The Role of M2 Macrophage in Primary Immune Thrombocytopenia

Background: Primary immune thrombocytopenia (ITP) is an acquired autoimmune hemorrhagic disorder, characterized by immune-mediated platelet destruction and impaired megakaryocyte maturation. Although impaired T cells have been implicated to participate in the pathogenesis of ITP, another immune cell signified as M2 macrophages has not been investigated properly in ITP patients. This study aimed to investigate the role of M2 macrophage subsets in primary immune thrombocytopenia (ITP). Methods: Peripheral blood mononuclear cells (PBMC) from newly diagnosed ITP patients and healthy controls (HC) were isolated. M2-like macrophages (CD68+CD163+) and M2 macrophages (CX3CR1+CD163+) were measured by flow cytometry. The correlation between CD68+CD163+ cells and CX3CR1+CD163+ cells was also analyzed. The CX3CR1+cells were sorted by magnetic bead, CD68+CD163+ in PBMC of ITP patients and healthy controls were then isolated, and the proportion of m2-like macrophages before and after the sorting was analyzed. The PPAR gamma and arg-1 levels of mRNAs and proteins of CX3CR1+ M2 macrophages were examined by Real-time PCR and Western Blot, respectively. Results: CX3CR1+CD163+M2 macrophages were positively correlated with CD68+ CD163+ M2-like macrophages in ITP patients (r = 0.54, p < 0.01). After magnetic bead separation, the proportion of CD68+CD163+ cells in CX3CR1+ cells was significantly increased (p = 0.02). Compared with HC, both the mRNA and protein levels of arg-1 of CX3CR1+ M2 macrophages were significantly increased in patients with ITP. The expression level of PPAR gamma protein was significantly increased in ITP than that of HC. However no statistical difference was detected at mRNA expression level, although it was numerically higher in ITP patients than in HC ( p = 0.19). Conclusion: The peripheral CX3CR1+ M2 macrophage exercises similar phenotypes and functions of M2 macrophage. The remarkably increased expression of arg-1 at both transcription and protein levels and PPAR gamma at protein level of CX3CR1+M2 macrophages in ITP patients suggests potential immunomodulatory functions of these macrophage subsets during ITP pathogenesis. However, no significant change at mRNA level of PPAR gamma indicating that the increased PPAR gamma protein level might be caused by other mechanisms, such as after transcription abnormalities, which warrants further investigation. Disclosures No relevant conflicts of interest to declare.

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Interleukin (IL)-1 family cytokine in primary immune thrombocytopenia: a comparison with systemic lupus erythematosus-associated thrombocytopenia

10.21203/rs.3.rs-17605/v1 ◽

2020 ◽

Author(s):

Yanxia Zhan ◽

Boting Wu ◽

Chanjuan liu ◽

Luya Cheng ◽

Lili Ji ◽

...

Keyword(s):

Systemic Lupus Erythematosus ◽

Platelet Count ◽

Lupus Erythematosus ◽

Immune Thrombocytopenia ◽

Serum Levels ◽

Healthy Controls ◽

Systemic Lupus ◽

Primary Immune Thrombocytopenia ◽

Polymerase Chain

Abstract Background : Primary immune thrombocytopenia (ITP) is an autoimmune-mediated disorder characterized by decreased platelet count. Systemic lupus erythematosus (SLE) is also an autoimmune disease which thrombocytopenia is a common hematologic manifestation. Interleukin (IL)-1 family cytokines are major proinflammatory and immunoregulatory mediators. This study aimed to investigate the role of IL-1 cytokines in patients with ITP and SLE and the potential pathophysiologic mechanism to differentiate SLE-associated thrombocytopenia (SLE-TP) from ITP. Methods : Multiplex cytokine assay and real-time polymerase chain reaction (RT-PCR) were used to measure the IL-1 cytokines in 17 newly diagnosed ITP patients, 17 SLE-TP patients, 19 SLE patients without thrombocytopenia (SLE-NTP) and 10 healthy controls. Results : The serum levels of IL-1β, IL-18, IL-36α, IL-36β, IL-36γ and IL-33 were decreased significantly in ITP patients as compared with SLE-TP, SLE-NTP patients and healthy controls ( p <0.05). There was no significantly difference in the serum level of IL-37 between ITP and SLE-TP patients, however, there is a positive correlation between platelet count with IL-37 level in ITP patients. Our data suggested that serum IL-1β, IL-18, IL-36α, IL-36β, IL-36γ, IL-33 and IL-37 were involved in the pathogenesis of ITP. Conclusions : Serum IL-1β, IL-18, IL-36α, IL-36β, IL-36γ and IL-33 could be considered biomarkers to differentiate SLE-TP from ITP patients.

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MicroRNA expression profile in Treg cells in the course of primary immune thrombocytopenia

Journal of Investigative Medicine ◽

10.1136/jim-2019-001020 ◽

2019 ◽

Vol 67 (8) ◽

pp. 1118-1124 ◽

Cited By ~ 4

Author(s):

Yuandong Zhu ◽

Huan Zhu ◽

Xiaobao Xie ◽

Zhuojun Zheng ◽

Yun Ling

Keyword(s):

Expression Profile ◽

Mirna Expression ◽

Immune Thrombocytopenia ◽

Magnetic Bead ◽

Treg Cells ◽

Mirna Expression Profile ◽

Healthy Controls ◽

Loss Of Function ◽

Real Time Quantitative Pcr ◽

Primary Immune Thrombocytopenia

Primary immune thrombocytopenia (ITP) is an autoimmune bleeding disorder which characterizes with platelet production impairment and platelet destruction increment. CD4+CD25+Foxp3+ Treg cells (Tregs) are involved in the immune pathogenesis of ITP. MicroRNAs (miRNAs) are also involved in ITP and their loss of function is shown to facilitate immune disorders. Thus, the miRNA expression profile in Tregs from ITP was analyzed in this study. We assessed the genome-wide miRNA expression profile of three newly diagnosed adult patients with ITP and three healthy controls using microarray analysis of CD4+CD25+CD127dim/− Tregs that were sorted using an immune magnetic bead kit. The miRNA microarray chip was based on miRBase 18.0 and Volcano Plot filtering software used to analyze the miRNA profile in Tregs. Distinct miRNA expression was further validated by fluorescence-based real-time quantitative PCR (qPCR). We found that 502 human miRNAs were differentially expressed (244 upregulated and 258 downregulated) in patients with ITP compared with healthy donors. We identified 37 miRNAs expressed significantly, including 26 upregulated and 11 downregulated. Among the deregulated miRNAs, three downregulated miRNAs including miR-155–5p, miR-146b-5p, and miR-142–3p were selected for qPCR verification. We confirmed that miR-155–5p, miR-146b–5p, and miR-142–3p were significantly decreased in Tregs from patients with ITP compared with healthy controls. Compared with the healthy controls, miRNAs expressed differentially in the Tregs of patients with ITP. The levels of expression of miR-155–5p, miR-146b-5p, and miR-142–3p were significantly decreased. Therefore, the deregulation of miRNAs may affect the function of Tregs in the course of ITP.

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Complement protein levels and MBL2 polymorphisms are associated with dengue and disease severity

Scientific Reports ◽

10.1038/s41598-020-71947-2 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Ngo Truong Giang ◽

Hoang van Tong ◽

Do Quyet ◽

Nghiem Xuan Hoan ◽

Trinh Huu Nghia ◽

...

Keyword(s):

Warning Signs ◽

Severe Dengue ◽

Healthy Controls ◽

Complement Protein ◽

Complement Proteins ◽

Protein Levels ◽

Study Population ◽

Dengue With Warning Signs ◽

The Complement System

Abstract The complement system may be crucial during dengue virus infection and progression to severe dengue. This study investigates the role of MBL2 genetic variants and levels of MBL in serum and complement proteins in Vietnamese dengue patients. MBL2 genotypes (− 550L/H, MBL2 codon 54), MBL2 diplotypes (XA/XO, YA/XO) and MBL2 haplotypes (LXPB, HXPA, XO) were associated with dengue in the study population. The levels of complement factors C2, C5, and C5a were higher in dengue and dengue with warning signs (DWS) patients compared to those in healthy controls, while factor D levels were decreased in dengue and DWS patients compared to the levels determined in healthy controls. C2 and C5a levels were associated with the levels of AST and ALT and with WBC counts. C9 levels were negatively correlated with ALT levels and WBC counts, and factor D levels were associated with AST and ALT levels and with platelet counts. In conclusions, MBL2 polymorphisms are associated with dengue in the Vietnamese study population. The levels of the complement proteins C2, C4b, C5, C5a, C9, factor D and factor I are modulated in dengue patients during the clinical course of dengue.

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Immunomodulation in Primary Immune Thrombocytopenia: A Possible Role of the Fc Fragment of Romiplostim?

Frontiers in Immunology ◽

10.3389/fimmu.2019.01196 ◽

2019 ◽

Vol 10 ◽

Cited By ~ 6

Author(s):

Alexandra Schifferli ◽

Falk Nimmerjahn ◽

Thomas Kühne

Keyword(s):

Immune Thrombocytopenia ◽

Fc Fragment ◽

Primary Immune Thrombocytopenia

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The Ratio of Treg/Th17 Cells Correlates with the Platelet Number in Different Disease State of Primary Immune Thrombocytopenia

Blood ◽

10.1182/blood.v120.21.4649.4649 ◽

2012 ◽

Vol 120 (21) ◽

pp. 4649-4649

Author(s):

Lili Ji ◽

Feng Li ◽

Yanxia Zhan ◽

Fanli Hua ◽

Shanhua Zou ◽

...

Keyword(s):

Autoimmune Diseases ◽

Th17 Cells ◽

Immune Thrombocytopenia ◽

Conflicts Of Interest ◽

Disease Onset ◽

Treg Cells ◽

Healthy Controls ◽

T Helper ◽

Platelet Number ◽

Primary Immune Thrombocytopenia

Abstract Abstract 4649 Background: Primary immune thrombocytopenia (ITP) is an autoimmune heterogeneous disorder that is characterized by decreased platelet count. Regulatory T (Treg) cells and T helper type 17 (Th17) cells are two subtypes of CD4+T helper (Th) cells. They play opposite roles in immune tolerance and autoimmune diseases, while they share a common differentiation pathway. The imbalance of Treg/Th17 has been demonstrated in several autoimmune diseases. In this study, we aimed to investigate the ratio of the number of Tregs to the number of Th17 cells in ITP patients and evaluate the clinical implications of the alterations in this ratio. Methods: Thirty adult patients with newly diagnosed ITP enrolled in this study. Patients who needed treatment had been clinically followed up for 12 months. The percentages of CD4+CD25hiFoxp3+ Treg cells and CD3+CD4+IL-17-producing Th17 cells in these patients and healthy controls (n=17) were longitudinally analyzed by flow cytometry. Results: The percentage of Treg cells in ITP patients was significantly lower than that of healthy controls and the percentage of Th17 cells increased significantly at disease onset. It is suggested that the ratio of Treg/Th17 correlated with the disease activity. Conclusion: The ratio of Treg/Th17 might be relevant to the clinical diversity of ITP patients, and this Treg/Th17 ratio might have prognostic role in ITP patients. Disclosures: No relevant conflicts of interest to declare.

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Low-dose decitabine promotes megakaryocyte maturation and platelet production in healthy controls and immune thrombocytopenia

Thrombosis and Haemostasis ◽

10.1160/th14-04-0342 ◽

2015 ◽

Vol 113 (05) ◽

pp. 1021-1034 ◽

Cited By ~ 18

Author(s):

Hai Zhou ◽

Yu Hou ◽

Xuena Liu ◽

Jihua Qiu ◽

Qi Feng ◽

...

Keyword(s):

Immune Thrombocytopenia ◽

Low Dose ◽

Methylation Status ◽

Healthy Controls ◽

Trail Expression ◽

Platelet Production ◽

Potential Therapeutic Role ◽

Platelet Release

SummaryImpaired megakaryocyte maturation and insufficient platelet production have been shown to participate in the pathogenesis of immune thrombocytopenia (ITP). Our previous study demonstrated that low expression of tumour necrosis factor-related apoptosis-inducing ligand (TRAIL) in megakaryocytes contributed to impaired platelet production in ITP. Decitabine (DAC), a demethylating agent, is known to promote cell differentiation and maturation at low doses. However, whether decitabine is potential in promoting megakaryocyte maturation and platelet release in ITP is unclear. In this study, we evaluated the effect of DAC on megakaryocyte maturation and platelet release in the presence of ITP plasma that has been shown to cause impaired megakaryocyte maturation and platelet production. We observed that low-dose DAC (10 nM) could significantly increase the number of mature polyploid (≥ 4N) megakaryocytes in cultures with plasma from healthy controls and more than one-half of ITP patients in vitro. Furthermore, the number of platelets released from these megakaryocytes significantly increased compared with those untreated with DAC. In these megakaryocytes, DAC significantly enhanced TRAIL expression via decreasing its promoter methylation status. These findings demonstrate that low-dose DAC can promote megakaryocyte maturation and platelet production and enhance TRAIL expression in megakaryocytes in healthy controls and ITP. The potential therapeutic role of low-dose DAC may be beneficial for thrombocytopenic disorders.H. Z. and Y. H. contributed equally to this work.

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Effects of Rituximab and Dexamethasone on Regulatory and Pro-Inflammatory B-Cell Subsets in Patients with Primary Immune Thrombocytopenia

Blood ◽

10.1182/blood.v128.22.1378.1378 ◽

2016 ◽

Vol 128 (22) ◽

pp. 1378-1378

Author(s):

Sif Gudbrandsdottir ◽

Marie Brimnes ◽

Tania Kollgaard ◽

Hans Carl Hasselbalch ◽

Claus Henrik Nielsen

Keyword(s):

B Cells ◽

Autoimmune Diseases ◽

B Cell ◽

Research Funding ◽

Immune Thrombocytopenia ◽

Lower Proportion ◽

Surface Markers ◽

Healthy Controls ◽

Cell Functions ◽

Primary Immune Thrombocytopenia

Abstract Background B-cell depletion with rituximab (RTX) is widely accepted as first- or second-line therapy in primary immune thrombocytopenia (ITP), but it is still unclear how RTX mediates its positive effect in ITP patients. RTX has been reported to induce a reduced titer of platelet antibodies. However, this finding is inconsistent and other B-cell functions, such as the ability to secrete cytokines or to function as antigen-presenting cells for T cells, may be involved in the pathogenesis of ITP. Evidence suggests that B cells participate in the regulation of autoimmune diseases by virtue of their ability to produce the regulatory cytokines interleukin (IL)-10, IL-35, or transforming growth factor β. The various functions of B cells involved in the pathogenesis of autoimmune diseases can in part be deducted by their phenotype as recognized by measurement of specific surface markers and cytokine secretion. Materials and Methods We previously conducted a trial involving 137 newly diagnosed adult ITP patients randomized to treatment with RTX (375 mg/m2/week for 4 weeks) + dexamethasone (DXM) (40 mg/day for 4 days repeated up to 6 cycles) or DXM monotherapy. From this cohort, we identified 16 patients with available samples of peripheral blood mononuclear cells (PBMCs) at baseline and 12 months after treatment; 9 patients from the RTX+DXM group, 7 patients from the DXM group. Seven anonymous blood donors served as healthy controls. PBMCs were incubated for 18 h at 37°C under 5% CO2 in RPMI-1640 containing 10% (v/v) serum from healthy blood group AB donors, either alone or stimulated with 10 µg/ml CpG oligodeoxynucleotides. Expression of the cell-surface markers CD5, CD27, CD25 and CD19, and intracellular content of IL-6 and IL-10 were measured by flow cytometry. Results All patients responded to therapy and were in complete or partial remission at 12 months. Patient characteristics are listed in table I. We observed a significant increase in the proportion of CD5+ B cells 12 months after treatment with RTX+DXM compared to baseline (p < 0.01, Fig. 1A). The percentage of CD27+ memory B cells was significantly decreased at 12 months compared to baseline in patients receiving RTX+DXM (p < 0.05, Fig. 1B), and there was an inverse correlation between platelet numbers and the proportion of CD27+ B cells (R = -0.71; p < 0.05). The proportion of CD25+ B cells tended to decrease in patients treated with RTX+DXM, and was lower at 12 months than in patients treated with DMX only (p < 0.05, Fig 1C). PBMCs from ITP patients contained a lower proportion of IL-10+ B cells (p < 0.01) as well as a lower proportion of B cells producing IL-6 (p < 0.01) at baseline than PBMCs from healthy controls. At 12 months the low proportions had normalized in both treatment groups (Fig. 2). Conclusion B cells from ITP patients treated with RTX+DXM contained a high proportion of CD5+ B cells and low proportions of CD25+ and CD27+ B cells. Before treatment, B cells from ITP patients contained low frequencies of IL-10+ and IL-6+ B cells. Treatment with RTX + DXM or DXM alone reverted these aberrancies to normal. The increase in IL-10+ B cells as well as CD5+ B cells, which may represent overlapping subsets, is compatible with induction of Bregs and may support Treg development. Given the role of CD5+ B cells in maintenance of tolerance, the high frequency of these cells, which has also been observed after RTX therapy in rheumatoid arthritis, is compatible with amelioration of disease. Table 1 Table 1. Disclosures Gudbrandsdottir: GSK: Research Funding; Amgen: Research Funding.

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Molecular and Cellular Impact of Inflammatory Extracellular Vesicles (EVs) Derived from M1 and M2 Macrophages on Neural Action Potentials

Brain Sciences ◽

10.3390/brainsci10070424 ◽

2020 ◽

Vol 10 (7) ◽

pp. 424

Author(s):

Sarah Vakili ◽

Taha Mohseni Ahooyi ◽

Shadan S. Yarandi ◽

Martina Donadoni ◽

Jay Rappaport ◽

...

Keyword(s):

Extracellular Vesicles ◽

Immune Cells ◽

Action Potentials ◽

M2 Macrophage ◽

M2 Macrophages ◽

Neuronal Functions ◽

The Brain ◽

Macrophage Subtypes ◽

M1 And M2 Macrophages

Several factors can contribute to neuroinflammatory disorders, such as cytokine and chemokines that are produced and released from peripherally derived immune cells or from locally activated cells such as microglia and perivascular macrophages in the brain. The primary function of these cells is to clear inflammation; however, following inflammation, circulating monocytes are recruited to the central nervous system (CNS). Monocyte-derived macrophages in the CNS play pivotal roles in mediating neuroinflammatory responses. Macrophages are heterogeneous both in normal and in pathological conditions due to their plasticity, and they are classified in two main subsets, classically activated (M1) or alternatively activated (M2). There is accumulating evidence suggesting that extracellular vesicles (EVs) released from activated immune cells may play crucial roles in mediating inflammation. However, a possible role of EVs released from immune cells such as M1 and M2 macrophages on neuronal functions in the brain is not known. In order to investigate the molecular and cellular impacts of macrophages and EVs released from macrophage subtypes on neuronal functions, we used a recently established in vitro M1 and M2 macrophage culture model and isolated and characterized EVs from these macrophage subtypes, treated primary neurons with M1 or M2 EVs, and analyzed the extracellular action potentials of neurons with microelectrode array studies (MEA). Our results introduce evidence on the interfering role of inflammatory EVs released from macrophages in interneuronal signal transmission processes, with implications in the pathogenesis of neuroinflammatory diseases induced by a variety of inflammatory insults.

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