Shaping the Tumor Stroma and Sparking Immune Activation by CD40 and 4-1BB Signaling Induced by an Armed Oncolytic Virus

Clin Cancer Res. 2017 Oct 1;23(19):5846-5857. doi: 10.1158/1078-0432.CCR-17-0285. Epub 2017 May 23.


Purpose: Pancreatic cancer is a severe indication with short expected survival despite surgery and/or combination chemotherapeutics. Checkpoint blockade antibodies are approved for several cancer indications, but pancreatic cancer has remained refractory. However, there are clinical data suggesting that stimulation of the CD40 pathway may be of interest for these patients. Oncolytic viruses armed with immunostimulatory genes represent an interesting approach. Herein, we present LOAd703, a designed adenovirus armed with trimerized CD40L and 4-1BBL that activates the CD40 and 4-1BB pathways, respectively. As many cells in the tumor stroma, including stellate cells and the infiltrating immune cells, express CD40 and some 4-1BB, we hypothesize that LOAd703 activates immunity and simultaneously modulates the biology of the tumor stroma.Experimental Design: Tumor, stellate, endothelial, and immune cells were infected by LOAd703 and investigated by flow cytometry, proteomics, and functional analyses.Results: LOAd703-infected pancreatic cell lines were killed by oncolysis, and the virus was more effective than standard-of-care gemcitabine. In in vivo xenograft models, LOAd703 efficiently reduced established tumors and could be combined with gemcitabine for additional effect. Infected stellate and tumor cells reduced factors that promote tumor growth (Spp-1, Gal-3, HGF, TGFβ and collagen type I), while chemokines were increased. Molecules involved in lymphocyte migration were upregulated on infected endothelial cells. Dendritic cells were robustly stimulated by LOAd703 to produce costimulators, cytokines and chemokines, and such DCs potently expanded both antigen-specific T cells and NK cells.Conclusions: LOAd703 is a potent immune activator that modulates the stroma to support antitumor responses. Clin Cancer Res; 23(19); 5846-57. ©2017 AACR.

MeSH terms

  • Adenoviridae / genetics
  • Animals
  • CD40 Antigens / antagonists & inhibitors
  • CD40 Antigens / immunology*
  • Cell Line, Tumor
  • Cell Movement / immunology
  • Dendritic Cells / immunology
  • Dendritic Cells / virology
  • Humans
  • Killer Cells, Natural / immunology
  • Killer Cells, Natural / virology
  • Lymphocyte Activation / immunology
  • Mice
  • Oncolytic Virotherapy / methods*
  • Oncolytic Viruses / genetics
  • Oncolytic Viruses / immunology*
  • Pancreatic Neoplasms / immunology
  • Pancreatic Neoplasms / pathology
  • Pancreatic Neoplasms / therapy*
  • Pancreatic Neoplasms / virology
  • Signal Transduction / immunology
  • Tumor Necrosis Factor Receptor Superfamily, Member 9 / genetics
  • Tumor Necrosis Factor Receptor Superfamily, Member 9 / immunology
  • Xenograft Model Antitumor Assays


  • CD40 Antigens
  • TNFRSF9 protein, human
  • Tumor Necrosis Factor Receptor Superfamily, Member 9