title: Improved immunotherapy of a recombinant carcinoembryonic antigen vaccinia vaccine when given in combination with interleukin-2.
abstract: Interleukin-2 (IL-2) has been an effective immune modulator in several active-specific immunotherapy experimental protocols using either viral or oncolysate-based vaccines. In this report, data indicate that IL-2 administration can appreciably augment the therapeutic effect of a single immunization of a recombinant vaccinia virus-carcinoembryonic antigen (rV-CEA) vaccine using a CEA-expressing syngeneic experimental murine model system. A single rV-CEA immunization of C57BL/6 mice bearing palpable CEA-positive colon adenocarcinoma tumors results in complete tumor regression in approximately 20% of the mice. The addition of a course of low-dose IL-2 results in complete tumor regression in 60-70% of the mice. Moreover, the combination of rV-CEA and IL-2 induces systemic immunity, which protects those tumor-free mice from subsequent rechallenge with the CEA-expressing tumor cells. No such tumor regression or protection was observed in those mice immunized with the wild-type vaccinia vaccine (V-Wyeth) alone or with IL-2 administration alone. Cellular immune assays revealed that the addition of IL-2 to rV-CEA immunization significantly increased the CEA-specific T-cell proliferative responses as well as the cytolytic T-cell responses when compared with rV-CEA immunization alone. The enhanced CEA-specific immune response, coupled with the improved experimental therapeutic outcome following IL-2 administration, suggests that treatment with that cytokine may effectively substitute for multiple rV-CEA immunizations in active-specific immunotherapy clinical protocols directed at CEA-expressing tumors.
authors.affiliation: Laboratory of Tumor Immunology and Biology, National Cancer Institute, NIH, Bethesda, Maryland 20892, USA.
authors.forename: J P
authors.initials: JP
authors.lastname: McLaughlin
authors.forename: J
authors.initials: J
authors.lastname: Schlom
authors.forename: J A
authors.initials: JA
authors.lastname: Kantor
authors.forename: J W
authors.initials: JW
authors.lastname: Greiner
mesh_terms: D000276:Adjuvants, Immunologic / Q000494:pharmacology / Q000627:therapeutic use*; D000818:Animals; D000951:Antigens, Neoplasm / Q000276:immunology*; D002272:Carcinoembryonic Antigen / Q000276:immunology*; D003110:Colonic Neoplasms / Q000276:immunology / Q000473:pathology / Q000628:therapy*; D005260:Female; D006801:Humans; D016233:Immunotherapy, Active; D007376:Interleukin-2 / Q000494:pharmacology / Q000627:therapeutic use*; D051379:Mice; D008810:Mice, Inbred C57BL; D009368:Neoplasm Transplantation; D011993:Recombinant Fusion Proteins / Q000276:immunology*; D012900:Smallpox Vaccine / Q000008:administration & dosage* / Q000276:immunology / Q000627:therapeutic use; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology; D014407:Tumor Cells, Cultured; D014616:Vaccinia virus / Q000276:immunology*
chemical_list: D000276:Adjuvants, Immunologic; D000951:Antigens, Neoplasm; D002272:Carcinoembryonic Antigen; D007376:Interleukin-2; D011993:Recombinant Fusion Proteins; D012900:Smallpox Vaccine