title: Tumor cells expressing anti-CD137 scFv induce a tumor-destructive environment.
abstract: For immunotherapy to become more effective, there is a need to maximize the antitumor response at the tumor site as well as to eliminate tumor cell variants that lack a given tumor antigen or the ability to present it. We have previously shown that wild-type (WT) cells from the K1735 melanoma (K1735-WT) are rejected following vaccination with cells (K1735-1D8) transfected to express scFv from the anti-CD137 monoclonal antibody 1D8, and that CD4(+) T cells and natural killer (NK) cells are needed for this rejection. We now show that tumors harvested 4 to 10 days after mice had been transplanted with K1735-1D8 cells or a mixture of K1735-1D8 and K1735-WT cells contained more NK cells and that they had an increased percentage of CD4(+) T lymphocytes producing IFNgamma or tumor necrosis factor-alpha. We further show that the percentage of NK cells was higher in B16-1D8 melanomas expressing anti-CD137 scFv than in the WT tumors and that the percentage of FoxP3(+) cells was lower. Admixture of 10% K1735-1D8 cells prevented the progressive growth of transplanted K1735-WT cells in syngeneic mice and also of cells from the antigenically different sarcoma Ag104. Inhibition of WT tumor cells by tumor cells transfected to express anti-CD137 scFv was shown also with the TC1 carcinoma and B16 melanoma. Furthermore, injection of an adenovirus vector, Ad-1D8, which encodes anti-CD137 scFv into established B16 melanomas, significantly prolonged the survival of tumor-bearing mice and could induce regression. Our data suggest that targeting of anti-CD137 scFv to tumors should be explored for therapy for some human cancers.
authors.affiliation: Department of Pathology, University of Washington, Harborview Medical Center, 325 Ninth Avenue, Seattle, WA 98109, USA.
authors.forename: Yi
authors.initials: Y
authors.lastname: Yang
authors.forename: Shilin
authors.initials: S
authors.lastname: Yang
authors.forename: Zhengmao
authors.initials: Z
authors.lastname: Ye
authors.forename: Jade
authors.initials: J
authors.lastname: Jaffar
authors.forename: Yifeng
authors.initials: Y
authors.lastname: Zhou
authors.forename: Erin
authors.initials: E
authors.lastname: Cutter
authors.forename: Andre
authors.initials: A
authors.lastname: Lieber
authors.forename: Ingegerd
authors.initials: I
authors.lastname: Hellström
authors.forename: Karl Erik
authors.initials: KE
authors.lastname: Hellström
mesh_terms: D000818:Animals; D005260:Female; D007111:Immunity, Cellular; D007128:Immunoglobulin Fragments / Q000627:therapeutic use*; D007167:Immunotherapy / Q000379:methods; D008198:Lymph Nodes / Q000378:metabolism; D008222:Lymphokines / Q000378:metabolism; D008546:Melanoma, Experimental / Q000276:immunology / Q000473:pathology / Q000628:therapy*; D051379:Mice; D008809:Mice, Inbred C3H; D009368:Neoplasm Transplantation; D011993:Recombinant Fusion Proteins / Q000378:metabolism / Q000627:therapeutic use*; D013154:Spleen / Q000378:metabolism; D014407:Tumor Cells, Cultured; D053261:Tumor Necrosis Factor Receptor Superfamily, Member 9 / Q000276:immunology*
chemical_list: D007128:Immunoglobulin Fragments; D008222:Lymphokines; D011993:Recombinant Fusion Proteins; D053261:Tumor Necrosis Factor Receptor Superfamily, Member 9; C055966:immunoglobulin Fv