Development of a DC-based therapeutic vaccine for AML patients: Characterization of TLR-agonist matured 3-day DCs expressing the leukemia associated antigens WT1 and PRAME
-
1
Helmholtz Zentrum München, Clinical Cooperation Group Immunotherapy, Germany
-
2
University of Munich, Department of Internal Medicine III, Germany
-
3
Helmholtz Zentrum München, Institute of Molecular Immunology, Germany
-
4
Leiden University Medical Center, Department of Hematology, Netherlands
-
5
Oslo University Hospital, Department of Cellular Therapy, Norway
We have designed a new generation of dendritic cells (DCs) optimized for the use in cell-based immunotherapy of cancer patients. Our goal was to tailor these DCs to be used for vaccination in acute myeloid leukemia (AML) patients with a high risk of relapse after intense induction/consolidation therapy in order to eradicate minimal residual disease (MRD).
We have developed a three-day manufacturing protocol using a cytokine cocktail containing a synthetic TLR7/8-agonist for generation of monocyte-derived mature DCs (mDCs) with improved immunogenicity. For induction of a specific T cell-based anti-AML response against residual tumor cells, our mDCs are loaded with RNA encoding the leukemia-associated antigens WT1 and PRAME. Additionally, DCs transfected with RNA encoding CMV-pp65 will be included as a surrogate antigen.
In this study, we present the careful evaluation of our 3d mDCs generated from healthy donors and AML patient after consolidation therapy. Following RNA electroporation and cryopreservation, we could ensure a fully functional phenotype of the autologous vaccine formulation. Our studies demonstrate for the first time a high and controllable expression of all three antigens following RNA loading, which was also stably detected after cryopreservation. Additionally, expression of common DC surface markers was not altered by these processing steps. To ensure functional integrity of our DCs we tested for the ability to secrete the critical cytokine IL12p70 upon T cell encounter - an important characteristic of our non-manipulated cells - was analyzed in a so-called signal-3 assay with CD40 ligand transfected fibroblasts. We could show that antigen expression and cryopreservation did not alter this capacity. Cryopreserved DCs expressing the different antigens also displayed a high capacity both for reactivation of antigen-specific pre-primed effector cells and for priming of naïve T cells in vitro, showing proper processing and presentation of the introduced antigens. These studies demonstrate that our manufacturing protocol yields improved DCs with a high potential to initiate long-lasting anti-leukemic responses in patients with AML.
Keywords:
Cancer,
AML,
DC,
Therapeutic vaccine,
WT-1,
PRAME
Conference:
15th International Congress of Immunology (ICI), Milan, Italy, 22 Aug - 27 Aug, 2013.
Presentation Type:
Abstract
Topic:
Translational immunology and immune intervention
Citation:
Beck
B,
Geiger
C,
Bigalke
I,
Lichtenegger
FS,
Heemskerk
M,
Saboe-Larssen
S,
Schendel
DJ and
Subklewe
M
(2013). Development of a DC-based therapeutic vaccine for AML patients: Characterization of TLR-agonist matured 3-day DCs expressing the leukemia associated antigens WT1 and PRAME.
Front. Immunol.
Conference Abstract:
15th International Congress of Immunology (ICI).
doi: 10.3389/conf.fimmu.2013.02.01107
Copyright:
The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers.
They are made available through the Frontiers publishing platform as a service to conference organizers and presenters.
The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated.
Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed.
For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions.
Received:
25 Jul 2013;
Published Online:
22 Aug 2013.
*
Correspondence:
Prof. Dolores J Schendel, Helmholtz Zentrum München, Institute of Molecular Immunology, Munich, Germany, schendel@helmholtz-muenchen.de
Dr. Marion Subklewe, University of Munich, Department of Internal Medicine III, Munich, Germany, marion.subklewe@med.uni-muenchen.de