title: Targeting of the WT191-138fragment to human dendritic cells improves leukemia-specific T-cell responses providing an alternative approach to WT1-based vaccination.
abstract: Due to its immunogenicity and overexpression concomitant with leukemia progression, Wilms tumor protein 1 (WT1) is of particular interest for immunotherapy of AML relapse after allogeneic hematopoietic stem cell transplantation (allo-HSCT). So far, WT1-specific T-cell responses have mainly been induced by vaccination with peptides presented by certain HLA alleles. However, this approach is still not widely applicable in clinical practice due to common limitations of HLA restriction. Dendritic cell (DC) vaccines electroporated with mRNA encoding full-length protein have also been tested for generating WT1-derived peptides for presentation to T-cells. Alternatively, an efficient and broad WT1 peptide presentation could be elicited by triggering receptor-mediated protein endocytosis of DCs. Therefore, we developed antibody fusion proteins consisting of an antibody specific for the DEC205 endocytic receptor on human DCs and various fragments of WT1 as DC-targeting recombinant WT1 vaccines (anti-hDEC205-WT1). Of all anti-hDEC205-WT1 fusion proteins designed for overcoming insufficient expression, anti-hDEC205-WT110-35, anti-hDEC205-WT191-138, anti-hDEC205-WT1223-273, and anti-hDEC205-WT1324-371were identified in good yields. The anti-hDEC205-WT191-138was capable of directly inducing ex vivo T-cell responses by co-incubation of the fusion protein-loaded monocyte-derived mature DCs and autologous T-cells of either healthy or HSCT individuals. Furthermore, the DC-targeted WT191-138-induced specific T-cells showed a strong cytotoxic activity by lysing WT1-overexpressing THP-1 leukemia cells in vitro while sparing WT1-negative hematopoietic cells. In conclusion, our approach identifies four WT1 peptide-antibody fusion proteins with sufficient production and introduces an alternative vaccine that could be easily translated into clinical practice to improve WT1-directed antileukemia immune responses after allo-HSCT.
authors.affiliation: Laboratory for Immunotherapy, Department of Internal Medicine II, University Hospital of Würzburg, Josef-Schneider-Str. 2, 97080, Würzburg, Germany.|Mongolian National University of Medical Sciences, Ulaanbaatar, Mongolia.
authors.forename: Nergui
authors.initials: N
authors.lastname: Dagvadorj
authors.affiliation: Laboratory for Immunotherapy, Department of Internal Medicine II, University Hospital of Würzburg, Josef-Schneider-Str. 2, 97080, Würzburg, Germany.
authors.forename: Anne
authors.initials: A
authors.lastname: Deuretzbacher
authors.affiliation: Division of Molecular Internal Medicine, Department of Internal Medicine II, University Hospital of Würzburg, Würzburg, Germany.
authors.forename: Daniela
authors.initials: D
authors.lastname: Weisenberger
authors.affiliation: Laboratory for Immunotherapy, Department of Internal Medicine II, University Hospital of Würzburg, Josef-Schneider-Str. 2, 97080, Würzburg, Germany.
authors.forename: Elke
authors.initials: E
authors.lastname: Baumeister
authors.affiliation: Division of Molecular Internal Medicine, Department of Internal Medicine II, University Hospital of Würzburg, Würzburg, Germany.
authors.forename: Johannes
authors.initials: J
authors.lastname: Trebing
authors.affiliation: Division of Molecular Internal Medicine, Department of Internal Medicine II, University Hospital of Würzburg, Würzburg, Germany.
authors.forename: Isabell
authors.initials: I
authors.lastname: Lang
authors.affiliation: Laboratory for Immunotherapy, Department of Internal Medicine II, University Hospital of Würzburg, Josef-Schneider-Str. 2, 97080, Würzburg, Germany.
authors.forename: Carolin
authors.initials: C
authors.lastname: Köchel
authors.affiliation: Laboratory for Immunotherapy, Department of Internal Medicine II, University Hospital of Würzburg, Josef-Schneider-Str. 2, 97080, Würzburg, Germany.
authors.forename: Markus
authors.initials: M
authors.lastname: Kapp
authors.affiliation: Laboratory for Immunotherapy, Department of Internal Medicine II, University Hospital of Würzburg, Josef-Schneider-Str. 2, 97080, Würzburg, Germany.
authors.forename: Kerstin
authors.initials: K
authors.lastname: Kapp
authors.affiliation: Division of Experimental Stem Cell Transplantation, Interdisciplinary Center for Clinical Research, University of Würzburg, Würzburg, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Beilhack
authors.affiliation: Institute for Virology and Immunobiology, University of Würzburg, Würzburg, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Hünig
authors.affiliation: Laboratory for Immunotherapy, Department of Internal Medicine II, University Hospital of Würzburg, Josef-Schneider-Str. 2, 97080, Würzburg, Germany.
authors.forename: Hermann
authors.initials: H
authors.lastname: Einsele
authors.affiliation: Division of Molecular Internal Medicine, Department of Internal Medicine II, University Hospital of Würzburg, Würzburg, Germany.
authors.forename: Harald
authors.initials: H
authors.lastname: Wajant
authors.affiliation: Laboratory for Immunotherapy, Department of Internal Medicine II, University Hospital of Würzburg, Josef-Schneider-Str. 2, 97080, Würzburg, Germany. grigoleit_g@ukw.de.
authors.forename: Götz Ulrich
authors.initials: GU
authors.lastname: Grigoleit
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D017951:Antigen Presentation; D016466:CHO Cells; D019496:Cancer Vaccines / Q000235:genetics / Q000276:immunology*; D003412:Cricetulus; D003713:Dendritic Cells / Q000276:immunology*; D018274:Electroporation; D057809:HEK293 Cells; D006801:Humans; D016219:Immunotherapy, Adoptive / Q000379:methods*; D008213:Lymphocyte Activation; D012333:RNA, Messenger / Q000235:genetics / Q000276:immunology; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D025721:WT1 Proteins / Q000235:genetics / Q000276:immunology*
chemical_list: D019496:Cancer Vaccines; D012333:RNA, Messenger; D025721:WT1 Proteins; C583751:WT1 protein, human
keywords: Anti-hDEC205-WT1 antibody fusion protein; Cytotoxic T-cells; Immunotherapy against high-risk AML; Tumor vaccine; Tumor-associated antigen; Wilms tumor protein 1