title: Gene therapy-mediated reprogramming tumor infiltrating T cells using IL-2 and inhibiting NF-κB signaling improves the efficacy of immunotherapy in a brain cancer model.
abstract: Immune-mediated gene therapy using adenovirus expressing Flt3 ligand and thymidine kinase followed by ganciclovir administration (Flt3/TK) effectively elicits tumor regression in preclinical glioma models. Herein, we assessed new strategies to optimize Flt3L/TK therapeutic efficacy in a refractory RG2 orthotopic glioblastoma model. Specifically, we aimed to optimize the therapeutic efficacy of Flt3L/TK treatment in the RG2 model by overexpressing the following genes within the brain tumor microenvironment: 1) a TK mutant with enhanced cytotoxicity (SR39 mutant TK), 2) Flt3L-IgG fusion protein that has a longer half-life, 3) CD40L to stimulate DC maturation, 4) T helper cell type 1 polarizing dendritic cell cytokines interleukin-12 or C-X-C motif ligand 10 chemokine (CXCL)-10, 5) C-C motif ligand 2 chemokine (CCL2) or C-C motif ligand 3 chemokine (CCL3) to enhance dendritic cell recruitment into the tumor microenvironment, 6) T helper cell type 1 cytokines interferon-γ or interleukin-2 to enhance effector T-cell functions, and 7) IκBα or p65RHD (nuclear factor kappa-B [NF-κB] inhibitors) to suppress the function of Foxp3+ Tregs and enhanced effector T-cell functions. Anti-tumor immunity and tumor specific effector T-cell functions were assessed by cytotoxic T lymphocyte assay and intracellular IFN-γ staining. Our data showed that overexpression of interferon-γ or interleukin-2, or inhibition of the nuclear factor kappa-B within the tumor microenvironment, enhanced cytotoxic T lymphocyte-mediated immune responses and successfully extended the median survival of rats bearing intracranial RG2 when combined with Flt3L/TK. These findings indicate that enhancement of T-cell functions constitutes a critical therapeutic target to overcome immune evasion and enhance therapeutic efficacy for brain cancer. In addition, our study provides novel targets to be used in combination with immune-therapeutic strategies for glioblastoma, which are currently being tested in the clinic.
authors.affiliation: Gene Therapeutics Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA 90095, USA.
authors.forename: Yohei
authors.initials: Y
authors.lastname: Mineharu
authors.forename: A K M Ghulam
authors.initials: AK
authors.lastname: Muhammad
authors.forename: Kader
authors.initials: K
authors.lastname: Yagiz
authors.forename: Marianela
authors.initials: M
authors.lastname: Candolfi
authors.forename: Kurt M
authors.initials: KM
authors.lastname: Kroeger
authors.forename: Weidong
authors.initials: W
authors.lastname: Xiong
authors.forename: Mariana
authors.initials: M
authors.lastname: Puntel
authors.forename: Chunyan
authors.initials: C
authors.lastname: Liu
authors.forename: Eva
authors.initials: E
authors.lastname: Levy
authors.forename: Claudia
authors.initials: C
authors.lastname: Lugo
authors.forename: Adrina
authors.initials: A
authors.lastname: Kocharian
authors.forename: James P
authors.initials: JP
authors.lastname: Allison
authors.forename: Michael A
authors.initials: MA
authors.lastname: Curran
authors.forename: Pedro R
authors.initials: PR
authors.lastname: Lowenstein
authors.forename: Maria G
authors.initials: MG
authors.lastname: Castro
mesh_terms: D000256:Adenoviridae / Q000235:genetics; D000818:Animals; D000998:Antiviral Agents / Q000627:therapeutic use; D001932:Brain Neoplasms / Q000235:genetics / Q000276:immunology / Q000628:therapy*; D003713:Dendritic Cells / Q000276:immunology; D004195:Disease Models, Animal; D015774:Ganciclovir / Q000627:therapeutic use; D015316:Genetic Therapy / Q000379:methods*; D005822:Genetic Vectors; D005909:Glioblastoma / Q000235:genetics / Q000276:immunology / Q000628:therapy*; D006801:Humans; D007167:Immunotherapy / Q000379:methods*; D007376:Interleukin-2 / Q000276:immunology; D016246:Lymphocytes, Tumor-Infiltrating / Q000276:immunology; D008565:Membrane Proteins / Q000627:therapeutic use; D016328:NF-kappa B / Q000276:immunology; D051381:Rats; D011994:Recombinant Proteins / Q000627:therapeutic use; D015398:Signal Transduction; D013601:T-Lymphocytes / Q000276:immunology*; D013937:Thymidine Kinase / Q000627:therapeutic use; D059016:Tumor Microenvironment / Q000276:immunology
chemical_list: D000998:Antiviral Agents; D007376:Interleukin-2; D008565:Membrane Proteins; D016328:NF-kappa B; D011994:Recombinant Proteins; C084881:flt3 ligand protein; D013937:Thymidine Kinase; D015774:Ganciclovir