Granulocyte-Macrophage-Colony-Stimulating-Factor Combined with Prostaglandin E1 Create Dendritic Cells of Leukemic Origin from AML Patients' Whole Blood and Whole Bone Marrow That Mediate Antileukemic Processes after Mixed Lymphocyte Culture

• Published in: International journal of molecular sciences 2023-12, Vol.24 (24), p.17436
• Main Authors: Unterfrauner, Marianne, Rejeski, Hazal Aslan, Hartz, Anne, Bohlscheid, Sophia, Baudrexler, Tobias, Feng, Xiaojia, Rackl, Elias, Li, Lin, Rank, Andreas, Filippini Velázquez, Giuliano, Schmid, Christoph, Schmohl, Jörg, Bojko, Peter, Schmetzer, Helga
• Format: Article
• Language: English
• Subjects: Adipocytes; AML; Antigens; Blood; Bone marrow; Chemotherapy; Cytokines; dendritic cell-based therapy; Dendritic cells; Granulocytes; immune escape; Immune system; Leukemia; leukemia-derived dendritic cells; Lymphocytes; Mutation; Patients; Physiology; Stem cells; whole blood; whole bone marrow
• ISSN: 1422-0067; 1661-6596; 1422-0067
• DOI: 10.3390/ijms242417436

Although several (chemotherapeutic) protocols to treat acute myeloid leukemia (AML) are available, high rates of relapses in successfully treated patients occur. Strategies to stabilize remissions are greatly needed. The combination of the (clinically approved) immune-modulatory compounds Granulocyte-Macrophage-Colony-Stimulating-Factor (GM-CSF) and Prostaglandine E1 (PGE-1) (Kit-M) converts myeloid blasts into dendritic cells of leukemic origin (DC ). After stimulation with DC ex vivo, leukemia-specific antileukemic immune cells are activated. Therefore, Kit-M treatment may be an attractive immunotherapeutic tool to treat patients with myeloid leukemia. Kit-M-mediated antileukemic effects on whole bone marrow (WBM) were evaluated and compared to whole blood (WB) to evaluate the potential effects of Kit-M on both compartments. WB and WBM samples from 17 AML patients at first diagnosis, in persisting disease and at relapse after allogeneic stem cell transplantation (SCT) were treated in parallel with Kit-M to generate DC/DC . Untreated samples served as controls. After a mixed lymphocyte culture enriched with patients' T cells (MLC), the leukemia-specific antileukemic effects were assessed through the degranulation- (CD107a T cells), the intracellular IFNγ production- and the cytotoxicity fluorolysis assay. Quantification of cell subtypes was performed via flow cytometry. In both WB and WBM significantly higher frequencies of (mature) DC were generated without induction of blast proliferation in Kit-M-treated samples compared to control. After MLC with Kit-M-treated vs. not pretreated WB or WBM, frequencies of (leukemia-specific) immunoreactive cells (e.g., non-naive, effector-, memory-, CD3 β7 T cells, NK- cells) were (significantly) increased, whereas leukemia-specific regulatory T cells (T , CD152 T cells) were (significantly) decreased. The cytotoxicity fluorolysis assay showed a significantly improved blast lysis in Kit-M-treated WB and WBM compared to control. A parallel comparison of WB and WBM samples revealed no significant differences in frequencies of DC , (leukemia-specific) immunoreactive cells and achieved antileukemic processes. Kit-M was shown to have comparable effects on WB and WBM samples regarding the generation of DC and activation of (antileukemic) immune cells after MLC. This was true for samples before or after SCT. In summary, a potential Kit-M in vivo treatment could lead to antileukemic effects in WB as well as WBM in vivo and to