title: Regulation of dendritic cell function by NK cells: mechanisms underlying the synergism in the combination therapy of IL-12 and 4-1BB activation.
abstract: The interactions between NK cells and dendritic cells (DCs) have been previously demonstrated in vitro. In this report, the in vivo cross-regulation between NK cells and DCs was studied in tumor-bearing mice treated with adenoviral vector expressing IL-12 and agonistic anti-4-1BB Abs. NK cells are essential for both tumor rejection and CTL development in the combination therapy (IL-12 plus anti-4-1BB). The numbers and functional activities of both NK cells and DCs in tumor-infiltrating leukocytes were synergistically increased in the IL-12 plus anti-4-1BB-treated mice compared with treatment with either reagent alone. NK depletion in vivo resulted in a significant decrease in the number of DCs in tumor-infiltrating leukocytes, strongly suggesting that NK cells are involved in the activation and expansion of DCs. The mechanism by which IL-12-activated NK cells regulate DC functions is, in part, mediated through the secretion of IFN-gamma that leads to the up-regulation of 4-1BB by DCs. Furthermore, 4-1BB activation in conjunction with IL-12 gene delivery increased tumor infiltration of green fluorescence protein-labeled DCs and enhanced their MHC class II expression. The activation of DCs by NK cells and the subsequent development of antitumoral CTL responses facilitated by 4-1BB-activated DCs may account for the synergistic effects observed in the combination therapy in comparison to adenoviral vector expressing IL-12 or anti-4-1BB treatment alone.
authors.affiliation: Carl C. Icahn Institute for Gene Therapy and Molecular Medicine, Mount Sinai School of Medicine, New York, NY 10029, USA.
authors.forename: Ping-Ying
authors.initials: PY
authors.lastname: Pan
authors.forename: Peidi
authors.initials: P
authors.lastname: Gu
authors.forename: Qingsheng
authors.initials: Q
authors.lastname: Li
authors.forename: Dongping
authors.initials: D
authors.lastname: Xu
authors.forename: Kaare
authors.initials: K
authors.lastname: Weber
authors.forename: Shu-Hsia
authors.initials: SH
authors.lastname: Chen
mesh_terms: D053330:4-1BB Ligand; D000256:Adenoviridae / Q000235:genetics; D000818:Animals; D000911:Antibodies, Monoclonal / Q000008:administration & dosage; D017951:Antigen Presentation; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000008:administration & dosage*; D002454:Cell Differentiation / Q000276:immunology; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000276:immunology; D003110:Colonic Neoplasms / Q000276:immunology / Q000517:prevention & control*; D003602:Cytotoxicity, Immunologic; D003713:Dendritic Cells / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D004357:Drug Synergism; D005260:Female; D006084:Graft Rejection / Q000276:immunology; D007371:Interferon-gamma / Q000502:physiology; D018664:Interleukin-12 / Q000008:administration & dosage / Q000235:genetics / Q000378:metabolism; D007694:Killer Cells, Natural / Q000276:immunology*; D008113:Liver Neoplasms / Q000276:immunology / Q000517:prevention & control* / Q000556:secondary; D018655:Lymphocyte Count; D051379:Mice; D008807:Mice, Inbred BALB C; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis / Q000276:immunology / Q000378:metabolism; D015854:Up-Regulation / Q000276:immunology
chemical_list: D053330:4-1BB Ligand; D000911:Antibodies, Monoclonal; C505975:Tnfsf9 protein, mouse; D014409:Tumor Necrosis Factor-alpha; D018664:Interleukin-12; D007371:Interferon-gamma