Biology subjects

Szegezdi, E.

Publications and source records attributed to Szegezdi, E..

3 recordsLinked to original sources

bioRxiv2023

TRAIL promotes the polarization of human macrophages toward a proinflammatory M1 phenotype and is associated with increased survival in cancer patients with high tumor macrophage content

BackgroundTNF-related apoptosis-inducing ligand (TRAIL) is a member of the TNF superfamily that can either induce cell death or activate survival pathways after binding to death receptors (DRs) DR4 or DR5. TRAIL is investigated as a therapeutic agent in clinical trials due to its selective toxicity to transformed cells. Macrophages can be polarized into pro-inflammatory/tumor-fighting M1 macrophages or anti-inflammatory/tumor-supportive M2 macrophages and an inbalance between M1 and M2 macrophages can promote diseases. Therefore, identifying modulators that regulate macrophage polarization is important to design effective macrophage-targeted immunotherapies. The impact of TRAIL on macrophage polarization is not known. MethodsPrimary human monocyte-derived macrophages were pre-treated with either TRAIL or with DR4 or DR5-specific ligands and then polarized into M1, M2a, or M2c phenotypes in vitro. The expression of M1 and M2 markers in macrophage subtypes was analyzed by RNA sequencing, qPCR, ELISA, and flow cytometry. Furthermore, the cytotoxicity of the macrophages against U937 AML tumor targets was assessed by flow cytometry. TCGA datasets were also analyzed to correlate TRAIL with M1/M2 markers, and the overall survival of cancer patients. ResultsTRAIL increased the expression of M1 markers at both mRNA and protein levels while decreasing the expression of M2 markers at the mRNA level in human macrophages. TRAIL also shifted M2 macrophages towards an M1 phenotype. Our data showed that both DR4 and DR5 death receptors play a role in macrophage polarization. Furthermore, TRAIL enhanced the cytotoxicity of macrophages against the AML cancer cells in vitro. Finally, TRAIL expression was positively correlated with increased expression of M1 markers in the tumors from ovarian and sarcoma cancer patients and longer overall survival in cases with high, but not low, tumor macrophage content. ConclusionsTRAIL promotes the polarization of human macrophages toward a proinflammatory M1 phenotype via both DR4 and DR5. Our study defines TRAIL as a new regulator of macrophage polarization and suggests that targeting DRs can enhance the anti-tumorigenic response of macrophages in the tumor microenvironment by increasing M1 polarization.

immunology↗

bioRxiv2022

Natural killer cell-mimic nanoparticles can actively target and kill acute myeloid leukemia cells

Natural killer (NK) cells are effector lymphocytes of the innate immune system which play a crucial role in recognizing and killing emerging tumor cells. However, as the tumor evolves, it develops mechanisms to inactivate NK cells or hide from them. Here, we engineered a modular nanoplatform that acts as NK cells (NK cell-mimics), carrying the tumor-recognition and death ligand-mediated tumor-killing properties of an NK cell, yet without being subject to tumor-mediated inactivation. In particular, NK cell mimic nanoparticles (NK.NPs) incorporate two key features of activated NK cells: cytotoxic activity via the death ligand, tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), and an adjustable tumor cell recognition feature based on functionalization with the NK cell Fc-binding receptor (CD16, FCGR3A) peptide, enabling the NK.NPs to bind antibodies targeting tumor antigens. NK.NPs showed potent in vitro cytotoxicity against a broad panel of cancer cell lines. Upon functionalizing the NK.NPs with daratumumab, a clinically used antibody specific for the CD38 protein expressed by AML cells, NK.NPs effectively targeted and eliminated patient-derived acute myeloid leukemia (AML) blasts and leukemia-initiating cells as well as CD38-positive AML cells in vivo, in a disseminated AML xenograft system. Specifically, NK.NPs lead to a significant reduction of AML burden in the bone marrow, spleen, and peripheral blood compared to non-targeted TRAIL-functionalized liposomes. Taken together, these findings demonstrate that NK.NPs are effective in mimicking NK cells antitumorigenic function and thereby underline their use as therapeutic tools.

cancer biology↗

bioRxiv2022

Single-cell characterisation of the hematopoietic bone marrow interactome in health and disease

1The bone marrow (BM) is a complex microenvironment and the primary site of hematopoiesis, coordinating the production of billions of blood cells every day. Despite the essential role of the hematopoietic niche in maintaining hemostasis and its relevance to hematopoietic diseases, many aspects of this environment remain poorly characterised due to experimental hurdles. Here we present a high-resolution characterisation of the niche in health and acute myeloid leukemia (AML) by establishing a comprehensive single-cell gene expression database of nearly 340,000 BM constituent cells encompassing all disease stages (healthy BM, AML at diagnosis, remission and relapse). We characterised the cell type composition of the BM and found that the proportions of both myeloid and lymphoid lineage cell types are significantly altered in AML. We also determined broadscale dysregulation of gene expression in almost all BM cell types upon establishment of AML, indicating that the entire niche is disrupted by the disease. Given the importance of interactions between hematopoietic cells and their microenvironment in regulating their function and properties, we determined all possible ligand-receptor interactions between hematopoietic stem and progenitor cells (HSPC) and every other BM constituent cell type. This analysis revealed a remarkable expansion of HSPC interactions in AML involving multiple BM constituent cells that can drive dysregulated HSPC-cell adhesion, immunosuppression and enhanced cytokine signalling. In particular, we found that interactions involving TGFB1 become widespread in AML and present evidence that these interactions can drive AML cell quiescence in vitro, thus highlighting TGFB1 signalling as a potential target for increasing drug sensitivity and preventing relapse. Our results shed light on potential mechanisms of enhanced competitiveness of AML HSPCs and an overall skewed microenvironment that fosters AML growth.

cancer biology↗