Co-delivery of antigen and IL-12 by Venezuelan equine encephalitis virus replicon particles enhances antigen-specific immune responses and antitumor effects.

Published

Journal Article

We recently demonstrated that Venezuelan equine encephalitis virus-based replicon particle (VRPs) encoding tumor antigens could break tolerance in the immunomodulatory environment of advanced cancer. We hypothesized that local injection of VRP-expressing interleukin-12 (IL-12) at the site of injections of VRP-based cancer vaccines would enhance the tumor-antigen-specific T cell and antibody responses and antitumor efficacy. Mice were immunized with VRP encoding the human tumor-associated antigen, carcinoembryonic antigen (CEA) (VRP-CEA(6D)), and VRP-IL-12 was also administered at the same site or at a distant location. CEA-specific T cell and antibody responses were measured. To determine antitumor activity, mice were implanted with MC38-CEA-2 cells and immunized with VRP-CEA with and without VRP-IL-12, and tumor growth and mouse survival were measured. VRP-IL-12 greatly enhanced CEA-specific T cell and antibody responses when combined with VRP-CEA(6D) vaccination. VRP-IL-12 was superior to IL-12 protein at enhancing immune responses. Vaccination with VRP-CEA(6D) plus VRP-IL-12 was superior to VRP-CEA(6D) or VRP-IL-12 alone in inducing antitumor activity and prolonging survival in tumor-bearing mice. Importantly, local injection of VRP-IL-12 at the VRP-CEA(6D) injection site provided more potent activation of CEA-specific immune responses than that of VRP-IL-12 injected at a distant site from the VRP-CEA injections. Together, this study shows that VRP-IL-12 enhances vaccination with VRP-CEA(6D) and was more effective at activating CEA-specific T cell responses when locally expressed at the vaccine site. Clinical trials evaluating the adjuvant effect of VRP-IL-12 at enhancing the immunogenicity of cancer vaccines are warranted.

Full Text

Duke Authors

Cited Authors

  • Osada, T; Berglund, P; Morse, MA; Hubby, B; Lewis, W; Niedzwiecki, D; Yang, XY; Hobeika, A; Burnett, B; Devi, GR; Clay, TM; Smith, J; Kim Lyerly, H

Published Date

  • November 2012

Published In

Volume / Issue

  • 61 / 11

Start / End Page

  • 1941 - 1951

PubMed ID

  • 22488274

Pubmed Central ID

  • 22488274

Electronic International Standard Serial Number (EISSN)

  • 1432-0851

Digital Object Identifier (DOI)

  • 10.1007/s00262-012-1248-y

Language

  • eng

Conference Location

  • Germany