Q000627:therapeutic use; D016219:Immunotherapy, Adoptive / Q000379:methods*; D007279:Injections, Subcutaneous; D008099:Liver / Q000276:immunology / Q000473:pathology; D008114:Liver Neoplasms, Experimental / Q000276:immunology / Q000378:metabolism* / Q000473:pathology* / Q000517:prevention & control; D016246:Lymphocytes, Tumor-Infiltrating / Q000276:immunology* / Q000473:pathology; D008297:Male; D009368:Neoplasm Transplantation; D051381:Rats; D011916:Rats, Inbred F344; D012867:Skin / Q000276:immunology / Q000473:pathology; D013160:Splenic Neoplasms / Q000276:immunology / Q000473:pathology / Q000517:prevention & control
chemical_list: D019496:Cancer Vaccines; D016207:Cytokines; D006131:Growth Inhibitors; D016178:Granulocyte-Macrophage Colony-Stimulating Factor