Mechanism of third signals provided by IL-12 and OX-40R ligation in eliciting therapeutic immunity following dendritic-tumor fusion vaccination

Hideyuki Kuriyama, Satoshi Watanabe, Jorgen Kjaergaard, Hidemasa Tamai, Rongxiu Zheng, Andrew D. Weinberg, Hong Ming Hu, Peter A. Cohen, Gregory E. Plautz, Suyu Shu

Research output: Contribution to journalArticle

20 Scopus citations


Dendritic-tumor heterokaryons generated by electrofusion are highly immunogenic. In animal studies, a single vaccination was therapeutic for tumors established in the lung, skin, and brain. However, effective therapy required a third signal which could be provided by exogenous IL-12 or the agonistic anti-OX-40R monoclonal antibody (mAb). In this study, we investigated the mechanism and mode of actions of these two seemingly distinct adjuvants. In immunotherapy of the MCA205 sarcoma, administration of the neutralizing anti-IL-12 mAb nearly completely blocked the adjuvant effect of IL-12, but had minimal inhibitory effects on anti-OX-40R mAb. By contrast, in vivo administration of the antagonistic anti-OX-40L mAb inhibited the adjuvant effects of both IL-12 and anti-OX-40R mAb. Thus, a common pathway of endogenous OX-40 interaction is critical for the development of a therapeutic immune response. Analysis of the third signal mechanism revealed that in the absence of an adjuvant, vaccination with fusion hybrids led to IL-10 production without eliciting IFN-γ secreting cells. The addition of IL-12 to vaccination suppressed IL-10 production and initiated sensitization of specific IFN-γ secreting cells, resulting in a type 1-like antitumor immunity. These findings underscore the significance of the third signal in the design of dendritic cell-based cancer vaccines.

Original languageEnglish (US)
Pages (from-to)30-40
Number of pages11
JournalCellular Immunology
Issue number1
StatePublished - Dec 1 2006



  • Active immunotherapy
  • DC-tumor electrofusion hybrids
  • IL-12
  • OX-40R/OX-40L interaction

ASJC Scopus subject areas

  • Immunology

Cite this