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Sample records for myeloid cells regulate

  1. BCOR regulates myeloid cell proliferation and differentiation.

    PubMed

    Cao, Q; Gearhart, M D; Gery, S; Shojaee, S; Yang, H; Sun, H; Lin, D-C; Bai, J-W; Mead, M; Zhao, Z; Chen, Q; Chien, W-W; Alkan, S; Alpermann, T; Haferlach, T; Müschen, M; Bardwell, V J; Koeffler, H P

    2016-05-01

    BCOR is a component of a variant Polycomb group repressive complex 1 (PRC1). Recently, we and others reported recurrent somatic BCOR loss-of-function mutations in myelodysplastic syndrome and acute myelogenous leukemia (AML). However, the role of BCOR in normal hematopoiesis is largely unknown. Here, we explored the function of BCOR in myeloid cells using myeloid murine models with Bcor conditional loss-of-function or overexpression alleles. Bcor mutant bone marrow cells showed significantly higher proliferation and differentiation rates with upregulated expression of Hox genes. Mutation of Bcor reduced protein levels of RING1B, an H2A ubiquitin ligase subunit of PRC1 family complexes and reduced H2AK119ub upstream of upregulated HoxA genes. Global RNA expression profiling in murine cells and AML patient samples with BCOR loss-of-function mutation suggested that loss of BCOR expression is associated with enhanced cell proliferation and myeloid differentiation. Our results strongly suggest that BCOR plays an indispensable role in hematopoiesis by inhibiting myeloid cell proliferation and differentiation and offer a mechanistic explanation for how BCOR regulates gene expression such as Hox genes. PMID:26847029

  2. Myeloid cell-driven angiogenesis and immune regulation in tumors

    PubMed Central

    Rivera, Lee B.; Bergers, Gabriele

    2015-01-01

    Angiogenesis is a hallmark of cancer as its induction is indispensable to fuel an expanding tumor. The tumor microenvironment contributes to tumor vessel growth, and distinct myeloid cells recruited by the tumor have been shown to not only support angiogenesis but to foster an immune suppressive environment that supports tumor expansion and progression. Recent findings suggest that the intertwined regulation of angiogenesis and immune modulation can offer therapeutic opportunities for the treatment of cancer. Here we review the mechanisms by which distinct myeloid cell populations contribute to tumor angiogenesis, discuss current approaches in the clinic that are targeting both angiogenic and immune suppressive pathways, and highlight important areas of future research. PMID:25770923

  3. Myeloid cell-derived reactive oxygen species externally regulate the proliferation of myeloid progenitors in emergency granulopoiesis

    PubMed Central

    Kwak, Hyun-Jeong; Liu, Peng; Bajrami, Besnik; Xu, Yuanfu; Park, Shin-Young; Nombela-Arrieta, Cesar; Mondal, Subhanjan; Sun, Yan; Zhu, Haiyan; Chai, Li; Silberstein, Leslie E.; Cheng, Tao; Luo, Hongbo R.

    2015-01-01

    Summary The cellular mechanisms controlling infection-induced emergency granulopoiesis are poorly defined. Here we found that reactive oxygen species (ROS) concentrations in the bone marrow (BM) were elevated during acute infection in a phagocytic NADPH oxidase-dependent manner in myeloid cells. Gr1+ myeloid cells were uniformly distributed in the BM, and all c-Kit+ progenitor cells were adjacent to Gr1+ myeloid cells. Inflammation-induced ROS production in the BM played a critical role in myeloid progenitor expansion during emergency granulopoiesis. ROS elicited oxidation and deactivation of phosphatase and tensin homolog (PTEN), resulting in up-regulation of PtdIns(3,4,5)P3 signaling in BM myeloid progenitors. We further revealed that BM myeloid cell-produced ROS stimulated proliferation of myeloid progenitors via a paracrine mechanism. Taken together, our results establish that phagocytic NADPH oxidase-mediated ROS production by BM myeloid cells plays a critical role in mediating emergency granulopoiesis during acute infection. PMID:25579427

  4. Mesenchymal Stem Cells and Myeloid Derived Suppressor Cells: Common Traits in Immune Regulation

    PubMed Central

    Nikolaev, Alexander

    2016-01-01

    To protect host against immune-mediated damage, immune responses are tightly regulated. The regulation of immune responses is mediated by various populations of mature immune cells, such as T regulatory cells and B regulatory cells, but also by immature cells of different origins. In this review, we discuss regulatory properties and mechanisms whereby two distinct populations of immature cells, mesenchymal stem cells, and myeloid derived suppressor cells mediate immune regulation, focusing on their similarities, discrepancies, and potential clinical applications. PMID:27529074

  5. Regulation of cell surface receptors for different hematopoietic growth factors on myeloid leukemic cells.

    PubMed Central

    Lotem, J; Sachs, L

    1986-01-01

    There are clones of myeloid leukemic cells which are different from normal myeloid cells in that they have become independent of hematopoietic growth factor for cell viability and growth. The ability of these clones to bind three types of hematopoietic growth factors (MGI-1GM = GM-CSF, IL-3 = multi-CSF and MGI-1M = M-CSF = CSF-1) was measured using the method of quantitative absorption at 1 degree C and low pH elution of cell-bound biological activity. Results of binding to normal myeloid and lymphoid cells were similar to those obtained by radioreceptor assays. The results indicate that the number of receptors on different clones of these leukemic cells varied from 0 to 1,300 per cell. The receptors have a high binding affinity. Receptors for different growth factors can be independently expressed in different clones. There was no relationship between expression of receptors for these growth factors and the phenotype of the leukemic cells regarding their ability to be induced to differentiate. The number of receptors on the leukemic cells was lower than on normal mature macrophages. Myeloid leukemic cells induced to differentiate by normal myeloid cell differentiation factor MGI-2 (= DF), or by low doses of actinomycin D or cytosine arabinoside, showed an up-regulation of the number of MGI-1GM and IL-3 receptors. Induction of differentiation of leukemic cells by MGI-2 also induced production and secretion of the growth factor MGI-1GM, and this induced MGI-1GM saturated the up-regulated MGI-1GM receptors. It is suggested that up-regulation of these receptors during differentiation is required for the functioning of differentiated cells. PMID:3023059

  6. Myeloid cell TRAF3 regulates immune responses and inhibits inflammation and tumor development in mice.

    PubMed

    Lalani, Almin I; Moore, Carissa R; Luo, Chang; Kreider, Benjamin Z; Liu, Yan; Morse, Herbert C; Xie, Ping

    2015-01-01

    Myeloid cells, including granulocytes, monocytes, macrophages, and dendritic cells, are crucial players in innate immunity and inflammation. These cells constitutively or inducibly express a number of receptors of the TNFR and TLR families, whose signals are transduced by TNFR-associated factor (TRAF) molecules. In vitro studies showed that TRAF3 is required for TLR-induced type I IFN production, but the in vivo function of TRAF3 in myeloid cells remains unknown. In this article, we report the generation and characterization of myeloid cell-specific TRAF3-deficient (M-TRAF3(-/-)) mice, which allowed us to gain insights into the in vivo functions of TRAF3 in myeloid cells. We found that TRAF3 ablation did not affect the maturation or homeostasis of myeloid cells in young adult mice, even though TRAF3-deficient macrophages and neutrophils exhibited constitutive NF-κB2 activation. However, in response to injections with LPS (a bacterial mimic) or polyinosinic-polycytidylic acid (a viral mimic), M-TRAF3(-/-) mice exhibited an altered profile of cytokine production. M-TRAF3(-/-) mice immunized with T cell-independent and -dependent Ags displayed elevated T cell-independent IgG3 and T cell-dependent IgG2b responses. Interestingly, 15- to 22-mo-old M-TRAF3(-/-) mice spontaneously developed chronic inflammation or tumors, often affecting multiple organs. Taken together, our findings indicate that TRAF3 expressed in myeloid cells regulates immune responses in myeloid cells and acts to inhibit inflammation and tumor development in mice. PMID:25422508

  7. EVOLUTION OF MYELOID CELLS

    PubMed Central

    Barreda, Daniel R.; Neely, Harold R.; Flajnik, Martin F.

    2015-01-01

    In 1882, Elie Metchnikoff identified myeloid-like cells from starfish larvae responding to the invasion by a foreign body (rose thorn). This marked the origins of the study of innate immunity, and an appreciation that cellular immunity is already well established in these “primitive” organisms. This chapter focuses on these myeloid cells as well as the newest members of this family, the dendritic cells (DC), and explores their evolutionary origins. Our goal is to provide evolutionary context for the development of the multilayered immune system of mammals, where myeloid cells now serve as central effectors of innate immunity and regulators of adaptive immunity. Overall, we find that core contributions of myeloid cells to the regulation of inflammation are based on mechanisms that have been honed over hundreds of millions of years of evolution. Using phagocytosis as a platform, we show how fairly simple beginnings have offered a robust foundation onto which additional control features have been integrated, resulting in central regulatory nodes that now manage multi-factorial aspects of homeostasis and immunity. PMID:27337471

  8. Myeloid-derived suppressor cell development is regulated by a STAT/IRF-8 axis

    PubMed Central

    Waight, Jeremy D.; Netherby, Colleen; Hensen, Mary L.; Miller, Austin; Hu, Qiang; Liu, Song; Bogner, Paul N.; Farren, Matthew R.; Lee, Kelvin P.; Liu, Kebin; Abrams, Scott I.

    2013-01-01

    Myeloid-derived suppressor cells (MDSCs) comprise immature myeloid populations produced in diverse pathologies, including neoplasia. Because MDSCs can impair antitumor immunity, these cells have emerged as a significant barrier to cancer therapy. Although much research has focused on how MDSCs promote tumor progression, it remains unclear how MDSCs develop and why the MDSC response is heavily granulocytic. Given that MDSCs are a manifestation of aberrant myelopoiesis, we hypothesized that MDSCs arise from perturbations in the regulation of interferon regulatory factor–8 (IRF-8), an integral transcriptional component of myeloid differentiation and lineage commitment. Overall, we demonstrated that (a) Irf8-deficient mice generated myeloid populations highly homologous to tumor-induced MDSCs with respect to phenotype, function, and gene expression profiles; (b) IRF-8 overexpression in mice attenuated MDSC accumulation and enhanced immunotherapeutic efficacy; (c) the MDSC-inducing factors G-CSF and GM-CSF facilitated IRF-8 downregulation via STAT3- and STAT5-dependent pathways; and (d) IRF-8 levels in MDSCs of breast cancer patients declined with increasing MDSC frequency, implicating IRF-8 as a negative regulator in human MDSC biology. Together, our results reveal a previously unrecognized role for IRF-8 expression in MDSC subset development, which may provide new avenues to target MDSCs in neoplasia. PMID:24091328

  9. Identification of an interleukin-3-regulated aldoketo reductase gene in myeloid cells which may function in autocrine regulation of myelopoiesis.

    PubMed

    Du, Y; Tsai, S; Keller, J R; Williams, S C

    2000-03-10

    The EML hematopoietic progenitor cell line is a model system for studying molecular events regulating myeloid commitment and terminal differentiation. We used representational difference analysis to identify genes that are expressed differentially during myeloid differentiation of EML cells. One gene (named mAKRa) encoded a novel member of the aldoketo reductase (AKR) superfamily of cytosolic NAD(P)(H)-dependent oxidoreductases. mAKRa mRNA was detected in murine hematopoietic tissues including bone marrow, spleen, and thymus. In myeloid cell lines, mAKRa was expressed at highest levels in cells representative of promyelocytes. mAKRa mRNA levels increased rapidly in response to interleukin-3 over the first 24 h of EML cell differentiation when the cells undergo lineage commitment and extensive proliferation. mAKRa mRNA levels decreased later in the differentiation process particularly when the EML cells were cultured with granulocyte/macrophage colony-stimulating factor and retinoic acid to induce terminal granulocytic maturation. mAKRa mRNA levels decreased during retinoic acid-induced terminal granulocytic differentiation of the MPRO promyelocyte cell line. AKRs act as molecular switches by catalyzing the interconversion or inactivation of bioactive molecules including steroids and prostaglandins. We propose that mAKRa may catalyze the production or catabolism of autocrine factors that promote the proliferation and/or lineage commitment of early myeloid progenitors. PMID:10702227

  10. Regulation of vitamin D receptor expression by retinoic acid receptor alpha in acute myeloid leukemia cells.

    PubMed

    Marchwicka, Aleksandra; Cebrat, Małgorzata; Łaszkiewicz, Agnieszka; Śnieżewski, Łukasz; Brown, Geoffrey; Marcinkowska, Ewa

    2016-05-01

    Acute myeloid leukemia (AML) is the predominant acute leukemia among adults, characterized by an accumulation of malignant immature myeloid precursors. A very promising way to treat AML is differentiation therapy using either all-trans-retinoic acid (ATRA) or 1,25-dihydroxyvitamin D3 (1,25D), or the use of both these differentiation-inducing agents. However, the effect of combination treatment varies in different AML cell lines, and this is due to ATRA either down- or up-regulating transcription of vitamin D receptor (VDR) in the cells examined. The mechanism of transcriptional regulation of VDR in response to ATRA has not been fully elucidated. Here, we show that the retinoic acid receptor α (RARα) is responsible for regulating VDR transcription in AML cells. We have shown that a VDR transcriptional variant, originating in exon 1a, is regulated by RARα agonists in AML cells. Moreover, in cells with a high basal level of RARα protein, the VDR gene is transcriptionally repressed as long as RARα agonist is absent. In these cells down-regulation of the level of RARα leads to increased expression of VDR. We consider that our findings provide a mechanistic background to explain the different outcomes from treating AML cell lines with a combination of ATRA and 1,25D. PMID:26969398

  11. ERK5 pathway regulates transcription factors important for monocytic differentiation of human myeloid leukemia cells.

    PubMed

    Wang, Xuening; Pesakhov, Stella; Harrison, Jonathan S; Danilenko, Michael; Studzinski, George P

    2014-07-01

    Mitogen-activated protein kinases (MAPKs) are important transducers of external signals for cell growth, survival, and other cellular responses including cell differentiation. Several MAPK cascades are known with the MEK1/2-ERK1/2, JNK, and p38MAPKs receiving most attention, but the role of MEK5-ERK5 in intracellular signaling deserves more scrutiny, as this pathway transmits signals that can complement ERK/2 signaling. We hypothesized that the ERK5 pathway plays a role in the control of monocytic differentiation, which is disturbed in myeloid leukemia. We therefore examined the cellular phenotype and key molecular events which occur when human myeloid leukemia cells, acute (AML) or chronic (CML), are forced to differentiate by vitamin D derivatives (VDDs). This study was performed using established cell lines HL60 and U937, and primary cultures of blasts from 10 patients with ML. We found that ERK5 and its direct downstream target transcription factor MEF2C are upregulated by 1,25D in parallel with monocytic differentiation. Further, inhibition of ERK5 activity by specific pharmacological agents BIX02189 and XMD8-92 alters the phenotype of these cells by reducing the abundance of the VDD-induced surface monocytic marker CD14, and concomitantly increasing surface expression of the general myeloid marker CD11b. Similar results were obtained when the expression of ERK5 was reduced by siRNA or short hairpin (sh) RNA. ERK5 inhibition resulted in an expected decrease in MEF2C activation. We also found that in AML cells the transcription factor C/EBPβ is positively regulated, while C/EBPα is negatively regulated by ERK5. These findings provide new understanding of dysregulated differentiation in human myeloid leukemia. PMID:24264602

  12. Histone deacetylase 11: A novel epigenetic regulator of myeloid derived suppressor cell expansion and function.

    PubMed

    Sahakian, Eva; Powers, John J; Chen, Jie; Deng, Susan L; Cheng, Fengdong; Distler, Allison; Woods, David M; Rock-Klotz, Jennifer; Sodre, Andressa L; Youn, Je-In; Woan, Karrune V; Villagra, Alejandro; Gabrilovich, Dmitry; Sotomayor, Eduardo M; Pinilla-Ibarz, Javier

    2015-02-01

    Myeloid-derived suppressor cells (MDSCs), a heterogeneous population of cells capable of suppressing anti-tumor T cell function in the tumor microenvironment, represent an imposing obstacle in the development of cancer immunotherapeutics. Thus, identifying elements essential to the development and perpetuation of these cells will undoubtedly improve our ability to circumvent their suppressive impact. HDAC11 has emerged as a key regulator of IL-10 gene expression in myeloid cells, suggesting that this may represent an important targetable axis through which to dampen MDSC formation. Using a murine transgenic reporter model system where eGFP expression is controlled by the HDAC11 promoter (Tg-HDAC11-eGFP), we provide evidence that HDAC11 appears to function as a negative regulator of MDSC expansion/function in vivo. MDSCs isolated from EL4 tumor-bearing Tg-HDAC11-eGFP display high expression of eGFP, indicative of HDAC11 transcriptional activation at steady state. In striking contrast, immature myeloid cells in tumor-bearing mice display a diminished eGFP expression, implying that the transition of IMC to MDSC's require a decrease in the expression of HDAC11, where we postulate that it acts as a gate-keeper of myeloid differentiation. Indeed, tumor-bearing HDAC11-knockout mice (HDAC11-KO) demonstrate a more suppressive MDSC population as compared to wild-type (WT) tumor-bearing control. Notably, the HDAC11-KO tumor-bearing mice exhibit enhanced tumor growth kinetics when compare to the WT control mice. Thus, through a better understanding of this previously unknown role of HDAC11 in MDSC expansion and function, rational development of targeted epigenetic modifiers may allow us to thwart a powerful barrier to efficacious immunotherapies. PMID:25155994

  13. Dasatinib accelerates valproic acid-induced acute myeloid leukemia cell death by regulation of differentiation capacity.

    PubMed

    Heo, Sook-Kyoung; Noh, Eui-Kyu; Yoon, Dong-Joon; Jo, Jae-Cheol; Park, Jae-Hoo; Kim, Hawk

    2014-01-01

    Dasatinib is a compound developed for chronic myeloid leukemia as a multi-targeted kinase inhibitor against wild-type BCR-ABL and SRC family kinases. Valproic acid (VPA) is an anti-epileptic drug that also acts as a class I histone deacetylase inhibitor. The aim of this research was to determine the anti-leukemic effects of dasatinib and VPA in combination and to identify their mechanism of action in acute myeloid leukemia (AML) cells. Dasatinib was found to exert potent synergistic inhibitory effects on VPA-treated AML cells in association with G1 phase cell cycle arrest and apoptosis induction involving the cleavage of poly (ADP-ribose) polymerase and caspase-3, -7 and -9. Dasatinib/VPA-induced cell death thus occurred via caspase-dependent apoptosis. Moreover, MEK/ERK and p38 MAPK inhibitors efficiently inhibited dasatinib/VPA-induced apoptosis. The combined effect of dasatinib and VPA on the differentiation capacity of AML cells was more powerful than the effect of each drug alone, being sufficiently strong to promote AML cell death through G1 cell cycle arrest and caspase-dependent apoptosis. MEK/ERK and p38 MAPK were found to control dasatinib/VPA-induced apoptosis as upstream regulators, and co-treatment with dasatinib and VPA to contribute to AML cell death through the regulation of differentiation capacity. Taken together, these results indicate that combined dasatinib and VPA treatment has a potential role in anti-leukemic therapy. PMID:24918603

  14. MerTK Is a Functional Regulator of Myelin Phagocytosis by Human Myeloid Cells.

    PubMed

    Healy, Luke M; Perron, Gabrielle; Won, So-Yoon; Michell-Robinson, Mackenzie A; Rezk, Ayman; Ludwin, Samuel K; Moore, Craig S; Hall, Jeffery A; Bar-Or, Amit; Antel, Jack P

    2016-04-15

    Multifocal inflammatory lesions featuring destruction of lipid-rich myelin are pathologic hallmarks of multiple sclerosis. Lesion activity is assessed by the extent and composition of myelin uptake by myeloid cells present in such lesions. In the inflamed CNS, myeloid cells are comprised of brain-resident microglia, an endogenous cell population, and monocyte-derived macrophages, which infiltrate from the systemic compartment. Using microglia isolated from the adult human brain, we demonstrate that myelin phagocytosis is dependent on the polarization state of the cells. Myelin ingestion is significantly enhanced in cells exposed to TGF-β compared with resting basal conditions and markedly reduced in classically activated polarized cells. Transcriptional analysis indicated that TGF-β-treated microglia closely resembled M0 cells. The tyrosine kinase phagocytic receptor MerTK was one of the most upregulated among a select number of differentially expressed genes in TGF-β-treated microglia. In contrast, MerTK and its known ligands, growth arrest-specific 6 and Protein S, were downregulated in classically activated cells. MerTK expression and myelin phagocytosis were higher in CNS-derived microglia than observed in monocyte-derived macrophages, both basally and under all tested polarization conditions. Specific MerTK inhibitors reduced myelin phagocytosis and the resultant anti-inflammatory biased cytokine responses for both cell types. Defining and modulating the mechanisms that regulate myelin phagocytosis has the potential to impact lesion and disease evolution in multiple sclerosis. Relevant effects would include enhancing myelin clearance, increasing anti-inflammatory molecule production by myeloid cells, and thereby permitting subsequent tissue repair. PMID:26962228

  15. β-Catenin–regulated myeloid cell adhesion and migration determine wound healing

    PubMed Central

    Amini-Nik, Saeid; Cambridge, Elizabeth; Yu, Winston; Guo, Anne; Whetstone, Heather; Nadesan, Puviindran; Poon, Raymond; Hinz, Boris; Alman, Benjamin A.

    2014-01-01

    A β-catenin/T cell factor–dependent transcriptional program is critical during cutaneous wound repair for the regulation of scar size; however, the relative contribution of β-catenin activity and function in specific cell types in the granulation tissue during the healing process is unknown. Here, cell lineage tracing revealed that cells in which β-catenin is transcriptionally active express a gene profile that is characteristic of the myeloid lineage. Mice harboring a macrophage-specific deletion of the gene encoding β-catenin exhibited insufficient skin wound healing due to macrophage-specific defects in migration, adhesion to fibroblasts, and ability to produce TGF-β1. In irradiated mice, only macrophages expressing β-catenin were able to rescue wound-healing deficiency. Evaluation of scar tissue collected from patients with hypertrophic and normal scars revealed a correlation between the number of macrophages within the wound, β-catenin levels, and cellularity. Our data indicate that β-catenin regulates myeloid cell motility and adhesion and that β-catenin–mediated macrophage motility contributes to the number of mesenchymal cells and ultimate scar size following cutaneous injury. PMID:24837430

  16. Myeloid cell leukemia-1 regulates the cell growth and predicts prognosis in gastric cancer.

    PubMed

    Lee, Wan-Sik; Park, Young-Lan; Kim, Nuri; Oh, Hyung-Hoon; Son, Dong-Jun; Kim, Mi-Young; Oak, Chan-Young; Chung, Cho-Yun; Park, Hyung-Chul; Kim, Jong-Sun; Myung, Dae-Seong; Cho, Sung-Bum; Joo, Young-Eun

    2015-05-01

    The expression of myeloid cell leukemia-1 (Mcl‑1), a member of the anti-apoptotic Bcl-2 protein family, has been associated with tumor progression and adverse patient outcome. The aims of current study were to evaluate whether Mcl-1 affects the survival or death of gastric cancer cells, and to investigate the prognostic value of its expression in gastric cancer. PcDNA3.1-Mcl-1 expression and Mcl-1 siRNA vectors were used to overexpress and silence Mcl-1 expression in gastric cancer cell lines including SNU638 and TMK1, respectively. Immunohistochemistry was used to determine the expression of Mcl-1 in gastric cancer tissues. Apoptosis was determined by the TUNEL assay, and cell proliferation was determined by immunostaining with a Ki-67 antibody. Mcl-1 knockdown induced apoptosis through the upregulation of caspase-3, and -7, and PARP activity, and the release of Smac/DIABLO and Omi/HtrA2 into the cytoplasm. Additionally, cell cycle arrest occurred due to decrease of cyclin D1, cell division cycle gene 2 (cdc2), and cyclin-dependent kinase 4 and 6. In contrast, overexpression of Mcl-1 inhibited apoptosis and cell cycle arrest. Mcl-1 knockdown did not suppress tumor cell proliferation in gastric cancer cells, whereas overexpression of Mcl-1 enhanced tumor cell proliferation. The JAK2 and STAT3 signaling cascades were significantly blocked by Mcl-1 knockdown. The mean Ki-67 labeling index (KI) value of Mcl-1 positive tumors was significantly lower than that of Mcl-1 negative tumors. However, there was no significant difference between Mcl-1 expression and the apoptotic index (AI). Mcl-1 expression was significantly increased in gastric cancer tissues compared to normal gastric mucosa tissues, and was associated with age, tumor size, stage, depth of invasion, lymph node metastasis and poor survival. Our study showed that Mcl-1 regulates the cell growth and might be a potential prognostic marker for gastric cancer. PMID:25672320

  17. Mesenchymal Stem Cells (MSC) Regulate Activation of Granulocyte-Like Myeloid Derived Suppressor Cells (G-MDSC) in Chronic Myeloid Leukemia Patients

    PubMed Central

    Parrinello, Nunziatina Laura; La Cava, Piera; Brundo, Maria Violetta; Bramanti, Vincenzo; Stagno, Fabio; Vigneri, Paolo; Chiarenza, Annalisa; Palumbo, Giuseppe Alberto; Tibullo, Daniele; Di Raimondo, Francesco

    2016-01-01

    It is well known that mesenchymal stem cells (MSC) have a role in promotion of tumor growth, survival and drug-resistance in chronic myeloid leukemia (CML). Recent reports indicated that a subpopulation of myeloid cells, defined as granulocyte-like myeloid-derived suppressor cells (G-MDSC) is increased in these patients. So far, the role of MSC in MDSC expansion and activation into the BM microenvironment remains unexplored. To address this question, here we use a specific experimental model in vitro, co-culturing MSC with peripheral blood mononucleated cells (PBMC) from normal individuals, in order to generate MSC-educated G-MDSC. Although MSC of healthy donors (HD) and CML patients were able to generate the same amount of MDSC, only CML-MSC-educated G-MDSC exhibited suppressive ability on autologous T lymphocytes. In addition, compared with HD-MSC, CML-MSC over-expressed some immunomodulatory factors including TGFβ, IL6 and IL10, that could be involved in MDSC activation. CML-MSC-educated G-MDSC expressed higher levels of ARG1, TNFα, IL1β, COX2 and IL6 than G-MDSC isolated from co-culture with HD-MSC. Our data provide evidence that CML-MSC may play a critical role in tumor microenvironment by orchestrating G-MDSC activation and regulating T lymphocytes-mediated leukemia surveillance, thus contributing to CML immune escape. PMID:27391078

  18. Lipid from Infective L. donovani Regulates Acute Myeloid Cell Growth via Mitochondria Dependent MAPK Pathway

    PubMed Central

    Chatterjee, Nabanita; Das, Subhadip; Bose, Dipayan; Banerjee, Somenath; Jha, Tarun; Das Saha, Krishna

    2015-01-01

    The microbial source, which includes live, attenuated, or genetically modified microbes or their cellular component(s) or metabolites, has gained increasing significance for therapeutic intervention against several pathophysiological conditions of disease including leukemia, which remains an incurable disease till now despite recent advances in the medical sciences. We therefore took up the present study to explore if the leishmanial lipid (pLLD) isolated from L. donovani can play an anti-neoplastic role in acute myeloid leukemia cells by regulating cellular growth. Indeed pLLD significantly inhibited cell proliferation of four AML cell lines (HL-60, MOLT-4, U937, and K562). Scanning electron microscopy and DNA fragmentation analysis revealed that it significantly induced apoptosis of U937 cells through morphological alteration. Occurrence of apoptosis was checked by using Annexin exposure and this established that the cell cycle was arrested at G0/G1 phase in time-dependent manner. pLLD increased the intracellular ROS with alteration of mitochondrial membrane potential, as detected using DCFDA. It also regulated the expression of apoptosis-related proteins like Bax, Bcl2, Bad and t-Bid besides causing cleavage of PARP as determined by western blot analysis. Treatment of U937 cells with pLLD induced the activation of extracellular signal-regulated kinase (ERK)1/2, c-Jun N-terminal kinase (JNK)1/2, p38, and caspases 9/3. The results suggest that pLLD induces apoptosis in acute myeloid leukemia cells possibly via increasing intracellular ROS and regulating the MAPK pathway. PMID:25750993

  19. Lipid from infective L. donovani regulates acute myeloid cell growth via mitochondria dependent MAPK pathway.

    PubMed

    Chatterjee, Nabanita; Das, Subhadip; Bose, Dipayan; Banerjee, Somenath; Jha, Tarun; Das Saha, Krishna

    2015-01-01

    The microbial source, which includes live, attenuated, or genetically modified microbes or their cellular component(s) or metabolites, has gained increasing significance for therapeutic intervention against several pathophysiological conditions of disease including leukemia, which remains an incurable disease till now despite recent advances in the medical sciences. We therefore took up the present study to explore if the leishmanial lipid (pLLD) isolated from L. donovani can play an anti-neoplastic role in acute myeloid leukemia cells by regulating cellular growth. Indeed pLLD significantly inhibited cell proliferation of four AML cell lines (HL-60, MOLT-4, U937, and K562). Scanning electron microscopy and DNA fragmentation analysis revealed that it significantly induced apoptosis of U937 cells through morphological alteration. Occurrence of apoptosis was checked by using Annexin exposure and this established that the cell cycle was arrested at G0/G1 phase in time-dependent manner. pLLD increased the intracellular ROS with alteration of mitochondrial membrane potential, as detected using DCFDA. It also regulated the expression of apoptosis-related proteins like Bax, Bcl2, Bad and t-Bid besides causing cleavage of PARP as determined by western blot analysis. Treatment of U937 cells with pLLD induced the activation of extracellular signal-regulated kinase (ERK)1/2, c-Jun N-terminal kinase (JNK)1/2, p38, and caspases 9/3. The results suggest that pLLD induces apoptosis in acute myeloid leukemia cells possibly via increasing intracellular ROS and regulating the MAPK pathway. PMID:25750993

  20. Tumor regulation of myeloid-derived suppressor cell proliferation and trafficking.

    PubMed

    Younos, Ibrahim H; Dafferner, Alicia J; Gulen, Dumrul; Britton, Holly C; Talmadge, James E

    2012-07-01

    A stress response can induce myeloid progenitor cell (MPC) proliferation, mobilization, and extramedullary hematopoiesis (EMH) within lymphoid and parenchymal organs. Our studies using in vivo BrdU labeling, Ki-67 IHC staining, and carboxyfluorescein succinimidyl ester (CFSE) adoptive cell transfer revealed that spleens, rather than bone marrow (BM) and peripheral blood (PB), from 4T1 mammary tumor-bearing (TB) mice were the primary site of MPC proliferation. The resultant increase in MPCs was associated with tumor hematopoietic growth factor (GF) transcription, decreased apoptosis, as well as, prolonged survival of splenic MPCs. In naïve mice, i.v. injected CFSE-labeled MDSCs (myeloid-derived suppressor cells) initially accumulated in the lungs, while in TB mice, they rapidly sequestered in the spleen. In contrast, a few of the injected MDSCs and leukocytes arrested, proliferated, or accumulated in the marrow, tumor, or PB of TB mice. However, BrdU labeling revealed a significant demargination of proliferating splenic MPCs into the PB. In tumors, despite high GF transcript levels, we found that a high frequency of MDSCs was apoptotic. In summary, tumor growth and cytokines regulate MPC proliferation, trafficking, accumulation, apoptosis, and survival. PMID:22609473

  1. MicroRNA-130a regulates cell malignancy by targeting RECK in chronic myeloid leukemia

    PubMed Central

    Li, Quan; Wu, Yaohui; Zhang, Jian; Yi, Tienan; Li, Weiming

    2016-01-01

    Emerging evidence has indicated that microRNAs are involved in tumor development and progression, acting as either tumor suppressors or oncogenes. In this study, we aimed to investigate the role of miR-130a in the pathogenesis of chronic myeloid leukemia (CML). Functional studies indicate that over-expression of miR-130a in A562 CML cells dramatically suppresses cell proliferation and induces cell apoptosis both in vitro and in vivo. Furthermore, we demonstrate that the transcriptional regulator RECK is a target of miR-130a. In conclusion, our study suggests that miR-130a may function as a novel tumor suppressor in CML, and its anti-oncogenic activity may involve the direct targeting and inhibition of RECK. PMID:27158382

  2. Induction of cytosine arabinoside-resistant human myeloid leukemia cell death through autophagy regulation by hydroxychloroquine.

    PubMed

    Kim, Yundeok; Eom, Ju-In; Jeung, Hoi-Kyung; Jang, Ji Eun; Kim, Jin Seok; Cheong, June-Won; Kim, Young Sam; Min, Yoo Hong

    2015-07-01

    We investigated the effects of the autophagy inhibitor hydroxychloroquine (HCQ) on cell death of cytosine arabinoside (Ara-C)-resistant human acute myeloid leukemia (AML) cells. Ara-C-sensitive (U937, AML-2) and Ara-C-resistant (U937/AR, AML-2/AR) human AML cell lines were used to evaluate HCQ-regulated cytotoxicity, autophagy, and apoptosis as well as effects on cell death-related signaling pathways. We found that HCQ-induced dose- and time-dependent cell death in Ara-C-resistant cells compared to Ara-C-sensitive cell lines. The extent of cell death and features of HCQ-induced autophagic markers including increase in microtubule-associated protein light chain 3 (LC3) I conversion to LC3-II, beclin-1, ATG5, as well as green fluorescent protein-LC3 positive puncta and autophagosome were remarkably greater in U937/AR cells. Also, p62/SQSTM1 was increased in response to HCQ. p62/SQSTM1 protein interacts with both LC3-II and ubiquitin protein and is degraded in autophagosomes. Therefore, a reduction of p62/SQSTM1 indicates increased autophagic degradation, whereas an increase of p62/SQSTM1 by HCQ indicates inhibited autophagic degradation. Knock down of p62/SQSTM1 using siRNA were prevented the HCQ-induced LC3-II protein level as well as significantly reduced the HCQ-induced cell death in U937/AR cells. Also, apoptotic cell death and caspase activation in U937/AR cells were increased by HCQ, provided evidence that HCQ-induced autophagy blockade. Taken together, our data show that HCQ-induced apoptotic cell death in Ara-C-resistant AML cells through autophagy regulation. PMID:26211587

  3. Myeloid-Derived Suppressor Cell Survival and Function Are Regulated by the Transcription Factor Nrf2.

    PubMed

    Beury, Daniel W; Carter, Kayla A; Nelson, Cassandra; Sinha, Pratima; Hanson, Erica; Nyandjo, Maeva; Fitzgerald, Phillip J; Majeed, Amry; Wali, Neha; Ostrand-Rosenberg, Suzanne

    2016-04-15

    Tumor-induced myeloid-derived suppressor cells (MDSC) contribute to immune suppression in tumor-bearing individuals and are a major obstacle to effective immunotherapy. Reactive oxygen species (ROS) are one of the mechanisms used by MDSC to suppress T cell activation. Although ROS are toxic to most cells, MDSC survive despite their elevated content and release of ROS. NF erythroid 2-related factor 2 (Nrf2) is a transcription factor that regulates a battery of genes that attenuate oxidative stress. Therefore, we hypothesized that MDSC resistance to ROS may be regulated by Nrf2. To test this hypothesis, we used Nrf2(+/+)and Nrf2(-/-)BALB/c and C57BL/6 mice bearing 4T1 mammary carcinoma and MC38 colon carcinoma, respectively. Nrf2 enhanced MDSC suppressive activity by increasing MDSC production of H2O2, and it increased the quantity of tumor-infiltrating MDSC by reducing their oxidative stress and rate of apoptosis. Nrf2 did not affect circulating levels of MDSC in tumor-bearing mice because the decreased apoptotic rate of tumor-infiltrating MDSC was balanced by a decreased rate of differentiation from bone marrow progenitor cells. These results demonstrate that Nrf2 regulates the generation, survival, and suppressive potency of MDSC, and that a feedback homeostatic mechanism maintains a steady-state level of circulating MDSC in tumor-bearing individuals. PMID:26936880

  4. IFN-γ differentially regulates subsets of Gr-1(+)CD11b(+) myeloid cells in chronic inflammation.

    PubMed

    Zhan, Xiaoxia; Fang, Yimin; Hu, Shengfeng; Wu, Yongjian; Yang, Kun; Liao, Chunxin; Zhang, Yuanqing; Huang, Xi; Wu, Minhao

    2015-08-01

    During chronic inflammation, prolonged over-reactive immune response may lead to tissue destruction, while immune suppression hinders tissue repair and pathogen elimination. Therefore, precise regulation of the immune response is needed to avoid immuno-pathology. Interferon-gamma (IFN-γ) is widely used in clinical treatment of inflammatory diseases. However, the underlying mechanism remains unclear. Here, we evaluated the role of IFN-γ on CD11b(+)Gr-1(+) myeloid cell differentiation and function, using a heat-killed Mycobacterium bovis BCG-induced chronic inflammation model. After challenge with heat-killed BCG, two subpopulations of CD11b(+)Gr-1(+) myeloid cells were generated in the mouse spleen. Phenotypical, morphological and functional analysis indicated that the CD11b(+)Gr-1(high) Ly6G(high) Ly6C(low) subset was neutrophil-like myeloid-derived inducer cells (N-MDICs), which promoted T cell activation, while the other subset was CD11b(+)Gr-1(low) Ly6G(neg) Ly6C(high) monocyte-like myeloid-derived suppressor cells (M-MDSCs) that displayed extensive suppressor function. IFN-γ treatment dampened N-MDICs-mediated T cell activation through up-regulating T cell suppressive mediators, reactive oxygen species (ROS) and arginase I. While for M-MDSCs, IFN-γ reduced their suppressing activity by decreasing the arginase activity. Our study provides evidence that IFN-γ balances the over-reactive vs compromised immune response through different regulation of distinct myeloid subsets, and therefore displays significant therapeutic potential for effective immuno-therapy of chronic inflammatory diseases. PMID:26021804

  5. Metabolic regulation of hepatitis B immunopathology by myeloid-derived suppressor cells

    PubMed Central

    Pallett, Laura J.; Gill, Upkar S.; Quaglia, Alberto; Sinclair, Linda V.; Jover-Cobos, Maria; Schurich, Anna; Singh, Kasha P.; Thomas, Niclas; Das, Abhishek; Chen, Antony; Fusai, Giuseppe; Bertoletti, Antonio; Cantrell, Doreen A.; Kennedy, Patrick T.; Davies, Nathan A.; Haniffa, Muzlifah; Maini, Mala K.

    2015-01-01

    Infection with hepatitis B virus (HBV) results in disparate degrees of tissue injury: it can replicate without pathological consequences or trigger immune-mediated necroinflammatory liver damage. We investigated the potential for myeloid-derived suppressor cells (MDSC) to suppress T cell-mediated immunopathology in this setting. Granulocytic MDSC (gMDSC) expanded transiently in acute resolving HBV, decreasing before peak hepatic injury. In persistent infection, arginase-expressing gMDSC (and circulating arginase) increased most in phases characterized by HBV replication without immunopathology, whilst L-arginine decreased. gMDSC expressed liver-homing chemokine receptors and accumulated in the liver, their expansion being supported by hepatic stellate cells. We provide in vitro and ex vivo evidence that gMDSC potently inhibited T cells in a partially arginase-dependent manner. L-arginine-deprived T cells upregulated system-L amino acid transporters to increase uptake of essential nutrients and attempt metabolic reprogramming. These data demonstrate the capacity of expanded arginase-expressing gMDSC to regulate liver immunopathology in HBV infection. PMID:25962123

  6. MT1-MMP is required for myeloid cell fusion via regulation of Rac1 signaling

    PubMed Central

    Gonzalo, Pilar; Guadamillas, Marta C.; Hernández-Riquer, Mª Victoria; Pollán, Ángela; Grande-García, Araceli; Bartolomé, Rubén A.; Vasanji, Amit; Ambrogio, Chiara; Chiarle, Roberto; Teixidó, Joaquín; Risteli, Juha; Apte, Suneel S.; del Pozo, Miguel A.; Arroyo, Alicia G.

    2009-01-01

    SUMMARY Cell fusion is essential for fertilization, myotube formation, and inflammation. Macrophages fuse in various circumstances but the molecular signals involved in the distinct steps of their fusion are not fully characterized. Using null mice and derived cells, we show that the protease MT1-MMP is necessary for macrophage fusion during osteoclast and giant cell formation in vitro and in vivo. Specifically, MT1-MMP is required for lamellipodia formation and for proper cell morphology and motility of bone marrow myeloid progenitors prior to membrane fusion. These functions of MT1-MMP do not depend on MT1-MMP catalytic activity or downstream pro-MMP-2 activation. Instead, MT1-MMP-null cells show a decreased Rac1 activity and reduced membrane targeting of Rac1 and the adaptor protein p130Cas. Retroviral rescue experiments and protein binding assays delineate a signaling pathway in which MT1-MMP, via its cytosolic tail, contributes to macrophage migration and fusion by regulating Rac1 activity through an association with p130Cas. PMID:20152179

  7. ER stress regulates myeloid-derived suppressor cell fate through TRAIL-R–mediated apoptosis

    PubMed Central

    Condamine, Thomas; Kumar, Vinit; Ramachandran, Indu R.; Youn, Je-In; Celis, Esteban; Finnberg, Niklas; El-Deiry, Wafik S.; Winograd, Rafael; Vonderheide, Robert H.; English, Nickolas R.; Knight, Stella C.; Yagita, Hideo; McCaffrey, Judith C.; Antonia, Scott; Hockstein, Neil; Witt, Robert; Masters, Gregory; Bauer, Thomas; Gabrilovich, Dmitry I.

    2014-01-01

    Myeloid-derived suppressor cells (MDSCs) dampen the immune response thorough inhibition of T cell activation and proliferation and often are expanded in pathological conditions. Here, we studied the fate of MDSCs in cancer. Unexpectedly, MDSCs had lower viability and a shorter half-life in tumor-bearing mice compared with neutrophils and monocytes. The reduction of MDSC viability was due to increased apoptosis, which was mediated by increased expression of TNF-related apoptosis–induced ligand receptors (TRAIL-Rs) in these cells. Targeting TRAIL-Rs in naive mice did not affect myeloid cell populations, but it dramatically reduced the presence of MDSCs and improved immune responses in tumor-bearing mice. Treatment of myeloid cells with proinflammatory cytokines did not affect TRAIL-R expression; however, induction of ER stress in myeloid cells recapitulated changes in TRAIL-R expression observed in tumor-bearing hosts. The ER stress response was detected in MDSCs isolated from cancer patients and tumor-bearing mice, but not in control neutrophils or monocytes, and blockade of ER stress abrogated tumor-associated changes in TRAIL-Rs. Together, these data indicate that MDSC pathophysiology is linked to ER stress, which shortens the lifespan of these cells in the periphery and promotes expansion in BM. Furthermore, TRAIL-Rs can be considered as potential targets for selectively inhibiting MDSCs. PMID:24789911

  8. Distal regulation of c-myb expression during IL-6-induced differentiation in murine myeloid progenitor M1 cells.

    PubMed

    Zhang, Junfang; Han, Bingshe; Li, Xiaoxia; Bies, Juraj; Jiang, Penglei; Koller, Richard P; Wolff, Linda

    2016-01-01

    The c-Myb transcription factor is a major regulator that controls differentiation and proliferation of hematopoietic progenitor cells, which is frequently deregulated in hematological diseases, such as lymphoma and leukemia. Understanding of the mechanisms regulating the transcription of c-myb gene is challenging as it lacks a typical promoter and multiple factors are involved. Our previous studies identified some distal regulatory elements in the upstream regions of c-myb gene in murine myeloid progenitor M1 cells, but the detailed mechanisms still remain unclear. In the present study, we found that a cell differentiation-related DNase1 hypersensitive site is located at a -28k region upstream of c-myb gene and that transcription factors Hoxa9, Meis1 and PU.1 bind to the -28k region. Circular chromosome conformation capture (4C) assay confirmed the interaction between the -28k region and the c-myb promoter, which is supported by the enrichment of CTCF and Cohesin. Our analysis also points to a critical role for Hoxa9 and PU.1 in distal regulation of c-myb expression in murine myeloid cells and cell differentiation. Overexpression of Hoxa9 disrupted the IL-6-induced differentiation of M1 cells and upregulated c-myb expression through binding of the -28k region. Taken together, our results provide an evidence for critical role of the -28k region in distal regulatory mechanism for c-myb gene expression during differentiation of myeloid progenitor M1 cells. PMID:27607579

  9. DACH1 regulates cell cycle progression of myeloid cells through the control of cyclin D, Cdk 4/6 and p21{sup Cip1}

    SciTech Connect

    Lee, Jae-Woong; Kim, Hyeng-Soo; Kim, Seonggon; Hwang, Junmo; Kim, Young Hun; Lim, Ga Young; Sohn, Wern-Joo; Yoon, Suk-Ran; Kim, Jae-Young; Park, Tae Sung; Park, Kwon Moo; Ryoo, Zae Young; Lee, Sanggyu

    2012-03-30

    Highlights: Black-Right-Pointing-Pointer DACH1 increases cyclin D, F and Cdk 1, 4, 6 in mouse myeloid progenitor cells. Black-Right-Pointing-Pointer The knockdown of DACH1 blocked the cell cycle progression of HL-60 cells. Black-Right-Pointing-Pointer The novel effect of DACH1 related with cell cycle regulation and leukemogenesis. -- Abstract: The cell-fate determination factor Dachshund, a component of the Retinal Determination Gene Network (RDGN), has a role in breast tumor proliferation through the repression of cyclin D1 and several key regulators of embryonic stem cell function, such as Nanog and Sox2. However, little is known about the role of DACH1 in a myeloid lineage as a cell cycle regulator. Here, we identified the differential expression levels of extensive cell cycle regulators controlled by DACH1 in myeloid progenitor cells. The forced expression of DACH1 induced p27{sup Kip1} and repressed p21{sup Cip1}, which is a pivotal characteristic of the myeloid progenitor. Furthermore, DACH1 significantly increased the expression of cyclin D1, D3, F, and Cdk 1, 4, and 6 in myeloid progenitor cells. The knockdown of DACH1 blocked the cell cycle progression of HL-60 promyeloblastic cells through the decrease of cyclin D1, D3, F, and Cdk 1, 4, and 6 and increase in p21{sup Cip1}, which in turn decreased the phosphorylation of the Rb protein. The expression of Sox2, Oct4, and Klf4 was significantly up-regulated by the forced expression of DACH1 in mouse myeloid progenitor cells.

  10. miR-125b regulates cell progression in chronic myeloid leukemia via targeting BAK1

    PubMed Central

    Li, Quan; Wu, Yaohui; Zhang, Yongkang; Sun, Huapeng; Lu, Zhaoli; Du, Ke; Fang, Shanshan; Li, Weiming

    2016-01-01

    Chronic myeloid leukemia (CML) is a type of malignant tumor characterized by the accumulation of a large number of immature white blood cells in the blood and bone marrow. BAK1 was predicted to be the target gene of microRNA-451 (miR-125b). The present study was designed to illustrate the mechanism of miR-125b in regulating CML via targeting BAK1. In this study, we found that the expression of miR-125b increased strongly, whereas the expression of BAK1 decreased significantly in CML patients and CML cell lines compared with healthy controls. Moreover, the luciferase report assay confirmed the interaction between miR-125b and BAK1 mRNA. After transfection of the miR-125b mimic or miR-125b inhibitor into CML cells, we found that the inhibition of miR-125b decreased the proliferation rates and promoted apoptosis with cell cycle arrest at the G0/G1 phase in both K562 and NB-4 cells, increased the expression of BAK1 and Caspase-3, and decreased the expression of Bcl-2 and c-myc; the miR-125b mimic yielded the opposite results. In addition, siBAK1 offset the suppression effect of the miR-125b inhibitor in K562 cells, indicating that miR-125b promotes these cellular processes by inhibiting the expression of BAK1. Further in vivo experiments supported these findings because miR-125b suppression reduced CML growth in mice. Taken together, our study suggests that the down-regulation of miR-125b affects the expression of BAK1, promotes cell apoptosis and inhibits cell proliferation, leading to up-regulated expression of pro-apoptosis factors, down–regulated expression of anti-apoptosis factors in the mitochondrial apoptotic pathway, and decreased tumor size and weight of CML in vivo. These results provide a potential therapeutic strategy for CML. PMID:27158338

  11. Differentiation and characterization of myeloid cells.

    PubMed

    Gupta, Dipti; Shah, Hetavi Parag; Malu, Krishnakumar; Berliner, Nancy; Gaines, Peter

    2014-01-01

    Ex vivo differentiation of myeloid cells begins with an enriched population of bone marrow-derived hematopoietic stem cells generated by lineage depletion and/or positive selection for CD34(+) antigen (human) or Sca-1(+) (mouse) cells, which are then expanded and subsequently induced in vitro in a process that recapitulates normal myeloid development. Myeloid cell lines include two human leukemic cell lines, NB-4 and HL-60, which have been demonstrated to undergo retinoic acid-induced myeloid development; however, both cell lines exhibit defects in the up-regulation of late-expressed neutrophil-specific genes. Multiple murine factor-dependent cell models of myelopoiesis are also available that express the full range of neutrophil maturation markers, including: 32Dcl3 cells, which undergo G-CSF-induced myeloid maturation; EML/EPRO cells, which develop into mature neutrophils in response to cytokines and retinoic acid; and ER-Hoxb8 cells, which undergo myeloid maturation upon removal of estradiol in the maintenance medium. In this unit, the induction of myeloid maturation in each of these model systems is described, including their differentiation to either neutrophils or macrophages, if applicable. Commonly used techniques to test for myeloid characteristics of developing cells are also described, including flow cytometry and real time RT-PCR. PMID:24510620

  12. Pathogenic fungi regulate immunity by inducing neutrophilic myeloid-derived suppressor cells.

    PubMed

    Rieber, Nikolaus; Singh, Anurag; Öz, Hasan; Carevic, Melanie; Bouzani, Maria; Amich, Jorge; Ost, Michael; Ye, Zhiyong; Ballbach, Marlene; Schäfer, Iris; Mezger, Markus; Klimosch, Sascha N; Weber, Alexander N R; Handgretinger, Rupert; Krappmann, Sven; Liese, Johannes; Engeholm, Maik; Schüle, Rebecca; Salih, Helmut Rainer; Marodi, Laszlo; Speckmann, Carsten; Grimbacher, Bodo; Ruland, Jürgen; Brown, Gordon D; Beilhack, Andreas; Loeffler, Juergen; Hartl, Dominik

    2015-04-01

    Despite continuous contact with fungi, immunocompetent individuals rarely develop pro-inflammatory antifungal immune responses. The underlying tolerogenic mechanisms are incompletely understood. Using both mouse models and human patients, we show that infection with the human pathogenic fungi Aspergillus fumigatus and Candida albicans induces a distinct subset of neutrophilic myeloid-derived suppressor cells (MDSCs), which functionally suppress T and NK cell responses. Mechanistically, pathogenic fungi induce neutrophilic MDSCs through the pattern recognition receptor Dectin-1 and its downstream adaptor protein CARD9. Fungal MDSC induction is further dependent on pathways downstream of Dectin-1 signaling, notably reactive oxygen species (ROS) generation as well as caspase-8 activity and interleukin-1 (IL-1) production. Additionally, exogenous IL-1β induces MDSCs to comparable levels observed during C. albicans infection. Adoptive transfer and survival experiments show that MDSCs are protective during invasive C. albicans infection, but not A. fumigatus infection. These studies define an innate immune mechanism by which pathogenic fungi regulate host defense. PMID:25771792

  13. Metalloproteinases: A functional pathway for myeloid cells

    PubMed Central

    Chou, Jonathan; Chan, Matilda F.; Werb, Zena

    2015-01-01

    Myeloid cells have diverse roles in regulating immunity, inflammation, and extracellular matrix (ECM) turnover. To accomplish these tasks, myeloid cells carry an arsenal of metalloproteinases, which include the matrix metalloproteinases (MMPs) and the adamalysins. These enzymes have diverse substrate repertoires, and are thus involved in mediating proteolytic cascades, cell migration and cell signaling. Dysregulation of metalloproteinases contributes to pathogenic processes, including inflammation, fibrosis and cancer. Metalloproteinases also have important non-proteolytic functions in controlling cytoskeletal dynamics during macrophage fusion and enhancing transcription to promote anti-viral immunity. This review highlights the diverse contributions of metalloproteinases to myeloid cell functions. PMID:27227311

  14. Twist-1, a novel regulator of hematopoietic stem cell self-renewal and myeloid lineage development.

    PubMed

    Dong, Cheng-Ya; Liu, Xiao-Yan; Wang, Nan; Wang, Li-Na; Yang, Bin-Xia; Ren, Qian; Liang, Hao-Yue; Ma, Xiao-Tong

    2014-12-01

    Transcription factor Twist-1 plays essential roles in specification and differentiation of mesoderm-derived tissues. Growing evidences now link Twist-1 to the acquisition of stem-cell-like properties. However, the role of Twist-1 in hematopoietic stem cell (HSC) remains largely uncharacterized. We report that Twist-1 is more highly expressed in murine HSC and its expression declines with differentiation. To investigate Twist-1 gene function, retroviral-mediated overexpression or removal experiments are performed. Competitive repopulation studies demonstrate that enforced expression of Twist-1 in HSC-enriched Lin(-) c-Kit(+) Sca-1(+) (LKS) cells results in an increase in the size of the G(0) population, and in their reconstitution ability after the first and a second transplantation. Conversely, removal of Twist-1 in LKS cells impairs their ability to repopulate. In addition, increased Twist-1 expression causes a shift toward production of myeloid cells. Twist-1 transduction in LKS cells activates myeloid lineage-determining factors PU.1 and GATA-1 and downregulates lymphoid factor GATA-3 in vitro, suggesting that Twist-1-mediated myeloid skewing occurs in hematopoietic stem and progenitor cells (HSPCs). These findings indicate that Twist-1 is not only involved in the maintenance of HSC dormancy and self-renewal capacity but also implicated in the myeloid lineage fate choice of HSPCs. Exploration of the underlying mechanisms reveals that Runx1/c-Mpl/Tie2 regulatory pathway could possibly account for the observed effects caused by Twist-1 overexpression. Our study provides the first evidence supporting a role for Twist-1 in hematopoiesis. PMID:25100001

  15. Myeloid cells and lymphangiogenesis.

    PubMed

    Zumsteg, Adrian; Christofori, Gerhard

    2012-06-01

    The lymphatic vascular system and the hematopoietic system are intimately connected in ontogeny and in physiology. During embryonic development, mammalian species derive a first lymphatic vascular plexus from the previously formed anterior cardinal vein, whereas birds and amphibians have a lymphatic vascular system of dual origin, composed of lymphatic endothelial cells (LECs) of venous origin combined with LECs derived from mesenchymal lymphangioblasts. The contribution of hematopoietic cells as building blocks of nascent lymphatic structures in mammals is still under debate. In contrast, the importance of myeloid cells to direct lymphatic vessel growth and function postnatally has been experimentally shown. For example, myeloid cells communicate with LECs via paracrine factors or cell-cell contacts, and they also can acquire lymphatic endothelial morphology and marker gene expression, a process reminiscent of developmental vasculogenesis. Here, we present an overview of the current understanding of how lymphatic vessels and the hematopoietic system, in particular myeloid cells, interact during embryonic development, in normal organ physiology, and in disease. PMID:22675661

  16. Regulation of surface expression of the granulocyte/macrophage colony-stimulating factor receptor in normal human myeloid cells

    SciTech Connect

    Cannistra, S.A.; Groshek, P.; Griffin, J.D. ); Garlick, R.; Miller, J. )

    1990-01-01

    Recombinant human granulocyte/macrophage colony-stimulating factor (GM-CSF) exerts stimulatory effects on hematopoietic cells through binding to specific, high-affinity receptors. By using radiolabeled GM-CSF with high specific activity, the authors have investigated the factors and mechanisms that regulate GM-CSF receptor expression in normal human neutrophils, monocytes, and partially purified bone marrow myeloid progenitor cells. The neutrophil GM-CSF receptor was found to rapidly internalize in the presence of ligand through a mechanism that required endocytosis. Out of a large panel of naturally occurring humoral factors tested, only GM-CSF itself, tumor necrosis factor, and formyl-Met-Leu-Phe were found to down-regulate neutrophil GM-CSF receptor expression after a 2-hr exposure at biologically active concentrations. Since formyl-Met-Leu-Phe is known to stimulate neutrophil protein kinase C activity, they also tested the ability of protein kinase C agonists to modulate GM-CSF receptor expression. Phorbol 12-myristate 13-acetate, bryostatin-1, and 1,2-dioctanoylglycerol were found to induce rapid down-regulation of the GM-CSF receptor in neutrophils, monocytes, and partially purified myeloid progenitor cells, suggesting that this effect may be at least partially mediated by protein kinase C. These data suggest that certain activators of neutrophil function may negatively regulate their biological effects by inducing down-regulation of the GM-CSF receptor.

  17. Fenretinide Targets Chronic Myeloid Leukemia Stem/Progenitor Cells by Regulation of Redox Signaling

    PubMed Central

    Du, Yanzhi; Xia, Yuan; Pan, Xiaoling; Chen, Zi; Wang, Aihua; Wang, Kankan; Li, Junmin

    2014-01-01

    Abstract Aims: We have recently shown that fenretinide preferentially targets CD34+ cells of acute myeloid leukemia (AML), and here, we test whether this agent exerts the effect on CD34+ cells of chronic myeloid leukemia (CML), which are refractory to imatinib. Results: As tested by colony-forming cell assays using clinical specimens, both number and size of total colonies derived from CD34+ CML cells were significantly reduced by fenretinide, and by combining fenretinide with imatinib. In particular, colonies derived from erythroid progenitors and more primitive pluripotent/multipotent progenitors were highly sensitive to fenretinide/fenretinide plus imatinib. Accordantly, fenretinide appeared to induce apoptosis in CD34+ CML cells, particularly with regard to the cells in the subpopulation of CD34+CD38−. Through cell quiescent assays, including Ki-67 negativity test, we added evidence that nonproliferative CD34+ CML cells were largely eliminated by fenretinide. Transcriptome and molecular data further showed that mechanisms underlying the apoptosis in CD34+ CML cells were highly complex, involving multiple events of oxidative stress responses. Innovation and Conclusion: As compared with CD34+ AML cells, the apoptotic effects of fenretinide on CD34+ CML cells were more prominent whereas less varied among the samples of different patients, and also various stress-responsive events appeared to be more robust in fenretinide-treated CD34+ CML cells. Thus, the combination of fenretinide with imatinib may represent a more sophisticated strategy for CML treatment, in which imatinib mainly targets leukemic blast cells through the intrinsic pathway of apopotosis, whereas fenretinide primarily targets CML stem/progenitor cells through the oxidative/endoplasmic reticulum stress-mediated pathway. Antioxid. Redox Signal. 20, 1866–1880. PMID:24021153

  18. Myeloid derived suppressor cells

    PubMed Central

    Waldron, Todd J.; Quatromoni, Jon G.; Karakasheva, Tatiana A.; Singhal, Sunil; Rustgi, Anil K.

    2013-01-01

    The goal of achieving measurable response with cancer immunotherapy requires counteracting the immunosuppressive characteristics of tumors. One of the mechanisms that tumors utilize to escape immunosurveillance is the activation of myeloid derived suppressor cells (MDSCs). Upon activation by tumor-derived signals, MDSCs inhibit the ability of the host to mount an anti-tumor immune response via their capacity to suppress both the innate and adaptive immune systems. Despite their relatively recent discovery and characterization, anti-MDSC agents have been identified, which may improve immunotherapy efficacy. PMID:23734336

  19. PU.1 affects proliferation of the human acute myeloid leukemia U937 cell line by directly regulating MEIS1

    PubMed Central

    ZHOU, JING; ZHANG, XIAOFENG; WANG, YUHUA; GUAN, YINGHUI

    2015-01-01

    The transcription factor PU.1 is a member of the ETS family, which is expressed in a wide variety of hematopoietic lineages. Accumulating evidence has indicated that PU.1 plays a key role in hematopoiesis, and reduced expression of PU.1 leads to the pathogenesis of human myeloid leukemia. As a multi-functional factor, PU.1 is also required for mixed lineage leukemia (MLL) stem cell potential and the development of MLL. However, the function of PU.1 in human non-MLL leukemia and its molecular mechanism remains poorly understood. In the present study, PU.1 siRNA was demonstrated to efficiently inhibit the transcription level of oncogene MEIS1 in the human acute myeloid non-MLL leukemia U937 cell line. In addition, PU.1, as a positive regulator of MEIS1, performed a crucial role in maintaining cell proliferation. Using electrophoretic mobility shift assay, chromatin immunoprecipitation analysis and luciferase reporter assay, previously unexplored evidence that PU.1 activated the MEIS1 promoter through a conserved binding motif in vitro and in vivo was further defined. Overall, the present study provides insight into the molecular mechanism of the contribution of PU.1 to the pathogenesis of non-MLL U937 cells, which is mediated by direct regulation of MEIS1 transcription. The present data reveal the possibility of developing an alternative therapy for non-MLL leukemia by targeting PU.1-mediated MEIS1 gene activation. PMID:26622774

  20. Particulate β-glucan regulates the immunosuppression of granulocytic myeloid-derived suppressor cells by inhibiting NFIA expression

    PubMed Central

    Tian, Xinyu; Tian, Jie; Tang, Xinyi; Rui, Ke; Zhang, Yue; Ma, Jie; Wang, Yungang; Xu, Huaxi; Lu, Liwei; Wang, Shengjun

    2015-01-01

    Myeloid-derived suppressor cells (MDSCs) are a heterogeneous group of cells which comprise two subsets: granulocytic MDSCs (G-MDSCs) and monocytic MDSCs (M-MDSCs). MDSCs involve in tumor-associated immune suppression by remarkably blocking effector T-cell activation and inducing expansion of regulatory T cells in the tumor microenvironment. The treatment that alters the suppression of MDSCs can effectively facilitate the antitumor immune responses. Recently, we showed that the whole β-glucan particles (WGPs) are capable of altering the suppression of MDSCs. However, the regulatory mechanism of MDSCs by WGP remains unknown. In this study, we found that the expression of nuclear factor I-A (NFIA), an integral transcriptional component of myeloid differentiation and lineage commitment, was inhibited by WGP in G-MDSCs. The effect of WGP on expression of NFIA was the c-jun molecule dependent via Dectin-1 pathway in vitro. Moreover, NFIA knockdown could alter the suppressive function of G-MDSCs, promote the antitumor immune responses and delay the tumor progression in tumor-bearing mice. Taken together, our results demonstrate a critical role of NFIA during WGP regulating the immunosuppression of G-MDSCs, with potential implications as an antitumor immune therapeutic approach. PMID:26405609

  1. Myeloid-derived suppressor cells contribute to systemic lupus erythaematosus by regulating differentiation of Th17 cells and Tregs.

    PubMed

    Ji, Jianjian; Xu, Jingjing; Zhao, Shuli; Liu, Fei; Qi, Jingjing; Song, Yuxian; Ren, Jing; Wang, Tingting; Dou, Huan; Hou, Yayi

    2016-08-01

    Although major advancements have made in investigating the aetiology of SLE (systemic lupus erythaematosus), the role of MDSCs (myeloid-derived suppressor cells) in SLE progression remains confused. Recently, some studies have revealed that MDSCs play an important role in lupus mice. However, the proportion and function of MDSCs in lupus mice and SLE patients are still poorly understood. In the present study, we investigated the proportion and function of MDSCs using different stages of MRL/lpr lupus mice and specimens from SLE patients with different activity. Results showed that splenic granulocytic (G-)MDSCs were significantly expanded by increasing the expression of CCR1 (CC chemokine receptor 1) in diseased MRL/lpr lupus mice and in high-disease-activity SLE patients. However, the proportion of monocytic (M-)MDSCs remains similar in MRL/lpr lupus mice and SLE patients. G-MDSCs produce high levels of ROS (reactive oxygen species) through increasing gp91(phox) expression, and activated TLR2 (Toll-like receptor 2) and AIM2 (absent in melanoma 2) inflammasome in M-MDSCs lead to IL-1β (interleukin 1β) expression in diseased MRL/lpr mice and high-disease-activity SLE patients. Previous study has revealed that MDSCs could alter the plasticity of Th17 (T helper 17) cells and Tregs (regulatory T-cells) via ROS and IL-1β. Co-culture experiments showed that G-MDSCs impaired Treg differentiation via ROS and M-MDSCs promoted Th17 cell polarization by IL-1β in vitro Furthermore, adoptive transfer or antibody depletion of MDSCs in MRL/lpr mice confirmed that MDSCs influenced the imbalance of Tregs and Th17 cells in vivo Our results indicate that MDSCs with the capacity to regulate Th17 cell/Treg balance may be a critical pathogenic factor in SLE. PMID:27231253

  2. Kindlin-3 interacts with the ribosome and regulates c-Myc expression required for proliferation of chronic myeloid leukemia cells

    PubMed Central

    Qu, Jing; Ero, Rya; Feng, Chen; Ong, Li-Teng; Tan, Hui-Foon; Lee, Hui-Shan; Ismail, Muhammad HB; Bu, Wen-Ting; Nama, Srikanth; Sampath, Prabha; Gao, Yong-Gui; Tan, Suet-Mien

    2015-01-01

    Kindlins are FERM-containing cytoplasmic proteins that regulate integrin-mediated cell-cell and cell-extracellular matrix (ECM) attachments. Kindlin-3 is expressed in hematopoietic cells, platelets, and endothelial cells. Studies have shown that kindlin-3 stabilizes cell adhesion mediated by ß1, ß2, and ß3 integrins. Apart from integrin cytoplasmic tails, kindlins are known to interact with other cytoplasmic proteins. Here we demonstrate that kindlin-3 can associate with ribosome via the receptor for activated-C kinase 1 (RACK1) scaffold protein based on immunoprecipitation, ribosome binding, and proximity ligation assays. We show that kindlin-3 regulates c-Myc protein expression in the human chronic myeloid leukemia cell line K562. Cell proliferation was reduced following siRNA reduction of kindlin-3 expression and a significant reduction in tumor mass was observed in xenograft experiments. Mechanistically, kindlin-3 is involved in integrin α5ß1-Akt-mTOR-p70S6K signaling; however, its regulation of c-Myc protein expression could be independent of this signaling axis. PMID:26677948

  3. Runx1 Regulates Myeloid Precursor Differentiation Into Osteoclasts Without Affecting Differentiation Into Antigen Presenting or Phagocytic Cells in Both Males and Females.

    PubMed

    Paglia, David N; Yang, Xiaochuan; Kalinowski, Judith; Jastrzebski, Sandra; Drissi, Hicham; Lorenzo, Joseph

    2016-08-01

    Runt-related transcription factor 1 (Runx1), a master regulator of hematopoiesis, is expressed in preosteoclasts. Previously we evaluated the bone phenotype of CD11b-Cre Runx1(fl/fl) mice and demonstrated enhanced osteoclasts and decreased bone mass in males. However, an assessment of the effects of Runx1 deletion in female osteoclast precursors was impossible with this model. Moreover, the role of Runx1 in myeloid cell differentiation into other lineages is unknown. Therefore, we generated LysM-Cre Runx1(fl/fl) mice, which delete Runx1 equally (∼80% deletion) in myeloid precursor cells from both sexes and examined the capacity of these cells to differentiate into osteoclasts and phagocytic and antigen-presenting cells. Both female and male LysM-Cre Runx1(fl/fl) mice had decreased trabecular bone mass (72% decrease in bone volume fraction) and increased osteoclast number (2-3 times) (P < .05) without alteration of osteoblast histomorphometric indices. We also demonstrated that loss of Runx1 in pluripotential myeloid precursors with LysM-Cre did not alter the number of myeloid precursor cells in bone marrow or their ability to differentiate into phagocytizing or antigen-presenting cells. This study demonstrates that abrogation of Runx1 in multipotential myeloid precursor cells significantly and specifically enhanced the ability of receptor activator of nuclear factor-κB ligand to stimulate osteoclast formation and fusion in female and male mice without affecting other myeloid cell fates. In turn, increased osteoclast activity in LysM-Cre Runx1(fl/fl) mice likely contributed to a decrease in bone mass. These dramatic effects were not due to increased osteoclast precursors in the deleted mutants and argue that inhibition of Runx1 in multipotential myeloid precursor cells is important for osteoclast formation and function. PMID:27267711

  4. Influence of DNA-methylation on zinc homeostasis in myeloid cells: Regulation of zinc transporters and zinc binding proteins.

    PubMed

    Kessels, Jana Elena; Wessels, Inga; Haase, Hajo; Rink, Lothar; Uciechowski, Peter

    2016-09-01

    The distribution of intracellular zinc, predominantly regulated through zinc transporters and zinc binding proteins, is required to support an efficient immune response. Epigenetic mechanisms such as DNA methylation are involved in the expression of these genes. In demethylation experiments using 5-Aza-2'-deoxycytidine (AZA) increased intracellular (after 24 and 48h) and total cellular zinc levels (after 48h) were observed in the myeloid cell line HL-60. To uncover the mechanisms that cause the disturbed zinc homeostasis after DNA demethylation, the expression of human zinc transporters and zinc binding proteins were investigated. Real time PCR analyses of 14 ZIP (solute-linked carrier (SLC) SLC39A; Zrt/IRT-like protein), and 9 ZnT (SLC30A) zinc transporters revealed significantly enhanced mRNA expression of the zinc importer ZIP1 after AZA treatment. Because ZIP1 protein was also enhanced after AZA treatment, ZIP1 up-regulation might be the mediator of enhanced intracellular zinc levels. The mRNA expression of ZIP14 was decreased, whereas zinc exporter ZnT3 mRNA was also significantly increased; which might be a cellular reaction to compensate elevated zinc levels. An enhanced but not significant chromatin accessibility of ZIP1 promoter region I was detected by chromatin accessibility by real-time PCR (CHART) assays after demethylation. Additionally, DNA demethylation resulted in increased mRNA accumulation of zinc binding proteins metallothionein (MT) and S100A8/S100A9 after 48h. MT mRNA was significantly enhanced after 24h of AZA treatment also suggesting a reaction of the cell to restore zinc homeostasis. These data indicate that DNA methylation is an important epigenetic mechanism affecting zinc binding proteins and transporters, and, therefore, regulating zinc homeostasis in myeloid cells. PMID:26905204

  5. Sphingosine kinase-1 is a downstream regulator of imatinib-induced apoptosis in chronic myeloid leukemia cells.

    PubMed

    Bonhoure, E; Lauret, A; Barnes, D J; Martin, C; Malavaud, B; Kohama, T; Melo, J V; Cuvillier, O

    2008-05-01

    We examined the involvement of sphingosine kinase-1 (SphK1), which governs the ceramide/sphingosine-1-phosphate balance, in susceptibility to imatinib of either sensitive or resistant chronic myeloid leukemia cells. Imatinib-sensitive LAMA84-s displayed marked SphK1 inhibition coupled with increased content of ceramide and decreased pro-survival sphingosine-1-phosphate. Conversely, no changes in the sphingolipid metabolism were observed in LAMA84-r treated with imatinib. Overcoming imatinib resistance in LAMA84-r with farnesyltransferase or MEK/ERK inhibitors as well as with cytosine arabinoside led to SphK1 inhibition. Overexpression of SphK1 in LAMA84-s cells impaired apoptosis and inhibited the effects of imatinib on caspase-3 activation, cytochrome c and Smac release from mitochondria through modulation of Bim, Bcl-xL and Mcl-1 expression. Pharmacological inhibition of SphK1 with F-12509a or its silencing by siRNA induced apoptosis of both imatinib-sensitive and -resistant cells, suggesting that SphK1 inhibition was critical for apoptosis signaling. We also show that imatinib-sensitive and -resistant primary cells from chronic myeloid leukemia patients can be successfully killed in vitro by the F-12509a inhibitor. These results uncover the involvement of SphK1 in regulating imatinib-induced apoptosis and establish that SphK1 is a downstream effector of the Bcr-Abl/Ras/ERK pathway inhibited by imatinib but upstream regulator of Bcl-2 family members. PMID:18401414

  6. Myeloid Cells in Cutaneous Wound Repair.

    PubMed

    Cash, Jenna L; Martin, Paul

    2016-06-01

    Cutaneous wound repair is a complex, dynamic process with the goal of rapidly sealing any breach in the skin's protective barrier. Myeloid cells compose a significant proportion of the inflammatory cells recruited to a wound site and play important roles in decontaminating the injured tissue of any invading microorganisms. Subsequently, myeloid cells are able to influence many aspects of the healing response, in part through their capacity to release a large array of signaling molecules that allow them to communicate with and regulate the behavior of other wound cells and in turn, be themselves exquisitely regulated by the wound microenvironment. Macrophages, for example, appear to play important, temporally changing roles in the initiation of scarring and subsequently in matrix remodeling to resolve fibrosis. In this way, myeloid cells seem to play both positive (e.g., pathogen killing and matrix remodeling) and negative (e.g., scarring) roles in wound repair. Further research is of course needed to elucidate the precise temporal and spatial myeloid cell phenotypes and behaviors and ultimately to design effective strategies to optimize the beneficial functions of these cells while minimizing their detrimental contributions to improve wound healing in the clinic. PMID:27337466

  7. Cancer-Associated Myeloid Regulatory Cells.

    PubMed

    De Vlaeminck, Yannick; González-Rascón, Anna; Goyvaerts, Cleo; Breckpot, Karine

    2016-01-01

    Myeloid cells are critically involved in the pathophysiology of cancers. In the tumor microenvironment (TME), they comprise tumor-associated macrophages (TAMs), neutrophils (TANs), dendritic cells, and myeloid-derived suppressor cells, which are further subdivided into a monocytic subset and a granulocytic subset. Some of these myeloid cells, in particular TAMs and TANs, are divided into type 1 or type 2 cells, according to the paradigm of T helper type 1 or type 2 cells. Type 1-activated cells are generally characterized as cells that aid tumor rejection, while all other myeloid cells are shown to favor tumor progression. Moreover, these cells are often at the basis of resistance to various therapies. Much research has been devoted to study the biology of myeloid cells. This endeavor has proven to be challenging, as the markers used to categorize myeloid cells in the TME are not restricted to particular subsets. Also from a functional and metabolic point of view, myeloid cells share many features. Finally, myeloid cells are endowed with a certain level of plasticity, which further complicates studying them outside their environment. In this article, we challenge the exclusive use of cell markers to unambiguously identify myeloid cell subsets in the TME. We further propose to divide myeloid cells into myeloid regulatory or stimulatory cells according to their pro- or antitumor function, because we contend that for therapeutic purposes it is not targeting the cell subsets but rather targeting their protumor traits; hence, myeloid regulatory cells will push antitumor immunotherapy to the next level. PMID:27065074

  8. Cancer-Associated Myeloid Regulatory Cells

    PubMed Central

    De Vlaeminck, Yannick; González-Rascón, Anna; Goyvaerts, Cleo; Breckpot, Karine

    2016-01-01

    Myeloid cells are critically involved in the pathophysiology of cancers. In the tumor microenvironment (TME), they comprise tumor-associated macrophages (TAMs), neutrophils (TANs), dendritic cells, and myeloid-derived suppressor cells, which are further subdivided into a monocytic subset and a granulocytic subset. Some of these myeloid cells, in particular TAMs and TANs, are divided into type 1 or type 2 cells, according to the paradigm of T helper type 1 or type 2 cells. Type 1-activated cells are generally characterized as cells that aid tumor rejection, while all other myeloid cells are shown to favor tumor progression. Moreover, these cells are often at the basis of resistance to various therapies. Much research has been devoted to study the biology of myeloid cells. This endeavor has proven to be challenging, as the markers used to categorize myeloid cells in the TME are not restricted to particular subsets. Also from a functional and metabolic point of view, myeloid cells share many features. Finally, myeloid cells are endowed with a certain level of plasticity, which further complicates studying them outside their environment. In this article, we challenge the exclusive use of cell markers to unambiguously identify myeloid cell subsets in the TME. We further propose to divide myeloid cells into myeloid regulatory or stimulatory cells according to their pro- or antitumor function, because we contend that for therapeutic purposes it is not targeting the cell subsets but rather targeting their protumor traits; hence, myeloid regulatory cells will push antitumor immunotherapy to the next level. PMID:27065074

  9. Increased expression of PcG protein YY1 negatively regulates B cell development while allowing accumulation of myeloid cells and LT-HSC cells.

    PubMed

    Pan, Xuan; Jones, Morgan; Jiang, Jie; Zaprazna, Kristina; Yu, Duonan; Pear, Warren; Maillard, Ivan; Atchison, Michael L

    2012-01-01

    Ying Yang 1 (YY1) is a multifunctional Polycomb Group (PcG) transcription factor that binds to multiple enhancer binding sites in the immunoglobulin (Ig) loci and plays vital roles in early B cell development. PcG proteins have important functions in hematopoietic stem cell renewal and YY1 is the only mammalian PcG protein with DNA binding specificity. Conditional knock-out of YY1 in the mouse B cell lineage results in arrest at the pro-B cell stage, and dosage effects have been observed at various YY1 expression levels. To investigate the impact of elevated YY1 expression on hematopoetic development, we utilized a mouse in vivo bone marrow reconstitution system. We found that mouse bone marrow cells expressing elevated levels of YY1 exhibited a selective disadvantage as they progressed from hematopoietic stem/progenitor cells to pro-B, pre-B, immature B and re-circulating B cell stages, but no disadvantage of YY1 over-expression was observed in myeloid lineage cells. Furthermore, mouse bone marrow cells expressing elevated levels of YY1 displayed enrichment for cells with surface markers characteristic of long-term hematopoietic stem cells (HSC). YY1 expression induced apoptosis in mouse B cell lines in vitro, and resulted in down-regulated expression of anti-apoptotic genes Bcl-xl and NFκB2, while no impact was observed in a mouse myeloid line. B cell apoptosis and LT-HSC enrichment induced by YY1 suggest that novel strategies to induce YY1 expression could have beneficial effects in the treatment of B lineage malignancies while preserving normal HSCs. PMID:22292011

  10. Long intergenic non-coding RNA HOTAIRM1 regulates cell cycle progression during myeloid maturation in NB4 human promyelocytic leukemia cells

    PubMed Central

    Zhang, Xueqing; Weissman, Sherman M; Newburger, Peter E

    2014-01-01

    HOTAIRM1 is a long intergenic non-coding RNA encoded in the human HOXA gene cluster, with gene expression highly specific for maturing myeloid cells. Knockdown of HOTAIRM1 in the NB4 acute promyelocytic leukemia cell line retarded all-trans retinoid acid (ATRA)-induced granulocytic differentiation, resulting in a significantly larger population of immature and proliferating cells that maintained cell cycle progression from G1 to S phases. Correspondingly, HOTAIRM1 knockdown resulted in retained expression of many otherwise ATRA-suppressed cell cycle and DNA replication genes, and abated ATRA induction of cell surface leukocyte activation, defense response, and other maturation-related genes. Resistance to ATRA-induced cell cycle arrest at the G1/S phase transition in knockdown cells was accompanied by retained expression of ITGA4 (CD49d) and decreased induction of ITGAX (CD11c). The coupling of cell cycle progression with temporal dynamics in the expression patterns of these integrin genes suggests a regulated switch to control the transit from the proliferative phase to granulocytic maturation. Furthermore, ITGAX was among a small number of genes showing perturbation in transcript levels upon HOTAIRM1 knockdown even without ATRA treatment, suggesting a direct pathway of regulation. These results indicate that HOTAIRM1 provides a regulatory link in myeloid maturation by modulating integrin-controlled cell cycle progression at the gene expression level. PMID:24824789

  11. Macrophage colony-stimulating factor receptor marks and regulates a fetal myeloid-primed B-cell progenitor in mice

    PubMed Central

    Zriwil, Alya; Böiers, Charlotta; Wittmann, Lilian; Green, Joanna C. A.; Woll, Petter S.; Jacobsen, Sten Eirik W.

    2016-01-01

    Although it is well established that unique B-cell lineages develop through distinct regulatory mechanisms during embryonic development, much less is understood about the differences between embryonic and adult B-cell progenitor cells, likely to underpin the genetics and biology of infant and childhood PreB acute lymphoblastic leukemia (PreB-ALL), initiated by distinct leukemia-initiating translocations during embryonic development. Herein, we establish that a distinct subset of the earliest CD19+ B-cell progenitors emerging in the E13.5 mouse fetal liver express the colony-stimulating factor-1 receptor (CSF1R), previously thought to be expressed, and play a lineage-restricted role in development of myeloid lineages, and macrophages in particular. These early embryonic CSF1R+CD19+ ProB cells also express multiple other myeloid genes and, in line with this, possess residual myeloid as well as B-cell, but not T-cell lineage potential. Notably, these CSF1R+ myeloid-primed ProB cells are uniquely present in a narrow window of embryonic fetal liver hematopoiesis and do not persist in adult bone marrow. Moreover, analysis of CSF1R-deficient mice establishes a distinct role of CSF1R in fetal B-lymphopoiesis. CSF1R+ myeloid-primed embryonic ProB cells are relevant for infant and childhood PreB-ALLs, which frequently have a bi-phenotypic B-myeloid phenotype, and in which CSF1R-rearrangements have recently been reported. PMID:27207794

  12. Macrophage colony-stimulating factor receptor marks and regulates a fetal myeloid-primed B-cell progenitor in mice.

    PubMed

    Zriwil, Alya; Böiers, Charlotta; Wittmann, Lilian; Green, Joanna C A; Woll, Petter S; Jacobsen, Sten Eirik W; Sitnicka, Ewa

    2016-07-14

    Although it is well established that unique B-cell lineages develop through distinct regulatory mechanisms during embryonic development, much less is understood about the differences between embryonic and adult B-cell progenitor cells, likely to underpin the genetics and biology of infant and childhood PreB acute lymphoblastic leukemia (PreB-ALL), initiated by distinct leukemia-initiating translocations during embryonic development. Herein, we establish that a distinct subset of the earliest CD19(+) B-cell progenitors emerging in the E13.5 mouse fetal liver express the colony-stimulating factor-1 receptor (CSF1R), previously thought to be expressed, and play a lineage-restricted role in development of myeloid lineages, and macrophages in particular. These early embryonic CSF1R(+)CD19(+) ProB cells also express multiple other myeloid genes and, in line with this, possess residual myeloid as well as B-cell, but not T-cell lineage potential. Notably, these CSF1R(+) myeloid-primed ProB cells are uniquely present in a narrow window of embryonic fetal liver hematopoiesis and do not persist in adult bone marrow. Moreover, analysis of CSF1R-deficient mice establishes a distinct role of CSF1R in fetal B-lymphopoiesis. CSF1R(+) myeloid-primed embryonic ProB cells are relevant for infant and childhood PreB-ALLs, which frequently have a bi-phenotypic B-myeloid phenotype, and in which CSF1R-rearrangements have recently been reported. PMID:27207794

  13. Antigen-specific CD4(+) T cells regulate function of myeloid-derived suppressor cells in cancer via retrograde MHC class II signaling.

    PubMed

    Nagaraj, Srinivas; Nelson, Allison; Youn, Je-in; Cheng, Pingyan; Quiceno, David; Gabrilovich, Dmitry I

    2012-02-15

    Myeloid-derived suppressor cells (MDSC) play a major role in cancer-related immune suppression, yet the nature of this suppression remains controversial. In this study, we evaluated the ability of MDSCs to elicit CD4(+) T-cell tolerance in different mouse tumor models. In contrast to CD8(+) T-cell tolerance, which could be induced by MDSCs in all the tumor models tested, CD4(+) T-cell tolerance could be elicited in only one of the models (MC38) in which a substantial level of MHC class II was expressed on MDSCs compared with control myeloid cells. Mechanistic investigations revealed that MDSCs deficient in MHC class II could induce tolerance to CD8(+) T cells but not to CD4(+) T cells. Unexpectedly, antigen-specific CD4(+) T cells (but not CD8(+) T cells) could dramatically enhance the immune suppressive activity of MDSCs by converting them into powerful nonspecific suppressor cells. This striking effect was mediated by direct cell-cell contact through cross-linking of MHC class II on MDSCs. We also implicated an Ets-1 transcription factor-regulated increase in expression of Cox-2 and prostaglandin E2 in MDSCs in mediating this effect. Together, our findings suggest that activated CD4(+) T cells that are antigen specific may enhance the immune suppressive activity of MDSCs, a mechanism that might serve normally as a negative feedback loop to control immune responses that becomes dysregulated in cancer. PMID:22237629

  14. The stress-response sensor Chop regulates the function and accumulation of myeloid-derived suppressor cells in tumors

    PubMed Central

    Thevenot, Paul T.; Sierra, Rosa A.; Raber, Patrick L.; Al-Khami, Amir A.; Trillo-Tinoco, Jimena; Zarreii, Parisa; Ochoa, Augusto C.; Cui, Yan; Del Valle, Luis; Rodriguez, Paulo C.

    2014-01-01

    Summary Adaptation of malignant cells to the hostile milieu present in tumors is an important determinant for their survival and growth. However, the interaction between tumor-linked stress and anti-tumor immunity remains poorly characterized. Here, we show the critical role of the cellular stress sensor C/EBP-homologous protein (Chop) in the accumulation and immune inhibitory activity of tumor-infiltrating myeloid-derived suppressor cells (MDSCs). MDSCs lacking Chop had decreased immune regulatory functions and showed the ability to prime T cell function and induce anti-tumor responses. Chop expression in MDSCs was induced by tumor-linked reactive oxygen and nitrogen species and regulated by the activating-transcription factor-4. Chop-deficient MDSCs displayed reduced signaling through CCAAT/enhancer-binding protein-β, leading to a decreased production of interleukin-6 (IL-6) and low expression phospho-STAT3. IL-6 over-expression restored immune suppressive activity of Chop-deficient MDSCs. These findings suggest the role of Chop in tumor-induced tolerance and the therapeutic potential of targeting Chop in MDSCs for cancer immunotherapy. PMID:25238096

  15. Resveratrol triggers apoptosis through regulating ceramide metabolizing genes in human K562 chronic myeloid leukemia cells.

    PubMed

    Kartal, Melis; Saydam, Guray; Sahin, Fahri; Baran, Yusuf

    2011-01-01

    Resveratrol, an important phytoalexin in many plants, has been reported to have cytotoxic effects on various types of cancer. Ceramide is a bioactive sphingolipid that regulates many signaling pathways, including cell growth and proliferation, senescence and quiescence, apoptosis, and cell cycle. Ceramides are generated by longevity assurance genes (LASS). Glucosylceramide synthase (GCS) and sphingosine kinase-1 (SK-1) enzymes can convert ceramides to antiapoptotic molecules, glucosylceramide, and sphingosine-1-phosphate, respectively. C8:ceramide, an important cell-permeable analogue of natural ceramides, increases intracellular ceramide levels significantly, while 1-phenyl-2-decanoylamino-3-morpholino-1-propanol (PDMP) and SK-1 inhibitor increase accumulation of ceramides by inhibiting GCS and SK-1, respectively. Chronic myelogenous leukemia (CML) is a hematological disorder resulting from generation of BCR/ABL oncogene. In this study, we examined the roles of ceramide metabolizing genes in resveratrol-induced apoptosis in K562 CML cells. There were synergistic cytotoxic and apoptotic effects of resveratrol with coadministration of C8:ceramide, PDMP, and SK-1 inhibitor. Interestingly, there were also significant increases in expression levels of LASS genes and decreases in expression levels of GCS and SK-1 in K562 cells in response to resveratrol. Our data, in total, showed for the first time that resveratrol might kill CML cells through increasing intracellular generation and accumulation of apoptotic ceramides. PMID:21500096

  16. Protection of human myeloid dendritic cell subsets against influenza A virus infection is differentially regulated upon TLR stimulation.

    PubMed

    Baharom, Faezzah; Thomas, Saskia; Bieder, Andrea; Hellmér, Maria; Volz, Julia; Sandgren, Kerrie J; McInerney, Gerald M; Karlsson Hedestam, Gunilla B; Mellman, Ira; Smed-Sörensen, Anna

    2015-05-01

    The proinflammatory microenvironment in the respiratory airway induces maturation of both resident and infiltrating dendritic cells (DCs) upon influenza A virus (IAV) infection. This results in upregulation of antiviral pathways as well as modulation of endocytic processes, which affect the susceptibility of DCs to IAV infection. Therefore, it is highly relevant to understand how IAV interacts with and infects mature DCs. To investigate how different subsets of human myeloid DCs (MDCs) involved in tissue inflammation are affected by inflammatory stimulation during IAV infection, we stimulated primary blood MDCs and inflammatory monocyte-derived DCs (MDDCs) with TLR ligands, resulting in maturation. Interestingly, MDDCs but not MDCs were protected against IAV infection after LPS (TLR4) stimulation. In contrast, stimulation with TLR7/8 ligand protected MDCs but not MDDCs from IAV infection. The reduced susceptibility to IAV infection correlated with induction of type I IFNs. We found that differential expression of TLR4, TRIF, and MyD88 in the two MDC subsets regulated the ability of the cells to enter an antiviral state upon maturation. This difference was functionally confirmed using small interfering RNA and inhibitors. Our data show that different human MDC subsets may play distinct roles during IAV infection, as their capacity to induce type I IFNs is dependent on TLR-specific maturation, resulting in differential susceptibility to IAV infection. PMID:25801434

  17. PU.1 (Spi-1) and C/EBP alpha regulate the granulocyte colony-stimulating factor receptor promoter in myeloid cells.

    PubMed

    Smith, L T; Hohaus, S; Gonzalez, D A; Dziennis, S E; Tenen, D G

    1996-08-15

    Cytokines, important for lineage commitment and differentiation during hematopoiesis, exert their influence by binding specific receptors. Receptor expression is tightly regulated and examining the factors that govern their expression will allow better understanding of the events that determine lineage commitment. The granulocyte colony-stimulating factor (G-CSF) receptor is expressed exclusively in myeloid cells and the placenta. We show here that the G-CSF receptor transcription start site is identical in each of these tissues. A 1,391-bp fragment of the G-CSF receptor promoter is both active in myeloid cell lines and tissue specific. We have also found two regions that are important for G-CSF receptor promoter activity. One region, located at bp -49, contains a GCAAT site that specifically binds the C/EBP alpha transcription factor in myeloid nuclear extracts. Mutation of this site prevents C/EBP alpha binding and reduces promoter activity by 60%. The other functionally important region of the G-CSF receptor promoter is in the 5' untranslated region, at bp +36 and +43, where there are two sites for the ets family member PU.1. Mutation of these sites prevents PU.1 binding and reduces promoter activity by 75%. These results reinforce the importance of both PU.1 and C/EBP alpha in the expression of myeloid-specific genes and neutrophil development. PMID:8695841

  18. UPF1 regulates myeloid cell functions and S100A9 expression by the hnRNP E2/miRNA-328 balance

    PubMed Central

    Saul, Meike J.; Stein, Stefan; Grez, Manuel; Jakobsson, Per-Johan; Steinhilber, Dieter; Suess, Beatrix

    2016-01-01

    UPF1 is a key player in nonsense mediated mRNA decay (NMD) but also involved in posttranscriptional gene regulation. In this study we found that UPF1 regulates the expression of genes with functions in inflammation and myeloid cell differentiation via hnRNP E2. The majority of the UPF1-regulated genes identified in monocytic cells contain a binding site for hnRNP E2 within 5′ UTR located introns with hnRNP E2 acting here as splicing regulator. We found that miRNA-328 which is significantly induced during monocytic cell differentiation acts independently from its gene silencing function as RNA decoy for hnRNP E2. One representative gene controlled by the hnRNP E2/miRNA-328 balance is S100A9 which plays an important role in cell differentiation and oxidative stress response of monocytes. Induction of miRNA-328 expression during cell differentiation antagonizes the blockade by hnRNP E2 which results in the upregulation of CD11b expression and ROS production in monocytic cells. Taken together, our data indicate that upregulation of miR-328 is responsible for the induction of hnRNP E2 target genes during myeloid cell differentiation. PMID:27573788

  19. UPF1 regulates myeloid cell functions and S100A9 expression by the hnRNP E2/miRNA-328 balance.

    PubMed

    Saul, Meike J; Stein, Stefan; Grez, Manuel; Jakobsson, Per-Johan; Steinhilber, Dieter; Suess, Beatrix

    2016-01-01

    UPF1 is a key player in nonsense mediated mRNA decay (NMD) but also involved in posttranscriptional gene regulation. In this study we found that UPF1 regulates the expression of genes with functions in inflammation and myeloid cell differentiation via hnRNP E2. The majority of the UPF1-regulated genes identified in monocytic cells contain a binding site for hnRNP E2 within 5' UTR located introns with hnRNP E2 acting here as splicing regulator. We found that miRNA-328 which is significantly induced during monocytic cell differentiation acts independently from its gene silencing function as RNA decoy for hnRNP E2. One representative gene controlled by the hnRNP E2/miRNA-328 balance is S100A9 which plays an important role in cell differentiation and oxidative stress response of monocytes. Induction of miRNA-328 expression during cell differentiation antagonizes the blockade by hnRNP E2 which results in the upregulation of CD11b expression and ROS production in monocytic cells. Taken together, our data indicate that upregulation of miR-328 is responsible for the induction of hnRNP E2 target genes during myeloid cell differentiation. PMID:27573788

  20. Hydrogen Sulfide Attenuates the Recruitment of CD11b+Gr-1+ Myeloid Cells and Regulates Bax/Bcl-2 Signaling in Myocardial Ischemia Injury

    PubMed Central

    Zhang, Youen; Li, Hua; Zhao, Gang; Sun, Aijun; Zong, Nobel C.; Li, Zhaofeng; Zhu, Hongming; Zou, Yunzeng; Yang, Xiangdong; Ge, Junbo

    2014-01-01

    Hydrogen sulfide, an endogenous signaling molecule, plays an important role in the physiology and pathophysiology of the cardiovascular system. Using a mouse model of myocardial infarction, we investigated the anti-inflammatory and anti-apoptotic effects of the H2S donor sodium hydrosulfide (NaHS). The results demonstrated that the administration of NaHS improved survival, preserved left ventricular function, limited infarct size, and improved H2S levels in cardiac tissue to attenuate the recruitment of CD11b+Gr-1+ myeloid cells and to regulate the Bax/Bcl-2 pathway. Furthermore, the cardioprotective effects of NaHS were enhanced by inhibiting the migration of CD11b+Gr-1+ myeloid cells from the spleen into the blood and by attenuating post-infarction inflammation. These observations suggest that the novel mechanism underlying the cardioprotective function of H2S is secondary to a combination of attenuation the recruitment of CD11b+Gr-1+ myeloid cells and regulation of the Bax/Bcl-2 apoptotic signaling. PMID:24758901

  1. Hepatitis C virus-induced myeloid-derived suppressor cells regulate T-cell differentiation and function via the signal transducer and activator of transcription 3 pathway.

    PubMed

    Ren, Jun P; Zhao, Juan; Dai, Jun; Griffin, Jeddidiah W D; Wang, Ling; Wu, Xiao Y; Morrison, Zheng D; Li, Guang Y; El Gazzar, Mohamed; Ning, Shun B; Moorman, Jonathan P; Yao, Zhi Q

    2016-08-01

    T cells play a pivotal role in controlling viral infection; however, the precise mechanisms responsible for regulating T-cell differentiation and function during infections are incompletely understood. In this study, we demonstrated an expansion of myeloid-derived suppressor cells (MDSCs), in particular the monocytic MDSCs (M-MDSCs; CD14(+) CD33(+) CD11b(+) HLA-DR(-/low) ), in patients with chronic hepatitis C virus (HCV) infection. Notably, HCV-induced M-MDSCs express high levels of phosphorylated signal transducer and activator of transcription 3 (pSTAT3) and interleukin-10 (IL-10) compared with healthy subjects. Blocking STAT3 signalling reduced HCV-mediated M-MDSC expansion and decreased IL-10 expression. Importantly, we observed a significant increase in the numbers of CD4(+) CD25(+) Foxp3(+) regulatory T (Treg) cells following incubation of healthy peripheral blood mononuclear cells (PBMCs) with MDSCs derived from HCV-infected patients or treated with HCV core protein. In addition, depletion of MDSCs from PBMCs led to a significant reduction of Foxp3(+) Treg cells developed during chronic HCV infection. Moreover, depletion of MDSCs from PBMCs significantly increased interferon-γ production by CD4(+) T effector (Teff) cells derived from HCV patients. These results suggest that HCV-induced MDSCs promote Treg cell development and inhibit Teff cell function, suggesting a novel mechanism for T-cell regulation and a new strategy for immunotherapy against human viral diseases. PMID:27149428

  2. Lack of Muc1-regulated beta-catenin stability results in aberrant expansion of CD11b+Gr1+ myeloid derived suppressor cells from the bone marrow

    PubMed Central

    Poh, Tze Wei; Bradley, Judy M.; Mukherjee, Pinku; Gendler, Sandra J.

    2009-01-01

    Myeloid Derived Suppressor Cells (MDSCs) are a heterogeneous population of myeloid cells that inhibit T cell activity and contribute to the immune suppression characteristic of most tumors. We discovered that bone marrow (BM) progenitor cells from the Muc1 knockout (KO) mice differentiated into CD11b+Gr1+ MDSCs in vitro under GM-CSF and IL-4 signaling. MUC1 is a tumor-associated mucin and its cytoplasmic tail (MUC1-CT) can regulate beta-catenin to promote oncogenesis. Given the importance of beta-catenin in hematopoiesis, we hypothesized that the MUC1 regulation of beta-catenin is important for MDSC development. Our current study shows that the aberrant development of BM progenitors into CD11b+Gr1+ MDSCs is dependent on the down regulation of beta-catenin levels that occurs in the absence of Muc1. In light of this, KO mice showed enhanced EL4 tumor growth and were able to better tolerate allogeneic BM185 tumor growth, with an accumulation of CD11b+Gr1+ cells in the blood and tumor draining lymph nodes. WT mice were able to similarly tolerate allogeneic tumor growth when they were injected with CD11b+Gr1+ cells from tumor-bearing KO mice, suggesting that tolerance of allogeneic tumors is dependent on MDSC-mediated immune suppression. This further delineates the ability of Muc1 to control MDSC development which could directly impact tumorigenesis. Knowledge of the biology by which Muc1 regulates the development of myeloid progenitors into MDSCs would also be very useful in enhancing the efficacy of cancer vaccines in the face of tumor immune suppression. PMID:19351842

  3. Emerging role of CD300 receptors in regulating myeloid cell efferocytosis.

    PubMed

    Voss, Oliver H; Tian, Linjie; Murakami, Yousuke; Coligan, John E; Krzewski, Konrad

    2015-01-01

    Engulfment of apoptotic cells is predominantly executed by phagocytes via the recognition of "eat me" signals like phosphatidylserine (PS). Various PS-specific receptors exist on phagocytes, including Tyro3, Axl, and MerTK receptor tyrosine kinases (TAMs), T-cell immunoglobulin and mucin domain containing 1 and 4 (TIM1/4), and the newly identified CD300 family. The aim of the present auto-commentary is to highlight recent findings regarding the Cd300lf and Cd300lb receptors and their emerging roles in the development of autoimmune disease. PMID:27308512

  4. Emerging role of CD300 receptors in regulating myeloid cell efferocytosis

    PubMed Central

    Voss, Oliver H; Tian, Linjie; Murakami, Yousuke; Coligan, John E; Krzewski, Konrad

    2015-01-01

    Engulfment of apoptotic cells is predominantly executed by phagocytes via the recognition of “eat me” signals like phosphatidylserine (PS). Various PS-specific receptors exist on phagocytes, including Tyro3, Axl, and MerTK receptor tyrosine kinases (TAMs), T-cell immunoglobulin and mucin domain containing 1 and 4 (TIM1/4), and the newly identified CD300 family. The aim of the present auto-commentary is to highlight recent findings regarding the Cd300lf and Cd300lb receptors and their emerging roles in the development of autoimmune disease. PMID:27308512

  5. Tim-3/galectin-9 pathway: regulation of Th1 immunity through promotion of CD11b+Ly-6G+ myeloid cells.

    PubMed

    Dardalhon, Valerie; Anderson, Ana C; Karman, Jozsef; Apetoh, Lionel; Chandwaskar, Rucha; Lee, David H; Cornejo, Melanie; Nishi, Nozomu; Yamauchi, Akira; Quintana, Francisco J; Sobel, Raymond A; Hirashima, Mitsuomi; Kuchroo, Vijay K

    2010-08-01

    IFN-gamma plays a central role in antitumor immunity. T cell Ig and mucin domain (Tim-3) is expressed on IFN-gamma-producing Th1 cells; on interaction with its ligand, galectin-9, Th1 immunity is terminated. In this study, we show that transgenic overexpression of Tim-3 on T cells results in an increase in CD11b(+)Ly-6G(+) cells and inhibition of immune responses. Molecular characterization of CD11b(+)Ly-6G(+) cells reveals a phenotype consistent with granulocytic myeloid-derived suppressor cells. Accordingly, we find that modulation of the Tim-3/galectin-9 (Gal-9) pathway impacts on tumor growth. Similarly, overexpression of Tim-3 ligand, Gal-9, results in an increase in CD11b(+)Ly-6G(+) cells and inhibition of immune responses. Loss of Tim-3 restores normal levels of CD11b(+)Ly-6G(+) cells and normal immune responses in Gal-9 transgenic mice. Our data uncover a novel mechanism by which the Tim-3/Gal-9 pathway regulates immune responses and identifies this pathway as a therapeutic target in diseases where myeloid-derived suppressor cells are disadvantageous. PMID:20574007

  6. Differentiation and Characterization of Myeloid Cells

    PubMed Central

    Gupta, Dipti; Shah, Hetavi Parag; Malu, Krishnakumar; Berliner, Nancy; Gaines, Peter

    2015-01-01

    Recent molecular studies of myeloid differentiation have utilized several in vitro models of myelopoiesis, generated from either ex vivo differentiated bone marrow progenitors or induced immortalized myeloid cell lines. Ex vivo differentiation begins with an enriched population of bone marrow-derived hematopoietic stem cells generated by lineage depletion and/or positive selection for CD34+ antigen (human) or Sca-1+ (mouse) cells, which are then expanded and subsequently induced in vitro in a process that recapitulates normal myeloid development. Myeloid cell lines include two human leukemic cell lines, NB-4 and HL-60, which have been demonstrated to undergo retinoic acid–induced myeloid development, however, both cell lines exhibit defects in the upregulation of late-expressed neutrophil-specific genes. Multiple murine factor–dependent cell models of myelopoiesis are also available that express the full range of neutrophil maturation markers, including: 32Dcl3 cells, which undergo G-CSF-induced myeloid maturation, EML/EPRO cells, which develop into mature neutrophils in response to cytokines and retinoic acid, and ER-Hoxb8 cells, which undergo myeloid maturation upon removal of estradial in the maintenance medium. In this unit, the induction of myeloid maturation in each of these model systems is described, including their differentiation to either neutrophils or macrophages, if applicable. Commonly used techniques to test for myeloid characteristics of developing cells are also described, including flow cytometry and real time RT-PCR. Together, these assays provide a solid foundation for in vitro investigations of myeloid development with either human or mouse models. PMID:24510620

  7. Elusive identities and overlapping phenotypes of proangiogenic myeloid cells in tumors.

    PubMed

    Coffelt, Seth B; Lewis, Claire E; Naldini, Luigi; Brown, J Martin; Ferrara, Napoleone; De Palma, Michele

    2010-04-01

    It is now established that bone marrow-derived myeloid cells regulate tumor angiogenesis. This was originally inferred from studies of human tumor biopsies in which a positive correlation was seen between the number of tumor-infiltrating myeloid cells, such as macrophages and neutrophils, and tumor microvessel density. However, unequivocal evidence was only provided once mouse models were used to examine the effects on tumor angiogenesis by genetically or pharmacologically targeting myeloid cells. Since then, identifying the exact myeloid cell types involved in this process has proved challenging because of myeloid cell heterogeneity and the expression of overlapping phenotypic markers in tumors. As a result, investigators often simply refer to them now as "bone marrow-derived myeloid cells." Here we review the findings of various attempts to phenotype the myeloid cells involved and discuss the therapeutic implications of correctly identifying-and thus being able to target-this proangiogenic force in tumors. PMID:20167863

  8. Elusive Identities and Overlapping Phenotypes of Proangiogenic Myeloid Cells in Tumors

    PubMed Central

    Coffelt, Seth B.; Lewis, Claire E.; Naldini, Luigi; Brown, J. Martin; Ferrara, Napoleone; De Palma, Michele

    2010-01-01

    It is now established that bone marrow–derived myeloid cells regulate tumor angiogenesis. This was originally inferred from studies of human tumor biopsies in which a positive correlation was seen between the number of tumor-infiltrating myeloid cells, such as macrophages and neutrophils, and tumor microvessel density. However, unequivocal evidence was only provided once mouse models were used to examine the effects on tumor angiogenesis by genetically or pharmacologically targeting myeloid cells. Since then, identifying the exact myeloid cell types involved in this process has proved challenging because of myeloid cell heterogeneity and the expression of overlapping phenotypic markers in tumors. As a result, investigators often simply refer to them now as “bone marrow–derived myeloid cells.” Here we review the findings of various attempts to phenotype the myeloid cells involved and discuss the therapeutic implications of correctly identifying—and thus being able to target—this proangiogenic force in tumors. PMID:20167863

  9. Hepatitis C virus regulates the production of monocytic myeloid-derived suppressor cells from peripheral blood mononuclear cells through PI3K pathway and autocrine signaling.

    PubMed

    Pang, Xiaoli; Song, Hongxiao; Zhang, Qianqian; Tu, Zhengkun; Niu, Junqi

    2016-03-01

    Hepatitis C virus (HCV) infection is a major liver disease that ultimately develops into chronic hepatitis. Consequently, such patients are predisposed to serious complications, such as hepatocellular carcinoma. In HCV-infected patients, impaired T-cell responses are associated with persistent infection. Myeloid-derived suppressor cells (MDSCs) play a pivotal role in suppressing T-cell responses. In this study, we investigated the capacity and mechanism through which HCV transforms CD14+ monocytes into monocytic (Mo)-MDSCs. We showed that HCV core protein promotes CD14+ monocytes to develop a CD14+HLA-DR/low phenotype with upregulated indoleamine 2,3-dioxygenase (IDO) expression and suppressed T-cell proliferation. Importantly, HCV-induced Mo-MDSC production was attributed to the PI3K pathway via induction of IL-10 and TNF-α secretion. This process could be reversed by polyinosinic:polycytidylic acid (polyI:C) treatment. In conclusion, our results suggest that HCV regulates Mo-MDSC production from monocytes through the PI3K pathway and autocrine cytokines. The latter can serve as effective targets for novel HCV therapies. PMID:26821305

  10. Redefining Myeloid Cell Subsets in Murine Spleen

    PubMed Central

    Hey, Ying-Ying; Tan, Jonathan K. H.; O’Neill, Helen C.

    2016-01-01

    Spleen is known to contain multiple dendritic and myeloid cell subsets, distinguishable on the basis of phenotype, function and anatomical location. As a result of recent intensive flow cytometric analyses, splenic dendritic cell (DC) subsets are now better characterized than other myeloid subsets. In order to identify and fully characterize a novel splenic subset termed “L-DC” in relation to other myeloid cells, it was necessary to investigate myeloid subsets in more detail. In terms of cell surface phenotype, L-DC were initially characterized as a CD11bhiCD11cloMHCII−Ly6C−Ly6G− subset in murine spleen. Their expression of CD43, lack of MHCII, and a low level of CD11c was shown to best differentiate L-DC by phenotype from conventional DC subsets. A complete analysis of all subsets in spleen led to the classification of CD11bhiCD11cloMHCII−Ly6CloLy6G− cells as monocytes expressing CX3CR1, CD43 and CD115. Siglec-F expression was used to identify a specific eosinophil population, distinguishable from both Ly6Clo and Ly6Chi monocytes, and other DC subsets. L-DC were characterized as a clear subset of CD11bhiCD11cloMHCII−Ly6C−Ly6G− cells, which are CD43+, Siglec-F− and CD115−. Changes in the prevalence of L-DC compared to other subsets in spleens of mutant mice confirmed the phenotypic distinction between L-DC, cDC and monocyte subsets. L-DC development in vivo was shown to occur independently of the BATF3 transcription factor that regulates cDC development, and also independently of the FLT3L and GM-CSF growth factors which drive cDC and monocyte development, so distinguishing L-DC from these commonly defined cell types. PMID:26793192

  11. Regulation and deregulation of mRNA translation during myeloid maturation.

    PubMed

    Khanna-Gupta, Arati

    2011-02-01

    Gene expression in the eukaryotic cell is regulated at a number of levels, including transcription of genomic DNA into messenger RNA (mRNA), nucleocytoplasmic export of mRNA, and translation of the exported mRNA into proteins in the cytoplasm by ribosomes. The role played by epigenetics and transcription factors associated with the control of gene expression in the developing neutrophil has been well documented and appreciated over the years. A wealth of information on the role played by transcription factors in myeloid biology has contributed to our understanding of both normal and abnormal neutrophil development. However, regulation of mRNA translation in myeloid cell maturation is much less well-studied. A better understanding of the translational control of myeloid gene expression may provide important insights into both normal and abnormal myeloid maturation. This review summarizes our current understanding of the regulation of myeloid gene expression at the mRNA translational level. PMID:21093533

  12. Differentiation and characterization of myeloid cells.

    PubMed

    Gaines, Peter; Berliner, Nancy

    2005-07-01

    Recent molecular studies of myeloid differentiation have utilized several in vitro models of myelopoiesis. Hematopoietic progenitors expressing the CD34+ antigen can be induced in vitro in a process that recapitulates the normal myeloid development. Two human leukemic cell lines, NB-4 and HL-60, have been demonstrated to undergo retinoic acid-induced myeloid development, however, both cell lines exhibit defects in the upregulation of late-expressed neutrophil-specific genes. In contrast, two murine factor-dependent cell models of myelopoiesis express the full range of neutrophil maturation markers: 32Dcl3 cells, which undergo G-CSF-induced myeloid maturation, and EML/EPRO cells, which develop into mature neutrophils in response to cytokines and retinoic acid. In this unit, the induction of myeloid maturation in each of these model systems is described. Commonly used techniques to test for myeloid characteristics of developing cells are also described. Together, these assays provide a solid foundation for in vitro investigations of myeloid development. PMID:18432952

  13. Immunotherapy with myeloid cells for tolerance induction

    PubMed Central

    Rodriguez-García, Mercedes; Boros, Peter; Bromberg, Jonathan S.; Ochando, Jordi C.

    2013-01-01

    Purpose of review Understanding the interplay between myeloid dendritic cells and T cells under tolerogenic conditions, and whether their interactions induce the development of antigen-specific regulatory T cells (Tregs) is critical to uncover the mechanisms involved in the induction of indefinite allograft survival. Recent findings Myeloid dendritic cell–T-cell interactions are seminal events that determine the outcome of the immune response, and multiple in-vitro protocols suggest the generation of tolerogenic myeloid dendritic cells that modulate T-cell responses, and determine the outcome of the immune response to an allograft following adoptive transfer. We believe that identifying specific conditions that lead to the generation of tolerogenic myeloid dendritic cells and Tregs are critical for the manipulation the immune response towards the development of transplantation tolerance. Summary We summarize recent findings regarding specific culture conditions that generate tolerogenic myeloid dendritic cells that induce T-cell hyporesponsiveness and Treg development, and represents a novel immunotherapeutic approach to promote the induction of indefinite graft survival prolongation. The interpretations presented here illustrate that different mechanisms govern the generation tolerogenic myeloid dendritic cells, and we discuss the concomitant therapeutic implications. PMID:20616727

  14. Genome-Wide CRISPR-Cas9 Screen Identifies MicroRNAs That Regulate Myeloid Leukemia Cell Growth

    PubMed Central

    Wallace, Jared; Hu, Ruozhen; Mosbruger, Timothy L.; Dahlem, Timothy J.; Stephens, W. Zac; Rao, Dinesh S.; Round, June L.; O’Connell, Ryan M.

    2016-01-01

    Mammalian microRNA expression is dysregulated in human cancer. However, the functional relevance of many microRNAs in the context of tumor biology remains unclear. Using CRISPR-Cas9 technology, we performed a global loss-of-function screen to simultaneously test the functions of individual microRNAs and protein-coding genes during the growth of a myeloid leukemia cell line. This approach identified evolutionarily conserved human microRNAs that suppress or promote cell growth, revealing that microRNAs are extensively integrated into the molecular networks that control tumor cell physiology. miR-155 was identified as a top microRNA candidate promoting cellular fitness, which we confirmed with two distinct miR-155-targeting CRISPR-Cas9 lentiviral constructs. Further, we performed anti-correlation functional profiling to predict relevant microRNA-tumor suppressor gene or microRNA-oncogene interactions in these cells. This analysis identified miR-150 targeting of p53, a connection that was experimentally validated. Taken together, our study describes a powerful genetic approach by which the function of individual microRNAs can be assessed on a global level, and its use will rapidly advance our understanding of how microRNAs contribute to human disease. PMID:27081855

  15. Paired immunoglobin-like receptor-B regulates the suppressive function and fate of myeloid-derived suppressor cells.

    PubMed

    Ma, Ge; Pan, Ping-Ying; Eisenstein, Samuel; Divino, Celia M; Lowell, Clifford A; Takai, Toshiyuki; Chen, Shu-Hsia

    2011-03-25

    Myeloid-derived suppressor cells (MDSCs) bear characteristics of precursors for both M1 and M2 macrophages. The molecular mechanism underlying the differentiation into M1 and M2 macrophages and the relationship of this differentiation to antitumor responses remains largely undefined. Herein, we investigate the potential function of paired immunoglobulin-like receptor B (PIR-B), also known as leukocyte immunoglobulin-like receptor subfamily B member 3 (LILRB3) in MDSC differentiation, and its role in tumor-induced immunity. Our studies indicated that MDSCs genetically ablated for PIR-B (Lilrb3(-/-)) underwent a specific transition to M1-like cells when entering the periphery from bone marrow, resulting in decreased suppressive function, regulatory T cell activation activity, primary tumor growth, and lung metastases. Activation of Toll-like receptor (TLR), signal transducers, and activators of transcription 1 (STAT1), and nuclear factor-kappa B (NF-κB) signaling in Lilrb3(-/-) MDSC promoted the acquisition of M1 phenotype. Inhibition of the PIR-B signaling pathway promoted MDSC differentiation into M1 macrophages. PMID:21376641

  16. Shared signaling systems in myeloid cell-mediated muscle regeneration

    PubMed Central

    Tidball, James G.; Dorshkind, Kenneth; Wehling-Henricks, Michelle

    2014-01-01

    Much of the focus in muscle regeneration has been placed on the identification and delivery of stem cells to promote regenerative capacity. As those efforts have advanced, we have learned that complex features of the microenvironment in which regeneration occurs can determine success or failure. The immune system is an important contributor to that complexity and can determine the extent to which muscle regeneration succeeds. Immune cells of the myeloid lineage play major regulatory roles in tissue regeneration through two general, inductive mechanisms: instructive mechanisms that act directly on muscle cells; and permissive mechanisms that act indirectly to influence regeneration by modulating angiogenesis and fibrosis. In this article, recent discoveries that identify inductive actions of specific populations of myeloid cells on muscle regeneration are presented, with an emphasis on how processes in muscle and myeloid cells are co-regulated. PMID:24595286

  17. A Subset of Patients with Acute Myeloid Leukemia Has Leukemia Cells Characterized by Chemokine Responsiveness and Altered Expression of Transcriptional as well as Angiogenic Regulators

    PubMed Central

    Brenner, Annette K.; Reikvam, Håkon; Bruserud, Øystein

    2016-01-01

    Acute myeloid leukemia (AML) is an aggressive and heterogeneous bone marrow malignancy, the only curative treatment being intensive chemotherapy eventually in combination with allogeneic stem cell transplantation. Both the AML and their neighboring stromal cells show constitutive chemokine release, but chemokines seem to function as regulators of AML cell proliferation only for a subset of patients. Chemokine targeting is therefore considered not only for immunosuppression in allotransplanted patients but also as a possible antileukemic strategy in combination with intensive chemotherapy or as part of disease-stabilizing treatment at least for the subset of patients with chemokine-responsive AML cells. In this study, we characterized more in detail the leukemia cell phenotype of the chemokine-responsive patients. We investigated primary AML cells derived from 79 unselected patients. Standardized in vitro suspension cultures were used to investigate AML cell proliferation, and global gene expression profiles were compared for chemokine responders and non-responders identified through the proliferation assays. CCL28-induced growth modulation was used as marker of chemokine responsiveness, and 38 patients were then classified as chemokine-responsive. The effects of exogenous CCL28 (growth inhibition/enhancement/no effect) thus differed among patients and was also dependent on the presence of exogenous hematopoietic growth factors as well as constitutive AML cell cytokine release. The effect of CCR1 inhibition in the presence of chemokine-secreting mesenchymal stem cells also differed among patients. Chemokine-responsive AML cells showed altered expression of genes important for (i) epigenetic transcriptional regulation, particularly lysine acetylation; (ii) helicase activity, especially DExD/H RNA helicases; and (iii) angioregulatory proteins important for integrin binding. Thus, chemokine responsiveness is part of a complex AML cell phenotype with regard to

  18. Aminoacyl-tRNA synthetase-interacting multifunctional protein 1 suppresses tumor growth in breast cancer-bearing mice by negatively regulating myeloid-derived suppressor cell functions.

    PubMed

    Hong, Hye-Jin; Lim, Hui Xuan; Song, Ju Han; Lee, Arim; Kim, Eugene; Cho, Daeho; Cohen, Edward P; Kim, Tae Sung

    2016-01-01

    Myeloid-derived suppressor cells (MDSCs) are one of the most important cell types that contribute to negative regulation of immune responses in the tumor microenvironment. Recently, aminoacyl-tRNA synthetase-interacting multifunctional protein 1 (AIMP1), a novel pleiotropic cytokine, was identified as an antitumor protein that inhibits angiogenesis and induces antitumor responses. However, the effect of AIMP1 on MDSCs in the tumor environment remains unclear. In the present study, we demonstrated that AIMP1 significantly inhibited tumor growth in 4T1 breast cancer-bearing mice and reduced MDSCs population of tumor sites and spleens of tumor-bearing mice. AIMP1 reduced expansion of MDSCs from bone marrow-derived cells in the tumor-conditioned media. AIMP1 also negatively regulated suppressive activities of MDSCs by inhibiting IL-6 and NO production, and Arg-1 expression. Furthermore, treatment of breast cancer-bearing mice with AIMP1 decreased the capacity of MDSCs to suppress T cell proliferation and Treg cell induction. Western blot and inhibition experiments showed that downregulation of MDSCs functions by AIMP1 may result from attenuated activation of STATs, Akt, and ERK. These findings indicate that AIMP1 plays an essential role in negative regulation of suppressive functions of MDSCs. Therefore, it has a significant potential as a therapeutic agent for cancer treatment. PMID:26613952

  19. 1,25-Dihydroxyvitamin D3 induces monocytic differentiation of human myeloid leukemia cells by regulating C/EBPβ expression through MEF2C.

    PubMed

    Zheng, Ruifang; Wang, Xuening; Studzinski, George P

    2015-04-01

    Myogenic enhancer factor2 (Mef2) consists of a family of transcription factors involved in morphogenesis of skeletal, cardiac and smooth muscle cells. Among the four isoforms (Mef2A, 2B, 2C, and 2D), Mef2C was also found to play important roles in hematopoiesis. At myeloid progenitor level, Mef2C expression favors monocytic differentiation. Previous studies from our laboratory demonstrated that ERK5 was activated in 1,25-dihydroxyvitamin D3 (1,25D)-induced monocytic differentiation in AML cells and ERK5 activation was accompanied by increased Mef2C phosphorylation. We therefore examined the role of Mef2C in 1,25D-induced monocytic differentiation in AML cell lines (HL60, U937 and THP1) and found that knockdown of Mef2C with small interfering RNA (siRNA) significantly decreases the expression of the monocytic marker, CD14, without affecting the expression of the general myeloid marker, CD11b. CCAAT/enhancer-binding protein (C/EBP) β, which can bind to CD14 promoter and increase its transcription, has been shown to be the downstream effector of 1,25D-induced monocytic differentiation in AML cells. When Mef2C was knocked down, expression of C/EBPβ was reduced at both mRNA and protein levels. The protein expression levels of cell cycle regulators, p27(Kip1) and cyclin D1, were not affected by Mef2C knockdown, nor the monopoiesis related transcription factor, ATF2 (activating transcription factor 2). Thus, we conclude that 1,25D-induced monocytic differentiation, and CD14 expression in particular, are mediated through activation of ERK5-Mef2C-C/EBPβ signaling pathway, and that Mef2C does not seem to modulate cell cycle progression. PMID:25448741

  20. Metabolic characterization of imatinib-resistant BCR-ABL T315I chronic myeloid leukemia cells indicates down-regulation of glycolytic pathway and low ROS production.

    PubMed

    Ko, Byung Woong; Han, Jeongsu; Heo, Jun Young; Jang, Yunseon; Kim, Soo Jeong; Kim, Jungim; Lee, Min Joung; Ryu, Min Jeong; Song, Ik Chan; Jo, Young Suk; Kweon, Gi Ryang

    2016-09-01

    Long-term imatinib treatment induces drug-resistant chronic myeloid leukemia (CML) cells harboring T315I gate keeper mutation of breakpoint cluster region (BCR)-ABL oncogenic kinase. However, although cell proliferation is coupled with cellular energy status in CML carcinogenesis, the metabolic characteristics of T315I-mutant CML cells have never been investigated. Here, we analyzed cell proliferation activities and metabolic phenotypes, including cell proliferation, oxygen consumption, lactate production, and redox state in the KBM5 (imatinib-sensitive) and KBM5-T315I (imatinib-resistant) CML cell lines. Interestingly, KBM5-T315I cells showed decreased cell proliferation, lactate production, fatty acid synthesis, ROS production, and down regulation of mRNA expression related to ROS scavengers, such as SOD2, catalase, GCLm, and GPx1. Taken together, our data demonstrate that the lower growth ability of KBM5-T315I CML cells might be related to the decreased expression of glycolysis-related genes and ROS levels, and this will be used to identify therapeutic targets for imatinib resistance in CML. PMID:26854822

  1. 1α,25-Dihydroxyvitamin D3–Induced Myeloid Cell Differentiation Is Regulated by a Vitamin D Receptor–Phosphatidylinositol 3-Kinase Signaling Complex

    PubMed Central

    Hmama, Zakaria; Nandan, Devki; Sly, Laura; Knutson, Keith L.; Herrera-Velit, Patricia; Reiner, Neil E.

    1999-01-01

    1α,25-dihydroxyvitamin D3 (D3) promotes the maturation of myeloid cells and surface expressions of CD14 and CD11b, markers of cell differentiation in response to D3. To examine how these responses are regulated, THP-1 cells were grown in serum-free medium and incubated with D3. This was associated with rapid and transient increases in phosphatidylinositol 3-kinase (PI 3-kinase) activity. Furthermore, induction of CD14 expression in response to D3 was abrogated by (a) the PI 3-kinase inhibitors LY294002 and wortmannin; (b) antisense oligonucleotides to mRNA for the p110 catalytic subunit of PI 3-kinase; and (c) a dominant negative mutant of PI 3-kinase. In THP-1 cells, induction of CD11b expression by D3 was also abrogated by LY294002 and wortmannin. Similarly, LY294002 and wortmannin inhibited D3-induced expression of both CD14 and CD11b in peripheral blood monocytes. In contrast to CD14 and CD11b, hormone-induced expression of the Cdk inhibitor p21 in THP-1 cells was unaffected by either wortmannin or LY294002. These findings suggest that PI 3-kinase selectively regulates D3-induced monocyte differentiation, independent of any effects on p21. PMID:10587349

  2. Multifactorial resistance to aminopeptidase inhibitor prodrug CHR2863 in myeloid leukemia cells: down-regulation of carboxylesterase 1, drug sequestration in lipid droplets and pro-survival activation ERK/Akt/mTOR

    PubMed Central

    Verbrugge, Sue Ellen; Al, Marjon; Assaraf, Yehuda G.; Kammerer, Sarah; Chandrupatla, Durga M.S.H.; Honeywell, Richard; Musters, Rene P.J.; Giovannetti, Elisa; O'Toole, Tom; Scheffer, George L.; Krige, David; de Gruijl, Tanja D.; Niessen, Hans W.M.; Lems, Willem F.; Kramer, Pieternella A.; Scheper, Rik J.; Cloos, Jacqueline; Ossenkoppele, Gert J.; Peters, Godefridus J.; Jansen, Gerrit

    2016-01-01

    Aminopeptidase inhibitors are receiving attention as combination chemotherapeutic agents for the treatment of refractory acute myeloid leukemia. However, the factors determining therapeutic efficacy remain elusive. Here we identified the molecular basis of acquired resistance to CHR2863, an orally available hydrophobic aminopeptidase inhibitor prodrug with an esterase-sensitive motif, in myeloid leukemia cells. CHR2863 enters cells by diffusion and is retained therein upon esterase activity-mediated conversion to its hydrophilic active metabolite drug CHR6768, thereby exerting amino acid depletion. Carboxylesterases (CES) serve as candidate prodrug activating enzymes given CES1 expression in acute myeloid leukemia specimens. We established two novel myeloid leukemia sublines U937/CHR2863(200) and U937/CHR2863(5uM), with low (14-fold) and high level (270-fold) CHR2863 resistance. The latter drug resistant cells displayed: (i) complete loss of CES1-mediated drug activation associated with down-regulation of CES1 mRNA and protein, (ii) marked retention/sequestration of the prodrug, (iii) a substantial increase in intracellular lipid droplets, and (iv) a dominant activation of the pro-survival Akt/mTOR pathway. Remarkably, the latter feature coincided with a gain of sensitivity to the mTOR inhibitor rapamycin. These finding delineate the molecular basis of CHR2863 resistance and offer a novel modality to overcome this drug resistance in myeloid leukemia cells. PMID:26496029

  3. STAT3 signaling pathway is involved in decitabine induced biological phenotype regulation of acute myeloid leukemia cells

    PubMed Central

    Zhu, Zhichao; Lu, Xuzhang; Jiang, Lijia; Sun, Xiao; Zhou, Haijun; Jia, Zhuxia; Zhang, Xiuwen; Ma, Lingdi

    2015-01-01

    Objective: This study aimed to investigate the role of signal transduction and transcriptional activator STAT3 and relevant signaling pathway in the DAC regulated biological phenotype of AML cells. Methods: The effect of DAC at different concentrations on the proliferation of HL-60 cells was determined. After DAC treatment for 48 h, the killing capability of NK cells against HL-60 cells and the protein expressions of STAT3, JAK1, JAK2, SOCS-1 and SOCS-3 were evaluated. Results: DAC markedly inhibited the proliferation of HL-60 cells. After the treatment of 48 hr with 0.2, 0.5 and 1.0 mol/L DAC, the HL-60 viability was reduced by 25±13%, 39±8% and 50±7% (P<0.01), respectively, and the early apoptosis rate was increased to 24.77±7.5%, 27.1±4.48% and 30.53±3.93%, respectively (control: 3.11±0.12%, P<0.01). DAC up-regulated the expression of MICA/B, ULBP-1 and ULBP-3 in HL-60 cells, and increased the killing activity of NK cells to HL-60 cells. DAC significantly induced the apoptosis of HL-60 cells and up-regulated the expression of NKG2D ligands in a dose dependent manner. Western blot assay showed the protein expression of STAT3, JAK, JAK2, phosphorylated STAT3, phosphorylated JAK1 and phosphorylated JAK2 decreased, while that of SOCS-1 and SOCS-3 increased in HL-60 cells after DAC treatment. Conclusion: In HL-60 cells, DAC can markedly inhibit their proliferation and up-regulate the expression of NKG2D ligands, and DAC also increase the cytotoxicity of NK cells to HL-60 cells, which may be related to the STAT3 related signaling pathway. PMID:26692933

  4. Myeloid-Derived Suppressor Cells in Bacterial Infections.

    PubMed

    Ost, Michael; Singh, Anurag; Peschel, Andreas; Mehling, Roman; Rieber, Nikolaus; Hartl, Dominik

    2016-01-01

    Myeloid-derived suppressor cells (MDSCs) comprise monocytic and granulocytic innate immune cells with the capability of suppressing T- and NK-cell responses. While the role of MDSCs has been studied in depth in malignant diseases, the understanding of their regulation and function in infectious disease conditions has just begun to evolve. Here we summarize and discuss the current view how MDSCs participate in bacterial infections and how this knowledge could be exploited for potential future therapeutics. PMID:27066459

  5. Myeloid-Derived Suppressor Cells in Bacterial Infections

    PubMed Central

    Ost, Michael; Singh, Anurag; Peschel, Andreas; Mehling, Roman; Rieber, Nikolaus; Hartl, Dominik

    2016-01-01

    Myeloid-derived suppressor cells (MDSCs) comprise monocytic and granulocytic innate immune cells with the capability of suppressing T- and NK-cell responses. While the role of MDSCs has been studied in depth in malignant diseases, the understanding of their regulation and function in infectious disease conditions has just begun to evolve. Here we summarize and discuss the current view how MDSCs participate in bacterial infections and how this knowledge could be exploited for potential future therapeutics. PMID:27066459

  6. Down-regulation of Myeloid Cell Leukemia-1 through Inhibiting Erk/Pin 1 Pathway by Sorafenib Facilitates Chemosensitization in Breast Cancer

    PubMed Central

    Ding, Qingqing; Huo, Longfei; Yang, Jer-Yen; Xia, Weiya; Wei, Yongkun; Liao, Yong; Chang, Chun-Ju; Yang, Yan; Lai, Chien-Chen; Lee, Dung-Fang; Yen, Chia-Jui; Chen, Yun-Ju Rita; Hsu, Jung-Mao; Kuo, Hsu-Ping; Lin, Chun-Yi; Tsai, Fuu-Jen; Li, Long-Yuan; Tsai, Chang-Hai; Hung, Mien-Chie

    2009-01-01

    Myeloid cell leukemia-1 (Mcl-1), a Bcl-2–like antiapoptotic protein, plays a role in cell immortalization and chemoresistance in a number of human malignancies. A peptidyl-prolyl cis/trans isomerase, Pin1 is involved in many cellular events, such as cell cycle progression, cell proliferation, and differentiation through isomerizing prophosphorylated substrates. It has been reported that down-regulation of Pin1 induces apoptosis, and that Erk phosphorylates and up-regulates Mcl-1; however, the underlying mechanisms for the two phenomena are not clear yet. Here, we showed that Pin 1 stabilizes Mcl-1, which is required for Mcl-1 posphorylation by Erk. First, we found expression of Mcl-1 and Pin1 were positively correlated and associated with poor survival in human breast cancer. We then showed that Erk could phosphorylate Mcl-1 at two consensus residues, Thr 92 and 163, which is required for the association of Mcl-1 and Pin1, resulting in stabilization of Mcl-1. Moreover, Pin1 is also required for the up-regulation of Mcl-1 by Erk activation. Based on this newly identified mechanism of Mcl-1 stabilization, two strategies were used to overcome Mcl-1–mediated chemoresistance: inhibiting Erk by Sorafenib, an approved clinical anticancer drug, or knocking down Pin1 by using a SiRNA technique. In conclusion, the current report not only unravels a novel mechanism to link Erk/Pin1 pathway and Mcl-1–mediated chemoresistance but also provides a plausible combination therapy, Taxol (Paclitaxel) plus Sorafenib, which was shown to be effective in killing breast cancer cells. PMID:18676833

  7. Long Non-Coding RNA CCAT1 Acts as a Competing Endogenous RNA to Regulate Cell Growth and Differentiation in Acute Myeloid Leukemia

    PubMed Central

    Chen, Lianxiang; Wang, Wei; Cao, Lixia; Li, Zhijun; Wang, Xing

    2016-01-01

    Long non-coding RNAs (lncRNAs) are involved in multiple cellular events, as well as in tumorigenesis. Colon cancer-associated transcript-1 (CCAT1) gene encodes an lncRNA whose over-activation was observed in an expanding list of primary human solid tumors and tumor cell lines, however its biological roles in acute myeloid leukaemia (AML) has not been reported yet at present. In this study, the aberrant upregulation of CCAT1 was detected in French-American-British M4 and M5 subtypes of adult AML patients. By gain- and loss-of-function analysis, we determined that CCAT1 repressed monocytic differentiation and promoted cell growth of HL-60 by sequestering tumor suppressive miR-155. Accordingly, a significant decrease in miR-155 level was detected in AML patients. Re-introduction of miR-155 into HL-60 cells restored monocytic maturation and repressed cell proliferation. Furthermore, CCAT1 could up-regulated c-Myc via its competing endogenous RNA (ceRNA) activity on miR-155. In conclusion, these results revealed new mechanism of lncRNA CCAT1 in AML development, and suggested that the manipulation of CCAT1 expression could serve as a potential strategy in AML therapy. PMID:26923190

  8. BCR/ABL increases EZH2 levels which regulates XIAP expression via miRNA-219 in chronic myeloid leukemia cells.

    PubMed

    Nishioka, Chie; Ikezoe, Takayuki; Yang, Jing; Yokoyama, Akihito

    2016-06-01

    In this study, we showed that the levels of EZH2 in bone marrow mononuclear cells (BMMNCs) isolated from individuals with chronic myeloid leukemia (CML) (n=12) were significantly greater than those in BMMNCs isolated from healthy volunteers (n=6) as well as individuals with Philadelphia chromosome-negative myeloproliferative neoplasms. Lentiviral transduction of the BCR/ABL gene in Ba/F3 cells increased EZH2 levels in parallel with phosphorylation of STAT5. Notably, chromatin immunoprecipitation assays showed that STAT5A bound to a promoter region of the EZH2 gene, resulting in an increase in the transcriptional activity of EZH2 in leukemia cells. Importantly, downregulation of EZH2 by short hairpin RNAs (shRNAs) inhibited the expression of XIAP and increased the miR-219 levels associated with a decrease in hypermethylation of miR-219-1 CpG islands. Moreover, overexpression of miR-219 decreased the levels of XIAP in CML cells. Since the 3'-untranslated region (3'-UTR) of XIAP contains miR219-5p-complementary binding site, miR-219 might modulate the expression of XIAP through binding of miR-219 on the 3'-UTR of XIAP. Taken together, BCR/ABL positively regulates the expression of EZH2 via STAT5 signaling. EZH2 modulates epigenetic changes at DNA methylated regions encoding miR-219 and downregulates the level of miR-219, resulting in upregulation of XIAP. PMID:27070757

  9. Long Non-Coding RNA CCAT1 Acts as a Competing Endogenous RNA to Regulate Cell Growth and Differentiation in Acute Myeloid Leukemia.

    PubMed

    Chen, Lianxiang; Wang, Wei; Cao, Lixia; Li, Zhijun; Wang, Xing

    2016-04-30

    Long non-coding RNAs (lncRNAs) are involved in multiple cellular events, as well as in tumorigenesis. Colon cancer-associated transcript-1 (CCAT1) gene encodes an lncRNA whose over-activation was observed in an expanding list of primary human solid tumors and tumor cell lines, however its biological roles in acute myeloid leukaemia (AML) has not been reported yet at present. In this study, the aberrant upregulation of CCAT1 was detected in French-American-British M4 and M5 subtypes of adult AML patients. By gain- and loss-of-function analysis, we determined that CCAT1 repressed monocytic differentiation and promoted cell growth of HL-60 by sequestering tumor suppressive miR-155. Accordingly, a significant decrease in miR-155 level was detected in AML patients. Re-introduction of miR-155 into HL-60 cells restored monocytic maturation and repressed cell proliferation. Furthermore, CCAT1 could up-regulated c-Myc via its competing endogenous RNA (ceRNA) activity on miR-155. In conclusion, these results revealed new mechanism of lncRNA CCAT1 in AML development, and suggested that the manipulation of CCAT1 expression could serve as a potential strategy in AML therapy. PMID:26923190

  10. Regulation of human immunodeficiency virus type 1 and cytokine gene expression in myeloid cells by NF-kappa B/Rel transcription factors.

    PubMed Central

    Roulston, A; Lin, R; Beauparlant, P; Wainberg, M A; Hiscott, J

    1995-01-01

    CD4+ macrophages in tissues such as lung, skin, and lymph nodes, promyelocytic cells in bone marrow, and peripheral blood monocytes serve as important targets and reservoirs for human immunodeficiency virus type 1 (HIV-1) replication. HIV-1-infected myeloid cells are often diminished in their ability to participate in chemotaxis, phagocytosis, and intracellular killing. HIV-1 infection of myeloid cells can lead to the expression of surface receptors associated with cellular activation and/or differentiation that increase the responsiveness of these cells to cytokines secreted by neighboring cells as well as to bacteria or other pathogens. Enhancement of HIV-1 replication is related in part to increased DNA-binding activity of cellular transcription factors such as NF-kappa B. NF-kappa B binds to the HIV-1 enhancer region of the long terminal repeat and contributes to the inducibility of HIV-1 gene expression in response to multiple activating agents. Phosphorylation and degradation of the cytoplasmic inhibitor I kappa B alpha are crucial regulatory events in the activation of NF-kappa B DNA-binding activity. Both N- and C-terminal residues of I kappa B alpha are required for inducer-mediated degradation. Chronic HIV-1 infection of myeloid cells leads to constitutive NF-kappa B DNA-binding activity and provides an intranuclear environment capable of perpetuating HIV-1 replication. Increased intracellular stores of latent NF-kappa B may also result in rapid inducibility of NF-kappa B-dependent cytokine gene expression. In response to secondary pathogenic infections or antigenic challenge, cytokine gene expression is rapidly induced, enhanced, and sustained over prolonged periods in HIV-1-infected myeloid cells compared with uninfected cells. Elevated levels of several inflammatory cytokines have been detected in the sera of HIV-1-infected individuals. Secretion of myeloid cell-derived cytokines may both increase virus production and contribute to AIDS

  11. Proliferation inhibition and apoptosis induction of imatinib-resistant chronic myeloid leukemia cells via PPP2R5C down-regulation.

    PubMed

    Shen, Qi; Liu, Sichu; Chen, Yu; Yang, Lijian; Chen, Shaohua; Wu, Xiuli; Li, Bo; Lu, Yuhong; Zhu, Kanger; Li, Yangqiu

    2013-01-01

    Despite the success of imatinib and other tyrosine kinase inhibitors (TKIs), chronic myeloid leukemia (CML) remains largely incurable, and a number of CML patients die due to Abl mutation-related drug resistance and blast crisis. The aim of this study was to evaluate proliferation inhibition and apoptosis induction by down-regulating PPP2R5C gene expression in the imatinib-sensitive and imatinib-resistant CML cell lines K562, K562R (imatinib resistant without an Abl gene mutation), 32D-Bcr-Abl WT (imatinib-sensitive murine CML cell line with a wild type Abl gene) and 32D-Bcr-Abl T315I (imatinib resistant with a T315I Abl gene mutation) and primary cells from CML patients by RNA interference. PPP2R5C siRNAs numbered 799 and 991 were obtained by chemosynthesis. Non-silencing siRNA scrambled control (SC)-treated, mock-transfected, and untreated cells were used as controls. The PPP2R5C mRNA and protein expression levels in treated CML cells were analyzed by quantitative real-time PCR and Western blotting, and in vitro cell proliferation was assayed with the cell counting kit-8 method. The morphology and percentage of apoptosis were revealed by Hoechst 33258 staining and flow cytometry (FCM). The results demonstrated that both siRNAs had the best silencing results after nucleofection in all four cell lines and primary cells. A reduction in PPP2R5C mRNA and protein levels was observed in the treated cells. The proliferation rate of the PPP2R5C-siRNA-treated CML cell lines was significantly decreased at 72 h, and apoptosis was significantly increased. Significantly higher proliferation inhibition and apoptosis induction were found in K562R cells treated with PPP2R5C-siRNA799 than K562 cells. In conclusion, the suppression of PPP2R5C by RNA interference could inhibit proliferation and effectively induce apoptosis in CML cells that were either imatinib sensitive or resistant. Down-regulating PPP2R5C gene expression might be considered as a new therapeutic target strategy

  12. Myeloid derived suppressor cells and autoimmunity.

    PubMed

    Boros, Peter; Ochando, Jordi; Zeher, Margit

    2016-08-01

    Myeloid-derived suppressor cells are a heterogeneous group of immature myeloid cells with immunoregulatory function. When activated and expanded, these cells can suppress T cell functions via cell-to cell interactions as well as soluble mediators. Recent studies investigated the involvement of MDSC in autoimmune diseases. Some papers have described beneficial effect of MDSC during the course of autoimmune diseases, and suggest a potential role as a treatment option, while others failed to detect these effects. Their contributions to autoimmune diseases are not fully understood, and many questions and some controversies remain as to the expansion, activation, and inhibitory functions of MDSC. This review aims to summarize current knowledge of MDSC in autoimmune disorders. PMID:27240453

  13. Cooperative loss of RAS feedback regulation drives myeloid leukemognesis

    PubMed Central

    Zhao, Zhen; Chen, Chi-Chao; Rillahan, Cory D.; Shen, Ronglai; Kitzing, Thomas; McNerney, Megan E.; Diaz-Flores, Ernesto; Zuber, Johannes; Shannon, Kevin; Le Beau, Michelle M.; Spector, Mona S.; Kogan, Scott C.; Lowe, Scott W.

    2015-01-01

    RAS network activation is common in human cancers and, in acute myeloid leukemia (AML), achieved mainly through gain-of-function mutations in KRAS, NRAS, or the FLT3 receptor tyrosine kinase1. In mice, we show that premalignant myeloid cells harboring a KrasG12D allele retain low Ras signaling owing to a negative feedback involving Spry4 that prevents transformation. In humans, SPRY4 is located on chromosome 5q, a region affected by large heterozygous deletion that are associated with an aggressive disease in which gain-of-function RAS pathway mutations are rare. These 5q deletions often co-occur with chromosome 17 alterations involving deletion of NF1 - another RAS negative regulator - and TP53. Accordingly, combined suppression of Spry4, Nf1 and Trp53 produces high Ras signaling and drives AML in mice. Therefore, SPRY4 is a 5q tumor suppressor whose disruption contributes to a lethal AML subtype that appears to acquire RAS pathway activation through loss of negative regulators. PMID:25822087

  14. IRF-3, IRF-5, and IRF-7 coordinately regulate the type I IFN response in myeloid dendritic cells downstream of MAVS signaling.

    PubMed

    Lazear, Helen M; Lancaster, Alissa; Wilkins, Courtney; Suthar, Mehul S; Huang, Albert; Vick, Sarah C; Clepper, Lisa; Thackray, Larissa; Brassil, Margaret M; Virgin, Herbert W; Nikolich-Zugich, Janko; Moses, Ashlee V; Gale, Michael; Früh, Klaus; Diamond, Michael S

    2013-01-01

    Although the transcription factors IRF-3 and IRF-7 are considered master regulators of type I interferon (IFN) induction and IFN stimulated gene (ISG) expression, Irf3(-/-)×Irf7(-/-) double knockout (DKO) myeloid dendritic cells (mDC) produce relatively normal levels of IFN-β after viral infection. We generated Irf3(-/-)×Irf5(-/-)×Irf7(-/-) triple knockout (TKO) mice to test whether IRF-5 was the source of the residual induction of IFN-β and ISGs in mDCs. In pathogenesis studies with two unrelated positive-sense RNA viruses (West Nile virus (WNV) and murine norovirus), TKO mice succumbed at rates greater than DKO mice and equal to or approaching those of mice lacking the type I IFN receptor (Ifnar(-/-)). In ex vivo studies, after WNV infection or exposure to Toll-like receptor agonists, TKO mDCs failed to produce IFN-β or express ISGs. In contrast, this response was sustained in TKO macrophages following WNV infection. To define IRF-regulated gene signatures, we performed microarray analysis on WNV-infected mDC from wild type (WT), DKO, TKO, or Ifnar(-/-) mice, as well as from mice lacking the RIG-I like receptor adaptor protein MAVS. Whereas the gene induction pattern in DKO mDC was similar to WT cells, remarkably, almost no ISG induction was detected in TKO or Mavs(-/-) mDC. The relative equivalence of TKO and Mavs(-/-) responses suggested that MAVS dominantly regulates ISG induction in mDC. Moreover, we showed that MAVS-dependent induction of ISGs can occur through an IRF-5-dependent yet IRF-3 and IRF-7-independent pathway. Our results establish IRF-3, -5, and -7 as the key transcription factors responsible for mediating the type I IFN and ISG response in mDC during WNV infection and suggest a novel signaling link between MAVS and IRF-5. PMID:23300459

  15. Targeting chronic myeloid leukemia stem cells.

    PubMed

    Kinstrie, Ross; Copland, Mhairi

    2013-03-01

    Chronic myeloid leukemia (CML) is a clonal myeloproliferative disorder that is characterized by the presence of the fusion oncogene BCR-ABL that encodes the tyrosine kinase BCR-ABL. Constitutive expression of BCR-ABL leads to the unregulated production of mature myeloid cells in the bone marrow and their subsequent release into the blood. Untreated, CML will progress from a chronic to accelerated phase over a number of years before quickly proceeding to a terminal blast crisis phase, reminiscent of acute leukemia. The advent of tyrosine kinase inhibitors has led to much improved management of the disease, but these drugs do not provide a cure as they are unable to eradicate the most primitive, quiescent fraction of CML stem cells. This review looks at recent research into targeting CML stem cells and focuses on major signalling pathways of interest. PMID:23264204

  16. Identification of Reprogrammed Myeloid Cell Transcriptomes in NSCLC

    PubMed Central

    Gupta, Ravi; Fischer, Kari R.; Choi, Hyejin; El Rayes, Tina; Ryu, Seongho; Nasar, Abu; Spinelli, Cathy F.; Andrews, Weston; Elemento, Olivier; Nolan, Daniel; Stiles, Brendon; Rafii, Shahin; Narula, Navneet; Davuluri, Ramana; Altorki, Nasser K.; Mittal, Vivek

    2015-01-01

    Lung cancer is the leading cause of cancer related mortality worldwide, with non-small cell lung cancer (NSCLC) as the most prevalent form. Despite advances in treatment options including minimally invasive surgery, CT-guided radiation, novel chemotherapeutic regimens, and targeted therapeutics, prognosis remains dismal. Therefore, further molecular analysis of NSCLC is necessary to identify novel molecular targets that impact prognosis and the design of new-targeted therapies. In recent years, tumor “activated/reprogrammed” stromal cells that promote carcinogenesis have emerged as potential therapeutic targets. However, the contribution of stromal cells to NSCLC is poorly understood. Here, we show increased numbers of bone marrow (BM)-derived hematopoietic cells in the tumor parenchyma of NSCLC patients compared with matched adjacent non-neoplastic lung tissue. By sorting specific cellular fractions from lung cancer patients, we compared the transcriptomes of intratumoral myeloid compartments within the tumor bed with their counterparts within adjacent non-neoplastic tissue from NSCLC patients. The RNA sequencing of specific myeloid compartments (immature monocytic myeloid cells and polymorphonuclear neutrophils) identified differentially regulated genes and mRNA isoforms, which were inconspicuous in whole tumor analysis. Genes encoding secreted factors, including osteopontin (OPN), chemokine (C-C motif) ligand 7 (CCL7) and thrombospondin 1 (TSP1) were identified, which enhanced tumorigenic properties of lung cancer cells indicative of their potential as targets for therapy. This study demonstrates that analysis of homogeneous stromal populations isolated directly from fresh clinical specimens can detect important stromal genes of therapeutic value. PMID:26046767

  17. Finasteride Enhances the Generation of Human Myeloid-Derived Suppressor Cells by Up-Regulating the COX2/PGE2 Pathway.

    PubMed

    Zhang, Shaoying; Wu, Kang; Liu, Yufeng; Lin, Yingtong; Zhang, Xu; Zhou, Jie; Zhang, Hui; Pan, Ting; Fu, Yongshui

    2016-01-01

    Myeloid-derived suppressor cells (MDSCs) have been known to be a key factor in the regulation of the immune system under numerous conditions such as tumors, infections, autoimmune diseases, and transplantations. In contrast to the proposed deleterious role of MDSCs in tumors and infections, MDSCs with their suppressive function are now proved to have the beneficial potential of suppressing the autoimmune response and promoting tolerance to transplantation. Therefore, the expansion of MDSCs could be a promising therapeutic strategy for many diseases. In this study, we aimed to identify FDA-approved drugs that could aid in the expansion of functional MDSCs. We performed a high-throughput screening (HTS) of FDA-approved drugs based on the in vitro human MDSC-differentiation system and identified finasteride (FIN) to have the best potency to aid the generation of human MDSCs. The FIN-induced MDSCs were quite similar to monocytic MDSCs with regard to their surface phenotype, morphology, immunosuppressive function, and related gene expression. Next, we aimed to determine the mechanism of action of FIN and found that FIN induced the expansion of MDSCs through up-regulation of the COX2/PGE2 pathway by enhancing the activity of COX2 promoter. In addition, the administration of indomethacin (IND), a COX2 inhibitor, abrogated the effect of FIN. Based on these results, we suggested that FIN could find applications in the future in the expansion of MDSCs. Further development of FIN-like compounds could be a novel strategy for generating functional MDSCs for immunosuppressive therapies in various immune disorder conditions. PMID:27253400

  18. Finasteride Enhances the Generation of Human Myeloid-Derived Suppressor Cells by Up-Regulating the COX2/PGE2 Pathway

    PubMed Central

    Liu, Yufeng; Lin, Yingtong; Zhang, Xu; Zhou, Jie; Zhang, Hui; Pan, Ting; Fu, Yongshui

    2016-01-01

    Myeloid-derived suppressor cells (MDSCs) have been known to be a key factor in the regulation of the immune system under numerous conditions such as tumors, infections, autoimmune diseases, and transplantations. In contrast to the proposed deleterious role of MDSCs in tumors and infections, MDSCs with their suppressive function are now proved to have the beneficial potential of suppressing the autoimmune response and promoting tolerance to transplantation. Therefore, the expansion of MDSCs could be a promising therapeutic strategy for many diseases. In this study, we aimed to identify FDA-approved drugs that could aid in the expansion of functional MDSCs. We performed a high-throughput screening (HTS) of FDA-approved drugs based on the in vitro human MDSC-differentiation system and identified finasteride (FIN) to have the best potency to aid the generation of human MDSCs. The FIN-induced MDSCs were quite similar to monocytic MDSCs with regard to their surface phenotype, morphology, immunosuppressive function, and related gene expression. Next, we aimed to determine the mechanism of action of FIN and found that FIN induced the expansion of MDSCs through up-regulation of the COX2/PGE2 pathway by enhancing the activity of COX2 promoter. In addition, the administration of indomethacin (IND), a COX2 inhibitor, abrogated the effect of FIN. Based on these results, we suggested that FIN could find applications in the future in the expansion of MDSCs. Further development of FIN-like compounds could be a novel strategy for generating functional MDSCs for immunosuppressive therapies in various immune disorder conditions. PMID:27253400

  19. IRF-3, IRF-5, and IRF-7 Coordinately Regulate the Type I IFN Response in Myeloid Dendritic Cells Downstream of MAVS Signaling

    PubMed Central

    Lazear, Helen M.; Lancaster, Alissa; Wilkins, Courtney; Suthar, Mehul S.; Huang, Albert; Vick, Sarah C.; Clepper, Lisa; Thackray, Larissa; Brassil, Margaret M.; Virgin, Herbert W.; Nikolich-Zugich, Janko; Moses, Ashlee V.; Gale, Michael; Früh, Klaus; Diamond, Michael S.

    2013-01-01

    Although the transcription factors IRF-3 and IRF-7 are considered master regulators of type I interferon (IFN) induction and IFN stimulated gene (ISG) expression, Irf3−/−×Irf7−/− double knockout (DKO) myeloid dendritic cells (mDC) produce relatively normal levels of IFN-β after viral infection. We generated Irf3−/−×Irf5−/−×Irf7−/− triple knockout (TKO) mice to test whether IRF-5 was the source of the residual induction of IFN-β and ISGs in mDCs. In pathogenesis studies with two unrelated positive-sense RNA viruses (West Nile virus (WNV) and murine norovirus), TKO mice succumbed at rates greater than DKO mice and equal to or approaching those of mice lacking the type I IFN receptor (Ifnar−/−). In ex vivo studies, after WNV infection or exposure to Toll-like receptor agonists, TKO mDCs failed to produce IFN-β or express ISGs. In contrast, this response was sustained in TKO macrophages following WNV infection. To define IRF-regulated gene signatures, we performed microarray analysis on WNV-infected mDC from wild type (WT), DKO, TKO, or Ifnar−/− mice, as well as from mice lacking the RIG-I like receptor adaptor protein MAVS. Whereas the gene induction pattern in DKO mDC was similar to WT cells, remarkably, almost no ISG induction was detected in TKO or Mavs−/− mDC. The relative equivalence of TKO and Mavs−/− responses suggested that MAVS dominantly regulates ISG induction in mDC. Moreover, we showed that MAVS-dependent induction of ISGs can occur through an IRF-5-dependent yet IRF-3 and IRF-7-independent pathway. Our results establish IRF-3, -5, and -7 as the key transcription factors responsible for mediating the type I IFN and ISG response in mDC during WNV infection and suggest a novel signaling link between MAVS and IRF-5. PMID:23300459

  20. Regulation of death induction and chemosensitizing action of 3-bromopyruvate in myeloid leukemia cells: energy depletion, oxidative stress, and protein kinase activity modulation.

    PubMed

    Calviño, Eva; Estañ, María Cristina; Sánchez-Martín, Carlos; Brea, Rocío; de Blas, Elena; Boyano-Adánez, María del Carmen; Rial, Eduardo; Aller, Patricio

    2014-02-01

    3-Bromopyruvate (3-BrP) is an alkylating, energy-depleting drug that is of interest in antitumor therapies, although the mechanisms underlying its cytotoxicity are ill-defined. We show here that 3-BrP causes concentration-dependent cell death of HL60 and other human myeloid leukemia cells, inducing both apoptosis and necrosis at 20-30 μM and a pure necrotic response at 60 μM. Low concentrations of 3-BrP (10-20 μM) brought about a rapid inhibition of glycolysis, which at higher concentrations was followed by the inhibition of mitochondrial respiration. The combination of these effects causes concentration-dependent ATP depletion, although this cannot explain the lethality at intermediate 3-BrP concentrations (20-30 μM). The oxidative stress caused by exposure to 3-BrP was evident as a moderate overproduction of reactive oxygen species and a concentration-dependent depletion of glutathione, which was an important determinant of 3-BrP toxicity. In addition, 3-BrP caused glutathione-dependent stimulation of p38 mitogen-activated protein kinase (MAPK), mitogen-induced extracellular kinase (MEK)/extracellular signal-regulated kinase (ERK), and protein kinase B (Akt)/mammalian target of rapamycin/p70S6K phosphorylation or activation, as well as rapid LKB-1/AMP kinase (AMPK) activation, which was later followed by Akt-mediated inactivation. Experiments with pharmacological inhibitors revealed that p38 MAPK activation enhances 3-BrP toxicity, which is conversely restrained by ERK and Akt activity. Finally, 3-BrP was seen to cooperate with antitumor agents like arsenic trioxide and curcumin in causing cell death, a response apparently mediated by both the generation of oxidative stress induced by 3-BrP and the attenuation of Akt and ERK activation by curcumin. In summary, 3-BrP cytotoxicity is the result of several combined regulatory mechanisms that might represent important targets to improve therapeutic efficacy. PMID:24307199

  1. The role of myeloid cells in the promotion of tumour angiogenesis.

    PubMed

    Murdoch, Craig; Muthana, Munitta; Coffelt, Seth B; Lewis, Claire E

    2008-08-01

    The use of various transgenic mouse models and analysis of human tumour biopsies has shown that bone marrow-derived myeloid cells, such as macrophages, neutrophils, eosinophils, mast cells and dendritic cells, have an important role in regulating the formation and maintenance of blood vessels in tumours. In this Review the evidence for each of these cell types driving tumour angiogenesis is outlined, along with the mechanisms regulating their recruitment and activation by the tumour microenvironment. We also discuss the therapeutic implications of recent findings that specific myeloid cell populations modulate the responses of tumours to agents such as chemotherapy and some anti-angiogenic therapies. PMID:18633355

  2. Myeloid cells - targets of medication in multiple sclerosis.

    PubMed

    Mishra, Manoj K; Yong, V Wee

    2016-09-01

    Discussions of multiple sclerosis (MS) pathophysiology tend to focus on T cells and B cells of the adaptive immune response. The innate immune system is less commonly considered in this context, although dendritic cells, monocytes, macrophages and microglia - collectively referred to as myeloid cells - have prominent roles in MS pathogenesis. These populations of myeloid cells function as antigen-presenting cells and effector cells in neuroinflammation. Furthermore, a vicious cycle of interactions between T cells and myeloid cells exacerbates pathology. Several disease-modifying therapies are now available to treat MS, and insights into their mechanisms of action have largely focused on the adaptive immune system, but these therapies also have important effects on myeloid cells. In this Review, we discuss the evidence for the roles of myeloid cells in MS and the experimental autoimmune encephalomyelitis model of MS, and consider how interactions between myeloid cells and T cells and/or B cells promote MS pathology. Finally, we discuss the direct and indirect effects of existing MS medications on myeloid cells. PMID:27514287

  3. DOWN-REGULATION OF SIGNAL TRANSDUCER AND ACTIVATOR OF TRANSCRIPTION 3 IMPROVES HUMAN ACUTE MYELOID LEUKEMIA-DERIVED DENDRITIC CELL FUNCTION

    PubMed Central

    Brady, Michael T.; Miller, Austin; Sait, Sheila N.; Ford, Laurie A.; Minderman, Hans; Wang, Eunice S.; Lee, Kelvin P.; Baumann, Heinz; Wetzler, Meir

    2013-01-01

    Signal transducer and activator of transcription (STAT) 3 inhibits dendritic cell (DC) differentiation and is constitutively activated in blasts of approximately half of AML patients. We investigated the correlation between STAT3 activity, DC maturation and the ability to stimulate T-cells in primary acute myeloid leukemia (AML)-derived DCs. STAT3 knock-down by shRNAmir increased the ability of AML-DCs to stimulate T-cells. Treatment of AML-DC with arsenic trioxide, but not AG490, JSI-124 or NSC-74859, led to a more mature phenotype and enhanced T-cell stimulation, while having minimal effect on normal DC. We conclude that AML-DCs have improved immunogenicity after reducing STAT3. PMID:23628554

  4. Role of myeloid-derived suppressor cells in autoimmune disease

    PubMed Central

    Crook, Kristen R; Liu, Peng

    2015-01-01

    Myeloid-derived suppressor cells (MDSCs) represent an important class of immunoregulatory cells that can be activated to suppress T cell functions. These MDSCs can inhibit T cell functions through cell surface interactions and the release of soluble mediators. MDSCs accumulate in the inflamed tissues and lymphoid organs of patients with autoimmune diseases. Much of our knowledge of MDSC function has come from studies involving cancer models, however many recent studies have helped to characterize MDSC involvement in autoimmune diseases. MDSCs are a heterogeneous group of immature myeloid cells with a number of different functions for the suppression of T cell responses. However, we have yet to fully understand their contributions to the development and regulation of autoimmune diseases. A number of studies have described beneficial functions of MDSCs during autoimmune diseases, and thus there appears to be a potential role for MDSCs in the treatment of these diseases. Nevertheless, many questions remain as to the activation, differentiation, and inhibitory functions of MDSCs. This review aims to summarize our current knowledge of MDSC subsets and suppressive functions in tissue-specific autoimmune disorders. We also describe the potential of MDSC-based cell therapy for the treatment of autoimmune diseases and note some of hurdles facing the implementation of this therapy. PMID:25621222

  5. Characterization of miRNomes in Acute and Chronic Myeloid Leukemia Cell Lines

    PubMed Central

    Xiong, Qian; Yang, Yadong; Wang, Hai; Li, Jie; Wang, Shaobin; Li, Yanming; Yang, Yaran; Cai, Kan; Ruan, Xiuyan; Yan, Jiangwei; Hu, Songnian; Fang, Xiangdong

    2014-01-01

    Myeloid leukemias are highly diverse diseases and have been shown to be associated with microRNA (miRNA) expression aberrations. The present study involved an in-depth miRNome analysis of two human acute myeloid leukemia (AML) cell lines, HL-60 and THP-1, and one human chronic myeloid leukemia (CML) cell line, K562, via massively parallel signature sequencing. mRNA expression profiles of these cell lines that were established previously in our lab facilitated an integrative analysis of miRNA and mRNA expression patterns. miRNA expression profiling followed by differential expression analysis and target prediction suggested numerous miRNA signatures in AML and CML cell lines. Some miRNAs may act as either tumor suppressors or oncomiRs in AML and CML by targeting key genes in AML and CML pathways. Expression patterns of cell type-specific miRNAs could partially reflect the characteristics of K562, HL-60 and THP-1 cell lines, such as actin filament-based processes, responsiveness to stimulus and phagocytic activity. miRNAs may also regulate myeloid differentiation, since they usually suppress differentiation regulators. Our study provides a resource to further investigate the employment of miRNAs in human leukemia subtyping, leukemogenesis and myeloid development. In addition, the distinctive miRNA signatures may be potential candidates for the clinical diagnosis, prognosis and treatment of myeloid leukemias. PMID:24755403

  6. CD13 is dispensable for normal hematopoiesis and myeloid cell functions in the mouse

    PubMed Central

    Winnicka, Beata; O'Conor, Catherine; Schacke, Wolfgang; Vernier, Kaitlyn; Grant, Christina L.; Fenteany, Fiona Hall; Pereira, Flavia E.; Liang, Brannen; Kaur, Anupinder; Zhao, Ran; Montrose, David C.; Rosenberg, Daniel W.; Aguila, Hector L.; Shapiro, Linda H.

    2010-01-01

    The robust and consistent expression of the CD13 cell surface marker on very early as well as differentiated myeloid hematopoietic cells has prompted numerous investigations seeking to define roles for CD13 in myeloid cells. To address the function of myeloid CD13 directly, we created a CD13 null mouse and assessed the responses of purified primary macrophages or DCs from WT and CD13 null animals in cell assays and inflammatory disease models, where CD13 has been implicated previously. We find that mice lacking CD13 develop normally with normal hematopoietic profiles except for an increase in thymic but not peripheral T cell numbers. Moreover, in in vitro assays, CD13 appears to be largely dispensable for the aspects of phagocytosis, proliferation, and antigen presentation that we tested, although we observed a slight decrease in actin-independent erythrocyte uptake. However, in agreement with our published studies, we show that lack of monocytic CD13 completely ablates anti-CD13-dependent monocyte adhesion to WT endothelial cells. In vivo assessment of four inflammatory disease models showed that lack of CD13 has little effect on disease onset or progression. Nominal alterations in gene expression levels between CD13 WT and null macrophages argue against compensatory mechanisms. Therefore, although CD13 is highly expressed on myeloid cells and is a reliable marker of the myeloid lineage of normal and leukemic cells, it is not a critical regulator of hematopoietic development, hemostasis, or myeloid cell function. PMID:20430777

  7. The Transcription Factor Wilms Tumor 1 Confers Resistance in Myeloid Leukemia Cells against the Proapoptotic Therapeutic Agent TRAIL (Tumor Necrosis Factor α-related Apoptosis-inducing Ligand) by Regulating the Antiapoptotic Protein Bcl-xL*

    PubMed Central

    Bansal, Hima; Seifert, Theresea; Bachier, Carlos; Rao, Manjeet; Tomlinson, Gail; Iyer, Swaminathan Padmanabhan; Bansal, Sanjay

    2012-01-01

    Tumor necrosis factor α-related apoptosis-inducing ligand (TRAIL) is considered a promising cancer therapeutic agent due to its ability to induce apoptosis in a variety of cancer cells, while sparing normal cells. However, many human tumors including acute myeloid leukemia (AML) are partially or completely resistant to monotherapy with TRAIL, limiting its therapeutic utility. Therefore, identification of factors that contribute to TRAIL resistance may facilitate future development of more effective TRAIL-based cancer therapies. Here, we report a previously unknown role for WT1 in mediating TRAIL resistance in leukemia. Knockdown of WT1 with shRNA rendered TRAIL-resistant myeloid leukemia cells sensitive to TRAIL-induced cell death, and re-expression of shRNA-resistant WT1 restored TRAIL resistance. Notably, TRAIL-mediated apoptosis in WT1-silenced cells was largely due to down-regulation of the antiapoptotic protein Bcl-xL. Moreover, WT1 expression strongly correlated with overexpression of Bcl-xL in AML cell lines and blasts from AML patients. Furthermore, we found that WT1 transactivates Bcl-xL by directly binding to its promoter. We previously showed that WT1 is a novel client protein of heat shock protein 90 (Hsp90). Consistent with this, pharmacological inhibition of Hsp90 resulted in reduced WT1 and Bcl-xL expression leading to increased sensitivity of leukemia cells to TRAIL-mediated apoptosis. Collectively, our results suggest that WT1-dependent Bcl-xL overexpression contributes to TRAIL resistance in myeloid leukemias. PMID:22898820

  8. Distinct microRNA expression profile and targeted biological pathways in functional myeloid-derived suppressor cells induced by Δ9-tetrahydrocannabinol in vivo: regulation of CCAAT/enhancer-binding protein α by microRNA-690.

    PubMed

    Hegde, Venkatesh L; Tomar, Sunil; Jackson, Austin; Rao, Roshni; Yang, Xiaoming; Singh, Udai P; Singh, Narendra P; Nagarkatti, Prakash S; Nagarkatti, Mitzi

    2013-12-27

    Δ(9)-Tetrahydrocannabinol (THC), the major bioactive component of marijuana, has been shown to induce functional myeloid-derived suppressor cells (MDSCs) in vivo. Here, we studied the involvement of microRNA (miRNA) in this process. CD11b(+)Gr-1(+) MDSCs were purified from peritoneal exudates of mice administered with THC and used for genome-wide miRNA profiling. Expression of CD31 and Ki-67 confirmed that the THC-MDSCs were immature and proliferating. THC-induced MDSCs exhibited distinct miRNA expression signature relative to various myeloid cells and BM precursors. We identified 13 differentially expressed (>2-fold) miRNA in THC-MDSCs relative to control BM precursors. In silico target prediction for these miRNA and pathway analysis using multiple bioinformatics tools revealed significant overrepresentation of Gene Ontology clusters within hematopoiesis, myeloid cell differentiation, and regulation categories. Insulin-like growth factor 1 signaling involved in cell growth and proliferation, and myeloid differentiation pathways were among the most significantly enriched canonical pathways. Among the differentially expressed, miRNA-690 was highly overexpressed in THC-MDSCs (∼16-fold). Transcription factor CCAAT/enhancer-binding protein α (C/EBPα) was identified as a potential functional target of miR-690. Supporting this, C/EBPα expression was attenuated in THC-MDSCs as compared with BM precursors and exhibited an inverse relation with miR-690. miR-690 knockdown using peptide nucleic acid-antagomiR was able to unblock and significantly increase C/EBPα expression establishing the functional link. Further, CD11b(+)Ly6G(+)Ly6C(+) and CD11b(+)Ly6G(-)Ly6C(+) purified subtypes showed high levels of miR-690 with attenuated C/EBPα expression. Moreover, EL-4 tumor-elicited MDSCs showed increased miR-690 expression. In conclusion, miRNA are significantly altered during the generation of functional MDSC from BM. Select miRNA such as miR-690 targeting genes involved in

  9. Inhibitory C-type lectin receptors in myeloid cells

    PubMed Central

    Redelinghuys, Pierre; Brown, Gordon D.

    2011-01-01

    C-type lectin receptors encoded by the natural killer gene complex play critical roles in enabling NK cell discrimination between self and non-self. In recent years, additional genes at this locus have been identified with patterns of expression that extend to cells of the myeloid lineage where many of the encoded inhibitory receptors have equally important functions as regulators of immune homeostasis. In the present review we highlight the roles of some of these receptors including recent insights gained with regard to the identification of exogenous and endogenous ligands, mechanisms of cellular inhibition and activation, regulated expression within different cellular and immune contexts, as well as functions that include the regulation of bone homeostasis and involvement in autoimmunity. PMID:20934454

  10. Down-regulation of Mcl-1 through GSK-3β activation contributes to arsenic trioxide-induced apoptosis in acute myeloid leukemia cells

    PubMed Central

    Wang, Rui; Xia, Lijuan; Gabrilove, Janice; Waxman, Samuel; Jing, Yongkui

    2012-01-01

    Arsenic trioxide (ATO) induces disease remission in acute promyelocytic leukemia (APL) patients, but not in non-APL acute myeloid leukemia (AML) patients. ATO at therapeutic concentrations (1-2 μM) induce APL NB4, but not non-APL HL-60, cells to undergo apoptosis through the mitochondrial pathway. The role of antiapoptotic protein Mcl-1 in ATO-induced apoptosis was determined. The levels of Mcl-1 were decreased in NB4, but not in HL-60, cells after ATO treatment through proteasomal degradation. Both GSK3β inhibitor SB216763 and siRNA blocked ATO-induced Mcl-1 reduction as well as attenuated ATO-induced apoptosis in NB4 cells. Silencing Mcl-1 sensitized HL-60 cells to ATO-induced apoptosis. Both ERK and AKT inhibitors decreased Mcl-1 levels and enhanced ATO-induced apoptosis in HL-60 cells. Sorafenib, a Raf inhibitor, activated GSK3β by inhibiting its phosphorylation, decreased Mcl-1 levels, and decreased intracellular glutathione levels in HL-60 cells. Sorafenib plus ATO augmented ROS production and apoptosis induction in HL-60 cells and in primary AML cells. These results indicate that ATO induces Mcl-1 degradation through activation of GSK3β in APL cells and provide a rationale for utilizing ATO in combination with sorafenib for the treatment of non-APL AML patients. PMID:22751450

  11. Myeloid-derived suppressor cells in B cell malignancies.

    PubMed

    Yazdani, Yaghoub; Mohammadnia-Afrouzi, Mousa; Yousefi, Mehdi; Anvari, Enayat; Ghalamfarsa, Ghasem; Hasannia, Hadi; Sadreddini, Sanam; Jadidi-Niaragh, Farhad

    2015-09-01

    Tumor cells use several mechanisms such as soluble immune modulators or suppressive immune cells to evade from anti-tumor responses. Immunomodulatory cytokines, such as transforming growth factor-β, interleukin (IL)-10, and IL-35, soluble factors, such as adenosine, immunosuppressive cells, such as regulatory T cells, NKT cells and myeloid-derived suppressor cells (MDSCs), are the main orchestra leaders involved in immune suppression in cancer by which tumor cells can freely expand without immune cell-mediated interference. Among them, MDSCs have attracted much attention as they represent a heterogenous population derived from myeloid progenitors that are expanded in tumor condition and can also shift toward other myeloid cells, such as macrophages and dendritic cells, after tumor clearing. MDSCs exert their immunosuppressive effects through various immune and non-immune mechanisms which make them as potent tumor-promoting cells. Although, there are several studies regarding the immunobiology of MDSCs in different solid tumors, little is known about the precise characteristics of these cells in hematological malignancies, particularly B cell malignancies. In this review, we tried to clarify the precise role of MDSCs in B cell-derived malignancies. PMID:26330296

  12. C/EBPβ promotes BCR-ABL-mediated myeloid expansion and leukemic stem cell exhaustion.

    PubMed

    Hayashi, Y; Hirai, H; Kamio, N; Yao, H; Yoshioka, S; Miura, Y; Ashihara, E; Fujiyama, Y; Tenen, D G; Maekawa, T

    2013-03-01

    The BCR-ABL fusion oncoprotein accelerates differentiation and proliferation of myeloid cells during the chronic phase of chronic myeloid leukemia (CP-CML). Here, the role of CCAAT/enhancer binding protein β (C/EBPβ), a regulator for 'emergency granulopoiesis,' in the pathogenesis of CP-CML was examined. C/EBPβ expression was upregulated in Lineage(-) CD34(+) CD38(-) hematopoietic stem cells (HSCs) and myeloid progenitors isolated from bone marrow of patients with CP-CML. In EML cells, a mouse HSC line, BCR-ABL upregulated C/EBPβ, at least in part, through the activation of STAT5. Myeloid differentiation and proliferation induced by BCR-ABL was significantly impaired in C/EBPβ-deficient bone marrow cells in vitro. Mice that were transplanted with BCR-ABL-transduced C/EBPβ knockout bone marrow cells survived longer than mice that received BCR-ABL-transduced wild-type (WT) bone marrow cells. Significantly higher levels of leukemic stem cells were maintained in BCR-ABL-transduced C/EBPβ-deficient cells than in BCR-ABL-transduced WT cells. These results suggest that C/EBPβ is involved in BCR-ABL-mediated myeloid expansion. Further elucidation of the molecular mechanisms underlying the C/EBPβ-mediated stem cell loss might reveal a novel therapeutic strategy for eradication of CML stem cells. PMID:22948537

  13. The Role and Potential Therapeutic Application of Myeloid-Derived Suppressor Cells in Allo- and Autoimmunity

    PubMed Central

    Zhang, Qi; Fujino, Masayuki; Xu, Jinhua; Li, Xiao-kang

    2015-01-01

    Myeloid-derived suppressor cells (MDSCs) are a heterogeneous population of cells that consists of myeloid progenitor cells and immature myeloid cells. They have been identified as a cell population that may affect the activation of CD4+ and CD8+ T-cells to regulate the immune response negatively, which makes them attractive targets for the treatment of transplantation and autoimmune diseases. Several studies have suggested the potential suppressive effect of MDSCs on allo- and autoimmune responses. Conversely, MDSCs have also been found at various stages of differentiation, accumulating during pathological situations, not only during tumor development but also in a variety of inflammatory immune responses, bone marrow transplantation, and some autoimmune diseases. These findings appear to be contradictory. In this review, we summarize the roles of MDSCs in different transplantation and autoimmune diseases models as well as the potential to target these cells for therapeutic benefit. PMID:26078493

  14. Loss of SOCS3 in myeloid cells prolongs survival in a syngeneic model of glioma

    PubMed Central

    McFarland, Braden C.; Marks, Margaret P.; Rowse, Amber L.; Fehling, Samuel C.; Gerigk, Magda; Qin, Hongwei; Benveniste, Etty N.

    2016-01-01

    In glioma, microglia and macrophages are the largest population of tumor-infiltrating cells, referred to as glioma associated macrophages (GAMs). Herein, we sought to determine the role of Suppressor of Cytokine Signaling 3 (SOCS3), a negative regulator of Signal Transducer and Activator of Transcription 3 (STAT3), in GAM functionality in glioma. We utilized a conditional model in which SOCS3 deletion is restricted to the myeloid cell population. We found that SOCS3-deficient bone marrow-derived macrophages display enhanced and prolonged expression of pro-inflammatory M1 cytokines when exposed to glioma tumor cell conditioned medium in vitro. Moreover, we found that deletion of SOCS3 in the myeloid cell population delays intracranial tumor growth and increases survival of mice bearing orthotopic glioma tumors in vivo. Although intracranial tumors from mice with SOCS3-deficient myeloid cells appear histologically similar to control mice, we observed that loss of SOCS3 in myeloid cells results in decreased M2 polarized macrophage infiltration in the tumors. Furthermore, loss of SOCS3 in myeloid cells results in increased CD8+ T-cell and decreased regulatory T-cell infiltration in the tumors. These findings demonstrate a beneficial effect of M1 polarized macrophages on suppressing glioma tumor growth, and highlight the importance of immune cells in the tumor microenvironment. PMID:26967393

  15. Myeloid cells in atherosclerosis: a delicate balance of anti-inflammatory and proinflammatory mechanisms

    PubMed Central

    Koltsova, Ekaterina K.; Hedrick, Catherine C.; Ley, Klaus

    2016-01-01

    Purpose of review Atherosclerosis is chronic disease, whose progression is orchestrated by the balance between proinflammatory and anti-inflammatory mechanisms. Various myeloid cells, including monocytes, macrophages, dendritic cells and neutrophils can be found in normal and atherosclerotic aortas, in which they regulate inflammation and progression of atherosclerosis. The lineage relationship between blood monocyte subsets and the various phenotypes and functions of myeloid cells in diseased aortas is under active investigation. Recent findings Various subsets of myeloid cells play diverse roles in atherosclerosis. This review discusses new findings in phenotypic and functional characterization of different subsets of macrophages, in part determined by the transcription factors IRF5 and Trib1, and dendritic cells, characterized by the transcription factor Zbtb46, in atherosclerosis. Summary Improved understanding proinflammatory and anti-inflammatory mechanisms of macrophages and dendritic cell functions is needed for better preventive and therapeutic measures in atherosclerosis. PMID:24005215

  16. Diabetes Inhibits Gr-1+ Myeloid Cell Maturation via Cebpa Deregulation.

    PubMed

    Wicks, Kate; Torbica, Tanja; Umehara, Takahiro; Amin, Shilu; Bobola, Nicoletta; Mace, Kimberly A

    2015-12-01

    Recruitment of innate immune cells from the bone marrow (BM) to an injury site is required for effective repair. In diabetes, this process is altered, leading to excessive recruitment and retention of dysfunctional myeloid cells that fail to promote angiogenesis, prolong inflammation, and block healing. The aberrant myeloid phenotype is partially mediated by stable intrinsic changes to developing cells in the BM that are induced by the diabetic (db) environment, but the exact mechanisms remain largely unknown. Here, we show that the db-derived Gr-1(+)CD11b(+) immature myeloid population has widespread misexpression of chromatin-remodeling enzymes and myeloid differentiation factors. Crucially, diabetes represses transcription of the key myeloid transcription factor CEBPA via diminished H3 Lys 27 promoter acetylation, leading to a failure in monocyte and granulocyte maturation. Restoring Cebpa expression by granulocyte colony-stimulating factor reverses the db phenotype and rescues myeloid maturation. Importantly, our data demonstrate a possible link between myeloid cell maturation and chronic inflammation. PMID:26324181

  17. Drafting the proteome landscape of myeloid-derived suppressor cells.

    PubMed

    Gato, María; Blanco-Luquin, Idoia; Zudaire, Maribel; de Morentin, Xabier Martínez; Perez-Valderrama, Estela; Zabaleta, Aintzane; Kochan, Grazyna; Escors, David; Fernandez-Irigoyen, Joaquín; Santamaría, Enrique

    2016-01-01

    Myeloid-derived suppressor cells (MDSCs) are a heterogeneous population of cells that are defined by their myeloid origin, immature state, and ability to potently suppress T-cell responses. They regulate immune responses and the population significantly increases in the tumor microenvironment of patients with glioma and other malignant tumors. For their study, MDSCs are usually isolated from the spleen or directly of tumors from a large number of tumor-bearing mice although promising ex vivo differentiated MDSC production systems have been recently developed. During the last years, proteomics has emerged as a powerful approach to analyze MDSCs proteomes using shotgun-based mass spectrometry (MS), providing functional information about cellular homeostasis and metabolic state at a global level. Here, we will revise recent proteome profiling studies performed in MDSCs from different origins. Moreover, we will perform an integrative functional analysis of the protein compilation derived from these large-scale proteomic studies in order to obtain a comprehensive view of MDSCs biology. Finally, we will also discuss the potential application of high-throughput proteomic approaches to study global proteome dynamics and post-translational modifications (PTMs) during the differentiation process of MDSCs that will greatly boost the identification of novel MDSC-specific therapeutic targets to apply in cancer immunotherapy. PMID:26403437

  18. Myeloid Cell Nuclear Differentiation Antigen (MNDA) Expression Distinguishes Extramedullary Presentations of Myeloid Leukemia From Blastic Plasmacytoid Dendritic Cell Neoplasm.

    PubMed

    Johnson, Ryan C; Kim, Jinah; Natkunam, Yasodha; Sundram, Uma; Freud, Aharon G; Gammon, Bryan; Cascio, Michael J

    2016-04-01

    Myeloid neoplasms constitute one of the most common malignancies in adults. In most cases these proliferations initially manifest in the blood and marrow; however, extramedullary involvement may precede blood or marrow involvement in a subset of cases, making a definitive diagnosis challenging by morphologic and immunohistochemical assessment alone. Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare, aggressive entity that frequently presents in extramedullary sites and can show morphologic and immunophenotypic overlap with myeloid neoplasms. Given that BPDCN and myeloid neoplasms may both initially present in extramedullary sites and that novel targeted therapies may be developed that exploit the unique molecular signature of BPDCN, new immunophenotypic markers that can reliably separate myeloid neoplasms from BPDCN are desirable. We evaluated the utility of myeloid cell nuclear differentiation antigen (MNDA) expression in a series of extramedullary myeloid leukemias (EMLs) and BPDCN. Forty biopsies containing EML and 19 biopsies containing BPDCN were studied by MNDA immunohistochemistry. The majority of myeloid neoplasms showed nuclear expression of MNDA (65%). In contrast, all cases of BPDCN lacked MNDA expression. These findings show that MNDA is expressed in the majority of EMLs and support the inclusion of MNDA immunohistochemistry in the diagnostic evaluation of blastic hematopoietic infiltrates, particularly when the differential diagnosis is between myeloid leukemia and BPDCN. PMID:26796502

  19. Epigenetic regulators as promising therapeutic targets in acute myeloid leukemia

    PubMed Central

    Gallipoli, Paolo; Giotopoulos, George

    2015-01-01

    Acute myeloid leukemia (AML), the most prevalent acute leukemia in adults, is an aggressive hematological malignancy arising in hematopoietic stem and progenitor cells. With the exception of a few specific AML subtypes, the mainstays of treatment have not significantly changed over the last 20 years, and are still based on standard cytotoxic chemotherapy. As a result, clinical outcome remains poor for the majority of patients, with overall long-term survival in the region of 20–30%. Recent successes in characterizing the genetic landscape of AML have highlighted that, despite its heterogeneity, many cases of AML carry recurrent mutations in genes encoding epigenetic regulators. Transcriptional dysregulation and altered epigenetic function have therefore emerged as exciting areas in AML research and it is becoming increasingly clear that epigenetic dysfunction is central to leukemogenesis in AML. This has subsequently paved the way for the development of epigenetically targeted therapies. In this review, we will discuss the most recent advances in our understanding of the role of epigenetic dysregulation in AML pathobiology. We will particularly focus on those altered epigenetic programs that have been shown to be central to the development and maintenance of AML in preclinical models. We will discuss the recent development of therapeutics specifically targeting these key epigenetic programs in AML, describe their mechanism of action and present their current clinical development. Finally, we will discuss the opportunities presented by epigenetically targeted therapy in AML and will highlight future challenges ahead for the AML community, to ensure that these novel therapeutics are optimally translated into clinical practice and result in clinical improvement for AML patients. PMID:26137202

  20. Pro-survival role of p62 during granulocytic differentiation of acute myeloid leukemia cells

    PubMed Central

    Ségal-Bendirdjian, Evelyne; Tschan, Mario P; Reiffers, Josy; Djavaheri-Mergny, Mojgan

    2014-01-01

    p62 regulates key signaling pathways including those that control cell death and autophagy. Recently, we reported that p62 is upregulated during all-trans retinoic acid (ATRA)-induced terminal differentiation of acute myeloid leukemia (AML) cells. This response reduces levels of ubiquitinated protein aggregates in mature cells and protects these cells against ATRA treatment. Thus, p62 confers a survival advantage to mature AML cells. PMID:27308379

  1. ERK5 Pathway Regulates Transcription Factors Important for Monocytic Differentiation of Human Myeloid Leukemia Cells†

    PubMed Central

    Wang, Xuening; Pesakhov, Stella; Harrison, Jonathan S; Danilenko, Michael; Studzinski, George P

    2014-01-01

    Mitogen-activated protein kinases (MAPKs) are important transducers of external signals for cell growth, survival and other cellular responses including cell differentiation. Several MAPK cascades are known with the MEK1/2-ERK1/2, JNK, and p38MAPKs receiving most attention, but the role of MEK5-ERK5 in intracellular signaling deserves more scrutiny, as this pathway transmits signals that can complement ERK/2 signaling. We hypothesized that the ERK5 pathway plays a role in the control of monocytic differentiation, which is disturbed in myeloid leukemia. We therefore examined the cellular phenotype and key molecular events which occur when human myeloid leukemia cells, acute (AML) or chronic (CML), are forced to differentiate by vitamin D derivatives (VDDs). This study was performed using established cell lines HL60 and U937, and primary cultures of blasts from 10 patients with ML. We found that ERK5 and its direct downstream target transcription factor MEF2C are upregulated by 1,25D in parallel with monocytic differentiation. Further, inhibition of ERK5 activity by specific pharmacological agents BIX02189 and XMD8-92 alters the phenotype of these cells by reducing the abundance of the VDD-induced surface monocytic marker CD14, and concomitantly increasing surface expression of the general myeloid marker CD11b. Similar results were obtained when the expression of ERK5 was reduced by siRNA or short hairpin (sh) RNA. ERK5 inhibition resulted in an expected decrease in MEF2C activation. We also found that in AML the transcription factor C/EBPβ is positively regulated, while C/EBPα is negatively regulated by ERK5. These findings provide new understanding of dysregulated differentiation in human myeloid leukemia. PMID:24264602

  2. Myeloid Cells as Targets for Therapy in Solid Tumors.

    PubMed

    Cotechini, Tiziana; Medler, Terry R; Coussens, Lisa M

    2015-01-01

    It is well established that cancer development ensues based on reciprocal interactions between genomically altered neoplastic cells and diverse populations of recruited "host" cells co-opted to support malignant progression. Among the host cells recruited into tumor microenvironments, several subtypes of myeloid cells, including macrophages, monocytes, dendritic cells, and granulocytes contribute to tumor development by providing tumor-promoting factors as well as a spectrum of molecules that suppress cytotoxic activities of T lymphocytes. Based on compelling preclinical data revealing that inhibition of critical myeloid-based programs leads to tumor suppression, novel immune-based therapies and approaches are now entering the clinic for evaluation. This review discusses mechanisms underlying protumorigenic programming of myeloid cells and discusses how targeting of these has potential to attenuate solid tumor progression via the induction and of mobilization CD8 cytotoxic T cell immunity. PMID:26222088

  3. Myeloid Cells as Targets for Therapy in Solid Tumors

    PubMed Central

    Cotechini, Tiziana; Medler, Terry R.; Coussens, Lisa M.

    2016-01-01

    It is well established that cancer development ensues based on reciprocal interactions between genomically altered neoplastic cells and diverse populations of recruited “host” cells co-opted to support malignant progression. Among the host cells recruited into tumor microenvironments, several subtypes of myeloid cells, including macrophages, monocytes, dendritic cells, and granulocytes contribute to tumor development by providing tumor-promoting factors as well as a spectrum of molecules that suppress cytotoxic activities of T lymphocytes. Based on compelling preclinical data revealing that inhibition of critical myeloid-based programs leads to tumor suppression, novel immune-based therapies and approaches are now entering the clinic for evaluation. This review discusses mechanisms underlying protumorigenic programming of myeloid cells and discusses how targeting of these has potential to attenuate solid tumor progression via the induction and of mobilization CD8+ cytotoxic T cell immunity. PMID:26222088

  4. Apoptotic Efficacy of Etomoxir in Human Acute Myeloid Leukemia Cells. Cooperation with Arsenic Trioxide and Glycolytic Inhibitors, and Regulation by Oxidative Stress and Protein Kinase Activities

    PubMed Central

    Estañ, María Cristina; Calviño, Eva; Calvo, Susana; Guillén-Guío, Beatriz; Boyano-Adánez, María del Carmen; de Blas, Elena; Rial, Eduardo; Aller, Patricio

    2014-01-01

    Fatty acid synthesis and oxidation are frequently exacerbated in leukemia cells, and may therefore represent a target for therapeutic intervention. In this work we analyzed the apoptotic and chemo-sensitizing action of the fatty acid oxidation inhibitor etomoxir in human acute myeloid leukemia cells. Etomoxir caused negligible lethality at concentrations up to 100 µM, but efficaciously cooperated to cause apoptosis with the anti-leukemic agent arsenic trioxide (ATO, Trisenox), and with lower efficacy with other anti-tumour drugs (etoposide, cisplatin), in HL60 cells. Etomoxir-ATO cooperation was also observed in NB4 human acute promyelocytic cells, but not in normal (non-tumour) mitogen-stimulated human peripheral blood lymphocytes. Biochemical determinations in HL60 cells indicated that etomoxir (25–200 µM) dose-dependently inhibited mitochondrial respiration while slightly stimulating glycolysis, and only caused marginal alterations in total ATP content and adenine nucleotide pool distribution. In addition, etomoxir caused oxidative stress (increase in intracellular reactive oxygen species accumulation, decrease in reduced glutathione content), as well as pro-apoptotic LKB-1/AMPK pathway activation, all of which may in part explain the chemo-sensitizing capacity of the drug. Etomoxir also cooperated with glycolytic inhibitors (2-deoxy-D-glucose, lonidamine) to induce apoptosis in HL60 cells, but not in NB4 cells. The combined etomoxir plus 2-deoxy-D-glucose treatment did not increase oxidative stress, caused moderate decrease in net ATP content, increased the AMP/ATP ratio with concomitant drop in energy charge, and caused defensive Akt and ERK kinase activation. Apoptosis generation by etomoxir plus 2-deoxy-D-glucose was further increased by co-incubation with ATO, which is apparently explained by the capacity of ATO to attenuate Akt and ERK activation. In summary, co-treatment with etomoxir may represent an interesting strategy to increase the apoptotic

  5. Apoptotic efficacy of etomoxir in human acute myeloid leukemia cells. Cooperation with arsenic trioxide and glycolytic inhibitors, and regulation by oxidative stress and protein kinase activities.

    PubMed

    Estañ, María Cristina; Calviño, Eva; Calvo, Susana; Guillén-Guío, Beatriz; Boyano-Adánez, María Del Carmen; de Blas, Elena; Rial, Eduardo; Aller, Patricio

    2014-01-01

    Fatty acid synthesis and oxidation are frequently exacerbated in leukemia cells, and may therefore represent a target for therapeutic intervention. In this work we analyzed the apoptotic and chemo-sensitizing action of the fatty acid oxidation inhibitor etomoxir in human acute myeloid leukemia cells. Etomoxir caused negligible lethality at concentrations up to 100 µM, but efficaciously cooperated to cause apoptosis with the anti-leukemic agent arsenic trioxide (ATO, Trisenox), and with lower efficacy with other anti-tumour drugs (etoposide, cisplatin), in HL60 cells. Etomoxir-ATO cooperation was also observed in NB4 human acute promyelocytic cells, but not in normal (non-tumour) mitogen-stimulated human peripheral blood lymphocytes. Biochemical determinations in HL60 cells indicated that etomoxir (25-200 µM) dose-dependently inhibited mitochondrial respiration while slightly stimulating glycolysis, and only caused marginal alterations in total ATP content and adenine nucleotide pool distribution. In addition, etomoxir caused oxidative stress (increase in intracellular reactive oxygen species accumulation, decrease in reduced glutathione content), as well as pro-apoptotic LKB-1/AMPK pathway activation, all of which may in part explain the chemo-sensitizing capacity of the drug. Etomoxir also cooperated with glycolytic inhibitors (2-deoxy-D-glucose, lonidamine) to induce apoptosis in HL60 cells, but not in NB4 cells. The combined etomoxir plus 2-deoxy-D-glucose treatment did not increase oxidative stress, caused moderate decrease in net ATP content, increased the AMP/ATP ratio with concomitant drop in energy charge, and caused defensive Akt and ERK kinase activation. Apoptosis generation by etomoxir plus 2-deoxy-D-glucose was further increased by co-incubation with ATO, which is apparently explained by the capacity of ATO to attenuate Akt and ERK activation. In summary, co-treatment with etomoxir may represent an interesting strategy to increase the apoptotic

  6. Altered gp130 signalling ameliorates experimental colitis via myeloid cell-specific STAT3 activation and myeloid-derived suppressor cells

    PubMed Central

    Däbritz, Jan; Judd, Louise M.; Chalinor, Heather V.; Menheniott, Trevelyan R.; Giraud, Andrew S.

    2016-01-01

    STAT3 regulates the expansion of myeloid-derived suppressor cells (MDSCs) during inflammation, infection and cancer. Hyperactivation of STAT3 in gp130757F/F mice is associated with protection from experimental colitis. This study determined mechanisms for this protection and compared this to mice with myeloid-specific STAT3-deficiency (LysMcre/STAT3flox; gp130757F/F LysMcre/STAT3flox). Acute and chronic colitis was induced and colons were removed for histological, mRNA and protein analysis. Cell populations from spleen, mesenteric lymph node and colon were analyzed for different myeloid cell populations using flow cytometry. Functions of MDSCs and LPS-stimulated peritoneal macrophages were further characterized by in vitro and in vivo assays. Here we show that the resistance to experimental colitis in gp130757F/F mice is via myeloid-cell specific STAT3 activation, MDSC expansion and increased production of suppressive and protective cytokines. PMID:26848037

  7. Myeloid cell distribution and activity in multiple sclerosis.

    PubMed

    Moliné-Velázquez, Verónica; Vila-Del Sol, Virginia; de Castro, Fernando; Clemente, Diego

    2016-04-01

    Multiple sclerosis (MS) is a demyelinating disease in which an exacerbated immune response provokes oligodendrocyte loss and demyelination, the hallmarks of this neurological disease. The destruction of myelin due to the uncontrolled activity of the invading immune cells leads to the formation of MS plaques. Among the different leukocytes that participate in the immune response associated with MS, the role of myeloid cells has been analyzed extensively (i.e. macrophages, dendritic cells -DCs- and neutrophils). Hence, in this review we will summarize what is known about the distribution, expression and markers available to study myeloid cells, and their histopathology, not only in a standard animal model of MS (autoimmune experimental encephalomyelitis -EAE) but also in MS tissue. In this review, we will not only refer to mature myeloid cells but also to the undifferentiated and almost unexplored myeloid-derived suppressor cells (MDSCs). The active role of MDSCs in the prompt resolution of an immune episode is gaining importance, yet is still the subject of some debate. Finally, the similarities and differences between MS and EAE are discussed, particularly in terms of myeloid cell phenotype, activity and the markers used. PMID:26592711

  8. Peruvoside, a Cardiac Glycoside, Induces Primitive Myeloid Leukemia Cell Death.

    PubMed

    Feng, Qian; Leong, Wa Seng; Liu, Liang; Chan, Wai-In

    2016-01-01

    Despite the available chemotherapy and treatment, leukemia remains a difficult disease to cure due to frequent relapses after treatment. Among the heterogeneous leukemic cells, a rare population referred as the leukemic stem cell (LSC), is thought to be responsible for relapses and drug resistance. Cardiac glycosides (CGs) have been used in treating heart failure despite its toxicity. Recently, increasing evidence has demonstrated its new usage as a potential anti-cancer drug. Ouabain, one of the CGs, specifically targeted CD34⁺CD38(-) leukemic stem-like cells, but not the more mature CD34⁺CD38⁺ leukemic cells, making this type of compounds a potential treatment for leukemia. In search of other potential anti-leukemia CGs, we found that Peruvoside, a less studied CG, is more effective than Ouabain and Digitoxin at inducing cell death in primitive myeloid leukemia cells without obvious cytotoxicity on normal blood cells. Similar to Ouabain and Digitoxin, Peruvoside also caused cell cycle arrest at G₂/M stage. It up-regulates CDKN1A expression and activated the cleavage of Caspase 3, 8 and PARP, resulting in apoptosis. Thus, Peruvoside showed potent anti-leukemia effect, which may serve as a new anti-leukemia agent in the future. PMID:27110755

  9. Tumor-induced myeloid deviation: when myeloid-derived suppressor cells meet tumor-associated macrophages

    PubMed Central

    Ugel, Stefano; De Sanctis, Francesco; Mandruzzato, Susanna; Bronte, Vincenzo

    2015-01-01

    The generation of an inflammatory environment is favorable and often decisive for the growth of both primary tumors and metastases. Tumor cells either express membrane molecules or release tumor-derived soluble factors able to alter myelopoiesis. Tumor-reprogrammed myeloid cells not only create a tolerogenic environment by blocking T cell functions and proliferation, but also directly drive tumor growth by promoting cancer stemness, angiogenesis, stroma deposition, epithelial-to-mesenchymal transition, and metastasis formation. In this Review, we discuss the interplay between immunosuppressive and protumoral myeloid cells and detail their immune-regulatory mechanisms, the molecular pathways involved in their differentiation, as well as their potential role as prognostic and diagnostic biomarkers and prospective targets for innovative approaches to treat tumor-bearing hosts. PMID:26325033

  10. The role of myeloid cells in cancer therapies.

    PubMed

    Engblom, Camilla; Pfirschke, Christina; Pittet, Mikael J

    2016-07-01

    Recent clinical trials have demonstrated the ability to durably control cancer in some patients by manipulating T lymphocytes. These immunotherapies are revolutionizing cancer treatment but benefit only a minority of patients. It is thus a crucial time for clinicians, cancer scientists and immunologists to determine the next steps in shifting cancer treatment towards better cancer control. This Review describes recent advances in our understanding of tumour-associated myeloid cells. These cells remain less studied than T lymphocytes but have attracted particular attention because their presence in tumours is often linked to altered patient survival. Also, experimental studies indicate that myeloid cells modulate key cancer-associated activities, including immune evasion, and affect virtually all types of cancer therapy. Consequently, targeting myeloid cells could overcome limitations of current treatment options. PMID:27339708

  11. Myeloid Cell-Restricted Insulin/IGF-1 Receptor Deficiency Protects against Skin Inflammation.

    PubMed

    Knuever, Jana; Willenborg, Sebastian; Ding, Xiaolei; Akyüz, Mehmet D; Partridge, Linda; Niessen, Carien M; Brüning, Jens C; Eming, Sabine A

    2015-12-01

    Myeloid cells are key regulators of tissue homeostasis and disease. Alterations in cell-autonomous insulin/IGF-1 signaling in myeloid cells have recently been implicated in the development of systemic inflammation and insulin-resistant diabetes mellitus type 2 (DM). Impaired wound healing and inflammatory skin diseases are frequent DM-associated skin pathologies, yet the underlying mechanisms are elusive. In this study, we investigated whether myeloid cell-restricted IR/IGF-1R signaling provides a pathophysiologic link between systemic insulin resistance and the development of cutaneous inflammation. Therefore, we generated mice lacking both the insulin and IGF-1 receptor in myeloid cells (IR/IGF-1R(MKO)). Whereas the kinetics of wound closure following acute skin injury was similar in control and IR/IGF-1R(MKO) mice, in two different conditions of dermatitis either induced by repetitive topical applications of the detergent SDS or by high-dose UV B radiation, IR/IGF-1R(MKO) mice were protected from inflammation, whereas controls developed severe skin dermatitis. Notably, whereas during the early phase in both inflammatory conditions the induction of epidermal proinflammatory cytokine expression was similar in control and IR/IGF-1R(MKO) mice, during the late stage, epidermal cytokine expression was sustained in controls but virtually abrogated in IR/IGF-1R(MKO) mice. This distinct kinetic of epidermal cytokine expression was paralleled by proinflammatory macrophage activation in controls and a noninflammatory phenotype in mutants. Collectively, our findings provide evidence for a proinflammatory IR/IGF-1R-dependent pathway in myeloid cells that plays a critical role in the dynamics of an epidermal-dermal cross-talk in cutaneous inflammatory responses, and may add to the mechanistic understanding of diseases associated with disturbances in myeloid cell IR/IGF-1R signaling, including DM. PMID:26519530

  12. High-dimensional analysis of the murine myeloid cell system.

    PubMed

    Becher, Burkhard; Schlitzer, Andreas; Chen, Jinmiao; Mair, Florian; Sumatoh, Hermi R; Teng, Karen Wei Weng; Low, Donovan; Ruedl, Christiane; Riccardi-Castagnoli, Paola; Poidinger, Michael; Greter, Melanie; Ginhoux, Florent; Newell, Evan W

    2014-12-01

    Advances in cell-fate mapping have revealed the complexity in phenotype, ontogeny and tissue distribution of the mammalian myeloid system. To capture this phenotypic diversity, we developed a 38-antibody panel for mass cytometry and used dimensionality reduction with machine learning-aided cluster analysis to build a composite of murine (mouse) myeloid cells in the steady state across lymphoid and nonlymphoid tissues. In addition to identifying all previously described myeloid populations, higher-order analysis allowed objective delineation of otherwise ambiguous subsets, including monocyte-macrophage intermediates and an array of granulocyte variants. Using mice that cannot sense granulocyte macrophage-colony stimulating factor GM-CSF (Csf2rb(-/-)), which have discrete alterations in myeloid development, we confirmed differences in barrier tissue dendritic cells, lung macrophages and eosinophils. The methodology further identified variations in the monocyte and innate lymphoid cell compartment that were unexpected, which confirmed that this approach is a powerful tool for unambiguous and unbiased characterization of the myeloid system. PMID:25306126

  13. HEBAlt enhances the T-cell potential of fetal myeloid-biased precursors.

    PubMed

    Braunstein, Marsela; Rajkumar, Paula; Claus, Carol L; Vaccarelli, Giovanna; Moore, Amanda J; Wang, Duncheng; Anderson, Michele K

    2010-12-01

    Hematopoiesis is controlled by the interplay between transcription factors and environmental signals. One of the primary determinants of the T-lineage choice is Delta-like (DL)-Notch signaling, which promotes T-cell development and inhibits B-cell development. We have found that the transcription factor HEBAlt is up-regulated in early hematopoietic precursors in response to DL-Notch signaling and that it can promote early T-cell development. Here, we identified a population of lineage-negative Sca-1⁻c-kit(+) (LK) cells in the mouse fetal liver that rapidly gave rise to myeloid cells and B cells but exhibited very little T-cell potential. However, forced expression of HEBAlt in these precursors restored their ability to develop into T cells. We also showed that Ikaros and Notch1 are up-regulated in response to HEBAlt over-expression and that activated Notch1 enhances the ability of LK cells to enter the T-cell lineage. Furthermore, the myeloid transcription factor C/EBPα is down-regulated in response to HEBAlt. We therefore propose that HEBAlt plays a role in the network that enforces the T-lineage fate and limits myeloid fate during hematopoiesis. PMID:21115673

  14. KLF6 contributes to myeloid cell plasticity in the pathogenesis of intestinal inflammation.

    PubMed

    Goodman, W A; Omenetti, S; Date, D; Di Martino, L; De Salvo, C; Kim, G-D; Chowdhry, S; Bamias, G; Cominelli, F; Pizarro, T T; Mahabeleshwar, G H

    2016-09-01

    Inflammatory bowel disease (IBD) is associated with dysregulated macrophage responses, such that quiescent macrophages acquire a pro-inflammatory activation state and contribute to chronic intestinal inflammation. The transcriptional events governing macrophage activation and gene expression in the context of chronic inflammation such as IBD remain incompletely understood. Here, we identify Kruppel-like transcription factor-6 (KLF6) as a critical regulator of pathogenic myeloid cell activation in human and experimental IBD. We found that KLF6 was significantly upregulated in myeloid cells and intestinal tissue from IBD patients and experimental models of IBD, particularly in actively inflamed regions of the colon. Using complementary gain- and loss-of-function studies, we observed that KLF6 promotes pro-inflammatory gene expression through enhancement of nuclear factor κB (NFκB) signaling, while simultaneously suppressing anti-inflammatory gene expression through repression of signal transducer and activator of transcription 3 (STAT3) signaling. To study the in vivo role of myeloid KLF6, we treated myeloid-specific KLF6-knockout mice (Mac-KLF6-KO) with dextran sulfate sodium (DSS) and found that Mac-KLF6-KO mice were protected against chemically-induced colitis; this highlights the central role of myeloid KLF6 in promoting intestinal inflammation. Collectively, our results point to a novel gene regulatory program underlying pathogenic, pro-inflammatory macrophage activation in the setting of chronic intestinal inflammation. PMID:26838049

  15. Immune Suppression by Myeloid Cells in HIV Infection: New Targets for Immunotherapy

    PubMed Central

    Mehraj, Vikram; Jenabian, Mohammad-Ali; Vyboh, Kishanda; Routy, Jean-Pierre

    2014-01-01

    Over thirty years of extensive research has not yet solved the complexity of HIV pathogenesis leading to a continued need for a successful cure. Recent immunotherapy-based approaches are aimed at controlling the infection by reverting immune dysfunction. Comparatively less appreciated than the role of T cells in the context of HIV infection, the myeloid cells including macrophages monocytes, dendritic cells (DCs) and neutrophils contribute significantly to immune dysfunction. Host restriction factors are cellular proteins expressed in these cells which are circumvented by HIV. Guided by the recent literature, the role of myeloid cells in HIV infection will be discussed highlighting potential targets for immunotherapy. HIV infection, which is mainly characterized by CD4 T cell dysfunction, also manifests in a vicious cycle of events comprising of inflammation and immune activation. Targeting the interaction of programmed death-1 (PD-1), an important regulator of T cell function; with PD-L1 expressed mainly on myeloid cells could bring promising results. Macrophage functional polarization from pro-inflammatory M1 to anti-inflammatory M2 and vice versa has significant implications in viral pathogenesis. Neutrophils, recently discovered low density granular cells, myeloid derived suppressor cells (MDSCs) and yolk sac macrophages provide new avenues of research on HIV pathogenesis and persistence. Recent evidence has also shown significant implications of neutrophil extracellular traps (NETs), antimicrobial peptides and opsonizing antibodies. Further studies aimed to understand and modify myeloid cell restriction mechanisms have the potential to contribute in the future development of more effective anti-HIV interventions that may pave the way to viral eradication. PMID:25624956

  16. CSF-1 Receptor Signaling in Myeloid Cells

    PubMed Central

    Stanley, E. Richard; Chitu, Violeta

    2014-01-01

    The CSF-1 receptor (CSF-1R) is activated by the homodimeric growth factors colony-stimulating factor-1 (CSF-1) and interleukin-34 (IL-34). It plays important roles in development and in innate immunity by regulating the development of most tissue macrophages and osteoclasts, of Langerhans cells of the skin, of Paneth cells of the small intestine, and of brain microglia. It also regulates the differentiation of neural progenitor cells and controls functions of oocytes and trophoblastic cells in the female reproductive tract. Owing to this broad tissue expression pattern, it plays a central role in neoplastic, inflammatory, and neurological diseases. In this review we summarize the evolution, structure, and regulation of expression of the CSF-1R gene. We review, the structures of CSF-1, IL-34, and the CSF-1R and the mechanism of ligand binding to and activation of the receptor. We further describe the pathways regulating macrophage survival, proliferation, differentiation, and chemotaxis downstream from the CSF-1R. PMID:24890514

  17. Antibodies to myeloid precursor cells in autoimmune neutropenia.

    PubMed

    Hartman, K R; LaRussa, V F; Rothwell, S W; Atolagbe, T O; Ward, F T; Klipple, G

    1994-07-15

    Antibodies to mature blood neutrophils and to bone marrow myeloid cells have been described in the sera of some patients with apparent autoimmune neutropenia. To further explore the prevalence and specificities of antibodies to myeloid precursor cells, we evaluated sera from 148 patients with suspected autoimmune neutropenia for the presence of antibodies to neutrophils, to cultured myeloid cell lines, and to highly purified bone marrow myeloid progenitor cells. Using an immunofluorescence flow cytometric assay, we identified IgG antibodies in 42 (28%) of these sera that bound specifically to K562 cells, a multilineage cell line originally derived from a patient with chronic myelogenous leukemia. Twenty-two (15%) of the sera also contained IgG antibodies that bound specifically to the primitive myelomonocytic leukemia cell line KG1a. Twenty-five (17%) of the sera had IgG antibodies to myeloid cell lines in the absence of antibodies to mature neutrophils. There was a trend toward more severe neutropenia in patients with antibodies to K562 cells, without antineutrophil antibodies. In further studies, antibodies from 12 sera bound to mononuclear CD34+ cells that had been purified from normal human bone marrow by an immunomagnetic separation procedure. Moreover, two of these sera suppressed the growth of granulocyte-macrophage colony-forming units (CFU-GM) in methylcellulose cultures. The presence of antibodies to primitive hematopoietic cells in the sera of some patients with suspected immune neutropenia suggests that these antibodies may have a role in the pathogenesis of the neutropenia observed. PMID:7517722

  18. Radiation combined with thermal injury induces immature myeloid cells.

    PubMed

    Mendoza, April Elizabeth; Neely, Crystal Judith; Charles, Anthony G; Kartchner, Laurel Briane; Brickey, Willie June; Khoury, Amal Lina; Sempowski, Gregory D; Ting, Jenny P Y; Cairns, Bruce A; Maile, Robert

    2012-11-01

    The continued development of nuclear weapons and the potential for thermonuclear injury necessitates the further understanding of the immune consequences after radiation combined with injury (RCI). We hypothesized that sublethal ionization radiation exposure combined with a full-thickness thermal injury would result in the production of immature myeloid cells. Mice underwent either a full-thickness contact burn of 20% total body surface area or sham procedure followed by a single whole-body dose of 5-Gy radiation. Serum, spleen, and peripheral lymph nodes were harvested at 3 and 14 days after injury. Flow cytometry was performed to identify and characterize adaptive and innate cell compartments. Elevated proinflammatory and anti-inflammatory serum cytokines and profound leukopenia were observed after RCI. A population of cells with dual expression of the cell surface markers Gr-1 and CD11b were identified in all experimental groups, but were significantly elevated after burn alone and RCI at 14 days after injury. In contrast to the T-cell-suppressive nature of myeloid-derived suppressor cells found after trauma and sepsis, myeloid cells after RCI augmented T-cell proliferation and were associated with a weak but significant increase in interferon γ and a decrease in interleukin 10. This is consistent with previous work in burn injury indicating that a myeloid-derived suppressor cell-like population increases innate immunity. Radiation combined injury results in the increase in distinct populations of Gr-1CD11b cells within the secondary lymphoid organs, and we propose these immature inflammatory myeloid cells provide innate immunity to the severely injured and immunocompromised host. PMID:23042190

  19. The role of Lin28b in myeloid and mast cell differentiation and mast cell malignancy

    PubMed Central

    Wang, Leo D.; Rao, Tata Nageswara; Rowe, R. Grant; Nguyen, Phi T.; Sullivan, Jessica L.; Pearson, Daniel S.; Doulatov, Sergei; Wu, Linwei; Lindsley, R. Coleman; Zhu, Hao; DeAngelo, Daniel J.; Daley, George Q.; Wagers, Amy J.

    2015-01-01

    Mast cells are critical components of the innate immune system and important for host defense, allergy, autoimmunity, tissue regeneration, and tumor progression. Dysregulated mast cell development leads to systemic mastocytosis, a clinically variable but often devastating family of hematologic disorders. Here we report that induced expression of Lin28, a heterochronic gene and pluripotency factor implicated in driving a fetal hematopoietic program, caused mast cell accumulation in adult mice in target organs such as the skin and peritoneal cavity. In vitro assays revealed a skewing of myeloid commitment in LIN28B-expressing hematopoietic progenitors, with increased levels of LIN28B in common myeloid and basophil-mast cell progenitors altering gene expression patterns to favor cell fate choices that enhanced mast cell specification. In addition, LIN28B-induced mast cells appeared phenotypically and functionally immature, and in vitro assays suggested a slowing of mast cell terminal differentiation in the context of LIN28B upregulation. Finally, interrogation of human mast cell leukemia samples revealed upregulation of LIN28B in abnormal mast cells from patients with systemic mastocytosis (SM). This work identifies Lin28 as a novel regulator of innate immune function and a new protein of interest in mast cell disease. PMID:25655194

  20. Technical Advance: Transcription factor, promoter, and enhancer utilization in human myeloid cells

    PubMed Central

    Joshi, Anagha; Pooley, Christopher; Freeman, Tom C.; Lennartsson, Andreas; Babina, Magda; Schmidl, Christian; Geijtenbeek, Teunis; Michoel, Tom; Severin, Jessica; Itoh, Masayoshi; Lassmann, Timo; Kawaji, Hideya; Hayashizaki, Yoshihide; Carninci, Piero; Forrest, Alistair R. R.; Rehli, Michael; Hume, David A.

    2015-01-01

    The generation of myeloid cells from their progenitors is regulated at the level of transcription by combinatorial control of key transcription factors influencing cell-fate choice. To unravel the global dynamics of this process at the transcript level, we generated transcription profiles for 91 human cell types of myeloid origin by use of CAGE profiling. The CAGE sequencing of these samples has allowed us to investigate diverse aspects of transcription control during myelopoiesis, such as identification of novel transcription factors, miRNAs, and noncoding RNAs specific to the myeloid lineage. We further reconstructed a transcription regulatory network by clustering coexpressed transcripts and associating them with enriched cis-regulatory motifs. With the use of the bidirectional expression as a proxy for enhancers, we predicted over 2000 novel enhancers, including an enhancer 38 kb downstream of IRF8 and an intronic enhancer in the KIT gene locus. Finally, we highlighted relevance of these data to dissect transcription dynamics during progressive maturation of granulocyte precursors. A multifaceted analysis of the myeloid transcriptome is made available (www.myeloidome.roslin.ed.ac.uk). This high-quality dataset provides a powerful resource to study transcriptional regulation during myelopoiesis and to infer the likely functions of unannotated genes in human innate immunity. PMID:25717144

  1. Bone marrow derived myeloid cells orchestrate antiangiogenic resistance in glioblastoma through coordinated molecular networks.

    PubMed

    Achyut, B R; Shankar, Adarsh; Iskander, A S M; Ara, Roxan; Angara, Kartik; Zeng, Peng; Knight, Robert A; Scicli, Alfonso G; Arbab, Ali S

    2015-12-28

    Glioblastoma (GBM) is a hypervascular and malignant form of brain tumors. Anti-angiogenic therapies (AAT) were used as an adjuvant against VEGF-VEGFR pathway to normalize blood vessels in clinical and preclinical studies, which resulted into marked hypoxia and recruited bone marrow derived cells (BMDCs) to the tumor microenvironment (TME). In vivo animal models to track BMDCs and investigate molecular mechanisms in AAT resistance are rare. We exploited recently established chimeric mouse to develop orthotopic U251 tumor, which uses as low as 5 × 10(6) GFP+ BM cells in athymic nude mice and engrafted >70% GFP+ cells within 14 days. Our unpublished data and published studies have indicated the involvement of immunosuppressive myeloid cells in therapeutic resistance in glioma. Similarly, in the present study, vatalanib significantly increased CD68+ myeloid cells, and CD133+, CD34+ and Tie2+ endothelial cell signatures. Therefore, we tested inhibition of CSF1R+ myeloid cells using GW2580 that reduced tumor growth by decreasing myeloid (Gr1+ CD11b+ and F4/80+) and angiogenic (CD202b+ and VEGFR2+) cell signatures in TME. CSF1R blockade significantly decreased inflammatory, proangiogenic and immunosuppressive molecular signatures compared to vehicle, vatalanib or combination. TCK1 or CXCL7, a potent chemoattractant and activator of neutrophils, was observed as most significantly decreased cytokine in CSF1R blockade. ERK MAPK pathway was involved in cytokine network regulation. In conclusion, present study confirmed the contribution of myeloid cells in GBM development and therapeutic resistance using chimeric mouse model. We identified novel molecular networks including CXCL7 chemokine as a promising target for future studies. Nonetheless, survival studies are required to assess the beneficial effect of CSF1R blockade. PMID:26404753

  2. Brachial Plexopathy due to Myeloid Sarcoma in a Patient With Acute Myeloid Leukemia After Allogenic Peripheral Blood Stem Cell Transplantation.

    PubMed

    Ha, Yumi; Sung, Duk Hyun; Park, Yoonhong; Kim, Du Hwan

    2013-04-01

    Myeloid sarcoma is a solid, extramedullary tumor comprising of immature myeloid cells. It may occur in any organ; however, the invasion of peripheral nervous system is rare. Herein, we report the case of myeloid sarcoma on the brachial plexus. A 37-year-old woman with acute myelogenous leukemia achieved complete remission after chemotherapy. One year later, she presented right shoulder pain, progressive weakness in the right upper extremity and hypesthesia. Based on magnetic resonance images (MRI) and electrophysiologic study, a provisional diagnosis of brachial plexus neuritis was done and hence steroid pulse therapy was carried out. Three months later the patient presented epigastric pain. After upper gastrointestinal endoscopy, myeloid sarcoma of gastrointestinal tract was confirmed pathologically. Moreover, 18-fluoride fluorodeoxyglucose positron emission tomography showed a fusiform shaped mass lesion at the brachial plexus overlapping with previous high signal lesion on the MRI. Therefore, we concluded the final diagnosis as brachial plexopathy due to myeloid sarcoma. PMID:23705126

  3. Leukomogenic factors downregulate heparanase expression in acute myeloid leukemia cells

    SciTech Connect

    Eshel, Rinat; Ben-Zaken, Olga; Vainas, Oded; Nadir, Yona; Minucci, Saverio; Polliack, Aaron; Naparstek, Ella; Vlodavsky, Israel; Katz, Ben-Zion; E-mail: bkatz@tasmc.healt.gov.il

    2005-10-07

    Heparanase is a heparan sulfate-degrading endoglycosidase expressed by mature monocytes and myeloid cells, but not by immature hematopoietic progenitors. Heparanase gene expression is upregulated during differentiation of immature myeloid cells. PML-RAR{alpha} and PLZF-RAR{alpha} fusion gene products associated with acute promyelocytic leukemia abrogate myeloid differentiation and heparanase expression. AML-Eto, a translocation product associated with AML FAB M2, also downregulates heparanase gene expression. The common mechanism that underlines the activity of these three fusion gene products involves the recruitment of histone deacetylase complexes to specific locations within the DNA. We found that retinoic acid that dissociates PML-RAR{alpha} from the DNA, and which is used to treat acute promyelocytic leukemia patients, restores heparanase expression to normal levels in an acute promyelocytic leukemia cell line. The retinoic acid effects were also observed in primary acute promyelocytic leukemia cells and in a retinoic acid-treated acute promyelocytic leukemia patient. Histone deacetylase inhibitor reverses the downregulation of heparanase expression induced by the AML-Eto fusion gene product in M2 type AML. In summary, we have characterized a link between leukomogenic factors and the downregulation of heparanase in myeloid leukemic cells.

  4. Myeloid cells as target of fingolimod action in multiple sclerosis

    PubMed Central

    Di Dario, Marco; Colombo, Emanuela; Govi, Chiara; De Feo, Donatella; Messina, Maria José; Romeo, Marzia; Sangalli, Francesca; Moiola, Lucia; Rodegher, Mariaemma; Martino, Gianvito; Martinelli, Vittorio; Comi, Giancarlo

    2015-01-01

    Objective: To track the effects of fingolimod, an approved drug for multiple sclerosis (MS), on the activation of myeloid cells from the periphery to the CNS. Methods: In vitro and ex vivo immunologic studies coupled with flow cytometry were performed to evaluate the action of fingolimod on lipopolysaccharide (LPS)–induced expression of activation markers in human monocytes from healthy participants, participants with untreated MS, and participants with fingolimod-treated MS. In vivo administration of fingolimod during experimental autoimmune encephalomyelitis (EAE) was established to verify the activation state of splenic, CNS infiltrating, and CNS resident myeloid cells ex vivo at flow cytometer. Results: We found that in vitro exposure of human monocytes to fingolimod inhibited LPS-induced CD25 and CD150 expression and tumor necrosis factor–α (TNF-α) secretion without altering immune cell survival. Further, EAE treatment with fingolimod led to reduced amounts of TNF-α produced by myeloid cells in vivo in the spleen and CNS. Finally, while displaying normal induction of CD25 and CD150 levels at high LPS concentration, monocytes from patients with fingolimod-treated MS showed significantly higher activation threshold at suboptimal LPS stimulation than controls. Conclusions: The inhibition of myeloid cell activation may be part of the immunosuppressive action of fingolimod and take place in the periphery and in the CNS. PMID:26587553

  5. CatacLysMic specificity when targeting myeloid cells?

    PubMed

    Blank, Thomas; Prinz, Marco

    2016-06-01

    The antibacterial enzyme lysozyme M (LysM) encoded by the Lyz2 gene is broadly expressed in myeloblasts, macrophages, and neutrophils, and thus has been used for a long time as a cell-specific marker for myeloid cells in mice. In order to delete loxP-site flanked genes in myeloid cells, a Cre-recombinase (Cre) expressing mouse line was created by inserting Cre-coding sequence into the translational start site of the LysM gene. In this issue of the European Journal of Immunology [2016. 46: 1529-1532], Orthgiess et al. verify, with the help of tdTomato and YFP reporter mouse lines, LysM-driven recombination. Unexpectedly, the authors also describe major expression of the tdTomato reporter protein in brain neurons of the central nervous system (CNS), with only a very small percentage of gene recombination in myeloid cells of the brain, called microglia. These findings cause justified concerns regarding the efficient and specific targeting of microglia and peripheral myeloid cells using LysM-Cre mice and should stimulate thoughts on conclusions drawn from past experiments on the diseased CNS employing this Cre/loxP-deleter line. PMID:27198084

  6. Differential regulation of myeloid leukemias by the bone marrow microenvironment.

    PubMed

    Krause, Daniela S; Fulzele, Keertik; Catic, André; Sun, Chia Chi; Dombkowski, David; Hurley, Michael P; Lezeau, Sanon; Attar, Eyal; Wu, Joy Y; Lin, Herbert Y; Divieti-Pajevic, Paola; Hasserjian, Robert P; Schipani, Ernestina; Van Etten, Richard A; Scadden, David T

    2013-11-01

    Like their normal hematopoietic stem cell counterparts, leukemia stem cells (LSCs) in chronic myelogenous leukemia (CML) and acute myeloid leukemia (AML) are presumed to reside in specific niches in the bone marrow microenvironment (BMM) and may be the cause of relapse following chemotherapy. Targeting the niche is a new strategy to eliminate persistent and drug-resistant LSCs. CD44 (refs. 3,4) and interleukin-6 (ref. 5) have been implicated previously in the LSC niche. Transforming growth factor-β1 (TGF-β1) is released during bone remodeling and plays a part in maintenance of CML LSCs, but a role for TGF-β1 from the BMM has not been defined. Here, we show that alteration of the BMM by osteoblastic cell-specific activation of the parathyroid hormone (PTH) receptor attenuates BCR-ABL1 oncogene-induced CML-like myeloproliferative neoplasia (MPN) but enhances MLL-AF9 oncogene-induced AML in mouse transplantation models, possibly through opposing effects of increased TGF-β1 on the respective LSCs. PTH treatment caused a 15-fold decrease in LSCs in wild-type mice with CML-like MPN and reduced engraftment of immune-deficient mice with primary human CML cells. These results demonstrate that LSC niches in CML and AML are distinct and suggest that modulation of the BMM by PTH may be a feasible strategy to reduce LSCs, a prerequisite for the cure of CML. PMID:24162813

  7. Defective regulation of leukemic hematopoiesis in chronic myeloid leukemia.

    PubMed

    Eaves, C; Cashman, J; Eaves, A

    1998-12-01

    Over the last two decades considerable knowledge has been acquired about the distribution of cell types within the dominant leukemic (Ph+/BCR-ABL+) clone that results in human chronic myeloid leukemia (CML). Evidence is now growing to indicate that three key biological changes affecting the development of such clones are: (1) an increased probability of differentiation at the level of the most primitive leukemic stem cells; (2) an increased turnover rate of the leukemic progenitors at all stages of differentiation: and (3) their increased ability to survive under conditions of factor-deprivation. Such a model explains the long latent period for the development of CML as well as why normal stem cells may persist in large numbers but still fail to compete in contributing to the daily output of mature blood cells in patients with disease. The recent development of new genetic and transplant models of human CML may now allow the molecular basis of these biological disturbances to be delineated and more effective therapeutic strategies developed. PMID:9922073

  8. Myeloid-Derived Suppressor Cells and Therapeutic Strategies in Cancer

    PubMed Central

    Katoh, Hiroshi; Watanabe, Masahiko

    2015-01-01

    Development of solid cancer depends on escape from host immunosurveillance. Various types of immune cells contribute to tumor-induced immune suppression, including tumor associated macrophages, regulatory T cells, type 2 NKT cells, and myeloid-derived suppressor cells (MDSCs). Growing body of evidences shows that MDSCs play pivotal roles among these immunosuppressive cells in multiple steps of cancer progression. MDSCs are immature myeloid cells that arise from myeloid progenitor cells and comprise a heterogeneous immune cell population. MDSCs are characterized by the ability to suppress both adaptive and innate immunities mainly through direct inhibition of the cytotoxic functions of T cells and NK cells. In clinical settings, the number of circulating MDSCs is associated with clinical stages and response to treatment in several cancers. Moreover, MDSCs are reported to contribute to chemoresistant phenotype. Collectively, targeting MDSCs could potentially provide a rationale for novel treatment strategies in cancer. This review summarizes recent understandings of MDSCs in cancer and discusses promissing clinical approaches in cancer patients. PMID:26078490

  9. Radiation Combined with Thermal Injury Induces Immature Myeloid Cells

    PubMed Central

    Mendoza, April Elizabeth; Neely, Crystal Judith; Charles, Anthony G.; Kartchner, Laurel Briane; Brickey, Willie June; Khoury, Amal Lina; Sempowski, Gregory D.; Ting, Jenny P.Y.; Cairns, Bruce A.; Maile, Robert

    2012-01-01

    The continued development of nuclear weapons and the potential for thermonuclear injury necessitates the further understanding of the immune consequences after radiation combined with injury (RCI). We hypothesized that sub-lethal ionization radiation exposure combined with a full thickness thermal injury would result in the production of immature myeloid cells. Mice underwent either a 20% total body surface area (TBSA) full-thickness contact burn or sham procedure followed by a single whole body dose of 5-Gy radiation. Serum, spleen and peripheral lymph nodes were harvested at 3 and 14 days post-injury. Flow cytometry was performed to identify and characterize adaptive and innate cell compartments. Elevated pro- and anti-inflammatory serum cytokines and profound leukopenia were observed after RCI. A population of cells with dual expression of the cell surface markers Gr-1 and CD11b were identified in all experimental groups, but was significantly elevated after burn alone and RCI at 14 days post-injury. In contrast to the T-cell suppressive nature of myeloid-derived suppressor cells (MDSC) found after trauma and sepsis, myeloid cells after RCI augmented T-cell proliferation and were associated with a weak but significant increase in IFN-γ and a decrease in IL-10. This is consistent with previous work in burn injury indicating that a MDSC-like population increases innate immunity. RCI results in the increase of distinct populations of Gr-1+ CD11b+cells within the secondary lymphoid organs, and we propose these immature inflammatory myeloid cells provide innate immunity to the severely injured and immunocompromised host. PMID:23042190

  10. Myeloid-derived suppressor cells in inflammatory bowel disease.

    PubMed

    Kim, Yeon-Jeong; Chang, Sun-Young; Ko, Hyun-Jeong

    2015-04-01

    Immature myeloid cells, also known as myeloid-derived suppressor cells (MDSCs), include neutrophilic and monocytic myeloid cells, and are found in inflammatory loci and secondary lymphoid organs in mice with intestinal inflammation, inflammatory bowel disease (IBD) patients, and tumor tissues. However, the roles of MDSCs in IBD are not yet well understood, and there are controversies regarding their immunosuppressive functions in IBD. In addition, recent studies have suggested that endoplasmic reticulum (ER) stress in intestinal epithelial cells, especially in Paneth cells, is closely associated with the induction of IBD. However, the ER stress in MDSCs accumulated in the inflamed tissues of IBD patients is not yet fully understood. In the current review, we discuss the presence of accumulated MDSCs in the intestines of IBD patients, and further speculate on their physiological roles in the inflammatory condition with interleukin 17-producing cells, including Th17 cells. In particular, we will discuss the divergent functions of MDSCs in ER stressed intestinal environments, including their pro-inflammatory or immunosuppressive roles, based on the consideration of unfolded protein responses initiated in intestinal epithelial cells by ER stress. PMID:25931994

  11. An Immature Myeloid/Myeloid-Suppressor Cell Response Associated with Necrotizing Inflammation Mediates Lethal Pulmonary Tularemia.

    PubMed

    Periasamy, Sivakumar; Avram, Dorina; McCabe, Amanda; MacNamara, Katherine C; Sellati, Timothy J; Harton, Jonathan A

    2016-03-01

    Inhalation of Francisella tularensis (Ft) causes acute and fatal pneumonia. The lung cytokine milieu favors exponential Ft replication, but the mechanisms underlying acute pathogenesis and death remain unknown. Evaluation of the sequential and systemic host immune response in pulmonary tularemia reveals that in contrast to overwhelming bacterial burden or cytokine production, an overt innate cellular response to Ft drives tissue pathology and host mortality. Lethal infection with Ft elicits medullary and extra-medullary myelopoiesis supporting recruitment of large numbers of immature myeloid cells and MDSC to the lungs. These cells fail to mature and die, leading to subsequent necrotic lung damage, loss of pulmonary function, and host death that is partially dependent upon immature Ly6G+ cells. Acceleration of this process may account for the rapid lethality seen with Ft SchuS4. In contrast, during sub-lethal infection with Ft LVS the pulmonary cellular response is characterized by a predominance of mature neutrophils and monocytes required for protection, suggesting a required threshold for lethal bacterial infection. Further, eliciting a mature phagocyte response provides transient, but dramatic, innate protection against Ft SchuS4. This study reveals that the nature of the myeloid cell response may be the primary determinant of host mortality versus survival following Francisella infection. PMID:27015566

  12. An Immature Myeloid/Myeloid-Suppressor Cell Response Associated with Necrotizing Inflammation Mediates Lethal Pulmonary Tularemia

    PubMed Central

    Periasamy, Sivakumar; Avram, Dorina; McCabe, Amanda; MacNamara, Katherine C.; Sellati, Timothy J.; Harton, Jonathan A.

    2016-01-01

    Inhalation of Francisella tularensis (Ft) causes acute and fatal pneumonia. The lung cytokine milieu favors exponential Ft replication, but the mechanisms underlying acute pathogenesis and death remain unknown. Evaluation of the sequential and systemic host immune response in pulmonary tularemia reveals that in contrast to overwhelming bacterial burden or cytokine production, an overt innate cellular response to Ft drives tissue pathology and host mortality. Lethal infection with Ft elicits medullary and extra-medullary myelopoiesis supporting recruitment of large numbers of immature myeloid cells and MDSC to the lungs. These cells fail to mature and die, leading to subsequent necrotic lung damage, loss of pulmonary function, and host death that is partially dependent upon immature Ly6G+ cells. Acceleration of this process may account for the rapid lethality seen with Ft SchuS4. In contrast, during sub-lethal infection with Ft LVS the pulmonary cellular response is characterized by a predominance of mature neutrophils and monocytes required for protection, suggesting a required threshold for lethal bacterial infection. Further, eliciting a mature phagocyte response provides transient, but dramatic, innate protection against Ft SchuS4. This study reveals that the nature of the myeloid cell response may be the primary determinant of host mortality versus survival following Francisella infection. PMID:27015566

  13. Tetraspanin CD82 Regulates the Spatiotemporal Dynamics of PKCα in Acute Myeloid Leukemia.

    PubMed

    Termini, Christina M; Lidke, Keith A; Gillette, Jennifer M

    2016-01-01

    Patients with acute myeloid leukemia (AML) have increased myeloid cells within their bone marrow that exhibit aberrant signaling. Therefore, therapeutic targets that modulate disrupted signaling cascades are of significant interest. In this study, we demonstrate that the tetraspanin membrane scaffold, CD82, regulates protein kinase c alpha (PKCα)-mediated signaling critical for AML progression. Utilizing a palmitoylation mutant form of CD82 with disrupted membrane organization, we find that the CD82 scaffold controls PKCα expression and activation. Combining single molecule and ensemble imaging measurements, we determine that CD82 stabilizes PKCα activation at the membrane and regulates the size of PKCα membrane clusters. Further evaluation of downstream effector signaling identified robust and sustained activation of ERK1/2 upon CD82 overexpression that results in enhanced AML colony formation. Together, these data propose a mechanism where CD82 membrane organization regulates sustained PKCα signaling that results in an aggressive leukemia phenotype. These observations suggest that the CD82 scaffold may be a potential therapeutic target for attenuating aberrant signal transduction in AML. PMID:27417454

  14. Tetraspanin CD82 Regulates the Spatiotemporal Dynamics of PKCα in Acute Myeloid Leukemia

    PubMed Central

    Termini, Christina M.; Lidke, Keith A.; Gillette, Jennifer M.

    2016-01-01

    Patients with acute myeloid leukemia (AML) have increased myeloid cells within their bone marrow that exhibit aberrant signaling. Therefore, therapeutic targets that modulate disrupted signaling cascades are of significant interest. In this study, we demonstrate that the tetraspanin membrane scaffold, CD82, regulates protein kinase c alpha (PKCα)-mediated signaling critical for AML progression. Utilizing a palmitoylation mutant form of CD82 with disrupted membrane organization, we find that the CD82 scaffold controls PKCα expression and activation. Combining single molecule and ensemble imaging measurements, we determine that CD82 stabilizes PKCα activation at the membrane and regulates the size of PKCα membrane clusters. Further evaluation of downstream effector signaling identified robust and sustained activation of ERK1/2 upon CD82 overexpression that results in enhanced AML colony formation. Together, these data propose a mechanism where CD82 membrane organization regulates sustained PKCα signaling that results in an aggressive leukemia phenotype. These observations suggest that the CD82 scaffold may be a potential therapeutic target for attenuating aberrant signal transduction in AML. PMID:27417454

  15. Adenosine influences myeloid cells to inhibit aeroallergen sensitization.

    PubMed

    Pei, Hong; Linden, Joel

    2016-05-15

    Agonists of adenosine A2A receptors (A2ARs) suppress the activation of most immune cells and reduce acute inflammatory responses. Asthma is characterized by sensitization in response to initial allergen exposure and by airway hyperreactivity in response to allergen rechallenge. We sought to determine if A2AR activation with CGS-21680 (CGS) is more effective when CGS is administered during sensitization or rechallenge. C57BL/6 wild-type mice and Adora2a(f/f)LysMCre(+/-) mice, which lack A2ARs on myeloid cells, were sensitized with intranasal ovalbumin (OVA) and LPS. Airway sensitization was characterized by a rapid increase in numbers of IL-6(+) and IL-12(+) macrophages and dendritic cells in lungs. A2AR activation with CGS (0.1 μg·kg(-1)·min(-1) sc) only during sensitization reduced numbers of IL-6(+) and IL-12(+) myeloid cells in the lungs and reversed the effects of OVA rechallenge to increase airway hyperresponsiveness to methacholine. CGS treatment during sensitization also reduced the expansion of lung T helper (Th1 and Th17) cells and increased expansion of regulatory T cells in response to OVA rechallenge. Most of the effects of CGS administered during sensitization were eliminated by myeloid-selective A2AR deletion. Administration of CGS only during OVA rechallenge failed to reduce airway hyperresponsiveness. We conclude that myeloid cells are key targets of adenosine during sensitization and indirectly modify T cell polarization. The results suggest that a clinically useful strategy might be to use A2AR agonists to inhibit sensitization to new aeroallergens. We speculate that adenosine production by macrophages engulfing bacteria contributes to the curious suppression of sensitization in response to early-life infections. PMID:27016586

  16. Myeloid-Derived Suppressor Cells: Critical Cells Driving Immune Suppression in the Tumor Microenvironment

    PubMed Central

    Parker, Katherine H.; Beury, Daniel W.; Ostrand-Rosenberg, Suzanne

    2015-01-01

    Myeloid-derived suppressor cells (MDSCs) are a heterogeneous population of immature myeloid cells that suppress innate and adaptive immunity. MDSCs are present in many disease settings; however, in cancer, they are a major obstacle for both natural antitumor immunity and immunotherapy. Tumor and host cells in the tumor microenvironment (TME) produce a myriad of pro-inflammatory mediators that activate MDSCs and drive their accumulation and suppressive activity. MDSCs utilize a variety of mechanisms to suppress T cell activation, induce other immune-suppressive cell populations, regulate inflammation in the TME, and promote the switching of the immune system to one that tolerates and enhances tumor growth. Because MDSCs are present in most cancer patients and are potent immune-suppressive cells, MDSCs have been the focus of intense research in recent years. This review describes the history and identification of MDSCs, the role of inflammation and intracellular signaling events governing MDSC accumulation and suppressive activity, immune-suppressive mechanisms utilized by MDSCs, and recent therapeutics that target MDSCs to enhance antitumor immunity. PMID:26216631

  17. Deletion of TGF-β signaling in myeloid cells enhances their anti-tumorigenic properties

    PubMed Central

    Novitskiy, Sergey V.; Pickup, Michael W.; Chytil, Anna; Polosukhina, Dina; Owens, Philip; Moses, Harold L.

    2012-01-01

    By crossing LysM-Cre and TGF-β type II receptor (Tgfbr2) floxed mice we achieved specific deletion of Tgfbr2 in myeloid cells (Tgfbr2MyeKO mice). S.c.-injected (LLC, EL4-OVA) and implanted (MMTV-PyMT) carcinoma cells grow slower in Tgfbr2MyeKO mice. The number of CD45+ cells in the tumor tissue was the same in both genotypes of mice, but upon analysis, the percentage of T cells (CD45+CD3+) in the KO mice was increased. By flow cytometry analysis, we did not detect any differences in the number and phenotype of TAMs, CD11b+Gr1+, and DCs in Tgfbr2MyeKO compared with Tgfbr2MyeWT mice. ELISA and qRT-PCR data showed differences in myeloid cell functions. In Tgfbr2MyeKO TAMs, TNF-α secretion was increased, basal IL-6 secretion was down-regulated, TGF-β did not induce any VEGF response, and there was decreased MMP9 and increased MMP2 and iNOS expression. TGF-β did not have any effect on CD11b+Gr1+ cells isolated from Tgfbr2MyeKO mice in the regulation of Arg, iNOS, VEGF, and CXCR4, and moreover, these cells have decreased suppressive activity relative to T cell proliferation. Also, we found that DCs from tumor tissue of Tgfbr2MyeKO mice have increased antigen-presented properties and an enhanced ability to stimulate antigen-specific T cell proliferation. We conclude that Tgfbr2 in myeloid cells has a negative role in the regulation of anti-tumorigenic functions of these cells, and deletion of this receptor decreases the suppressive function of CD11b+Gr1+ cells and increases antigen-presenting properties of DCs and anti-tumorigenic properties of TAMs. PMID:22685318

  18. A proteomic chronology of gene expression through the cell cycle in human myeloid leukemia cells

    PubMed Central

    Ly, Tony; Ahmad, Yasmeen; Shlien, Adam; Soroka, Dominique; Mills, Allie; Emanuele, Michael J; Stratton, Michael R; Lamond, Angus I

    2014-01-01

    Technological advances have enabled the analysis of cellular protein and RNA levels with unprecedented depth and sensitivity, allowing for an unbiased re-evaluation of gene regulation during fundamental biological processes. Here, we have chronicled the dynamics of protein and mRNA expression levels across a minimally perturbed cell cycle in human myeloid leukemia cells using centrifugal elutriation combined with mass spectrometry-based proteomics and RNA-Seq, avoiding artificial synchronization procedures. We identify myeloid-specific gene expression and variations in protein abundance, isoform expression and phosphorylation at different cell cycle stages. We dissect the relationship between protein and mRNA levels for both bulk gene expression and for over ∼6000 genes individually across the cell cycle, revealing complex, gene-specific patterns. This data set, one of the deepest surveys to date of gene expression in human cells, is presented in an online, searchable database, the Encyclopedia of Proteome Dynamics (http://www.peptracker.com/epd/). DOI: http://dx.doi.org/10.7554/eLife.01630.001 PMID:24596151

  19. MiR-181 family: regulators of myeloid differentiation and acute myeloid leukemia as well as potential therapeutic targets.

    PubMed

    Su, R; Lin, H-S; Zhang, X-H; Yin, X-L; Ning, H-M; Liu, B; Zhai, P-F; Gong, J-N; Shen, C; Song, L; Chen, J; Wang, F; Zhao, H-L; Ma, Y-N; Yu, J; Zhang, J-W

    2015-06-01

    MicroRNAs have been shown to play an important role in normal hematopoisis and leukemogenesis. Here, we report function and mechanisms of miR-181 family in myeloid differentiation and acute myeloid leukemia (AML). The aberrant overexpression of all the miR-181 family members (miR-181a/b/c/d) was detected in French-American-British M1, M2 and M3 subtypes of adult AML patients. By conducting gain- and loss-of-function experiments, we demonstrated that miR-181a inhibits granulocytic and macrophage-like differentiation of HL-60 cells and CD34+ hematopoietic stem/progenitor cells (HSPCs) by directly targeting and downregulating the expression of PRKCD (which then affected the PRKCD-P38-C/EBPα pathway), CTDSPL (which then affected the phosphorylation of retinoblastoma protein) and CAMKK1. The three genes were also demonstrated to be the targets of miR-181b, miR-181c and miR-181d, respectively. Significantly decreases in the expression levels of the target proteins were detected in AML patients. Inhibition of the expression of miR-181 family members owing to Lenti-miRZip-181a infection in bone marrow blasts of AML patients increased target protein expression levels and partially reversed myeloid differentiation blockage. In the mice implanted with AML CD34+ HSPCs, expression inhibition of the miR-181 family by Lenti-miRZip-181a injection improved myeloid differentiation, inhibited engraftment and infiltration of the leukemic CD34+ cells into the bone marrow and spleen, and released leukemic symptoms. In conclusion, our findings revealed new mechanism of miR-181 family in normal hematopoiesis and AML development, and suggested that expression inhibition of the miR-181 family could provide a new strategy for AML therapy. PMID:25174404

  20. Heterozygous inactivation of the Nf1 gene in myeloid cells enhances neointima formation via a rosuvastatin-sensitive cellular pathway.

    PubMed

    Stansfield, Brian K; Bessler, Waylan K; Mali, Raghuveer; Mund, Julie A; Downing, Brandon; Li, Fang; Sarchet, Kara N; DiStasi, Matthew R; Conway, Simon J; Kapur, Reuben; Ingram, David A

    2013-03-01

    Mutations in the NF1 tumor suppressor gene cause Neurofibromatosis type 1 (NF1). Neurofibromin, the protein product of NF1, functions as a negative regulator of Ras activity. Some NF1 patients develop cardiovascular disease, which represents an underrecognized disease complication and contributes to excess morbidity and mortality. Specifically, NF1 patients develop arterial occlusion resulting in tissue ischemia and sudden death. Murine studies demonstrate that heterozygous inactivation of Nf1 (Nf1(+/-)) in bone marrow cells enhances neointima formation following arterial injury. Macrophages infiltrate Nf1(+/-) neointimas, and NF1 patients have increased circulating inflammatory monocytes in their peripheral blood. Therefore, we tested the hypothesis that heterozygous inactivation of Nf1 in myeloid cells is sufficient for neointima formation. Specific ablation of a single copy of the Nf1 gene in myeloid cells alone mobilizes a discrete pro-inflammatory murine monocyte population via a cell autonomous and gene-dosage dependent mechanism. Furthermore, lineage-restricted heterozygous inactivation of Nf1 in myeloid cells is sufficient to reproduce the enhanced neointima formation observed in Nf1(+/-) mice when compared with wild-type controls, and homozygous inactivation of Nf1 in myeloid cells amplified the degree of arterial stenosis after arterial injury. Treatment of Nf1(+/-) mice with rosuvastatin, a stain with anti-inflammatory properties, significantly reduced neointima formation when compared with control. These studies identify neurofibromin-deficient myeloid cells as critical cellular effectors of Nf1(+/-) neointima formation and propose a potential therapeutic for NF1 cardiovascular disease. PMID:23197650

  1. Primary cerebellar extramedullary myeloid cell tumor mimicking oligodendroglioma.

    PubMed

    Ho, D M; Wong, T T; Guo, W Y; Chang, K P; Yen, S H

    1997-10-01

    Extramedullary myeloid cell tumors (EMCTs) are tumors consisting of immature cells of the myeloid series that occur outside the bone marrow. Most of them are associated with acute myelogenous leukemia or other myeloproliferative disorders, and a small number occur as primary lesions, i.e., are not associated with hematological disorders. Occurrence inside the cranium is rare, and there has been only one case of primary EMCT involving the cerebellum reported in the literature. The case we report here is a blastic EMCT occurring in the cerebellum of a 3-year-old boy who had no signs of leukemia or any hematological disorder throughout the entire course. The cerebellar tumor was at first misdiagnosed as an "oligodendroglioma" because of the uniformity and "fried egg" artifact of the tumor cells. The tumor disappeared during chemotherapy consisting of 12 treatments. However, it recurred and metastasized to the cerebrospinal fluid (CSF) shortly after the therapy was completed. A diagnosis of EMCT was suspected because of the presence of immature myeloid cells in the CSF, and was confirmed by anti-myeloperoxidase and anti-lysozyme immunoreactivity of the cerebellar tumor. The patient succumbed 1 year and 3 months after the first presentation of the disease. PMID:9341943

  2. Systemic RNAi-mediated Gene Silencing in Nonhuman Primate and Rodent Myeloid Cells.

    PubMed

    Novobrantseva, Tatiana I; Borodovsky, Anna; Wong, Jamie; Klebanov, Boris; Zafari, Mohammad; Yucius, Kristina; Querbes, William; Ge, Pei; Ruda, Vera M; Milstein, Stuart; Speciner, Lauren; Duncan, Rick; Barros, Scott; Basha, Genc; Cullis, Pieter; Akinc, Akin; Donahoe, Jessica S; Narayanannair Jayaprakash, K; Jayaraman, Muthusamy; Bogorad, Roman L; Love, Kevin; Whitehead, Katie; Levins, Chris; Manoharan, Muthiah; Swirski, Filip K; Weissleder, Ralph; Langer, Robert; Anderson, Daniel G; de Fougerolles, Antonin; Nahrendorf, Matthias; Koteliansky, Victor

    2012-01-01

    Leukocytes are central regulators of inflammation and the target cells of therapies for key diseases, including autoimmune, cardiovascular, and malignant disorders. Efficient in vivo delivery of small interfering RNA (siRNA) to immune cells could thus enable novel treatment strategies with broad applicability. In this report, we develop systemic delivery methods of siRNA encapsulated in lipid nanoparticles (LNP) for durable and potent in vivo RNA interference (RNAi)-mediated silencing in myeloid cells. This work provides the first demonstration of siRNA-mediated silencing in myeloid cell types of nonhuman primates (NHPs) and establishes the feasibility of targeting multiple gene targets in rodent myeloid cells. The therapeutic potential of these formulations was demonstrated using siRNA targeting tumor necrosis factor-α (TNFα) which induced substantial attenuation of disease progression comparable to a potent antibody treatment in a mouse model of rheumatoid arthritis (RA). In summary, we demonstrate a broadly applicable and therapeutically relevant platform for silencing disease genes in immune cells. PMID:23344621

  3. Role of myeloid-derived suppressor cells in tumor immunotherapy.

    PubMed

    Martin, François; Apetoh, Lionel; Ghiringhelli, François

    2012-01-01

    Myeloid-derived suppressor cells (MDSCs) are immature myeloid cells that infiltrate human and experimental tumors and strongly inhibit anticancer immune response directly or by inducing regulatory T-lymphocyte activity. Consequently, MDSCs are important actors of cancer-induced immune tolerance and a major obstacle to efficiency of cancer immunotherapy. Several means of preventing MDSCs accumulation or inhibiting their immunosuppressive effect were recently discovered in cancer-bearing hosts, contributing to restoring antitumor immunity and consequently to control of tumor growth. In experimental tumor models, targeting MDSCs can enhance the effects of active or passive immunotherapy. While similar effects have not yet been noted in cancer-bearing patients, recent preclinical findings demonstrating that the selective toxicity of conventional chemotherapies such as gemcitabine and 5-fluorouracil on MDSCs might contribute to their anticancer effect provide impetus to pursue investigations to unravel novel therapeutics that target MDSCs in humans. PMID:22150000

  4. Specific Btk inhibition suppresses B cell- and myeloid cell-mediated arthritis

    SciTech Connect

    Di Paolo, Julie A.; Huang, Tao; Balazs, Mercedesz; Barbosa, James; Barck, Kai H.; Bravo, Brandon J.; Carano, Richard A.D.; Darrow, James; Davies, Douglas R.; DeForge, Laura E.; Diehl, Lauri; Ferrando, Ronald; Gallion, Steven L.; Giannetti, Anthony M.; Gribling, Peter; Hurez, Vincent; Hymowitz, Sarah G.; Jones, Randall; Kropf, Jeffrey E.; Lee, Wyne P.; Maciejewski, Patricia M.; Mitchell, Scott A.; Rong, Hong; Staker, Bart L.; Whitney, J. Andrew; Yeh, Sherry; Young, Wendy B.; Yu, Christine; Zhang, Juan; Reif, Karin; Currie, Kevin S.

    2011-09-20

    Bruton's tyrosine kinase (Btk) is a therapeutic target for rheumatoid arthritis, but the cellular and molecular mechanisms by which Btk mediates inflammation are poorly understood. Here we describe the discovery of CGI1746, a small-molecule Btk inhibitor chemotype with a new binding mode that stabilizes an inactive nonphosphorylated enzyme conformation. CGI1746 has exquisite selectivity for Btk and inhibits both auto- and transphosphorylation steps necessary for enzyme activation. Using CGI1746, we demonstrate that Btk regulates inflammatory arthritis by two distinct mechanisms. CGI1746 blocks B cell receptor-dependent B cell proliferation and in prophylactic regimens reduces autoantibody levels in collagen-induced arthritis. In macrophages, Btk inhibition abolishes Fc{gamma}RIII-induced TNF{alpha}, IL-1{beta} and IL-6 production. Accordingly, in myeloid- and Fc{gamma}R-dependent autoantibody-induced arthritis, CGI1746 decreases cytokine levels within joints and ameliorates disease. These results provide new understanding of the function of Btk in both B cell- or myeloid cell-driven disease processes and provide a compelling rationale for targeting Btk in rheumatoid arthritis.

  5. The Cebpa +37-kb enhancer directs transgene expression to myeloid progenitors and to long-term hematopoietic stem cells.

    PubMed

    Guo, Hong; Ma, Ou; Friedman, Alan D

    2014-09-01

    C/EBPα is expressed preferentially in myeloid compared with lymphoid or erythroid cells and directs myeloid lineage specification. C/EBPα is also expressed at lower levels in HSCs and in several nonhematopoietic tissues. The Cebpa gene has a conserved, 450-bp segment at +37 kb that harbors enhancer-specific epigenetic marks and is activate in a myeloid cell line. Herein, we characterize transgenic C57BL/6 mice, in which the Cebpa enhancer and 845-bp promoter regulate a hCD4 reporter. FACS analysis, in vitro colony assays, and in vivo competitive and secondary transplantation revealed that myeloid but not MEPs or lymphoid progenitors and also functional LT-HSCs are found almost exclusively in the Cebpa-hCD4(+) compared with hCD4(-) marrow population. hCD4(+) CMP yielded predominantly myeloid, whereas hCD4(-) CMP generated mainly Meg/E colonies. Providing insight into control of CMP maturation, Cebpa and Pu.1 RNAs were preferentially expressed in hCD4(+) CMP, Scl, Gata2, Gata1, Klf1, Ets1, and Fli1 predominated in hCD4(-) CMP, and Runx1, Myb, HoxA9, and Erg levels were similar in both. Cebpa-hCD4 transgene expression was lacking in multiple nonhematopoietic tissues. In summary, the +37-kb Cebpa enhancer and promoter are sufficient for marrow myeloid progenitor and LT-HSC-specific expression. PMID:24868087

  6. CSF1-ETS2-induced microRNA in myeloid cells promote metastatic tumor growth.

    PubMed

    Mathsyaraja, H; Thies, K; Taffany, D A; Deighan, C; Liu, T; Yu, L; Fernandez, S A; Shapiro, C; Otero, J; Timmers, C; Lustberg, M B; Chalmers, J; Leone, G; Ostrowski, M C

    2015-07-01

    Metastasis of solid tumors is associated with poor prognosis and bleak survival rates. Tumor-infiltrating myeloid cells (TIMs) are known to promote metastasis, but the mechanisms underlying their collaboration with tumor cells remain unknown. Here, we report an oncogenic role for microRNA (miR) in driving M2 reprogramming in TIMs, characterized by the acquisition of pro-tumor and pro-angiogenic properties. The expression of miR-21, miR-29a, miR-142-3p and miR-223 increased in myeloid cells during tumor progression in mouse models of breast cancer and melanoma metastasis. Further, we show that these miRs are regulated by the CSF1-ETS2 pathway in macrophages. A loss-of-function approach utilizing selective depletion of the miR-processing enzyme Dicer in mature myeloid cells blocks angiogenesis and metastatic tumor growth. Ectopic expression of miR-21 and miR-29a promotes angiogenesis and tumor cell proliferation through the downregulation of anti-angiogenic genes such as Col4a2, Spry1 and Timp3, whereas knockdown of the miRs impedes these processes. miR-21 and miR-29a are expressed in Csf1r+ myeloid cells associated with human metastatic breast cancer, and levels of these miRs in CD115+ non-classical monocytes correlates with metastatic tumor burden in patients. Taken together, our results suggest that miR-21 and miR-29a are essential for the pro-tumor functions of myeloid cells and the CSF1-ETS2 pathway upstream of the miRs serves as an attractive therapeutic target for the inhibition of M2 remodeling of macrophages during malignancy. In addition, miR-21 and miR-29a in circulating myeloid cells may potentially serve as biomarkers to measure therapeutic efficacy of targeted therapies for CSF1 signaling. PMID:25241894

  7. Crucial involvement of xanthine oxidase in the intracellular signalling networks associated with human myeloid cell function

    PubMed Central

    Abooali, Maryam; Lall, Gurprit S.; Coughlan, Karen; Lall, Harjinder S.; Gibbs, Bernhard F.; Sumbayev, Vadim V.

    2014-01-01

    Xanthine oxidase (XOD) is an enzyme which plays a central role in purine catabolism by converting hypoxanthine into xanthine and then further into uric acid. Here we report that XOD is activated in THP-1 human myeloid cells in response to pro-inflammatory and growth factor stimulation. This effect occurred following stimulation of THP-1 cells with ligands of plasma membrane associated TLRs 2 and 4, endosomal TLRs 7 and 8 as well as stem cell growth factor (SCF). Hypoxia-inducible factor 1 (HIF-1) and activator protein 1 (AP-1) transcription complexes were found to be responsible for XOD upregulation. Importantly, the mammalian target of rapamycin (mTOR), a major myeloid cell translation regulator, was also found to be essential for XOD activation. Specific inhibition of XOD by allopurinol and sodium tungstate led to an increase in intracellular AMP levels triggering downregulation of mTOR activation by phosphorylation of its T2446 residue. Taken together, our results demonstrate for the first time that XOD is not only activated by pro-inflammatory stimuli or SCF but also plays an important role in maintaining mTOR-dependent translational control during the biological responses of human myeloid cells. PMID:25200751

  8. Crucial involvement of xanthine oxidase in the intracellular signalling networks associated with human myeloid cell function.

    PubMed

    Abooali, Maryam; Lall, Gurprit S; Coughlan, Karen; Lall, Harjinder S; Gibbs, Bernhard F; Sumbayev, Vadim V

    2014-01-01

    Xanthine oxidase (XOD) is an enzyme which plays a central role in purine catabolism by converting hypoxanthine into xanthine and then further into uric acid. Here we report that XOD is activated in THP-1 human myeloid cells in response to pro-inflammatory and growth factor stimulation. This effect occurred following stimulation of THP-1 cells with ligands of plasma membrane associated TLRs 2 and 4, endosomal TLRs 7 and 8 as well as stem cell growth factor (SCF). Hypoxia-inducible factor 1 (HIF-1) and activator protein 1 (AP-1) transcription complexes were found to be responsible for XOD upregulation. Importantly, the mammalian target of rapamycin (mTOR), a major myeloid cell translation regulator, was also found to be essential for XOD activation. Specific inhibition of XOD by allopurinol and sodium tungstate led to an increase in intracellular AMP levels triggering downregulation of mTOR activation by phosphorylation of its T2446 residue. Taken together, our results demonstrate for the first time that XOD is not only activated by pro-inflammatory stimuli or SCF but also plays an important role in maintaining mTOR-dependent translational control during the biological responses of human myeloid cells. PMID:25200751

  9. Impact of peripheral myeloid cells on amyloid-β pathology in Alzheimer's disease-like mice.

    PubMed

    Prokop, Stefan; Miller, Kelly R; Drost, Natalia; Handrick, Susann; Mathur, Vidhu; Luo, Jian; Wegner, Anja; Wyss-Coray, Tony; Heppner, Frank L

    2015-10-19

    Although central nervous system-resident microglia are believed to be ineffective at phagocytosing and clearing amyloid-β (Aβ), a major pathological hallmark of Alzheimer's disease (AD), it has been suggested that peripheral myeloid cells constitute a heterogeneous cell population with greater Aβ-clearing capabilities. Here, we demonstrate that the conditional ablation of resident microglia in CD11b-HSVTK (TK) mice is followed by a rapid repopulation of the brain by peripherally derived myeloid cells. We used this system to directly assess the ability of peripheral macrophages to reduce Aβ plaque pathology and therefore depleted and replaced the pool of resident microglia with peripherally derived myeloid cells in Aβ-carrying APPPS1 mice crossed to TK mice (APPPS1;TK). Despite a nearly complete exchange of resident microglia with peripheral myeloid cells, there was no significant change in Aβ burden or APP processing in APPPS1;TK mice. Importantly, however, newly recruited peripheral myeloid cells failed to cluster around Aβ deposits. Even additional anti-Aβ antibody treatment aimed at engaging myeloid cells with amyloid plaques neither directed peripherally derived myeloid cells to amyloid plaques nor altered Aβ burden. These data demonstrate that mere recruitment of peripheral myeloid cells to the brain is insufficient in substantially clearing Aβ burden and suggest that specific additional triggers appear to be required to exploit the full potential of myeloid cell-based therapies for AD. PMID:26458768

  10. Ruxolitinib induces autophagy in chronic myeloid leukemia cells.

    PubMed

    Bagca, Bakiye Goker; Ozalp, Ozgun; Kurt, Cansu Caliskan; Mutlu, Zeynep; Saydam, Guray; Gunduz, Cumhur; Avci, Cigir Biray

    2016-02-01

    Ruxolitinib is the first agent used in myelofibrosis treatment with its potent JAK2 inhibitory effect. In this novel study, we aimed to discover the anti-leukemic effect of ruxolitinib in K-562 human chronic myeloid leukemia cell line compared to NCI-BL 2171 human healthy B lymphocyte cell line. Cytotoxic effect of ruxolitinib was determined by using WST-1 assay. IC50 values for K-562 and NCI-BL 2171 cell lines were defined as 20 and 23.6 μM at the 48th hour, respectively. Autophagic effects of ruxolitinib were detected by measuring LC3B-II protein formation. Ruxolitinib induced autophagic cell death in K-562 and NCI-BL 2171 cell lines 2.11- and 1.79-fold compared to control groups, respectively. To determine the autophagy-related gene expression changes, total RNA was isolated from K-562 and NCI-BL 2171 cells treated with ruxolitinib and untreated cells as control group. Reverse transcription procedure was performed for cDNA synthesis, and gene expressions were shown by RT-qPCR. Ruxolitinib treatment caused a notable decrease in expression of AKT, mTOR, and STAT autophagy inhibitor genes in K-562 cells, contrariwise control cell line. Ruxolitinib is a promising agent in chronic myeloid leukemia treatment by blocking JAK/STAT pathway known as downstream of BCR-ABL and triggering autophagy. This is the first study that reveals the relationship between ruxolitinib and autophagy induction. PMID:26298727

  11. Neurofibromin Deficient Myeloid Cells are Critical Mediators of Aneurysm Formation In Vivo

    PubMed Central

    Li, Fang; Downing, Brandon D.; Smiley, Lucy C.; Mund, Julie A.; DiStasi, Matthew R.; Bessler, Waylan K.; Sarchet, Kara N.; Hinds, Daniel M.; Kamendulis, Lisa M.; Hingtgen, Cynthia M.; Case, Jamie; Clapp, D. Wade; Conway, Simon J.; Stansfield, Brian K.; Ingram, David A.

    2014-01-01

    Background Neurofibromatosis Type 1 (NF1) is a genetic disorder resulting from mutations in the NF1 tumor suppressor gene. Neurofibromin, the protein product of NF1, functions as a negative regulator of Ras activity in circulating hematopoietic and vascular wall cells, which are critical for maintaining vessel wall homeostasis. NF1 patients have evidence of chronic inflammation resulting in development of premature cardiovascular disease, including arterial aneurysms, which may manifest as sudden death. However, the molecular pathogenesis of NF1 aneurysm formation is unknown. Method and Results Utilizing an angiotensin II-induced aneurysm model, we demonstrate that heterozygous inactivation of Nf1 (Nf1+/−) enhanced aneurysm formation with myeloid cell infiltration and increased oxidative stress in the vessel wall. Using lineage-restricted transgenic mice, we show loss of a single Nf1 allele in myeloid cells is sufficient to recapitulate the Nf1+/− aneurysm phenotype in vivo. Finally, oral administration of simvastatin or the antioxidant apocynin, reduced aneurysm formation in Nf1+/− mice. Conclusion These data provide genetic and pharmacologic evidence that Nf1+/− myeloid cells are the cellular triggers for aneurysm formation in a novel model of NF1 vasculopathy and provide a potential therapeutic target. PMID:24370551

  12. Myeloid-specific Fos-related antigen-1 regulates cigarette smoke-induced lung inflammation, not emphysema, in mice.

    PubMed

    Vaz, Michelle; Rajasekaran, Subbiah; Potteti, Haranatha R; Reddy, Sekhar P

    2015-07-01

    Heightened lung inflammation is a cardinal feature of chronic obstructive pulmonary disease (COPD). Cigarette smoke (CS)-induced macrophage recruitment and activation, accompanied by abnormal secretion of a number of inflammatory cytokines and matrix metalloproteinases, play a major role in the pathophysiology of COPD. The Fos-related antigen-1 (Fra-1) transcription factor differentially regulates several cellular processes that are implicated in COPD, such as inflammation and immune responses, cell proliferation and death, and extracellular remodeling. Although CS stimulates Fra-1 expression in the lung, the precise role of this transcription factor in the regulation of CS-induced lung inflammation in vivo is poorly understood. Here, we report that myeloid-specific Fra-1 signaling is important for CS-induced lung macrophagic inflammatory response. In response to chronic CS exposure, mice with Fra-1 specifically deleted in myeloid cells showed reduced levels of CS-induced lung macrophagic inflammation, accompanied by decreased expression levels of proinflammatory cytokines compared with their wild-type counterparts. Consistent with this result, bone marrow-derived Fra-1-null macrophages treated with CS showed decreased levels of proinflammatory mediators and matrix metalloproteinases. Interestingly, deletion of Fra-1 in myeloid cells did not affect the severity of emphysema. We propose that Fra-1 plays a key role in promoting chronic CS-induced lung macrophagic inflammation in vivo, and that targeting this transcription factor may be useful in dampening persistent lung inflammation in patients with COPD. PMID:25489966

  13. Targeting DNA vaccines to myeloid cells using a small peptide.

    PubMed

    Ye, Chunting; Choi, Jang Gi; Abraham, Sojan; Shankar, Premlata; Manjunath, N

    2015-01-01

    Targeting DNA vaccines to dendritic cells (DCs) greatly enhances immunity. Although several approaches have been used to target protein Ags to DCs, currently there is no method that targets DNA vaccines directly to DCs. Here, we show that a small peptide derived from the rabies virus glycoprotein fused to protamine residues (RVG-P) can target DNA to myeloid cells, including DCs, which results in enhanced humoral and T-cell responses. DCs targeted with a DNA vaccine encoding the immunodominant vaccinia B8R gene via RVG-P were able to restimulate vaccinia-specific memory T cells in vitro. Importantly, a single i.v. injection of B8R gene bound to RVG-P was able to prime a vaccinia-specific T-cell response that was able to rapidly clear a subsequent vaccinia challenge in mice. Moreover, delivery of DNA in DCs was enough to induce DC maturation and efficient Ag presentation without the need for adjuvants. Finally, immunization of mice with a DNA-vaccine encoding West Nile virus (WNV) prM and E proteins via RVG-P elicited high titers of WNV-neutralizing Abs that protected mice from lethal WNV challenge. Thus, RVG-P provides a reagent to target DNA vaccines to myeloid cells and elicit robust T-cell and humoral immune responses. PMID:25270431

  14. Myeloid Cell Prostaglandin E2 Receptor EP4 Modulates Cytokine Production but Not Atherogenesis in a Mouse Model of Type 1 Diabetes

    PubMed Central

    Vallerie, Sara N.; Kramer, Farah; Barnhart, Shelley; Kanter, Jenny E.; Breyer, Richard M.; Andreasson, Katrin I.; Bornfeldt, Karin E.

    2016-01-01

    Type 1 diabetes mellitus (T1DM) is associated with cardiovascular complications induced by atherosclerosis. Prostaglandin E2 (PGE2) is often raised in states of inflammation, including diabetes, and regulates inflammatory processes. In myeloid cells, a key cell type in atherosclerosis, PGE2 acts predominately through its Prostaglandin E Receptor 4 (EP4; Ptger4) to modulate inflammation. The effect of PGE2-mediated EP4 signaling specifically in myeloid cells on atherosclerosis in the presence and absence of diabetes is unknown. Because diabetes promotes atherosclerosis through increased arterial myeloid cell accumulation, we generated a myeloid cell-targeted EP4-deficient mouse model (EP4M-/-) of T1DM-accelerated atherogenesis to investigate the relationship between myeloid cell EP4, inflammatory phenotypes of myeloid cells, and atherogenesis. Diabetic mice exhibited elevated plasma PGE metabolite levels and elevated Ptger4 mRNA in macrophages, as compared with non-diabetic littermates. PGE2 increased Il6, Il1b, Il23 and Ccr7 mRNA while reducing Tnfa mRNA through EP4 in isolated myeloid cells. Consistently, the stimulatory effect of diabetes on peritoneal macrophage Il6 was mediated by PGE2-EP4, while PGE2-EP4 suppressed the effect of diabetes on Tnfa in these cells. In addition, diabetes exerted effects independent of myeloid cell EP4, including a reduction in macrophage Ccr7 levels and increased early atherogenesis characterized by relative lesional macrophage accumulation. These studies suggest that this mouse model of T1DM is associated with increased myeloid cell PGE2-EP4 signaling, which is required for the stimulatory effect of diabetes on IL-6, markedly blunts the effect of diabetes on TNF-α and does not modulate diabetes-accelerated atherogenesis. PMID:27351842

  15. Specific Btk inhibition suppresses B cell- and myeloid cell-mediated arthritis

    SciTech Connect

    Di Paolo, Julie A; Huang, Tao; Balazs, Mercedesz; Barbosa, James; Barck, Kai H; Bravo, Brandon J; Carano, Richard A.D.; Darrow, James; Davies, Douglas R; DeForge, Laura E; Diehl, Lauri; Ferrando, Ronald; Gallion, Steven L; Giannetti, Anthony M; Gribling, Peter; Hurez, Vincent; Hymowitz, Sarah G; Jones, Randall; Kropf, Jeffrey E; Lee, Wyne P; Maciejewski, Patricia M; Mitchell, Scott A; Rong, Hong; Staker, Bart L; Whitney, J Andrew; Yeh, Sherry; Young, Wendy B; Yu, Christine; Zhang, Juan; Reif, Karin; Currie, Kevin S

    2011-08-29

    Bruton's tyrosine kinase (Btk) is a therapeutic target for rheumatoid arthritis, but the cellular and molecular mechanisms by which Btk mediates inflammation are poorly understood. Here we describe the discovery of CGI1746, a small-molecule Btk inhibitor chemotype with a new binding mode that stabilizes an inactive nonphosphorylated enzyme conformation. CGI1746 has exquisite selectivity for Btk and inhibits both auto- and transphosphorylation steps necessary for enzyme activation. Using CGI1746, we demonstrate that Btk regulates inflammatory arthritis by two distinct mechanisms. CGI1746 blocks B cell receptor–dependent B cell proliferation and in prophylactic regimens reduces autoantibody levels in collagen-induced arthritis. In macrophages, Btk inhibition abolishes FcγRIII-induced TNFα, IL-1β and IL-6 production. Accordingly, in myeloid- and FcγR-dependent autoantibody-induced arthritis, CGI1746 decreases cytokine levels within joints and ameliorates disease. These results provide new understanding of the function of Btk in both B cell– or myeloid cell–driven disease processes and provide a compelling rationale for targeting Btk in rheumatoid arthritis.

  16. Comprehensive analysis of mammalian miRNA* species and their role in myeloid cells.

    PubMed

    Kuchenbauer, Florian; Mah, Sarah M; Heuser, Michael; McPherson, Andrew; Rüschmann, Jens; Rouhi, Arefeh; Berg, Tobias; Bullinger, Lars; Argiropoulos, Bob; Morin, Ryan D; Lai, David; Starczynowski, Daniel T; Karsan, Aly; Eaves, Connie J; Watahiki, Akira; Wang, Yuzhuo; Aparicio, Samuel A; Ganser, Arnold; Krauter, Jürgen; Döhner, Hartmut; Döhner, Konstanze; Marra, Marco A; Camargo, Fernando D; Palmqvist, Lars; Buske, Christian; Humphries, R Keith

    2011-09-22

    Processing of pre-miRNA through Dicer1 generates an miRNA duplex that consists of an miRNA and miRNA* strand. Despite the general view that miRNA*s have no functional role, we further investigated miRNA* species in 10 deep-sequencing libraries from mouse and human tissue. Comparisons of miRNA/miRNA* ratios across the miRNA sequence libraries revealed that 50% of the investigated miRNA duplexes exhibited a highly dominant strand. Conversely, 10% of miRNA duplexes showed a comparable expression of both strands, whereas the remaining 40% exhibited variable ratios across the examined libraries, as exemplified by miR-223/miR-223* in murine and human cell lines. Functional analyses revealed a regulatory role for miR-223* in myeloid progenitor cells, which implies an active role for both arms of the miR-223 duplex. This was further underscored by the demonstration that miR-223 and miR-223* targeted the insulin-like growth factor 1 receptor/phosphatidylinositol 3-kinase axis and that high miR-223* levels were associated with increased overall survival in patients with acute myeloid leukemia. Thus, we found a supporting role for miR-223* in differentiating myeloid cells in normal and leukemic cell states. The fact that the miR-223 duplex acts through both arms extends the complexity of miRNA-directed gene regulation of this myeloid key miRNA. PMID:21628414

  17. Deregulated KLF4 Expression in Myeloid Leukemias Alters Cell Proliferation and Differentiation through MicroRNA and Gene Targets

    PubMed Central

    Morris, Valerie A.; Cummings, Carrie L.; Korb, Brendan; Boaglio, Sean

    2015-01-01

    Acute myeloid leukemia (AML) is characterized by increased proliferation and blocked differentiation of hematopoietic progenitors mediated, in part, by altered myeloid transcription factor expression. Decreased Krüppel-like factor 4 (KLF4) expression has been observed in AML, but how decreased KLF4 contributes to AML pathogenesis is largely unknown. We demonstrate decreased KLF4 expression in AML patient samples with various cytogenetic aberrations, confirm that KLF4 overexpression promotes myeloid differentiation and inhibits cell proliferation in AML cell lines, and identify new targets of KLF4. We have demonstrated that microRNA 150 (miR-150) expression is decreased in AML and that reintroducing miR-150 expression induces myeloid differentiation and inhibits proliferation of AML cells. We show that KLF family DNA binding sites are necessary for miR-150 promoter activity and that KLF2 or KLF4 overexpression induces miR-150 expression. miR-150 silencing, alone or in combination with silencing of CDKN1A, a well-described KLF4 target, did not fully reverse KLF4-mediated effects. Gene expression profiling and validation identified putative KLF4-regulated genes, including decreased MYC and downstream MYC-regulated gene expression in KLF4-overexpressing cells. Our findings indicate that decreased KLF4 expression mediates antileukemic effects through regulation of gene and microRNA networks, containing miR-150, CDKN1A, and MYC, and provide mechanistic support for therapeutic strategies increasing KLF4 expression. PMID:26644403

  18. Recommendations for myeloid-derived suppressor cell nomenclature and characterization standards.

    PubMed

    Bronte, Vincenzo; Brandau, Sven; Chen, Shu-Hsia; Colombo, Mario P; Frey, Alan B; Greten, Tim F; Mandruzzato, Susanna; Murray, Peter J; Ochoa, Augusto; Ostrand-Rosenberg, Suzanne; Rodriguez, Paulo C; Sica, Antonio; Umansky, Viktor; Vonderheide, Robert H; Gabrilovich, Dmitry I

    2016-01-01

    Myeloid-derived suppressor cells (MDSCs) have emerged as major regulators of immune responses in cancer and other pathological conditions. In recent years, ample evidence supports key contributions of MDSC to tumour progression through both immune-mediated mechanisms and those not directly associated with immune suppression. MDSC are the subject of intensive research with >500 papers published in 2015 alone. However, the phenotypic, morphological and functional heterogeneity of these cells generates confusion in investigation and analysis of their roles in inflammatory responses. The purpose of this communication is to suggest characterization standards in the burgeoning field of MDSC research. PMID:27381735

  19. Recommendations for myeloid-derived suppressor cell nomenclature and characterization standards

    PubMed Central

    Bronte, Vincenzo; Brandau, Sven; Chen, Shu-Hsia; Colombo, Mario P.; Frey, Alan B.; Greten, Tim F.; Mandruzzato, Susanna; Murray, Peter J.; Ochoa, Augusto; Ostrand-Rosenberg, Suzanne; Rodriguez, Paulo C.; Sica, Antonio; Umansky, Viktor; Vonderheide, Robert H.; Gabrilovich, Dmitry I.

    2016-01-01

    Myeloid-derived suppressor cells (MDSCs) have emerged as major regulators of immune responses in cancer and other pathological conditions. In recent years, ample evidence supports key contributions of MDSC to tumour progression through both immune-mediated mechanisms and those not directly associated with immune suppression. MDSC are the subject of intensive research with >500 papers published in 2015 alone. However, the phenotypic, morphological and functional heterogeneity of these cells generates confusion in investigation and analysis of their roles in inflammatory responses. The purpose of this communication is to suggest characterization standards in the burgeoning field of MDSC research. PMID:27381735

  20. Lamin B receptor (LBR) regulates the growth and maturation of myeloid progenitors via its sterol reductase domain: Implications for cholesterol biosynthesis in regulating myelopoiesis

    PubMed Central

    Subramanian, Gayathri; Chaudhury, Pulkit; Malu, Krishnakumar; Fowler, Samantha; Manmode, Rahul; Gotur, Deepali; Zwerger, Monika; Ryan, David; Roberti, Rita; Gaines, Peter

    2011-01-01

    Lamin B receptor (LBR) is a bifunctional nuclear membrane protein with N-terminal lamin B and chromatin binding domains plus a C-terminal sterol Δ14 reductase domain. LBR expression increases during neutrophil differentiation and deficient expression disrupts neutrophil nuclear lobulation characteristic of Pelger-Huët anomaly. Thus LBR plays a critical role in regulating myeloid differentiation, but how the two functional domains of LBR support this role is currently unclear. We previously identified abnormal proliferation and deficient functional maturation of promyelocytes (EPRO cells) derived from EML-ic/ic cells, a myeloid model of ichthyosis (ic) bone marrow that lacks Lbr expression. Here we provide new evidence that cholesterol biosynthesis is important to myeloid cell growth and is supported by the sterol reductase domain of Lbr. Cholesterol biosynthesis inhibitors caused growth inhibition of EML cells that increased in EPRO cells, whereas cells lacking Lbr exhibited complete growth arrest at both stages. Lipid production increased during wild-type neutrophil maturation, but ic/ic cells exhibited deficient levels of lipid and cholesterol production. Ectopic expression of a full length Lbr in EML-ic/ic cells rescued both nuclear lobulation and growth arrest in cholesterol starvation conditions. Lipid production also was rescued, and a deficient respiratory burst was corrected. Expression of just the C-terminal sterol reductase domain of Lbr in ic/ic cells also improved each of these phenotypes. Our data support the conclusion that the sterol Δ14 reductase domain of LBR plays a critical role in cholesterol biosynthesis, and that this process is essential to both myeloid cell growth and functional maturation. PMID:22140257

  1. Acute Myeloid Leukemia Complicated by Giant Cell Arteritis.

    PubMed

    Tsunemine, Hiroko; Umeda, Ryosuke; Nohda, Yasuhiro; Sakane, Emiko; Akasaka, Hiroshi; Itoh, Kiminari; Izumi, Mayuko; Tsuji, Goh; Kodaka, Taiichi; Itoh, Tomoo; Takahashi, Takayuki

    2016-01-01

    Giant cell arteritis (GCA), a type of systemic arteritis, is rare in Japan. We herein report a case of acute myeloid leukemia (AML) complicated by GCA that manifested during chemotherapy for AML. A 77-year-old woman with severe back pain was diagnosed with AML. She achieved complete remission with the resolution of her back pain following induction chemotherapy. However, she developed a headache and fever after consolidation chemotherapy. A diagnosis of GCA was made based on a biopsy of the temporal artery and arterial imaging. GCA should therefore be included in the differential diagnosis in AML patients complicated with a headache and fever of unknown origin. PMID:26831026

  2. Myeloid-derived suppressor cells: Cellular missiles to target tumors.

    PubMed

    Chandra, Dinesh; Gravekamp, Claudia

    2013-11-01

    While conventional anticancer therapies, including surgical resection, radiotherapy, and/or chemotherapy, are relatively efficient at eliminating primary tumors, these treatment modalities are largely ineffective against metastases. At least in part, this reflects the rather inefficient delivery of conventional anticancer agents to metastatic lesions. We have recently demonstrated that myeloid-derived suppressor cells (MDSCs) can be used as cellular missiles to selectively deliver a radioisotope-coupled attenuated variant of Listeria monocytogenes to both primary and metastatic neoplastic lesions in mice with pancreatic cancer. This novel immunotherapeutic intervention robustly inhibited tumor growth while promoting a dramatic decrease in the number of metastases. PMID:24427545

  3. Extramedullary myeloid cell tumours--the NIMS experience.

    PubMed

    Paul, T Roshni; Sundaram, C; Gayathri, K; Prayaga, Aruna; Rao, D Raghunadha

    2005-07-01

    Extramedullary myeloid cell tumours are rare clinical entities, which often pose diagnostic problems. From the pathology record files of Nizam's Institute of Medical Sciences, Hyderabad, 16 cases of EMCTs were traced, over a period of 14 years. The clinical details, follow-up were noted and morphology re-evaluated, and immunohistochemistry with LCA was performed. Of the 16 cases, the distribution was as follows--skin and subcutaneous nodules, lymph nodes, extradural masses presenting with cord compression and one case each with eyelid, orbital and breast masses. The problems in diagnosis are presented and a panel of immunohistochemical markers suggested for proper diagnosis and treatment. PMID:16761741

  4. Detection of human myeloid progenitor cells in a murine background.

    PubMed

    Carow, C E; Harrington, M A; Broxmeyer, H E

    1993-01-01

    Cell-mixing experiments were performed to determine whether human (hu) peripheral blood plasma would select for the growth of hu myeloid progenitor cells in vitro. Mixtures of hu male umbilical cord blood and murine (mu) female bone marrow (100% hu, 100% mu, 1.0% hu or 10% hu and 50% hu) were plated in methylcellulose cultures that contained either hu plasma or fetal bovine serum (FBS). Cultures were supplemented with recombinant (r) hu erythropoietin (Epo) alone or in combination with rhu granulocyte-macrophage colony stimulating factor (GM-CSF), rmuGM-CSF or rhu steel factor (SLF). DNA was extracted from day 14 colonies and clusters, and the polymerase chain reaction (PCR) was used to detect the hu Y-chromosome satellite DNA sequence. Results of these studies revealed that hu plasma used in combination with hu growth factors selected for the growth of hu progenitor cells. Mu cells grew in hu plasma only at high cell-plating concentrations. This selective effect was due to a heat labile factor or factors, since mu cells grew equally well in heat-inactivated hu plasma and FBS. Cells in individual progenitor cell colonies and clusters cultured in hu plasma contained hu Y-chromosome-specific DNA sequences that were detectable after PCR-mediated amplification, thus eliminating the need for time-consuming Southern transfer. This study describes a method whereby hu/immune-deficient mice can be screened rapidly for hu myeloid engraftment. These results also indicate that the hu identity of colonies and clusters cultured in hu plasma must be genetically confirmed, especially when hu cells may represent a low percentage of the total cells plated. PMID:7678088

  5. Myeloid Cell Arg1 Inhibits Control of Arthritogenic Alphavirus Infection by Suppressing Antiviral T Cells

    PubMed Central

    Burrack, Kristina S.; Tan, Jeslin J. L.; McCarthy, Mary K.; Her, Zhisheng; Berger, Jennifer N.; Ng, Lisa F. P.; Morrison, Thomas E.

    2015-01-01

    Arthritogenic alphaviruses, including Ross River virus (RRV) and chikungunya virus (CHIKV), are responsible for explosive epidemics involving millions of cases. These mosquito-transmitted viruses cause inflammation and injury in skeletal muscle and joint tissues that results in debilitating pain. We previously showed that arginase 1 (Arg1) was highly expressed in myeloid cells in the infected and inflamed musculoskeletal tissues of RRV- and CHIKV-infected mice, and specific deletion of Arg1 from myeloid cells resulted in enhanced viral control. Here, we show that Arg1, along with other genes associated with suppressive myeloid cells, is induced in PBMCs isolated from CHIKV-infected patients during the acute phase as well as the chronic phase, and that high Arg1 expression levels were associated with high viral loads and disease severity. Depletion of both CD4 and CD8 T cells from RRV-infected Arg1-deficient mice restored viral loads to levels detected in T cell-depleted wild-type mice. Moreover, Arg1-expressing myeloid cells inhibited virus-specific T cells in the inflamed and infected musculoskeletal tissues, but not lymphoid tissues, following RRV infection in mice, including suppression of interferon-γ and CD69 expression. Collectively, these data enhance our understanding of the immune response following arthritogenic alphavirus infection and suggest that immunosuppressive myeloid cells may contribute to the duration or severity of these debilitating infections. PMID:26436766

  6. Myeloid Cell Arg1 Inhibits Control of Arthritogenic Alphavirus Infection by Suppressing Antiviral T Cells.

    PubMed

    Burrack, Kristina S; Tan, Jeslin J L; McCarthy, Mary K; Her, Zhisheng; Berger, Jennifer N; Ng, Lisa F P; Morrison, Thomas E

    2015-10-01

    Arthritogenic alphaviruses, including Ross River virus (RRV) and chikungunya virus (CHIKV), are responsible for explosive epidemics involving millions of cases. These mosquito-transmitted viruses cause inflammation and injury in skeletal muscle and joint tissues that results in debilitating pain. We previously showed that arginase 1 (Arg1) was highly expressed in myeloid cells in the infected and inflamed musculoskeletal tissues of RRV- and CHIKV-infected mice, and specific deletion of Arg1 from myeloid cells resulted in enhanced viral control. Here, we show that Arg1, along with other genes associated with suppressive myeloid cells, is induced in PBMCs isolated from CHIKV-infected patients during the acute phase as well as the chronic phase, and that high Arg1 expression levels were associated with high viral loads and disease severity. Depletion of both CD4 and CD8 T cells from RRV-infected Arg1-deficient mice restored viral loads to levels detected in T cell-depleted wild-type mice. Moreover, Arg1-expressing myeloid cells inhibited virus-specific T cells in the inflamed and infected musculoskeletal tissues, but not lymphoid tissues, following RRV infection in mice, including suppression of interferon-γ and CD69 expression. Collectively, these data enhance our understanding of the immune response following arthritogenic alphavirus infection and suggest that immunosuppressive myeloid cells may contribute to the duration or severity of these debilitating infections. PMID:26436766

  7. Genetically Modified T-cell Immunotherapy in Treating Patients With Relapsed or Refractory Acute Myeloid Leukemia

    ClinicalTrials.gov

    2016-08-10

    Adult Acute Myeloid Leukemia in Remission; Donor; Early Relapse of Acute Myeloid Leukemia; Late Relapse of Acute Myeloid Leukemia; Recurrent Adult Acute Myeloid Leukemia; Secondary Acute Myeloid Leukemia

  8. Sensing of cell death by myeloid C-type lectin receptors

    PubMed Central

    Sancho, David; Reis e Sousa, Caetano

    2015-01-01

    Molecules associated with dead or dying cells can be detected by receptors on macrophages and dendritic cells. Signals from these receptors impact myeloid cell function and play a role in determining whether death is silent or proinflammatory, tolerogenic or immunogenic. Prominent among myeloid receptors detecting dead cells are C-type lectin receptors (CLRs). Signals from these receptors variably induce endocytosis of cell corpses, corpse degradation, retrieval of dead cell-associated antigens and/or modulation of immune responses. The sensing of tissue damage by myeloid CLRs complements detection of pathogens in immunity and represents an ancient response aimed at restoring tissue homeostasis. PMID:23332826

  9. Role and Regulation of Myeloid Zinc Finger Protein 1 in Cancer.

    PubMed

    Eguchi, Taka; Prince, Thomas; Wegiel, Barbara; Calderwood, Stuart K

    2015-10-01

    Myeloid zinc finger 1 (MZF1) belongs to the SCAN-Zinc Finger (SCAN-ZF) transcription factor family that has recently been implicated in a number of types of cancer. Although the initial studies concentrated on the role of MZF1 in myeloid differentiation and leukemia, the factor now appears to be involved in the etiology of major solid tumors such as lung, cervical, breast, and colorectal cancer. Here we discuss the regulation of MZF1 that mediated its recruitment and activation in cancer, concentrating on posttranslational modification by phosphorylation, and sumoylation, formation of promyelocytic leukemia nuclear bodies and its association with co-activators and co-repressors. PMID:25903835

  10. Tissue myeloid cells in SIV-infected primates acquire viral DNA through phagocytosis of infected T cells.

    PubMed

    Calantone, Nina; Wu, Fan; Klase, Zachary; Deleage, Claire; Perkins, Molly; Matsuda, Kenta; Thompson, Elizabeth A; Ortiz, Alexandra M; Vinton, Carol L; Ourmanov, Ilnour; Loré, Karin; Douek, Daniel C; Estes, Jacob D; Hirsch, Vanessa M; Brenchley, Jason M

    2014-09-18

    The viral accessory protein Vpx, expressed by certain simian and human immunodeficiency viruses (SIVs and HIVs), is thought to improve viral infectivity of myeloid cells. We infected 35 Asian macaques and African green monkeys with viruses that do or do not express Vpx and examined viral targeting of cells in vivo. While lack of Vpx expression affected viral dynamics in vivo, with decreased viral loads and infection of CD4⁺ T cells, Vpx expression had no detectable effect on infectivity of myeloid cells. Moreover, viral DNA was observed only within myeloid cells in tissues not massively depleted of CD4⁺ T cells. Myeloid cells containing viral DNA also showed evidence of T cell phagocytosis in vivo, suggesting that their viral DNA may be attributed to phagocytosis of SIV-infected T cells. These data suggest that myeloid cells are not a major source of SIV in vivo, irrespective of Vpx expression. PMID:25238099

  11. TGF-β–Responsive Myeloid Cells Suppress Type 2 Immunity and Emphysematous Pathology after Hookworm Infection

    PubMed Central

    Heitmann, Lisa; Rani, Reena; Dawson, Lucas; Perkins, Charles; Yang, Yanfen; Downey, Jordan; Hölscher, Christoph; Herbert, De'Broski R.

    2013-01-01

    Transforming growth factor β (TGF-β) regulates inflammation, immunosuppression, and wound-healing cascades, but it remains unclear whether any of these functions involve regulation of myeloid cell function. The present study demonstrates that selective deletion of TGF-βRII expression in myeloid phagocytes i) impairs macrophage-mediated suppressor activity, ii) increases baseline mRNA expression of proinflammatory chemokines/cytokines in the lung, and iii) enhances type 2 immunity against the hookworm parasite Nippostrongylus brasiliensis. Strikingly, TGF-β–responsive myeloid cells promote repair of hookworm-damaged lung tissue, because LysMCreTGF-βRIIflox/flox mice develop emphysema more rapidly than wild-type littermate controls. Emphysematous pathology in LysMCreTGF-βRIIflox/flox mice is characterized by excessive matrix metalloprotease (MMP) activity, reduced lung elasticity, increased total lung capacity, and dysregulated respiration. Thus, TGF-β effects on myeloid cells suppress helminth immunity as a consequence of restoring lung function after infection. PMID:22901754

  12. Oncogenic NRAS Primes Primary Acute Myeloid Leukemia Cells for Differentiation.

    PubMed

    Brendel, Cornelia; Teichler, Sabine; Millahn, Axel; Stiewe, Thorsten; Krause, Michael; Stabla, Kathleen; Ross, Petra; Huynh, Minh; Illmer, Thomas; Mernberger, Marco; Barckhausen, Christina; Neubauer, Andreas

    2015-01-01

    RAS mutations are frequently found among acute myeloid leukemia patients (AML), generating a constitutively active signaling protein changing cellular proliferation, differentiation and apoptosis. We have previously shown that treatment of AML patients with high-dose cytarabine is preferentially beneficial for those harboring oncogenic RAS. On the basis of a murine AML cell culture model, we ascribed this effect to a RAS-driven, p53-dependent induction of differentiation. Hence, in this study we sought to confirm the correlation between RAS status and differentiation of primary blasts obtained from AML patients. The gene expression signature of AML blasts with oncogenic NRAS indeed corresponded to a more mature profile compared to blasts with wildtype RAS, as demonstrated by gene set enrichment analysis (GSEA) and real-time PCR analysis of myeloid ecotropic viral integration site 1 homolog (MEIS1) in a unique cohort of AML patients. In addition, in vitro cell culture experiments with established cell lines and a second set of primary AML cells showed that oncogenic NRAS mutations predisposed cells to cytarabine (AraC) driven differentiation. Taken together, our findings show that AML with inv(16) and NRAS mutation have a differentiation gene signature, supporting the notion that NRAS mutation may predispose leukemic cells to AraC induced differentiation. We therefore suggest that promotion of differentiation pathways by specific genetic alterations could explain the superior treatment outcome after therapy in some AML patient subgroups. Whether a differentiation gene expression status may generally predict for a superior treatment outcome in AML needs to be addressed in future studies. PMID:25901794

  13. Hyaluronan oligomers sensitize chronic myeloid leukemia cell lines to the effect of Imatinib.

    PubMed

    Lompardía, Silvina Laura; Díaz, Mariángeles; Papademetrio, Daniela Laura; Mascaró, Marilina; Pibuel, Matías; Álvarez, Elida; Hajos, Silvia Elvira

    2016-04-01

    Chronic myeloid leukemia is a myeloproliferative syndrome characterized by the presence of the Philadelphia chromosome (Ph), generated by a reciprocal translocation occurring between chromosomes 9 and 22 [t(9;22)(q34;q11)]. As a consequence, a fusion gene (bcr-abl) encoding a constitutively active kinase is generated. The first-line treatment consists on BCR-ABL inhibitors such as Imatinib, Nilotinib and Dasatinib. Nevertheless, such treatment may lead to the selection of resistant cells. Therefore, finding molecules that enhance the anti-proliferative effect of first-line drugs is of value. Hyaluronan oligomers (oHA) are known to be able to sensitize several tumor cells to chemotherapy. We have previously demonstrated that oHA can revert Vincristine resistance in mouse lymphoma and human leukemia cell lines. However, little is known about the role of oHA in hematological malignancies. The aim of this work was to determine whether oHA are able to modulate the anti-proliferative effect of Imatinib in chronic myeloid leukemia (CML) cell lines. The effect on apoptosis and senescence as well as the involvement of signaling pathways were also evaluated. For this purpose, the human CML cell lines K562 and Kv562 (resistant) were used. We demonstrated that oHA sensitized both cell lines to the anti-proliferative effect of Imatinib increasing apoptosis and senescence. Moreover, this effect would be accomplished through the down-regulation of the PI3K signaling pathway. These findings highlight the potential of oHA when used as a co-adjuvant therapy for chronic myeloid leukemia. PMID:26582603

  14. Asparaginase induces apoptosis and cytoprotective autophagy in chronic myeloid leukemia cells

    PubMed Central

    Fan, Jiajun; Li, Yubin; Zeng, Xian; Wang, Ziyu; Wang, Shaofei; Zhang, Guoping; Yang, Ping; Cao, Zhonglian; Ju, Dianwen

    2015-01-01

    The antitumor enzyme asparaginase, which targets essential amino acid L-asparagine and catalyzes it to L-aspartic acid and ammonia, has been used for years in the treatment of acute lymphoblastic leukemia (ALL), subtypes of myeloid leukemia and T-cell lymphomas, whereas the anti-chronic myeloid leukemia (CML) effect of asparaginase and its underlying mechanism has not been completely elucidated. We have shown here that asparaginase induced significant growth inhibition and apoptosis in K562 and KU812 cells. Apart from induction of apoptosis, we reported for the first time that asparaginase induced autophagic response in K562 and KU812 cells as evidenced by the formation of autophagosome, microtubule-associated protein light chain 3 (LC3)-positive autophagy-like vacuoles, and the upregulation of LC3-II. Further study suggested that the Akt/mTOR (mammalian target of rapamycin) and Erk (extracellular signal-regulated kinase) signaling pathway were involved in asparaginase-induced autophagy in K562 cells. Moreover, blocking autophagy using pharmacological inhibitors LY294002, chloroquine (CQ) and quinacrine (QN) enhanced asparaginase-induced cell death and apoptosis, indicating the cytoprotective role of autophagy in asparaginase-treated K562 and KU812 cells. Together, these findings provide a rationale that combination of asparaginase anticancer activity and autophagic inhibition might be a promising new therapeutic strategy for CML. PMID:25738356

  15. Targeting STAT3 signaling reduces immunosuppressive myeloid cells in head and neck squamous cell carcinoma.

    PubMed

    Bu, Lin-Lin; Yu, Guang-Tao; Deng, Wei-Wei; Mao, Liang; Liu, Jian-Feng; Ma, Si-Rui; Fan, Teng-Fei; Hall, Bradford; Kulkarni, Ashok B; Zhang, Wen-Feng; Sun, Zhi-Jun

    2016-05-01

    Cumulative evidence suggests that constitutively activated signal transducer and activator of transcription (STAT3) may contribute to sustaining immunosuppressive status, and that inhibiting STAT3 signaling represents a potential strategy to improve antitumor immunity. In the present study, we observed that high levels phosphorylated of STAT3 are significantly associated with the markers for both myeloid-derived suppressor cells (MDSCs) and tumor-associated macrophages (TAMs) in human head and neck squamous cell carcinoma (HNSCC). Additionally, we showed that targeting STAT3 signaling with a tolerable selective inhibitor S3I-201 significantly decreased immature myeloid cells such as MDSCs, TAMs and iDCs in genetically defined mice HNSCC model. These findings highlight that targeting STAT3 signaling may be effective to enhance antitumor immunity via myeloid suppressor cells in HNSCC. PMID:27467947

  16. Human Head and Neck Squamous Cell Carcinoma–Associated Semaphorin 4D Induces Expansion of Myeloid-Derived Suppressor Cells

    PubMed Central

    Han, Kyu Lee; Webb, Tonya J.

    2016-01-01

    One of the mechanisms by which malignancies can induce immune suppression is through the production of cytokines that affect the maturation and differentiation of inflammatory cells in the tumor microenvironment. Semaphorin 4D (Sema4D) is a proangiogenic cytokine produced by several malignancies, which has been described in the regulation of the immune system. In the present study, we examined the role of human head and neck squamous cell carcinoma (HNSCC)–secreted Sema4D on myeloid cell differentiation. CD33+ cells cultured in HNSCC cell line–derived conditioned medium differentiated into myeloid derived suppressor cells (MDSC) (CD33+CD11b+HLA-DR−/low). The addition of anti-Sema4D Ab to HNSCC conditioned medium significantly reduced the expansion of the MDSC population. Similarly, knockdown of Sema4D in an HNSCC cell line resulted in a loss of MDSC function as shown by a decrease in the production of the immune-suppressive cytokines arginase-1, TGF-β, and IL-10 by MDSC, concomitant with recovery of T cell proliferation and IFN-γ production following stimulation of CD3/CD28. Importantly, CD33+ myeloid and T cells cultured in conditioned medium of HNSCC cells in which Sema4D was knocked down promoted antitumor inflammatory profile, through recovery of the effector T cells (CD4+T-bet+ and CD8+T-bet+), as well as a decrease in regulatory T cells (CD4+CD25+FOXP3+). We also showed that Sema4D was comparable to GM-CSF in its induction of MDSC. Collectively, this study describes a novel immunosuppressive role for Sema4D in HNSCC through induction of MDSC, and it highlights Sema4D as a therapeutic target for future studies to enhance the antitumorigenic inflammatory response in HNSCC and other epithelial malignancies. PMID:26740106

  17. Functional Niche Competition Between Normal Hematopoietic Stem and Progenitor Cells and Myeloid Leukemia Cells.

    PubMed

    Glait-Santar, Chen; Desmond, Ronan; Feng, Xingmin; Bat, Taha; Chen, Jichun; Heuston, Elisabeth; Mizukawa, Benjamin; Mulloy, James C; Bodine, David M; Larochelle, Andre; Dunbar, Cynthia E

    2015-12-01

    Hematopoietic stem and progenitor cells (HSPCs) reside in a specialized niche that regulates their proliferative capacity and their fate. There is increasing evidence for similar roles of marrow niches on controlling the behavior of leukemic cells; however, whether normal hematopoietic stem cell (HSC) and leukemic cells reside in or functionally compete for the same marrow niche is unclear. We used the mixed lineage leukemia-AF9 (MLL-AF9) murine acute myeloid leukemia (AML) in a competitive repopulation model to investigate whether normal HSPC and leukemic cells functionally compete for the same marrow niches. Irradiated recipient mice were transplanted with fixed numbers of MLL-AF9 cells mixed with increasing doses of normal syngeneic whole bone marrow (WBM) or with purified HSPC (LSK). Survival was significantly increased and leukemic progression was delayed proportional to increasing doses of normal WBM or normal LSK cells in multiple independent experiments, with all doses of WBM or LSK cells studied above the threshold for rapid and complete hematopoietic reconstitution in the absence of leukemia. Confocal microscopy demonstrated nests of either leukemic cells or normal hematopoietic cells but not both in the marrow adjacent to endosteum. Early following transplantation, leukemic cells from animals receiving lower LSK doses were cycling more actively than in those receiving higher doses. These results suggest that normal HSPC and AML cells compete for the same functional niche. Manipulation of the niche could impact on response to antileukemic therapies, and the numbers of normal HSPC could impact on leukemia outcome, informing approaches to cell dose in the context of stem cell transplantation. PMID:26388434

  18. Hematopoietic Cell Transplantation Outcomes in Monosomal Karyotype Myeloid Malignancies.

    PubMed

    Pasquini, Marcelo C; Zhang, Mei-Jie; Medeiros, Bruno C; Armand, Philippe; Hu, Zhen-Huan; Nishihori, Taiga; Aljurf, Mahmoud D; Akpek, Görgün; Cahn, Jean-Yves; Cairo, Mitchell S; Cerny, Jan; Copelan, Edward A; Deol, Abhinav; Freytes, César O; Gale, Robert Peter; Ganguly, Siddhartha; George, Biju; Gupta, Vikas; Hale, Gregory A; Kamble, Rammurti T; Klumpp, Thomas R; Lazarus, Hillard M; Luger, Selina M; Liesveld, Jane L; Litzow, Mark R; Marks, David I; Martino, Rodrigo; Norkin, Maxim; Olsson, Richard F; Oran, Betul; Pawarode, Attaphol; Pulsipher, Michael A; Ramanathan, Muthalagu; Reshef, Ran; Saad, Ayman A; Saber, Wael; Savani, Bipin N; Schouten, Harry C; Ringdén, Olle; Tallman, Martin S; Uy, Geoffrey L; Wood, William A; Wirk, Baldeep; Pérez, Waleska S; Batiwalla, Minoo; Weisdorf, Daniel J

    2016-02-01

    The presence of monosomal karyotype (MK+) in acute myeloid leukemia (AML) is associated with dismal outcomes. We evaluated the impact of MK+ in AML (MK+AML, n = 240) and in myelodysplastic syndrome (MDS) (MK+MDS, n = 221) on hematopoietic cell transplantation outcomes compared with other cytogenetically defined groups (AML, n = 3360; MDS, n = 1373) as reported to the Center for International Blood and Marrow Transplant Research from 1998 to 2011. MK+ AML was associated with higher disease relapse (hazard ratio, 1.98; P < .01), similar transplantation-related mortality (TRM) (hazard ratio, 1.01; P = .90), and worse survival (hazard ratio, 1.67; P < .01) compared with those outcomes for other cytogenetically defined AML. Among patients with MDS, MK+ MDS was associated with higher disease relapse (hazard ratio, 2.39; P < .01), higher TRM (hazard ratio, 1.80; P < .01), and worse survival (HR, 2.02; P < .01). Subset analyses comparing chromosome 7 abnormalities (del7/7q) with or without MK+ demonstrated higher mortality for MK+ disease in for both AML (hazard ratio, 1.72; P < .01) and MDS (hazard ratio, 1.79; P < .01). The strong negative impact of MK+ in myeloid malignancies was observed in all age groups and using either myeloablative or reduced-intensity conditioning regimens. Alternative approaches to mitigate disease relapse in this population are needed. PMID:26327629

  19. Reactive oxygen species in eradicating acute myeloid leukemic stem cells

    PubMed Central

    Zhang, Hui; Fang, Hai

    2014-01-01

    Leukemic stem cells (LSCs) have been proven to drive leukemia initiation, progression and relapse, and are increasingly being used as a critical target for therapeutic intervention. As an essential feature in LSCs, reactive oxygen species (ROS) homeostasis has been extensively exploited in the past decade for targeting LSCs in acute myeloid leukemia (AML). Most, if not all, agents that show therapeutic benefits are able to alter redox status by inducing ROS, which confers selectivity in eradicating AML stem cells but sparing normal counterparts. In this review, we provide the comprehensive update of ROS-generating agents in the context of their impacts on our understanding of the pathogenesis of AML and its therapy. We anticipate that further characterizing these ROS agents will help us combat against AML in the coming era of LSC-targeting strategy.

  20. Lumbar Myeloid Cell Trafficking into Locomotor Networks after Thoracic Spinal Cord Injury.

    PubMed

    Hansen, Christopher N; Norden, Diana M; Faw, Timothy D; Deibert, Rochelle; Wohleb, Eric S; Sheridan, John F; Godbout, Jonathan P; Basso, D Michele

    2016-08-01

    Spinal cord injury (SCI) promotes inflammation along the neuroaxis that jeopardizes plasticity, intrinsic repair and recovery. While inflammation at the injury site is well-established, less is known within remote spinal networks. The presence of bone marrow-derived immune (myeloid) cells in these areas may further impede functional recovery. Previously, high levels of the gelatinase, matrix metalloproteinase-9 (MMP-9) occurred within the lumbar enlargement after thoracic SCI and impeded activity-dependent recovery. Since SCI-induced MMP-9 potentially increases vascular permeability, myeloid cell infiltration may drive inflammatory toxicity in locomotor networks. Therefore, we examined neurovascular reactivity and myeloid cell infiltration in the lumbar cord after thoracic SCI. We show evidence of region-specific recruitment of myeloid cells into the lumbar but not cervical region. Myeloid infiltration occurred with concomitant increases in chemoattractants (CCL2) and cell adhesion molecules (ICAM-1) around lumbar vasculature 24h and 7days post injury. Bone marrow GFP chimeric mice established robust infiltration of bone marrow-derived myeloid cells into the lumbar gray matter 24h after SCI. This cell infiltration occurred when the blood-spinal cord barrier was intact, suggesting active recruitment across the endothelium. Myeloid cells persisted as ramified macrophages at 7days post injury in parallel with increased inhibitory GAD67 labeling. Importantly, macrophage infiltration required MMP-9. PMID:27191729

  1. Drosophila as a model for the two myeloid blood cell systems in vertebrates

    PubMed Central

    Gold, Katrina S.; Brückner, Katja

    2016-01-01

    Fish, mice and men rely on two coexisting myeloid blood cell systems. One is sustained by hematopoietic progenitor cells, which reside in specialized microenvironments in hematopoietic organs and give rise to cells of the monocyte lineage. The other system corresponds to the independent lineage of self-renewing tissue macrophages, which colonize organs during embryonic development and are maintained during later life by proliferation in local tissue microenvironments. However, little is known about the nature of these microenvironments and their regulation. Moreover, many vertebrate tissues contain a mix of both tissue-resident and monocyte-derived macrophages, posing a challenge to the study of lineage-specific regulatory mechanisms and function. This review highlights how research in the simple model organism Drosophila melanogaster can address many of these outstanding questions in the field. Drawing parallels between hematopoiesis in Drosophila and vertebrates, we illustrate the evolutionary conservation of the two myeloid systems across animal phyla. Much like vertebrates, Drosophila possesses a lineage of self-renewing tissue-resident macrophages, as well as a ‘definitive’ lineage of macrophages that derive from hematopoiesis in the progenitor-based lymph gland. We summarize key findings from Drosophila hematopoiesis that illustrate how local microenvironments, systemic signals, immune challenges and nervous inputs regulate adaptive responses of tissue-resident macrophages and progenitor-based hematopoiesis to achieve optimal fitness of the animal. PMID:24946019

  2. Circulating endothelial cells and their progenitors in acute myeloid leukemia

    PubMed Central

    Zahran, Asmaa Mohammed; Aly, Sanaa Shaker; Altayeb, Hanan Ahmed; Ali, Arwa Mohammed

    2016-01-01

    Acute myeloid leukemia (AML) is an aggressive hematological malignancy characterized by the accumulation of immature myeloid progenitor cells in the bone marrow. Studies are required to investigate the prognostic and predictive value of surrogate biomarkers. Given the importance of angiogenesis in oncology in terms of pathogenesis as well as being a target for treatment, circulating endothelial cells (CECs) and endothelial progenitor cells (EPCs) are promising candidates to serve as such markers. The aim of the present study was to quantify CECs and EPCs in patients with AML at initial diagnosis and following induction chemotherapy, and to correlate these findings with the response to treatment in AML patients. The present study included 40 patients with de novo AML and 20 age- and gender-matched healthy controls. CECs and EPCs were evaluated by flow cytometry at initial diagnosis and after induction chemotherapy (3+7 protocol for AML other than M3 and all-trans-retinoic acid plus anthracycline for M3 disease). CECs and EPCs were significantly higher in AML patients at diagnosis and after induction chemotherapy than in controls. After induction chemotherapy, CECs and EPCs were significantly decreased compared with the levels at initial diagnosis. Patients who achieved complete response (n=28) had lower initial CEC and EPC levels compared with patients who did not respond to treatment. These results suggest that CEC levels are higher in AML patients and may correlate with disease status and treatment response. Further investigations are required to better determine the predictive value and implication of these cells in AML management. PMID:27602121

  3. The Potential of Vitamin D-Regulated Intracellular Signaling Pathways as Targets for Myeloid Leukemia Therapy

    PubMed Central

    Gocek, Elzbieta; Studzinski, George P.

    2015-01-01

    The current standard regimens for the treatment of acute myeloid leukemia (AML) are curative in less than half of patients; therefore, there is a great need for innovative new approaches to this problem. One approach is to target new treatments to the pathways that are instrumental to cell growth and survival with drugs that are less harmful to normal cells than to neoplastic cells. In this review, we focus on the MAPK family of signaling pathways and those that are known to, or potentially can, interact with MAPKs, such as PI3K/AKT/FOXO and JAK/STAT. We exemplify the recent studies in this field with specific relevance to vitamin D and its derivatives, since they have featured prominently in recent scientific literature as having anti-cancer properties. Since microRNAs also are known to be regulated by activated vitamin D, this is also briefly discussed here, as are the implications of the emerging acquisition of transcriptosome data and potentiation of the biological effects of vitamin D by other compounds. While there are ongoing clinical trials of various compounds that affect signaling pathways, more studies are needed to establish the clinical utility of vitamin D in the treatment of cancer. PMID:26239344

  4. Increased NK Cell Maturation in Patients with Acute Myeloid Leukemia

    PubMed Central

    Chretien, Anne-Sophie; Granjeaud, Samuel; Gondois-Rey, Françoise; Harbi, Samia; Orlanducci, Florence; Blaise, Didier; Vey, Norbert; Arnoulet, Christine; Fauriat, Cyril; Olive, Daniel

    2015-01-01

    Understanding immune alterations in cancer patients is a major challenge and requires precise phenotypic study of immune subsets. Improvement of knowledge regarding the biology of natural killer (NK) cells and technical advances leads to the generation of high dimensional dataset. High dimensional flow cytometry requires tools adapted to complex dataset analyses. This study presents an example of NK cell maturation analysis in Healthy Volunteers (HV) and patients with Acute Myeloid Leukemia (AML) with an automated procedure using the FLOCK algorithm. This procedure enabled to automatically identify NK cell subsets according to maturation profiles, with 2D mapping of a four-dimensional dataset. Differences were highlighted in AML patients compared to HV, with an overall increase of NK maturation. Among patients, a strong heterogeneity in NK cell maturation defined three distinct profiles. Overall, automatic gating with FLOCK algorithm is a recent procedure, which enables fast and reliable identification of cell populations from high-dimensional cytometry data. Such tools are necessary for immune subset characterization and standardization of data analyses. This tool is adapted to new immune cell subsets discovery, and may lead to a better knowledge of NK cell defects in cancer patients. Overall, 2D mapping of NK maturation profiles enabled fast and reliable identification of NK cell subsets. PMID:26594214

  5. MicroRNA-126-mediated control of cell fate in B-cell myeloid progenitors as a potential alternative to transcriptional factors.

    PubMed

    Okuyama, Kazuki; Ikawa, Tomokatsu; Gentner, Bernhard; Hozumi, Katsuto; Harnprasopwat, Ratanakanit; Lu, Jun; Yamashita, Riu; Ha, Daon; Toyoshima, Takae; Chanda, Bidisha; Kawamata, Toyotaka; Yokoyama, Kazuaki; Wang, Shusheng; Ando, Kiyoshi; Lodish, Harvey F; Tojo, Arinobu; Kawamoto, Hiroshi; Kotani, Ai

    2013-08-13

    Lineage specification is thought to be largely regulated at the level of transcription, where lineage-specific transcription factors drive specific cell fates. MicroRNAs (miR), vital to many cell functions, act posttranscriptionally to decrease the expression of target mRNAs. MLL-AF4 acute lymphocytic leukemia exhibits both myeloid and B-cell surface markers, suggesting that the transformed cells are B-cell myeloid progenitor cells. Through gain- and loss-of-function experiments, we demonstrated that microRNA 126 (miR-126) drives B-cell myeloid biphenotypic leukemia differentiation toward B cells without changing expression of E2A immunoglobulin enhancer-binding factor E12/E47 (E2A), early B-cell factor 1 (EBF1), or paired box protein 5, which are critical transcription factors in B-lymphopoiesis. Similar induction of B-cell differentiation by miR-126 was observed in normal hematopoietic cells in vitro and in vivo in uncommitted murine c-Kit(+)Sca1(+)Lineage(-) cells, with insulin regulatory subunit-1 acting as a target of miR-126. Importantly, in EBF1-deficient hematopoietic progenitor cells, which fail to differentiate into B cells, miR-126 significantly up-regulated B220, and induced the expression of B-cell genes, including recombination activating genes-1/2 and CD79a/b. These data suggest that miR-126 can at least partly rescue B-cell development independently of EBF1. These experiments show that miR-126 regulates myeloid vs. B-cell fate through an alternative machinery, establishing the critical role of miRNAs in the lineage specification of multipotent mammalian cells. PMID:23893300

  6. Heterozygous inactivation of the Nf1 gene in myeloid cells enhances neointima formation via a rosuvastatin-sensitive cellular pathway

    PubMed Central

    Stansfield, Brian K.; Bessler, Waylan K.; Mali, Raghuveer; Mund, Julie A.; Downing, Brandon; Li, Fang; Sarchet, Kara N.; DiStasi, Matthew R.; Conway, Simon J.; Kapur, Reuben; Ingram, David A.

    2013-01-01

    Mutations in the NF1 tumor suppressor gene cause Neurofibromatosis type 1 (NF1). Neurofibromin, the protein product of NF1, functions as a negative regulator of Ras activity. Some NF1 patients develop cardiovascular disease, which represents an underrecognized disease complication and contributes to excess morbidity and mortality. Specifically, NF1 patients develop arterial occlusion resulting in tissue ischemia and sudden death. Murine studies demonstrate that heterozygous inactivation of Nf1 (Nf1+/−) in bone marrow cells enhances neointima formation following arterial injury. Macrophages infiltrate Nf1+/− neointimas, and NF1 patients have increased circulating inflammatory monocytes in their peripheral blood. Therefore, we tested the hypothesis that heterozygous inactivation of Nf1 in myeloid cells is sufficient for neointima formation. Specific ablation of a single copy of the Nf1 gene in myeloid cells alone mobilizes a discrete pro-inflammatory murine monocyte population via a cell autonomous and gene-dosage dependent mechanism. Furthermore, lineage-restricted heterozygous inactivation of Nf1 in myeloid cells is sufficient to reproduce the enhanced neointima formation observed in Nf1+/− mice when compared with wild-type controls, and homozygous inactivation of Nf1 in myeloid cells amplified the degree of arterial stenosis after arterial injury. Treatment of Nf1+/− mice with rosuvastatin, a stain with anti-inflammatory properties, significantly reduced neointima formation when compared with control. These studies identify neurofibromin-deficient myeloid cells as critical cellular effectors of Nf1+/− neointima formation and propose a potential therapeutic for NF1 cardiovascular disease. PMID:23197650

  7. Instructive role of M-CSF on commitment of bipotent myeloid cells involves ERK-dependent positive and negative signaling.

    PubMed

    Carras, Sylvain; Valayer, Alexandre; Moratal, Claudine; Weiss-Gayet, Michèle; Pages, Gilles; Morlé, François; Mouchiroud, Guy; Gobert, Stéphanie

    2016-02-01

    M-CSF and G-CSF are instructive cytokines that specifically induce differentiation of bipotent myeloid progenitors into macrophages and granulocytes, respectively. Through morphology and colony assay studies, flow cytometry analysis of specific markers, and expression of myeloid transcription factors, we show here that the Eger/Fms cell line is composed of cells whose differentiation fate is instructed by M-CSF and G-CSF, thus representing a good in vitro model of myeloid bipotent progenitors. Consistent with the essential role of ERK1/2 during macrophage differentiation and defects of macrophagic differentiation in native ERK1(-/-) progenitors, ERK signaling is strongly activated in Eger/Fms cells upon M-CSF-induced macrophagic differentiation but only to a very small extent during G-CSF-induced granulocytic differentiation. Previous in vivo studies indicated a key role of Fli-1 in myeloid differentiation and demonstrated its weak expression during macrophagic differentiation with a strong expression during granulocytic differentiation. Here, we demonstrated that this effect could be mediated by a differential regulation of protein kinase Cδ (PKCd) on Fli-1 expression in response to M-CSF and G-CSF. With the use of knockdown of PKCd by small interfering RNA, we demonstrated that M-CSF activates PKCd, which in turn, inhibits Fli-1 expression and granulocytic differentiation. Finally, we studied the connection between ERK and PKCd and showed that in the presence of the MEK inhibitor U0126, PKCd expression is decreased, and Fli-1 expression is increased in response to M-CSF. Altogether, we demonstrated that in bipotent myeloid cells, M-CSF promotes macrophagic over granulocytic differentiation by inducing ERK activation but also PKCd expression, which in turn, down-regulates Fli-1 expression and prevents granulocytic differentiation. PMID:26336156

  8. Identification of a myeloid-derived suppressor cell cystatin-like protein that inhibits metastasis.

    PubMed

    Boutté, Angela M; Friedman, David B; Bogyo, Matthew; Min, Yongfen; Yang, Li; Lin, P Charles

    2011-08-01

    Myeloid-derived suppressor cells (MDSCs) are significantly increased in cancer patients and tumor bearing-animals. MDSCs infiltrate into tumors and promote tumor invasion and metastasis. To identify the mediator responsible for the prometastatic property of MDSCs, we used proteomics. We found neutrophilic granule protein (NGP) was decreased >2-fold in MDSCs from metastatic 4T1 tumor-bearing mice compared to nonmetastatic 67NR controls. NGP mRNA levels were decreased in bone marrow and in tumor-infiltrating MDSCs by 45 and 66%, respectively, in 4T1 tumor-bearing mice compared to 67NR controls. Interestingly, 4T1-conditioned medium reduced myeloid cell NGP expression by ∼ 40%, suggesting that a secreted factor mediates gene reduction. Sequence analysis shows a putative cystatin domain in NGP, and biochemical analysis confirms NGP a novel cathepsin inhibitor. It inhibited cathepsin B activity by nearly 40% in vitro. NGP expression in 4T1 tumor cells suppressed cell invasion, delayed primary tumor growth, and greatly reduced lung metastasis in vivo. A 2.8-fold reduction of cathepsin activity was found in tumors expressing NGP compared to controls. NGP significantly reduced tumor angiogenesis to 12.6 from 19.6 and lymphangiogenesis to 4.6 from 9.1 vessels/field. Necrosis was detectable only in NGP-expressing tumors, and the number of apoptotic cells increased to 22.4 from 8.3 in controls. Taken together, this study identifies a negative regulator of tumor metastasis in MDSCs, NGP, which is down-regulated in metastatic conditions. The finding suggests that malignant tumors promote invasion/metastasis not only through up-regulation of proteases but also down-regulation of protease inhibitors. PMID:21518852

  9. Langerhans cell origin and regulation

    PubMed Central

    Collin, Matthew; Milne, Paul

    2015-01-01

    Purpose To summarize recent research on the ontogeny of Langerhans cells and regulation of their homeostasis in quiescent and inflamed conditions Recent findings Langerhans cells (LCs) originate pre-natally and may endure throughout life, independently of bone marrow derived precursors. Fate mapping experiments have recently resolved the relative contribution of primitive yolk sac and fetal liver hematopoiesis to the initial formation of LCs. In post-natal life, local self-renewal restores LC numbers following chronic or low grade inflammatory insults. However, severe inflammation recruits de novo bone marrow derived precursors in two waves; a transient population of classical monocytes followed by uncharacterized myeloid precursors that form a stable self-renewing LC network as inflammation subsides. Human CD1c+ dendritic cells have LC potential in vitro, raising the possibility that DC progenitors provide the second wave. LC development depends upon TGFβ receptor signaling with distinct pathways active during differentiation and homeostasis. LC survival is mediated by multiple pathways including mTOR and ERK signaling, mechanisms that become highly relevant in LC neoplasia. Summary The study of LCs continues to provide novel and unexpected insights into the origin and regulation of myeloid cell populations. The melding of macrophage and DC biology, shaped by a unique habitat, is a special feature of LCs. PMID:26554892

  10. The tumor microenvironment shapes lineage, transcriptional, and functional diversity of infiltrating myeloid cells.

    PubMed

    Elpek, Kutlu G; Cremasco, Viviana; Shen, Hua; Harvey, Christopher J; Wucherpfennig, Kai W; Goldstein, Daniel R; Monach, Paul A; Turley, Shannon J

    2014-07-01

    Myeloid cells play important regulatory roles within the tumor environment by directly promoting tumor progression and modulating the function of tumor-infiltrating lymphocytes, and as such, they represent a potential therapeutic target for the treatment of cancer. Although distinct subsets of tumor-associated myeloid cells have been identified, a broader analysis of the complete myeloid cell landscape within individual tumors and also across different tumor types has been lacking. By establishing the developmental and transcriptomic signatures of infiltrating myeloid cells from multiple primary tumors, we found that tumor-associated macrophages (TAM) and tumor-associated neutrophils (TAN), while present within all tumors analyzed, exhibited strikingly different frequencies, gene expression profiles, and functions across cancer types. We also evaluated the impact of anatomic location and circulating factors on the myeloid cell composition of tumors. The makeup of the myeloid compartment was determined by the tumor microenvironment rather than the anatomic location of tumor development or tumor-derived circulating factors. Protumorigenic and hypoxia-associated genes were enriched in TAMs and TANs compared with splenic myeloid-derived suppressor cells. Although all TANs had an altered expression pattern of secretory effector molecules, in each tumor type they exhibited a unique cytokine, chemokine, and associated receptor expression profile. One such molecule, haptoglobin, was uniquely expressed by 4T1 TANs and identified as a possible diagnostic biomarker for tumors characterized by the accumulation of myeloid cells. Thus, we have identified considerable cancer-specific diversity in the lineage, gene expression, and function of tumor-infiltrating myeloid cells. PMID:24801837

  11. Myeloid SIRT1 regulates macrophage infiltration and insulin sensitivity in mice fed a high-fat diet.

    PubMed

    Ka, Sun-O; Song, Mi-Young; Bae, Eun Ju; Park, Byung-Hyun

    2015-02-01

    Inflammation is an important factor in the development of insulin resistance. SIRT1, a class 3 histone/protein deacetylase, has anti-inflammatory functions. Myeloid-specific deletion of Sirt1 promotes macrophage infiltration into insulin-sensitive organs and aggravates tissue inflammation. In this study, we investigated how SIRT1 in macrophages alters tissue inflammation in the pancreas as well as liver and adipose tissue, and further explored the role of SIRT1 in locomotion of macrophages. Myeloid-specific Sirt1-deleted mice (mS1KO) and WT littermates were fed a 60% calorie high-fat diet (HFD) for 16 weeks. Tissue inflammation and metabolic phenotypes were compared. Bone marrow macrophages (BMMs) from WT or mS1KO mice were used in in vitro chemotaxis assays and macrophage polarization studies. mS1KO mice fed a HFD exhibited glucose intolerance, reduced insulin secretion, and insulin sensitivity with a slight decrease in body weight. Consistent with these results, pancreatic islets of mS1KO mice fed a HFD displayed decreased mass with profound apoptotic cell damage and increased macrophage infiltration and inflammation. Liver and adipose tissues from mS1KO HFD mice also showed greater accumulation of macrophages and tissue inflammation. Results from in vitro experiments indicated that deletion of myeloid Sirt1 stimulated proinflammatory M1-like polarization of BMMs and augmented the adipocyte-mediated macrophage chemotaxis. The latter effect was accompanied by increased expression and acetylation of focal adhesion kinase, as well as nuclear factor kappa B. Our results indicate that myeloid SIRT1 plays a crucial role in macrophage polarization and chemotaxis, and thus regulates the development of HFD-induced pancreatic inflammation and insulin secretion, and metabolic derangements in liver and adipose tissue. PMID:25349250

  12. Inverse regulation of bridging integrator 1 and BCR-ABL1 in chronic myeloid leukemia.

    PubMed

    Trino, Stefania; De Luca, Luciana; Simeon, Vittorio; Laurenzana, Ilaria; Morano, Annalisa; Caivano, Antonella; La Rocca, Francesco; Pietrantuono, Giuseppe; Bianchino, Gabriella; Grieco, Vitina; Signorino, Elisabetta; Fragasso, Alberto; Bochicchio, Maria Teresa; Venturi, Claudia; Rosti, Gianantonio; Martinelli, Giovanni; Del Vecchio, Luigi; Cilloni, Daniela; Musto, Pellegrino

    2016-01-01

    Endocytosis is the major regulator process of tyrosine kinase receptor (RTK) functional activities. Bridging integrator 1 (BIN1) is a key protein involved in RTK intracellular trafficking. Here, we report, by studying 34 patients with chronic myeloid leukemia (CML) at diagnosis, that BIN1 gene is downregulated in CML as compared to healthy controls, suggesting an altered endocytosis of RTKs. Rab interactor 1 (RIN1), an activator of BIN1, displayed a similar behavior. Treatment of 57 patients by tyrosine kinase inhibitors caused, along with BCR-ABL1 inactivation, an increase of BIN1 and RIN1 expression, potentially restoring endocytosis. There was a significant inverse correlation between BIN1-RIN1 and BCR-ABL1 expression. In vitro experiments on both CML and nontumorigenic cell lines treated with Imatinib confirmed these results. In order to provide another proof in favor of BIN1 and RIN1 endocytosis function in CML, we demonstrated that Imatinib induced, in K562 cell line, BIN1-RIN1 upregulation accompanied by a parallel AXL receptor internalization into cytoplasmic compartment. This study shows a novel deregulated mechanism in CML patients, indicating BIN1 and RIN1 as players in the maintenance of the abnormal RTK signaling in this hematological disease. PMID:26194865

  13. Stem Cell Modeling of Core Binding Factor Acute Myeloid Leukemia

    PubMed Central

    Mosna, Federico

    2016-01-01

    Even though clonally originated from a single cell, acute leukemia loses its homogeneity soon and presents at clinical diagnosis as a hierarchy of cells endowed with different functions, of which only a minority possesses the ability to recapitulate the disease. Due to their analogy to hematopoietic stem cells, these cells have been named “leukemia stem cells,” and are thought to be chiefly responsible for disease relapse and ultimate survival after chemotherapy. Core Binding Factor (CBF) Acute Myeloid Leukemia (AML) is cytogenetically characterized by either the t(8;21) or the inv(16)/t(16;16) chromosomal abnormalities, which, although being pathognomonic, are not sufficient per se to induce overt leukemia but rather determine a preclinical phase of disease when preleukemic subclones compete until the acquisition of clonal dominance by one of them. In this review we summarize the concepts regarding the application of the “leukemia stem cell” theory to the development of CBF AML; we will analyze the studies investigating the leukemogenetic role of t(8;21) and inv(16)/t(16;16), the proposed theories of its clonal evolution, and the role played by the hematopoietic niches in preserving the disease. Finally, we will discuss the clinical implications of stem cell modeling of CBF AML for the therapy of the disease. PMID:26880987

  14. Epigenetic regulators and their impact on therapy in acute myeloid leukemia.

    PubMed

    Pastore, Friederike; Levine, Ross L

    2016-03-01

    Genomic studies of hematologic malignancies have identified a spectrum of recurrent somatic alterations that contribute to acute myeloid leukemia initiation and maintenance, and which confer sensitivities to molecularly targeted therapies. The majority of these genetic events are small, site-specific alterations in DNA sequence. In more than two thirds of patients with de novo acute myeloid leukemia mutations epigenetic modifiers are detected. Epigenetic modifiers encompass a large group of proteins that modify DNA at cytosine residues or cause post-translational histone modifications such as methylations or acetylations. Altered functions of these epigenetic modifiers disturb the physiological balance between gene activation and gene repression and contribute to aberrant gene expression regulation found in acute myeloid leukemia. This review provides an overview of the epigenetic modifiers mutated in acute myeloid leukemia, their clinical relevance and how a deeper understanding of their biological function has led to the discovery of new specific targets, some of which are currently tested in mechanism-based clinical trials. PMID:26928248

  15. Epigenetic regulators and their impact on therapy in acute myeloid leukemia

    PubMed Central

    Pastore, Friederike; Levine, Ross L.

    2016-01-01

    Genomic studies of hematologic malignancies have identified a spectrum of recurrent somatic alterations that contribute to acute myeloid leukemia initiation and maintenance, and which confer sensitivities to molecularly targeted therapies. The majority of these genetic events are small, site-specific alterations in DNA sequence. In more than two thirds of patients with de novo acute myeloid leukemia mutations epigenetic modifiers are detected. Epigenetic modifiers encompass a large group of proteins that modify DNA at cytosine residues or cause post-translational histone modifications such as methylations or acetylations. Altered functions of these epigenetic modifiers disturb the physiological balance between gene activation and gene repression and contribute to aberrant gene expression regulation found in acute myeloid leukemia. This review provides an overview of the epigenetic modifiers mutated in acute myeloid leukemia, their clinical relevance and how a deeper understanding of their biological function has led to the discovery of new specific targets, some of which are currently tested in mechanism-based clinical trials. PMID:26928248

  16. Proteomic Cornerstones of Hematopoietic Stem Cell Differentiation: Distinct Signatures of Multipotent Progenitors and Myeloid Committed Cells*

    PubMed Central

    Klimmeck, Daniel; Hansson, Jenny; Raffel, Simon; Vakhrushev, Sergey Y.; Trumpp, Andreas; Krijgsveld, Jeroen

    2012-01-01

    Regenerative tissues such as the skin epidermis, the intestinal mucosa or the hematopoietic system are organized in a hierarchical manner with stem cells building the top of this hierarchy. Somatic stem cells harbor the highest self-renewal activity and generate a series of multipotent progenitors which differentiate into lineage committed progenitors and subsequently mature cells. In this report, we applied an in-depth quantitative proteomic approach to analyze and compare the full proteomes of ex vivo isolated and FACS-sorted populations highly enriched for either multipotent hematopoietic stem/progenitor cells (HSPCs, LinnegSca-1+c-Kit+) or myeloid committed precursors (LinnegSca-1−c-Kit+). By employing stable isotope dimethyl labeling and high-resolution mass spectrometry, more than 5000 proteins were quantified. From biological triplicate experiments subjected to rigorous statistical evaluation, 893 proteins were found differentially expressed between multipotent and myeloid committed cells. The differential protein content in these cell populations points to a distinct structural organization of the cytoskeleton including remodeling activity. In addition, we found a marked difference in the expression of metabolic enzymes, including a clear shift of specific protein isoforms of the glycolytic pathway. Proteins involved in translation showed a collective higher expression in myeloid progenitors, indicating an increased translational activity. Strikingly, the data uncover a unique signature related to immune defense mechanisms, centering on the RIG-I and type-1 interferon response systems, which are installed in multipotent progenitors but not evident in myeloid committed cells. This suggests that specific, and so far unrecognized, mechanisms protect these immature cells before they mature. In conclusion, this study indicates that the transition of hematopoietic stem/progenitors toward myeloid commitment is accompanied by a profound change in processing of

  17. TLR-2/TLR-4 TREM-1 Signaling Pathway Is Dispensable in Inflammatory Myeloid Cells during Sterile Kidney Injury

    PubMed Central

    Campanholle, Gabriela; Mittelsteadt, Kristen; Nakagawa, Shunsaku; Kobayashi, Akio; Lin, Shuei-Liong; Gharib, Sina A.; Heinecke, Jay W.; Hamerman, Jessica A.; Altemeier, William A.; Duffield, Jeremy S.

    2013-01-01

    Inflammatory macrophages are abundant in kidney disease, stimulating repair, or driving chronic inflammation and fibrosis. Damage associated molecules (DAMPs), released from injured cells engage pattern recognition receptors (PRRs) on macrophages, contributing to activation. Understanding mechanisms of macrophage activation during kidney injury may lead to strategies to alleviate chronic disease. We identified Triggering-Receptor-in-Myeloid-cells (TREM)-1, a regulator of TLR signaling, as highly upregulated in kidney inflammatory macrophages and tested the roles of these receptors in macrophage activation and kidney disease. Kidney DAMPs activated macrophages in vitro, independently of TREM-1, but partially dependent on TLR-2/−4, MyD88. In two models of progressive interstitial kidney disease, TREM-1 blockade had no impact on disease or macrophage activation in vivo, but TLR-2/−4, or MyD88 deficiency was anti-inflammatory and anti-fibrotic. When MyD88 was mutated only in the myeloid lineage, however, there was no bearing on macrophage activation or disease progression. Instead, TLR-2/−4 or MyD88 deficiency reduced activation of mesenchyme lineage cells resulting in reduced inflammation and fibrosis, indicating that these pathways play dominant roles in activation of myofibroblasts but not macrophages. To conclude, TREM-1, TLR2/4 and MyD88 signaling pathways are redundant in myeloid cell activation in kidney injury, but the latter appear to regulate activation of mesenchymal cells. PMID:23844229

  18. Interaction of Rotavirus with Human Myeloid Dendritic Cells

    PubMed Central

    Narváez, Carlos F.; Angel, Juana; Franco, Manuel A.

    2005-01-01

    We have previously shown that very few rotavirus (RV)-specific T cells that secrete gamma interferon circulate in recently infected and seropositive adults and children. Here, we have studied the interaction of RV with myeloid immature (IDC) and mature dendritic cells (MDC) in vitro. RV did not induce cell death of IDC or MDC and induced maturation of between 12 and 48% of IDC. Nonetheless, RV did not inhibit the maturation of IDC or change the expression of maturation markers on MDC. After treatment with RV, few IDC expressed the nonstructural viral protein NSP4. In contrast, a discrete productive viral infection was shown in MDC of a subset of volunteers, and between 3 and 46% of these cells expressed NSP4. RV-treated IDC secreted interleukin 6 (IL-6) (but not IL-1β, IL-8, IL-10, IL-12, tumor necrosis factor alpha, or transforming growth factor beta), and MDC released IL-6 and small amounts of IL-10 and IL-12p70. The patterns of cytokines secreted by T cells stimulated by staphylococcal enterotoxin B presented by MDC infected with RV or uninfected were comparable. The frequencies and patterns of cytokines secreted by memory RV-specific T cells evidenced after stimulation of peripheral blood mononuclear cells (PBMC) with RV were similar to those evidenced after stimulation of PBMC with RV-infected MDC. Finally, IDC treated with RV strongly stimulated naive allogeneic CD4+ T cells to secrete Th1 cytokines. Thus, although RV does not seem to be a strong maturing stimulus for DC, it promotes their capacity to prime Th1 cells. PMID:16282452

  19. The oncogene EVI1 enhances transcriptional and biological responses of human myeloid cells to all-trans retinoic acid.

    PubMed

    Steinmetz, Birgit; Hackl, Hubert; Slabáková, Eva; Schwarzinger, Ilse; Smějová, Monika; Spittler, Andreas; Arbesu, Itziar; Shehata, Medhat; Souček, Karel; Wieser, Rotraud

    2014-01-01

    The product of the ecotropic virus integration site 1 (EVI1) gene, whose overexpression is associated with a poor prognosis in myeloid leukemias and some epithelial tumors, regulates gene transcription both through direct DNA binding and through modulation of the activity of other sequence specific transcription factors. Previous results from our laboratory have shown that EVI1 influenced transcription regulation in response to the myeloid differentiation inducing agent, all-trans retinoic acid (ATRA), in a dual manner: it enhanced ATRA induced transcription of the RARβ gene, but repressed the ATRA induction of the EVI1 gene itself. In the present study, we asked whether EVI1 would modulate the ATRA regulation of a larger number of genes, as well as biological responses to this agent, in human myeloid cells. U937 and HL-60 cells ectopically expressing EVI1 through retroviral transduction were subjected to microarray based gene expression analysis, and to assays measuring cellular proliferation, differentiation, and apoptosis. These experiments showed that EVI1 modulated the ATRA response of several dozens of genes, and in fact reinforced it in the vast majority of cases. A particularly strong synergy between EVI1 and ATRA was observed for GDF15, which codes for a member of the TGF-β superfamily of cytokines. In line with the gene expression results, EVI1 enhanced cell cycle arrest, differentiation, and apoptosis in response to ATRA, and knockdown of GDF15 counteracted some of these effects. The potential clinical implications of these findings are discussed. PMID:25486480

  20. The oncogene EVI1 enhances transcriptional and biological responses of human myeloid cells to all-trans retinoic acid

    PubMed Central

    Steinmetz, Birgit; Hackl, Hubert; Slabáková, Eva; Schwarzinger, Ilse; Smějová, Monika; Spittler, Andreas; Arbesu, Itziar; Shehata, Medhat; Souček, Karel; Wieser, Rotraud

    2014-01-01

    The product of the ecotropic virus integration site 1 (EVI1) gene, whose overexpression is associated with a poor prognosis in myeloid leukemias and some epithelial tumors, regulates gene transcription both through direct DNA binding and through modulation of the activity of other sequence specific transcription factors. Previous results from our laboratory have shown that EVI1 influenced transcription regulation in response to the myeloid differentiation inducing agent, all-trans retinoic acid (ATRA), in a dual manner: it enhanced ATRA induced transcription of the RARβ gene, but repressed the ATRA induction of the EVI1 gene itself. In the present study, we asked whether EVI1 would modulate the ATRA regulation of a larger number of genes, as well as biological responses to this agent, in human myeloid cells. U937 and HL-60 cells ectopically expressing EVI1 through retroviral transduction were subjected to microarray based gene expression analysis, and to assays measuring cellular proliferation, differentiation, and apoptosis. These experiments showed that EVI1 modulated the ATRA response of several dozens of genes, and in fact reinforced it in the vast majority of cases. A particularly strong synergy between EVI1 and ATRA was observed for GDF15, which codes for a member of the TGF-β superfamily of cytokines. In line with the gene expression results, EVI1 enhanced cell cycle arrest, differentiation, and apoptosis in response to ATRA, and knockdown of GDF15 counteracted some of these effects. The potential clinical implications of these findings are discussed. PMID:25486480

  1. Cloning of the novel human myeloid-cell-specific C/EBP-epsilon transcription factor.

    PubMed Central

    Chumakov, A M; Grillier, I; Chumakova, E; Chih, D; Slater, J; Koeffler, H P

    1997-01-01

    Chicken NF-M transcription factor, in cooperation with either c-Myb or v-Myb, is active in the combinatorial activation of myeloid-cell-specific genes in heterologous cell types, such as embryonic fibroblasts. In humans, similar effects were observed with homologous members of the CCAAT/enhancer-binding protein (C/EBP) family of transcriptional regulators, especially the human homolog of chicken NF-M, C/EBP-beta (NF-IL6). However, the NF-IL6 gene is expressed in a variety of nonmyeloid cell types and is strongly inducible in response to inflammatory stimuli, making it an unlikely candidate to have an exclusive role as a combinatorial differentiation switch during myelopoiesis in human cells. By using a reverse transcription-PCR-based approach and a set of primers specific for the DNA-binding domains of highly homologous members of the C/EBP family of transcriptional regulators, we have cloned a novel human gene encoding a member of the C/EBP gene family, identified as the human homolog of CRP1, C/EBP-epsilon. A 1.2-kb cDNA encoding full-length human C/EBP-epsilon was cloned from a promyelocyte-late myeloblast-derived lambda gt11 library. Molecular analysis of the cDNA and genomic clones indicated the presence of two exons encoding a protein with an apparent molecular mass of 32 kDa and a pI of 9.5. Primer extension analysis of C/EBP-epsilon mRNA detected a single major transcription start site approximately 200 bp upstream of the start codon. The putative promoter area is similar to those of several other myeloid-cell-specific genes in that it contains no TATAAA box but has a number of purine-rich stretches with multiple sites for the factors of the Ets family of transcriptional regulators. Northern blot analyses indicated a highly restricted mRNA expression pattern, with the strongest expression occurring in promyelocyte and late-myeloblast-like cell lines. Western blot and immunoprecipitation studies using rabbit anti-C/EBP-epsilon antibodies raised against the N

  2. CD45 Phosphatase Inhibits STAT3 Transcription Factor Activity in Myeloid Cells and Promotes Tumor-Associated Macrophage Differentiation.

    PubMed

    Kumar, Vinit; Cheng, Pingyan; Condamine, Thomas; Mony, Sridevi; Languino, Lucia R; McCaffrey, Judith C; Hockstein, Neil; Guarino, Michael; Masters, Gregory; Penman, Emily; Denstman, Fred; Xu, Xiaowei; Altieri, Dario C; Du, Hong; Yan, Cong; Gabrilovich, Dmitry I

    2016-02-16

    Recruitment of monocytic myeloid-derived suppressor cells (MDSCs) and differentiation of tumor-associated macrophages (TAMs) are the major factors contributing to tumor progression and metastasis. We demonstrated that differentiation of TAMs in tumor site from monocytic precursors was controlled by downregulation of the activity of the transcription factor STAT3. Decreased STAT3 activity was caused by hypoxia and affected all myeloid cells but was not observed in tumor cells. Upregulation of CD45 tyrosine phosphatase activity in MDSCs exposed to hypoxia in tumor site was responsible for downregulation of STAT3. This effect was mediated by the disruption of CD45 protein dimerization regulated by sialic acid. Thus, STAT3 has a unique function in the tumor environment in controlling the differentiation of MDSC into TAM, and its regulatory pathway could be a potential target for therapy. PMID:26885857

  3. Myeloid DAP12-associating lectin (MDL)-1 regulates synovial inflammation and bone erosion associated with autoimmune arthritis

    PubMed Central

    Joyce-Shaikh, Barbara; Bigler, Michael E.; Chao, Cheng-Chi; Murphy, Erin E.; Blumenschein, Wendy M.; Adamopoulos, Iannis E.; Heyworth, Paul G.; Antonenko, Svetlana; Bowman, Edward P.; McClanahan, Terrill K.; Phillips, Joseph H.

    2010-01-01

    DNAX adaptor protein 12 (DAP12) is a trans-membrane adaptor molecule that transduces activating signals in NK and myeloid cells. Absence of functional Dap12 results in osteoclast defects and bone abnormalities. Because DAP12 has no extracelluar binding domains, it must pair with cell surface receptors for signal transduction. There are at least 15 known DAP12-associating cell surface receptors with distinct temporal and cell type–specific expression patterns. Our aim was to determine which receptors may be important in DAP12-associated bone pathologies. Here, we identify myeloid DAP12-associating lectin (MDL)-1 receptor (also known as CLEC5A) as a key regulator of synovial injury and bone erosion during autoimmune joint inflammation. Activation of MDL-1 leads to enhanced recruitment of inflammatory macrophages and neutrophils to the joint and promotes bone erosion. Functional blockade of MDL-1 receptor via Mdl1 deletion or treatment with MDL-1-Ig fusion protein reduces the clinical signs of autoimmune joint inflammation. These findings suggest that MDL-1 receptor may be a therapeutic target for treatment of immune-mediated skeletal disorders. PMID:20212065

  4. Myeloid DAP12-associating lectin (MDL)-1 regulates synovial inflammation and bone erosion associated with autoimmune arthritis.

    PubMed

    Joyce-Shaikh, Barbara; Bigler, Michael E; Chao, Cheng-Chi; Murphy, Erin E; Blumenschein, Wendy M; Adamopoulos, Iannis E; Heyworth, Paul G; Antonenko, Svetlana; Bowman, Edward P; McClanahan, Terrill K; Phillips, Joseph H; Cua, Daniel J

    2010-03-15

    DNAX adaptor protein 12 (DAP12) is a trans-membrane adaptor molecule that transduces activating signals in NK and myeloid cells. Absence of functional Dap12 results in osteoclast defects and bone abnormalities. Because DAP12 has no extracelluar binding domains, it must pair with cell surface receptors for signal transduction. There are at least 15 known DAP12-associating cell surface receptors with distinct temporal and cell type-specific expression patterns. Our aim was to determine which receptors may be important in DAP12-associated bone pathologies. Here, we identify myeloid DAP12-associating lectin (MDL)-1 receptor (also known as CLEC5A) as a key regulator of synovial injury and bone erosion during autoimmune joint inflammation. Activation of MDL-1 leads to enhanced recruitment of inflammatory macrophages and neutrophils to the joint and promotes bone erosion. Functional blockade of MDL-1 receptor via Mdl1 deletion or treatment with MDL-1-Ig fusion protein reduces the clinical signs of autoimmune joint inflammation. These findings suggest that MDL-1 receptor may be a therapeutic target for treatment of immune-mediated skeletal disorders. PMID:20212065

  5. EVI1 and MDS1/EVI1 Expression During Primary Human Hematopoietic Progenitor Cell Differentiation into Various Myeloid Lineages

    PubMed Central

    Steinleitner, Katarina; Rampetsreiter, Paulina; Köffel, Rene; Ramanathan, Gajalakshmi; Mannhalter, Christine; Strobl, Herbert; Wieser, Rotraud

    2012-01-01

    Background and Aim Overexpression of ecotropic viral integration site 1 (EVI1) is associated with aggressive disease in myeloid leukemia. We therefore studied its expression and function in cluster of differentiation 34 positive (CD 34+) primary human hematopoietic progenitor cells. Materials and Methods CD34+ cells were differentiated into various myeloid lineages using appropriate cytokines. EVI1 expression was measured by quantitative real time reverse transcriptase polymerase chain reaction (qRT-PCR) and intranuclear fluorescence activated cell sorting (FACS). Experimental manipulation of EVI1 levels was achieved using retroviral infection. Results EVI1 mRNA and its variant myelodysplastic syndrome 1 (MDS1)/EVI1, which gives rise to a partially antagonistic protein, were detectable in CD34+ cells, but their levels declined rapidly during differentiation into the granulocytic, monocytic, dendritic, erythroid, and megakaryocytic lineages. Similarly, EVI1 protein levels decreased during myeloid differentiation. Attempts to experimentally express EVI1 in CD34+ and U937 cells indicated that ectopic expression of EVI1 may cause growth arrest, apoptosis and/or senescence of human hematopoietic cells. Conclusion EVI1 is expressed in human hematopoietic progenitor cells, but is down-regulated during differentiation. Ectopic expression of EVI1 may activate cellular safeguards against oncogene activation. PMID:23155256

  6. Label-free detection of immune complexes with myeloid cells.

    PubMed

    Szittner, Z; Bentlage, A E H; Rovero, P; Migliorini, P; Lóránd, V; Prechl, J; Vidarsson, G

    2016-07-01

    The aim of this study was to provide proof-of-concept for quantitative and qualitative label-free detection of immune complexes through myeloid cells with imaging surface plasmon resonance. Surface plasmon resonance imaging was first applied to monitor the binding of human sera from healthy and rheumatoid arthritis (RA) patients to immobilized citrullinated RA-specific peptide antigens, histone citrullinated peptide 2 (HCP2) and viral citrullinated peptide 2 (VCP2). Next, the binding of monocytoid cell line U937 to the resulting immune complexes on the sensor surface was monitored. As control, binding of U937 was monitored to immunoglobulin (Ig)G subclasses simultaneously. Cell response results were compared to results of cyclic citrullinated peptide 2 (CCP2) enzyme-linked immunosorbent assay (ELISA), clinical RA diagnosis and antigen-specific antibody distribution of the samples. Human IgG3 triggered the most pronounced response, followed by IgG1 and IgG4, while IgG2 did not result in U937 cell binding. Serum samples obtained from RA patients resulted in a significantly increased cell response to VCP2 compared to healthy controls. The strength of cell response towards VCP2 immune complexes showed significant correlation with levels of antigen-specific IgA, IgG and IgG3. Cellular responses on VCP2 immune complexes showed significant association with both CCP2-based serological positivity and European League Against Rheumatism (EULAR) criteria-based clinical RA diagnosis. Immunoglobulin-triggered binding of monocytoid cells can be monitored using a label-free multiplex technology. Because these binding events are presumably initiated by Fc receptors, the system provides a tool for biological detection of autoantibodies with diagnostic value, here exemplified by anti-citrullinated antibodies. This provides added information to antibody levels, as interaction with Fc-receptor-expressing cells is also affected by post-translational modification of the immunoglobulins

  7. Myeloid Dendritic Cells (DCs) of Mice Susceptible to Paracoccidioidomycosis Suppress T Cell Responses whereas Myeloid and Plasmacytoid DCs from Resistant Mice Induce Effector and Regulatory T Cells

    PubMed Central

    Pina, Adriana; Frank de Araujo, Eliseu; Felonato, Maíra; Loures, Flávio V.; Feriotti, Claudia; Bernardino, Simone; Barbuto, José Alexandre M.

    2013-01-01

    The protective adaptive immune response in paracoccidioidomycosis, a mycosis endemic among humans, is mediated by T cell immunity, whereas impaired T cell responses are associated with severe, progressive disease. The early host response to Paracoccidioides brasiliensis infection is not known since the disease is diagnosed at later phases of infection. Our laboratory established a murine model of infection where susceptible mice reproduce the severe disease, while resistant mice develop a mild infection. This work aimed to characterize the influence of dendritic cells in the innate and adaptive immunity of susceptible and resistant mice. We verified that P. brasiliensis infection induced in bone marrow-derived dendritic cells (DCs) of susceptible mice a prevalent proinflammatory myeloid phenotype that secreted high levels of interleukin-12 (IL-12), tumor necrosis factor alpha, and IL-β, whereas in resistant mice, a mixed population of myeloid and plasmacytoid DCs secreting proinflammatory cytokines and expressing elevated levels of secreted and membrane-bound transforming growth factor β was observed. In proliferation assays, the proinflammatory DCs from B10.A mice induced anergy of naïve T cells, whereas the mixed DC subsets from resistant mice induced the concomitant proliferation of effector and regulatory T cells (Tregs). Equivalent results were observed during pulmonary infection. The susceptible mice displayed preferential expansion of proinflammatory myeloid DCs, resulting in impaired proliferation of effector T cells. Conversely, the resistant mice developed myeloid and plasmacytoid DCs that efficiently expanded gamma interferon-, IL-4-, and IL-17-positive effector T cells associated with increased development of Tregs. Our work highlights the deleterious effect of excessive innate proinflammatory reactions and provides new evidence for the importance of immunomodulation during pulmonary paracoccidioidomycosis. PMID:23340311

  8. Green tea polyphenol epigallocatechin-O-gallate induces cell death by acid sphingomyelinase activation in chronic myeloid leukemia cells.

    PubMed

    Huang, Yuhui; Kumazoe, Motofumi; Bae, Jaehoon; Yamada, Shuhei; Takai, Mika; Hidaka, Shiori; Yamashita, Shuya; Kim, Yoonhee; Won, Yeongseon; Murata, Motoki; Tsukamoto, Shuntaro; Tachibana, Hirofumi

    2015-09-01

    An epidemiological study showed that green tea consumption is associated with a reduced risk of hematopoietic malignancy. The major green tea polyphenol epigallocatechin‑3-O-gallate (EGCG) is reported to have anticancer effects. Chronic myeloid leukemia (CML) is a major hematopoietic malignancy characterized by expansion of myeloid cells. In the present study, we showed EGCG-induced acid sphingomyelinase (ASM) activation and lipid raft clustering in CML cells. The ASM inhibitor desipramine significantly reduced EGCG-induced cell death. Protein kinase Cδ is a well‑known kinase that plays an important role in ASM activation. We observed EGCG-induced phosphorylation of protein kinase Cδ at Ser664. Importantly, EGCG-induced ASM activation was significantly reduced by pretreatment of CML cells with the soluble guanylate cyclase inhibitor NS2028, suggesting that EGCG induced ASM activation through the cyclic guanosine monophosphate (cGMP)-dependent pathway. Indeed, pharmacological inhibition of a cGMP-negative regulator enhanced the anti-CML effect of EGCG. These results indicate that EGCG-induced cell death via the cGMP/ASM pathway in CML cells. PMID:26135316

  9. Green tea polyphenol epigallocatechin-O-gallate induces cell death by acid sphingomyelinase activation in chronic myeloid leukemia cells

    PubMed Central

    HUANG, YUHUI; KUMAZOE, MOTOFUMI; BAE, JAEHOON; YAMADA, SHUHEI; TAKAI, MIKA; HIDAKA, SHIORI; YAMASHITA, SHUYA; KIM, YOONHEE; WON, YEONGSEON; MURATA, MOTOKI; TSUKAMOTO, SHUNTARO; TACHIBANA, HIROFUMI

    2015-01-01

    An epidemiological study showed that green tea consumption is associated with a reduced risk of hematopoietic malignancy. The major green tea polyphenol epigallocatechin-3-O-gallate (EGCG) is reported to have anticancer effects. Chronic myeloid leukemia (CML) is a major hematopoietic malignancy characterized by expansion of myeloid cells. In the present study, we showed EGCG-induced acid sphingomyelinase (ASM) activation and lipid raft clustering in CML cells. The ASM inhibitor desipramine significantly reduced EGCG-induced cell death. Protein kinase Cδ is a well-known kinase that plays an important role in ASM activation. We observed EGCG-induced phos-phorylation of protein kinase Cδ at Ser664. Importantly, EGCG-induced ASM activation was significantly reduced by pretreatment of CML cells with the soluble guanylate cyclase inhibitor NS2028, suggesting that EGCG induced ASM activation through the cyclic guanosine monophosphate (cGMP)-dependent pathway. Indeed, pharmacological inhibition of a cGMP-negative regulator enhanced the anti-CML effect of EGCG. These results indicate that EGCG-induced cell death via the cGMP/ASM pathway in CML cells. PMID:26135316

  10. Myeloid suppressor cells and immune modulation in lung cancer

    PubMed Central

    Srivastava, Minu K.; Andersson, Åsa; Zhu, Li; Harris-White, Marni; Lee, Jay M.; Dubinett, Steven; Sharma, Sherven

    2012-01-01

    Many tumors, including lung cancers, promote immune tolerance to escape host immune surveillance and facilitate tumor growth. Tumors utilize numerous pathways to inhibit immune responses, including the elaboration of immune-suppressive mediators such as PGE2, TGF-β, IL-10, VEGF, GM-CSF, IL-6, S100A8/A9 and SCF, which recruit and/or activate myeloid-derived suppressor cells (MDSCs). MDSCs, a subset of heterogeneous bone marrow-derived hematopoietic cells, are found in the peripheral blood of cancer patients and positively correlate to malignancy. Solid tumors contain MDSCs that maintain an immune-suppressive network in the tumor microenvironment. This review will focus on the interaction of tumors with MDSCs that lead to dysregulation of antigen presentation and T-cell activities in murine tumor models. Specific genetic signatures in lung cancer modulate the activities of MDSCs and impact tumor progression. Targeting MDSCs may have a long-term antitumor benefit and is at the forefront of anticancer therapeutic strategies. PMID:22401635

  11. Human cytomegalovirus tropism for mucosal myeloid dendritic cells

    PubMed Central

    Hertel, Laura

    2014-01-01

    SUMMARY Human CMV infections are a serious source of morbidity and mortality for immunocompromised patients and for the developing fetus. Because of this, the development of new strategies to prevent CMV acquisition and transmission is a top priority. Myeloid dendritic cells (DC) residing in the oral and nasal mucosae are among the first immune cells to encounter CMV during entry, and greatly contribute to virus dissemination, reactivation from latency, and horizontal spread. Albeit affected by the immunoevasive tactics of CMV, mucosal DC remain potent inducers of cellular and humoral immune responses against this virus. Their natural functions could thus be exploited to generate long-lasting protective immunity against CMV by vaccination via the oro-nasal mucosae. Although related, epithelial Langerhans-type DC (LC) and dermal monocyte-derived DC (MDDC) interact with CMV in dramatically different ways. While immature MDDC are fully permissive to infection, for instance, immature LC are completely resistant. Understanding these differences is essential to design innovative vaccines and new antiviral compounds to protect these cells from CMV infection in vivo. PMID:24888709

  12. Tumoral NKG2D alters cell cycle of acute myeloid leukemic cells and reduces NK cell-mediated immune surveillance.

    PubMed

    Tang, Mingying; Acheampong, Desmond Omane; Wang, Youfu; Xie, Wei; Wang, Min; Zhang, Juan

    2016-06-01

    The stimulatory natural killer group 2 member D (NKG2D) lymphocyte receptor, initially discovered and expressed mostly on natural killer (NK) cells, T cells and natural killer T cells, can promote tumor immune surveillance. However, with increasing tumor grade, tumors themselves express NKG2D to self-stimulate oncogenic pathways. To confirm that cancer cells themselves express NKG2D, we have now investigated the role of the tumoral NKG2D in NK cell-mediated immune surveillance. Both anti-NKG2D and shRNA to that down-regulated tumoral NKG2D increased the number of cells in G1 phase and S phase, increased the expression of cyclin E-CDK2 and decreased P21. In addition, CD107a, IFN-γ and TNF-α increased when the cells were treated with anti-NKG2D which suggests that blocking tumoral NKG2D could augment tumor surveillance of NK cells. Altogether, tumoral NKG2D stimulates cell propagation and immune escape in acute myeloid leukemia cells. PMID:26740330

  13. Targeting survival pathways in chronic myeloid leukaemia stem cells

    PubMed Central

    Sinclair, A; Latif, A L; Holyoake, T L

    2013-01-01

    Chronic myeloid leukaemia (CML) is a clonal myeloproliferative disorder characterized by the presence of a fusion oncogene BCR-ABL, which encodes a protein with constitutive TK activity. The implementation of tyrosine kinase inhibitors (TKIs) marked a major advance in CML therapy; however, there are problems with current treatment. For example, relapse occurs when these drugs are discontinued in the majority of patients who have achieved a complete molecular response on TKI and these agents are less effective in patients with mutations in the BCR-ABL kinase domain. Importantly, TKI can effectively target proliferating mature cells, but do not eradicate quiescent leukaemic stem cells (LSCs), therefore allowing disease persistence despite treatment. It is essential that alternative strategies are used to target the LSC population. BCR-ABL activation is responsible for the modulation of different signalling pathways, which allows the LSC fraction to evade cell death. Several pathways have been shown to be modulated by BCR-ABL, including PI3K/AKT/mTOR, JAK-STAT and autophagy signalling pathways. Targeting components of these survival pathways, alone or in combination with TKI, therefore represents an attractive potential therapeutic approach for targeting the LSC. However, many pathways are also active in normal stem cells. Therefore, potential targets must be validated to effectively eradicate CML stem cells while sparing normal counterparts. This review summarizes the main pathways modulated in CML stem cells, the recent developments and the use of novel drugs to target components in these pathways which may be used to target the LSC population. Linked Articles This article is part of a themed section on Emerging Therapeutic Aspects in Oncology. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2013.169.issue-8 PMID:23517124

  14. GATA2 regulates dendritic cell differentiation.

    PubMed

    Onodera, Koichi; Fujiwara, Tohru; Onishi, Yasushi; Itoh-Nakadai, Ari; Okitsu, Yoko; Fukuhara, Noriko; Ishizawa, Kenichi; Shimizu, Ritsuko; Yamamoto, Masayuki; Harigae, Hideo

    2016-07-28

    Dendritic cells (DCs) are critical immune response regulators; however, the mechanism of DC differentiation is not fully understood. Heterozygous germ line GATA2 mutations induce GATA2-deficiency syndrome, characterized by monocytopenia, a predisposition to myelodysplasia/acute myeloid leukemia, and a profoundly reduced DC population, which is associated with increased susceptibility to viral infections, impaired phagocytosis, and decreased cytokine production. To define the role of GATA2 in DC differentiation and function, we studied Gata2 conditional knockout and haploinsufficient mice. Gata2 conditional deficiency significantly reduced the DC count, whereas Gata2 haploinsufficiency did not affect this population. GATA2 was required for the in vitro generation of DCs from Lin(-)Sca-1(+)Kit(+) cells, common myeloid-restricted progenitors, and common dendritic cell precursors, but not common lymphoid-restricted progenitors or granulocyte-macrophage progenitors, suggesting that GATA2 functions in the myeloid pathway of DC differentiation. Moreover, expression profiling demonstrated reduced expression of myeloid-related genes, including mafb, and increased expression of T-lymphocyte-related genes, including Gata3 and Tcf7, in Gata2-deficient DC progenitors. In addition, GATA2 was found to bind an enhancer element 190-kb downstream region of Gata3, and a reporter assay exhibited significantly reduced luciferase activity after adding this enhancer region to the Gata3 promoter, which was recovered by GATA sequence deletion within Gata3 +190. These results suggest that GATA2 plays an important role in cell-fate specification toward the myeloid vs T-lymphocyte lineage by regulating lineage-specific transcription factors in DC progenitors, thereby contributing to DC differentiation. PMID:27259979

  15. Bisphenol A (BPA) stimulates the interferon signaling and activates the inflammasome activity in myeloid cells.

    PubMed

    Panchanathan, Ravichandran; Liu, Hongzhu; Leung, Yuet-Kin; Ho, Shuk-mei; Choubey, Divaker

    2015-11-01

    Environmental factors contribute to the development of autoimmune diseases, including systemic lupus erythematosus (SLE), which exhibits a strong female bias (female-to-male ratio 9:1). However, the molecular mechanisms remain largely unknown. Because a feedforward loop between the female sex hormone estrogen (E2) and type I interferon (IFN-α/β)-signaling induces the expression of certain p200-family proteins (such as murine p202 and human IFI16) that regulate innate immune responses and modify lupus susceptibility, we investigated whether treatment of myeloid cells with bisphenol A (BPA), an environmental estrogen, could regulate the p200-family proteins and activate innate immune responses. We found that treatment of murine bone marrow-derived cells (BMCs) and human peripheral blood mononuclear cells with BPA induced the expression of ERα and IFN-β, activated the IFN-signaling, and stimulated the expression of the p202 and IFI16 proteins. Further, the treatment increased levels of the NLRP3 inflammasome and stimulated its activity. Accordingly, BPA-treatment of BMCs from non lupus-prone C57BL/6 and the lupus-prone (NZB×NZW)F1 mice activated the type I IFN-signaling, induced the expression of p202, and activated an inflammasome activity. Our study demonstrates that BPA-induced signaling in the murine and human myeloid cells stimulates the type I IFN-signaling that results in an induction of the p202 and IFI16 innate immune sensors for the cytosolic DNA and activates an inflammasome activity. These observations provide novel molecular insights into the role of environmental BPA exposures in potentiating the development of certain autoimmune diseases such as SLE. PMID:26277401

  16. Myeloid-derived suppressor cells in patients with myeloproliferative neoplasm.

    PubMed

    Wang, Jen Chin; Kundra, Ajay; Andrei, Mirela; Baptiste, Stacey; Chen, Chi; Wong, Ching; Sindhu, Hemant

    2016-04-01

    Although BCR-ABL negative myeloproliferative neoplasms (MPN)--and especially myelofibrosis (MF)--are recognized to be associated with autoimmune phenomena, immune derangements in MPN have been much less studied. Myeloid-derived suppressor cells (MDSC) are one type of important immune modulator cell. Therefore, we studied MDSCs in MPN disease. MDSCs were studied in two cohorts: the first cohort was 55 patients including 16 primary myelofibrosis (PMF), 7 post-polycythemia vera (PV)-MF, 2 post-essential thrombocythemia (ET)-MF, 11 ET, 17 PV, 2 undefined MPN disorder, and 23 normal controls; the second cohort included 38 patients: 17 ET, 7 PMF, 3 ET-MF, 2 PV-MF, 9 PV patients, and 20 normal volunteers. The second cohort was studied using freshly collected specimens and a comparable age group as controls. CD11b(+), CD14(-), and CD33(+) cells were defined as MDSCs in both cohorts by flow cytometry. Since there are no differences in MDSC levels among different MPN categories, they were grouped as MPNs. The results showed that MDSCs were significantly elevated in MPNs compared with controls in both cohorts. We also performed RT-PCR and found that MPN patients have significantly elevated arginase-1 mRNA compared with controls, and sorted MDSCs were found to have suppressor T cell activity in MPNs, substantiating the hypothesis that levels of MDSCs are, in fact, deranged in MPNs. MDSC levels were not correlated with JAK2 status, white blood cells, Hb levels, platelet counts, splenomegaly, or the degree of bone marrow fibrosis (in MF). Further studies in immune therapy involving MDSC inhibitors or differentiation may be developed to treat MPN disease. PMID:26943702

  17. β-Arrestin1 promotes the progression of chronic myeloid leukaemia by regulating BCR/ABL H4 acetylation

    PubMed Central

    Qin, R; Li, K; Qi, X; Zhou, X; Wang, L; Zhang, P; Zou, L

    2014-01-01

    Background: β-Arrestins are scaffold proteins that interact with various cellular signals. Although β-arrestin2 mediates the initiation and progression of myeloid leukaemia, the critical role of β-arrestin1 in the chronic myeloid leukaemia (CML) is still unknown. The aim of this study is to investigate the essential function of β-arrestin1 in CML. Methods: The expressions of β-arrestin1 and BCR/ABL in CML patients, animal models and K562 cells were measured by RT–PCR, immunofluorescence and western blotting. The effect of β-arrestin1 on CML animal models and K562 cells by colony formation, MTT and survival analysis were assessed. BCR/ABL H4 acetylation was analysed through the use of Chromatin-immunoprecipitation (ChIP) -on-chip and confirmed by ChIP respectively. Co-immunoprecipitation and confocal were examined for the binding of β-arrestin1 with enhancer of zeste homologue 2 (EZH2). Results: The higher expression of β-arrestin1 is positively correlated with clinical phases of CML patients. Depletion of β-arrestin1 decelerates progression of K562 and primary cells, and increases survival of CML mice. Importantly, silenced β-arrestin1 results in the decrease of BCR/ABL H4 acetylation level in K562 cells. Further data illustrate that nuclear β-arrestin1 binds to EZH2 to mediate BCR/ABL acetylation and thus regulates cell progression in K562 cells and the survival of CML mice. Conclusions: Our findings reveal a novel function of β-arrestin1 binding to EZH2 to promote CML progression by regulating BCR/ABL H4 acetylation. PMID:24937675

  18. Extracellular vesicle miR-7977 is involved in hematopoietic dysfunction of mesenchymal stromal cells via poly(rC) binding protein 1 reduction in myeloid neoplasms

    PubMed Central

    Horiguchi, Hiroto; Kobune, Masayoshi; Kikuchi, Shohei; Yoshida, Masahiro; Murata, Masaki; Murase, Kazuyuki; Iyama, Satoshi; Takada, Kohichi; Sato, Tsutomu; Ono, Kaoru; Hashimoto, Akari; Tatekoshi, Ayumi; Kamihara, Yusuke; Kawano, Yutaka; Miyanishi, Koji; Sawada, Norimasa; Kato, Junji

    2016-01-01

    The failure of normal hematopoiesis is observed in myeloid neoplasms. However, the precise mechanisms governing the replacement of normal hematopoietic stem cells in their niche by myeloid neoplasm stem cells have not yet been clarified. Primary acute myeloid leukemia and myelodysplastic syndrome cells induced aberrant expression of multiple hematopoietic factors including Jagged-1, stem cell factor and angiopoietin-1 in mesenchymal stem cells even in non-contact conditions, and this abnormality was reverted by extracellular vesicle inhibition. Importantly, the transfer of myeloid neoplasm-derived extracellular vesicles reduced the hematopoietic supportive capacity of mesenchymal stem cells. Analysis of extracellular vesicle microRNA indicated that several species, including miR-7977 from acute myeloid leukemia cells, were higher than those from normal CD34+ cells. Remarkably, the copy number of miR-7977 in bone marrow interstitial fluid was elevated not only in acute myeloid leukemia, but also in myelodysplastic syndrome, as compared with lymphoma without bone marrow localization. The transfection of the miR-7977 mimic reduced the expression of the posttranscriptional regulator, poly(rC) binding protein 1, in mesenchymal stem cells. Moreover, the miR-7977 mimic induced aberrant reduction of hematopoietic growth factors in mesenchymal stem cells, resulting in decreased hematopoietic-supporting capacity of bone marrow CD34+ cells. Furthermore, the reduction of hematopoietic growth factors including Jagged-1, stem cell factor and angiopoietin-1 were reverted by target protection of poly(rC) binding protein 1, suggesting that poly(rC) binding protein 1 could be involved in the stabilization of several growth factors. Thus, miR-7977 in extracellular vesicles may be a critical factor that induces failure of normal hematopoiesis via poly(rC) binding protein 1 suppression. PMID:26802051

  19. Enhanced Generation of Myeloid Lineages in Hematopoietic Differentiation from Embryonic Stem Cells by Silencing Transcriptional Repressor Twist-2

    PubMed Central

    Sharabi, Andrew B.; Lee, Sung-Hyung; Goodell, Margaret A.; Huang, Xue F.

    2009-01-01

    Abstract The self-renewal and multilineage differentiation of embryonic stem cells (ESC) is largely governed by transcription factors or repressors. Extensive efforts have focused on elucidating critical factors that control the differentiation of specific cell lineages, for instance, myeloid lineages in hematopoietic development. In this study, we found that Twist-2, a basic helix-loop-helix (bHLH) transcription factor, plays a critical role in inhibiting the differentiation of ESC. Murine ES cells, in which Twist-2 expression is silenced by lentivirally delivered shRNA, exhibit an enhanced formation of primary embryoid bodies (EB) and enhanced differentiation into mesodermally derived hematopoietic colonies. Furthermore, Twist-2 silenced (LV-siTwist-2) ESC display significantly increased generation of myeloid lineages (Gr-1+ and F4/80+ cells) during in vitro hematopoietic differentiation. Treatment with the Toll-like receptor (TLR) 4 ligand synergistically stimulates the generation of primary EB formation as well as of hematopoietic progenitors differentiated from LV-siTwist-2 ES cells. Thus, this study reveals the critical role of the transcriptional repressor Twist-2 in regulating the development of myeloid lineage in hematopoietic differentiation from ESC. This study also suggests a potential strategy for directional differentiation of ESC by inhibiting a transcriptional repressor. PMID:20025523

  20. Reduction of Myeloid-derived Suppressor Cells and Lymphoma Growth by a Natural Triterpenoid

    PubMed Central

    Radwan, Faisal F. Y.; Hossain, Azim; God, Jason M.; Leaphart, Nathan; Elvington, Michelle; Nagarkatti, Mitzi; Tomlinson, Stephen; Haque, Azizul

    2016-01-01

    Lymphoma is a potentially life threatening disease. The goal of this study was to investigate the therapeutic potential of a natural triterpenoid, Ganoderic acid A (GA-A) in controlling lymphoma growth both in vitro and in vivo. Here, we show that GA-A treatment induces caspase-dependent apoptotic cell death characterized by a dose-dependent increase in active caspases 9 and 3, up-regulation of pro-apoptotic BIM and BAX proteins, and a subsequent loss of mitochondrial membrane potential with release of cytochrome c. In addition to GA-A’s anti-growth activity, we show that lower doses of GA-A enhance HLA class II-mediated antigen presentation and CD4+ T cell recognition of lymphoma in vitro. The therapeutic relevance of GA-A treatment was also tested in vivo using the EL4 syngeneic mouse model of metastatic lymphoma. GA-A-treatment significantly prolonged survival of EL4 challenged mice and decreased tumor metastasis to the liver, an outcome accompanied by a marked down-regulation of STAT3 phosphorylation, reduction myeloid-derived suppressor cells (MDSCs), and enhancement of cytotoxic CD8+ T cells in the host. Thus, GA-A not only selectively induces apoptosis in lymphoma cells, but also enhances cell-mediated immune responses by attenuating MDSCs, and elevating Ag presentation and T cell recognition. The demonstrated therapeutic benefit indicates that GA-A is a candidate for future drug design for the treatment of lymphoma. PMID:25142864

  1. Spred2 is involved in imatinib-induced cytotoxicity in chronic myeloid leukemia cells

    SciTech Connect

    Liu, Xiao-Yun; Yang, Yue-Feng; Wu, Chu-Tse; Xiao, Feng-Jun; Zhang, Qun-Wei; Ma, Xiao-Ni; Li, Qing-Fang; Yan, Jun; Wang, Hua; Wang, Li-Sheng

    2010-03-19

    Spreds, a recently established class of negative regulators of the Ras-ERK (extracellular signal-regulated kinase) pathway, are involved in hematogenesises, allergic disorders and tumourigenesis. However, their role in hematologic neoplasms is largely unknown. Possible effects of Spreds on other signal pathways closely related to Ras-ERK have been poorly investigated. In this study, we investigated the in vitro effects of Spred2 on chronic myeloid leukemia (CML) cells. In addition to inhibiting the well-established Ras-ERK cascade, adenovirus-mediated Spred2 over-expression inhibits constitutive and stem cell factor (SCF)-stimulated sphingosine kinase-1 (SPHK1) and Mcl-1 expression, as well as inhibiting proliferation and inducing apoptosis in CML cells. In K562 cells and primary CML cells, imatinib induces endogenous Spred2 expression. Spred2 silencing by stable RNA interference partly protects K562 cells against imatinib-induced apoptosis. Together, these data implicate Spred2 in imatinib-induced cytotoxicity in CML cells, possibly by inhibiting the Ras-ERK cascade and the pro-survival signaling molecules SPHK1 and Mcl-1. These findings reveal potential targets for selective therapy of CML.

  2. Hampering the Immune Suppressors: Therapeutic Targeting of Myeloid-Derived Suppressor Cells (MDSC) in Cancer

    PubMed Central

    Albeituni, Sabrin Husein; Ding, Chuanlin; Yan, Jun

    2014-01-01

    Myeloid-derived suppressor cells (MDSC) are a heterogeneous population of immature myeloid cells with suppressive properties that preferentially expand in cancer. MDSC mainly suppress T cell proliferation and cytotoxicity, inhibit NK cell activation, and induce the differentiation and expansion of regulatory T cells (Tregs). The wide spectrum of MDSC suppressive activity in cancer and its role in tumor progression have rendered these cells a promising target for effective cancer immunotherapy. In this review we briefly discuss the origin of MDSC and their main mechanisms of suppression and focus more on the approaches developed up to date targeting of MDSC in tumor-bearing animals and cancer patients. PMID:24270348

  3. Pam2 lipopeptides systemically increase myeloid-derived suppressor cells through TLR2 signaling

    SciTech Connect

    Maruyama, Akira; Shime, Hiroaki Takeda, Yohei; Azuma, Masahiro; Matsumoto, Misako; Seya, Tsukasa

    2015-02-13

    Myeloid-derived suppressor cells (MDSCs) are immature myeloid cells that exhibit potent immunosuppressive activity. They are increased in tumor-bearing hosts and contribute to tumor development. Toll-like receptors (TLRs) on MDSCs may modulate the tumor-supporting properties of MDSCs through pattern-recognition. Pam2 lipopeptides represented by Pam2CSK4 serve as a TLR2 agonist to exert anti-tumor function by dendritic cell (DC)-priming that leads to NK cell activation and cytotoxic T cell proliferation. On the other hand, TLR2 enhances tumor cell progression/invasion by activating tumor-infiltrating macrophages. How MDSCs respond to TLR2 agonists has not yet been determined. In this study, we found intravenous administration of Pam2CSK4 systemically up-regulated the frequency of MDSCs in EG7 tumor-bearing mice. The frequency of tumor-infiltrating MDSCs was accordingly increased in response to Pam2CSK4. MDSCs were not increased by Pam2CSK4 stimuli in TLR2 knockout (KO) mice. Adoptive transfer experiments using CFSE-labeled MDSCs revealed that the TLR2-positive MDSCs survived long in tumor-bearing mice in response to Pam2CSK4 treatment. Since the increased MDSC population sustained immune-suppressive properties, our study suggests that Pam2CSK4-triggered TLR2 activation enhances the MDSC potential and suppress antitumor immune response in tumor microenvironment. - Highlights: • Pam2CSK4 administration induces systemic accumulation of CD11b{sup +}Gr1{sup +} MDSCs. • TLR2 is essential for Pam2CSK4-induced accumulation of CD11b{sup +}Gr1{sup +} MDSCs. • Pam2CSK4 supports survival of CD11b{sup +}Gr1{sup +} MDSCs in vivo.

  4. Diminished immune response to vaccinations in obesity: role of myeloid-derived suppressor and other myeloid cells.

    PubMed

    Chen, Shiyi; Akbar, Sheikh Mohammad Fazle; Miyake, Teruki; Abe, Masanori; Al-Mahtab, Mamun; Furukawa, Shinya; Bunzo, Matsuura; Hiasa, Yoichi; Onji, Morikazu

    2015-01-01

    Obesity is a chronic inflammatory condition associated with an increased production of cytokines and exacerbated immune response. However, obese subjects are susceptible to infections and respond poorly to vaccines. This study evaluated the immune responses of obese mice and the underlying mechanisms by exploring the roles of myeloid cells. Diet-induced obese (DIO) mice were prepared from C57BL/6J mice fed a high-calorie and high-fat diet for 12 weeks. Humoral and cellular immune responses of DIO mice to a hepatitis B vaccine containing the hepatitis B surface antigen (HBsAg) were assessed in sera and via a lymphoproliferative assay, respectively. The effects of CD11b(+)GR1(+) myeloid-derived suppressor cells (MDSC) and CD11b(+)GR1(-) non-MDSC on T cell proliferation and cytokine production were compared via a cell culture system. The production of cytokines, expression of activation and exhaustion markers, and proportions of apoptotic T cells were estimated with flow cytometry. Increased T and B lymphocyte proliferation and higher interferon-γ and tumor necrosis factor-α levels were detected in spleen cells and liver non-parenchymal cell cultures of DIO mice compared to controls (p<0.05). However, antibody to HBsAg (anti-HBs) levels and HBsAg-specific T cell proliferation were significantly lower in DIO mice compared to controls (p<0.05). The addition of MDSC, but not non-MDSC, induced a decrease in HBsAg-specific T cell proliferation, lower cytokine production, decrease in T cell activation, and increase in T cell exhaustion and apoptosis (p<0.05). MDSC play an important role in mediating impaired antigen-specific immunity. PMID:25660173

  5. Laquinimod dampens hyperactive cytokine production in Huntington's disease patient myeloid cells.

    PubMed

    Dobson, Lucianne; Träger, Ulrike; Farmer, Ruth; Hayardeny, Liat; Loupe, Pippa; Hayden, Michael R; Tabrizi, Sarah J

    2016-06-01

    Huntington's disease (HD) is a neurodegenerative condition characterized by pathology in the brain and peripheral tissues. Hyperactivity of the innate immune system, due in part to NFκB pathway dysregulation, is an early and active component of HD. Evidence suggests targeting immune disruption may slow disease progression. Laquinimod is an orally active immunomodulator that down-regulates proinflammatory cytokine production in peripheral blood mononuclear cells, and in the brain down-regulates astrocytic and microglial activation by modulating NFκB signalling. Laquinimod had beneficial effects on inflammation, brain atrophy and disease progression in multiple sclerosis (MS) in two phase III clinical trials. This study investigated the effects of laquinimod on hyperactive proinflammatory cytokine release and NFκB signalling in HD patient myeloid cell cultures. Monocytes from manifest (manHD) and pre-manifest (preHD) HD gene carriers and healthy volunteers (HV) were treated with laquinimod and stimulated with lipopolysaccharide. After 24 h pre-treatment with 5 μM laquinimod, manHD monocytes released lower levels of IL-1β, IL-5, IL-8, IL-10, IL-13 and TNFα in response to stimulation. PreHD monocytes released lower levels of IL-8, IL-10 and IL-13, with no reduction observed in HV monocytes. The effects of laquinimod on dysfunctional NFκB signalling in HD was assessed by inhibitor of kappa B (IκB) degradation kinetics, nuclear translocation of NFκB and interactions between IκB kinase (IKK) and HTT, in HD myeloid cells. No differences were observed between laquinimod-treated and untreated conditions. These results provide evidence that laquinimod dampens hyper-reactive cytokine release from manHD and preHD monocytes, with a much reduced effect on HV monocytes. Evidence suggests targeting CNS and peripheral immune disruption may slow Huntington's disease (HD) neurodegenerative processes. The effects of laquinimod, an orally active immunomodulator, on

  6. Triggering Receptor Expressed on Myeloid Cells in Cutaneous Melanoma.

    PubMed

    Nguyen, Austin Huy; Koenck, Carleigh; Quirk, Shannon K; Lim, Victoria M; Mitkov, Mario V; Trowbridge, Ryan M; Hunter, William J; Agrawal, Devendra K

    2015-10-01

    The tumor microenvironment plays an important role in the progression of melanoma, the prototypical immunologic cutaneous malignancy. The triggering receptor expressed on myeloid cells (TREM) family of innate immune receptors modulates inflammatory and innate immune signaling. It has been investigated in various neoplastic diseases, but not in melanoma. This study examines the expression of TREM-1 (a proinflammatory amplifier) and TREM-2 (an anti-inflammatory modulator and phagocytic promoter) in human cutaneous melanoma and surrounding tissue. Indirect immunofluorescence staining was performed on skin biopsies from 10 melanoma patients and staining intensity was semiquantitatively scored. Expression of TREM-1 and TREM-2 was higher in keratinocytes than melanoma tissue (TREM-1: p < 0.01; TREM-2: p < 0.01). Whereas TREM-2 was the dominant isoform expressed in normal keratinocytes, TREM-1 expression predominated in melanoma tissue (TREM-1 to TREM-2 ratio: keratinocytes = 0.78; melanoma = 2.08; p < 0.01). The increased TREM ratio in melanoma tissue could give rise to a proinflammatory and protumor state of the microenvironment. This evidence may be suggestive of a TREM-1/TREM-2 paradigm in which relative levels dictate inflammatory and immune states, rather than absolute expression of one or the other. Further investigation regarding this paradigm is warranted and could carry prognostic or therapeutic value in treatment for melanoma. PMID:26184544

  7. Tetraspanin CD82 regulates bone marrow homing of acute myeloid leukemia by modulating the molecular organization of N-cadherin.

    PubMed

    Marjon, K D; Termini, C M; Karlen, K L; Saito-Reis, C; Soria, C E; Lidke, K A; Gillette, J M

    2016-08-01

    Communication between acute myeloid leukemia (AML) and the bone marrow microenvironment is known to control disease progression. Therefore, regulation of AML cell trafficking and adhesion to the bone marrow is of significant interest. In this study, we demonstrate that differential expression of the membrane scaffold CD82 modulates the bone marrow homing of AML cells. By combining mutational analysis and super-resolution imaging, we identify membrane protein clustering by CD82 as a regulator of AML cell adhesion and bone marrow homing. Cluster analysis of super-resolution data indicates that N-linked glycosylation and palmitoylation of CD82 are both critical modifications that control the microdomain organization of CD82 as well as the nanoscale clustering of associated adhesion protein, N-cadherin. We demonstrate that the inhibition of CD82 glycosylation increases the molecular packing of N-cadherin and promotes the bone marrow homing of AML cells. In contrast, we find that the inhibition of CD82 palmitoylation disrupts the formation and organization of N-cadherin clusters and significantly diminishes bone marrow trafficking of AML. Taken together, these data establish a mechanism where the membrane organization of CD82, through specific posttranslational modifications, regulates N-cadherin clustering and membrane density, which impacts the in vivo trafficking of AML cells. As such, these observations provide an alternative model for targeting AML where modulation of protein organization within the membrane may be an effective treatment therapy to disrupt the bone marrow homing potential of AML cells. PMID:26592446

  8. Tetraspanin CD82 regulates bone marrow homing of acute myeloid leukemia by modulating the molecular organization of N-cadherin

    PubMed Central

    Marjon, Kristopher D.; Termini, Christina M.; Karlen, Karin L.; Saito-Reis, Chelsea; Soria, Cesar E.; Lidke, Keith A.; Gillette, Jennifer M.

    2016-01-01

    Communication between acute myeloid leukemia (AML) and the bone marrow microenvironment is known to control disease progression. Therefore, regulation of AML cell trafficking and adhesion to the bone marrow is of significant interest. In this study, we demonstrate that differential expression of the membrane scaffold CD82 modulates the bone marrow homing of AML cells. By combining mutational analysis and super-resolution imaging, we identify membrane protein clustering by CD82 as a regulator of AML cell adhesion and bone marrow homing. Cluster analysis of super-resolution data indicates that N-linked glycosylation and palmitoylation of CD82 are both critical modifications that control the microdomain organization of CD82 as well as the nanoscale clustering of associated adhesion protein, N-cadherin. We demonstrate that inhibition of CD82 glycosylation increases the molecular packing of N-cadherin and promotes the bone marrow homing of AML cells. In contrast, we find that inhibition of CD82 palmitoylation disrupts the formation and organization of N-cadherin clusters and significantly diminishes bone marrow trafficking of AML. Taken together, these data establish a mechanism where the membrane organization of CD82, through specific post-translational modifications, regulates N-cadherin clustering and membrane density, which impacts the in vivo trafficking of AML cells. As such, these observations provide an alternative model for targeting AML where modulation of protein organization within the membrane may be an effective treatment therapy to disrupt the bone marrow homing potential of AML cells. PMID:26592446

  9. Elevated presence of myeloid dendritic cells in nasal polyps of patients with chronic rhinosinusitis

    PubMed Central

    Poposki, Julie A.; Peterson, Sarah; Welch, Kate; Schleimer, Robert P.; Hulse, Kathryn E.; Peters, Anju T.; Norton, James; Suh, Lydia A.; Carter, Roderick; Harris, Kathleen E.; Grammer, Leslie C.; Tan, Bruce K.; Chandra, Rakesh K.; Conley, David B.; Kern, Robert C.; Kato, Atsushi

    2015-01-01

    Background Although chronic rhinosinusitis with nasal polyps (CRSwNP) is characterized by Th2 inflammation, the mechanism underlying the onset and amplification of this inflammation has not been fully elucidated. Dendritic cells (DCs) are major antigen presenting cells, central inducers of adaptive immunity and critical regulators of many inflammatory diseases. However, the presence of DCs in CRS, especially in nasal polyps (NPs), has not been extensively studied. Objective The objective of this study was to characterize DC subsets in CRS. Methods We used real-time PCR to assess the expression of mRNA for markers of myeloid DCs (mDCs; CD1c), plasmacytoid DCs (pDCs; CD303) and Langerhans cells (LCs; CD1a, CD207) in uncinate tissue (UT) from controls and patients with CRS as well as in NP. We assayed the presence of DCs by immunohistochemistry and flow cytometry. Results Compared to UT from control subjects (n=15) and patients with CRS without NP (CRSsNP) (n=16) and CRSwNP (n=17), mRNAs for CD1a and CD1c were significantly elevated in NPs (n=29). In contrast, CD207 mRNA was not elevated in NPs. Immunohistochemistry showed that CD1c+ cells but not CD303+ cells were significantly elevated in NPs compared to control subjects or patients with CRSsNP. Flow cytometric analysis showed that CD1a+ cells in NPs might be a subset of mDC1s, and that CD45+CD19-CD1c+CD11c+CD141-CD303-HLA-DR+ mDC1s and CD45+CD19-CD11c+CD1c-CD141high mDC2s were significantly elevated in NPs compared to UT from controls and CRSsNP, but CD45+CD11c-CD303+HLA-DR+ pDCs were only elevated in NPs compared to control UT. Conclusion & Clinical Relevance Myeloid DCs are elevated in CRSwNP, especially in NPs. Myeloid DCs thus may indirectly contribute to the inflammation observed in CRSwNP. PMID:25469646

  10. Transcriptome-wide profiling and posttranscriptional analysis of hematopoietic stem/progenitor cell differentiation toward myeloid commitment.

    PubMed

    Klimmeck, Daniel; Cabezas-Wallscheid, Nina; Reyes, Alejandro; von Paleske, Lisa; Renders, Simon; Hansson, Jenny; Krijgsveld, Jeroen; Huber, Wolfgang; Trumpp, Andreas

    2014-11-11

    Hematopoietic stem cells possess lifelong self-renewal activity and generate multipotent progenitors that differentiate into lineage-committed and subsequently mature cells. We present a comparative transcriptome analysis of ex vivo isolated mouse multipotent hematopoietic stem/progenitor cells (Lin(neg)SCA-1(+)c-KIT(+)) and myeloid committed precursors (Lin(neg)SCA-1(neg)c-KIT(+)). Our data display dynamic transcriptional networks and identify a stem/progenitor gene expression pattern that is characterized by cell adhesion and immune response components including kallikrein-related proteases. We identify 498 expressed lncRNAs, which are potential regulators of multipotency or lineage commitment. By integrating these transcriptome with our recently reported proteome data, we found evidence for posttranscriptional regulation of processes including metabolism and response to oxidative stress. Finally, our study identifies a high number of genes with transcript isoform regulation upon lineage commitment. This in-depth molecular analysis outlines the enormous complexity of expressed coding and noncoding RNAs and posttranscriptional regulation during the early differentiation steps of hematopoietic stem cells toward the myeloid lineage. PMID:25418729