title: Gene therapy with interleukin-10 receptor and interleukin-12 induces a protective interferon-γ-dependent response against B16F10-Nex2 melanoma.
abstract: Antitumor immune responses are associated with proinflammatory cytokines, whereas tumor-developing animals generally have increased the production of immunosuppressive cytokines. Here, we show that splenocytes from C57Bl/6 mice resistant to low doses of B16F10-Nex2 melanoma cells produced twofold or higher interferon-γ (IFN-γ)/interleukin-10 (IL-10) ratios, whereas cells from tumor-bearing animals produced predominantly IL-10. IL-10-knockout (IL-10KO) mice were significantly more resistant to B16F10-Nex2 development, producing increased amounts of IL-12 and IFN-γ. To neutralize IL-10 in vivo, aiming at cancer therapy, recombinant eukaryotic plasmid expressing the soluble extracellular region of the murine IL-10 receptor α-chain was constructed (pcDNA3-sIL-10R). Plasmid-treated melanoma-challenged animals showed extended survival time, the protective response was IFN-γ dependent and enhanced by co-immunization with a plasmid expressing IL-12. Dendritic cells (DCs) from IL-10KO mice, primed with B16F10-Nex2 antigens (TAg), secreted increased amounts of T-helper 1-type cytokines and increased the expression of surface activation markers. Vaccination of C57Bl/6 mice with TAg-activated IL-10KO DCs, as well as with TAg-primed DCs from C57Bl/6 mice transfected with pcDNA3-sIL10R plasmid, significantly increased animal survival. In conclusion, an IFN-γ-dependent protective response was induced against B16F10-Nex2 cells by neutralization of IL-10 with pcDNA3-sIL10R plasmid. This effect was enhanced by association with IL-12 gene therapy (80% protection), and could be mediated by TAg-primed DCs.
authors.affiliation: Experimental Oncology Unit, Department of Microbiology, Immunology and Parasitology, Universidade Federal de São Paulo-Escola Paulista de Medicina, São Paulo, Brazil.
authors.forename: L H L
authors.initials: LH
authors.lastname: Marchi
authors.forename: T
authors.initials: T
authors.lastname: Paschoalin
authors.forename: L R
authors.initials: LR
authors.lastname: Travassos
authors.forename: E G
authors.initials: EG
authors.lastname: Rodrigues
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D003713:Dendritic Cells / Q000276:immunology; D015316:Genetic Therapy / Q000379:methods*; D006801:Humans; D016219:Immunotherapy, Adoptive / Q000379:methods*; D007371:Interferon-gamma / Q000276:immunology*; D018664:Interleukin-12 / Q000096:biosynthesis / Q000235:genetics* / Q000276:immunology; D008297:Male; D008546:Melanoma, Experimental / Q000235:genetics / Q000276:immunology / Q000628:therapy*; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D010957:Plasmids / Q000235:genetics; D053701:Receptors, Interleukin-10 / Q000096:biosynthesis / Q000235:genetics* / Q000276:immunology; D014162:Transfection
chemical_list: D053701:Receptors, Interleukin-10; D018664:Interleukin-12; D007371:Interferon-gamma