title: Efficient activation of LRH-1-specific CD8+ T-cell responses from transplanted leukemia patients by stimulation with P2X5 mRNA-electroporated dendritic cells.
abstract: Alloreactive CD8+ T cells targeting minor histocompatibility antigens (MiHA) on malignant cells of the recipient play a pivotal role in graft-versus-tumor responses observed after allogeneic stem cell transplantation and donor lymphocyte infusion (DLI). However, these MiHA-specific CD8+ T-cell responses do not result in complete eradication of tumor cells in all patients. Furthermore, CD8+ memory T cells persisting after DLI do not always efficiently expand with recurrence of the disease. Adjuvant immunotherapy using dendritic cells (DC) loaded with hematopoietic-restricted MiHA may boost antitumor CD8+ T-cell immunity without inducing graft-versus-host disease. Here, we explored the use of mRNA-electroporated DC to stimulate MiHA-specific CD8+ T-cell responses. We demonstrate that electroporation of mature DC with P2X5 mRNA encoding for hematopoietic-restricted MiHA LRH-1 results in high expression of both mRNA and protein, and has no negative effect on the mature phenotype and migratory capacity of the DC. Furthermore, these DC can efficiently stimulate LRH-1-specific CD8+ effector T cells to proliferate and produce interferon-gamma. In addition, LRH-1-specific CD8+ memory T cells that are present in patient-derived peripheral blood mononuclear cells at long periods post-DLI can be effectively activated by stimulation with P2X5 mRNA-electroporated DC to proliferate and degranulate upon target cell recognition. These results indicate that adjuvant immunotherapy using DC electroporated with mRNA encoding hematopoietic-restricted MiHA mismatched between patients and donors may enhance the graft versus tumor response induced by stem cell transplantation and DLI.
authors.affiliation: Central Hematology Laboratory, Nijmegen Centre for Molecular Life Sciences, Radboud University Nijmegen Medical Centre (RUNMC), Nijmegen, The Netherlands.
authors.forename: Ingrid M
authors.initials: IM
authors.lastname: Overes
authors.forename: Hanny
authors.initials: H
authors.lastname: Fredrix
authors.forename: Michel G D
authors.initials: MG
authors.lastname: Kester
authors.forename: J H Frederik
authors.initials: JH
authors.lastname: Falkenburg
authors.forename: Robbert
authors.initials: R
authors.lastname: van der Voort
authors.forename: Theo M
authors.initials: TM
authors.lastname: de Witte
authors.forename: Harry
authors.initials: H
authors.lastname: Dolstra
mesh_terms: D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D015550:Cell Degranulation / Q000276:immunology; D003713:Dendritic Cells / Q000276:immunology / Q000637:transplantation*; D018274:Electroporation; D020544:Graft vs Leukemia Effect; D006801:Humans; D007167:Immunotherapy; D007371:Interferon-gamma / Q000096:biosynthesis / Q000276:immunology; D015464:Leukemia, Myelogenous, Chronic, BCR-ABL Positive / Q000628:therapy*; D015470:Leukemia, Myeloid, Acute / Q000628:therapy*; D015778:Minor Histocompatibility Antigens / Q000276:immunology; D012333:RNA, Messenger / Q000235:genetics; D018048:Receptors, Purinergic P2 / Q000235:genetics / Q000276:immunology*; D058485:Receptors, Purinergic P2X5; D033581:Stem Cell Transplantation
chemical_list: D015778:Minor Histocompatibility Antigens; C546465:P2RX5 protein, human; D012333:RNA, Messenger; D018048:Receptors, Purinergic P2; D058485:Receptors, Purinergic P2X5; D007371:Interferon-gamma