RNA-loaded CD40-activated B cells stimulate antigen-specific T-cell responses in dogs with spontaneous lymphoma

Gene Ther. 2008 Jul;15(13):955-65. doi: 10.1038/gt.2008.22. Epub 2008 Mar 13.


Cell-based vaccination strategies to induce functional tumor-specific T cells in cancer patients have focused on using autologous dendritic cells. An alternative approach is to use RNA-loaded CD40 activated B cells (CD40-B) that are highly efficient antigen-presenting cells capable of priming naive T cells, boosting memory T-cell responses and breaking tolerance to tumor antigens. The use of tumor RNA as the antigenic payload allows for gene transfer without viruses or vectors and permits major histocompatibility complex (MHC)-independent, multiple-antigen targeting. Here, we use CD40L transfected K562 cells to generate functional CD40-B cells from the peripheral blood of humans and dogs. Testing of RNA-loaded CD40-B cells in dogs allows not only for its development in veterinary medicine but also for determination of its safety and efficacy in a large animal model of spontaneous cancer prior to initiation of human clinical trials. We found that CD40-B cells from healthy humans, healthy dogs and tumor-bearing dogs express increased levels of immune molecules such as MHC and CCR7. Moreover, RNA-loaded CD40-B cells induce functional, antigen-specific T cells from healthy dogs and dogs with lymphoma. These findings pave the way for immunotherapy trials using tumor RNA-loaded CD40-B cells to stimulate antitumor immunity in a large animal model of spontaneous neoplasia.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antigen-Presenting Cells / immunology
  • Base Sequence
  • CD40 Antigens / immunology
  • Cell Line, Tumor
  • Cells, Cultured
  • Dog Diseases / immunology
  • Dog Diseases / therapy*
  • Dogs
  • Genetic Therapy / methods*
  • Humans
  • Immunophenotyping
  • Immunotherapy, Adoptive / methods*
  • Lymphocyte Activation
  • Lymphoma / immunology
  • Lymphoma / therapy*
  • Lymphoma / veterinary*
  • Molecular Sequence Data
  • RNA, Neoplasm / genetics*
  • Receptors, CCR7 / genetics
  • Reverse Transcriptase Polymerase Chain Reaction
  • T-Lymphocytes / immunology
  • Transfection


  • CD40 Antigens
  • RNA, Neoplasm
  • Receptors, CCR7