title: Improving efficacy of interleukin-12-transfected dendritic cells injected into murine colon cancer with anti-CD137 monoclonal antibodies and alloantigens.
abstract: Intralesional administration of cultured dendritic cells (DCs) engineered to produce IL-12 by in vitro infection with recombinant adenovirus frequently displays eradicating efficacy against established subcutaneous tumors derived from the CT26 murine colon carcinoma cell line. The elicited response is mainly mediated by cytolytic T lymphocytes. In order to search for strategies that would enhance the efficacy of the therapeutic procedure against less immunogenic tumors, we moved onto malignancies derived from the inoculation of MC38 colon cancer cells that are less prone to undergo complete regression upon a single intratumoral injection of IL-12-secreting DCs. In this model, we found that repeated injections of such DCs, as opposed to a single injection, achieved better efficacy against both the injected and a distantly implanted tumor; that the use of semiallogeneic DCs that are mismatched in one MHC haplotype with the tumor host showed slightly better efficacy; and that the combination of this treatment with systemic injections of immunostimulatory anti-CD137 (4-1BB) monoclonal antibody achieved potent combined effects that correlated with the antitumor immune response measured in IFN-gamma ELISPOT assays. The elicited systemic immune response eradicates concomitant untreated lesions in most cases. Curative efficacy was also found against some tumors established for 2 weeks when these strategies were used in combination. These are preclinical pieces of evidence to be considered in order to enhance the therapeutic benefit of a strategy that is currently being tested in clinical trials. Supplementary Material for this article can be found on the International Journal of Cancer website at http://www.interscience.wiley.com/jpages/0020-7136/suppmat/index.html.
authors.affiliation: Gene Therapy Division, Fundación para la Investigación Médica Aplicada, University of Navarre, Irunlarrea s/n 31008 Pamplona, Navarre, Spain.
authors.forename: Iñigo
authors.initials: I
authors.lastname: Tirapu
authors.forename: Ainhoa
authors.initials: A
authors.lastname: Arina
authors.forename: Guillermo
authors.initials: G
authors.lastname: Mazzolini
authors.forename: Marina
authors.initials: M
authors.lastname: Duarte
authors.forename: Carlos
authors.initials: C
authors.lastname: Alfaro
authors.forename: Esperanza
authors.initials: E
authors.lastname: Feijoo
authors.forename: Cheng
authors.initials: C
authors.lastname: Qian
authors.forename: Lieping
authors.initials: L
authors.lastname: Chen
authors.forename: Jesus
authors.initials: J
authors.lastname: Prieto
authors.forename: Ignacio
authors.initials: I
authors.lastname: Melero
mesh_terms: D000256:Adenoviridae / Q000235:genetics; D000818:Animals; D000911:Antibodies, Monoclonal / Q000627:therapeutic use*; D015703:Antigens, CD; D002465:Cell Movement; D003110:Colonic Neoplasms / Q000628:therapy*; D003713:Dendritic Cells / Q000276:immunology*; D015316:Genetic Therapy; D007371:Interferon-gamma / Q000096:biosynthesis; D018664:Interleukin-12 / Q000235:genetics* / Q000502:physiology; D007519:Isoantigens / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D017475:Receptors, Nerve Growth Factor / Q000037:antagonists & inhibitors / Q000276:immunology*; D018124:Receptors, Tumor Necrosis Factor / Q000037:antagonists & inhibitors / Q000276:immunology*; D014162:Transfection; D053261:Tumor Necrosis Factor Receptor Superfamily, Member 9
chemical_list: D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D007519:Isoantigens; D017475:Receptors, Nerve Growth Factor; D018124:Receptors, Tumor Necrosis Factor; C505715:Tnfrsf9 protein, mouse; D053261:Tumor Necrosis Factor Receptor Superfamily, Member 9; D018664:Interleukin-12; D007371:Interferon-gamma