Role Of Monocytes In Immunopathology

单核细胞在免疫病理学中的作用

基本信息

批准号：
7593361
负责人：
LARRY M WAHL
金额：
$ 98.54万
依托单位：
NATIONAL INSTITUTE OF DENTAL & CRANIOFACIAL RESEARCH
依托单位国家：
美国
项目类别：
财政年份：
资助国家：
美国
起止时间：
至
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/7593361
关键词：
ANXA2 gene Acute monocytic leukemia Affect Affinity Anti-Bacterial Agents Antibodies Antibody Repertoire Antigens Arterial Fatty Streak Atherosclerosis Binding Biological Biological Markers Catalytic Domain Cell Line Cell Proliferation Cells Chronic Classical Complement Pathway Clinical Research Connective Tissue Cytolysis Dinoprostone Disease Disorder by Site Endotoxins Enzyme Inhibitor Drugs Enzyme Inhibitors Enzymes Equilibrium Event Genetic Polymorphism Goals Gram-Positive Bacteria Growth Human Immunity Inflammation Inflammatory Inflammatory Response Interstitial Collagenase Lead Lesion MAPK phosphatase MAPK14 gene Manuscripts Matrix Metalloproteinase Inhibitor Matrix Metalloproteinases Mediator of activation protein Medicine Messenger RNA Molecular Weight NF-kappa B Neoplasm Metastasis Periodontal Diseases Phagocytosis Phosphoric Monoester Hydrolases Phosphorylation Plasmin Plasminogen Play Production Protein Dephosphorylation Protein phosphatase Proteins Regulation Research Research Personnel Rheumatoid Arthritis Risk Factors Role Rupture Signal Transduction Signal Transduction Pathway Signaling Protein Site System Therapeutic Intervention Tissues Transfection Tumor Suppressor Proteins Urokinase Urokinase Plasminogen Activator Receptor c-myc Genes cancer cell cell type cyclooxygenase 2 cytokine immune function immunopathology inhibitor/antagonist monocyte oral infection receptor receptor binding research study transcription factor upstream kinase

项目摘要

Research in the Immunopathology Section focuses on the biological mediators and signal transduction pathways involved in the modulation of human monocyte functions that may contribute to the immunopathology associated with various inflammatory lesions. Connective tissue destruction is associated with many diseases in which the monocytemacrophage is a prominent cell. Examples of these chronic inflammatory lesions include periodontal disease and rheumatoid arthritis where destruction of connective tissue leads to loss of structural integrity and atherosclerosis where degradation of connective tissue in vulnerable plaques leads to rupture and subsequent ischemic events. Additionally, the interaction of monocytesmacrophages with cancer cells has the potential for regulating or contributing to metastasis through the induction of connective tissue degrading enzymes. Since matrix metalloproteinases (MMPs) and tissue inhibitors of MMPs (TIMPs) are believed to play a major role in the destruction and remodeling of connective tissue, a major emphasis has been placed on how these enzymes and inhibitors are regulated in the human monocyte and how the monocyte may regulate the function of other cell types. Determining the inflammatory agents and signal transduction pathways that lead to the production of MMPs by monocytes is important to potential therapeutic intervention. Phosphorylation and dephosphorylation of signaling proteins is controlled by precise interactions with upstream kinases and can also be strongly regulated by phosphatases. We have examined the potential role of MAPK phosphatase 1 (MKP1), one of the dual-specific protein phosphatases, in the regulation of monocyte signaling and the production of MMPs. To carry out this study THP-1 cells (a human acute monocytic leukemia cell line) were compared with human primary monocytes. THP-1 cells were found to be deficient in MKP1 mRNA which resulted in constitutive activation of the transcription factors, c-Myc, and NF-kB, culminating in the proliferation of these cells and increased production of MMPs. Transfection of THP-1 cells with MKP1 suppressed constitutive activation of c-Myc and NF-kB resulting in decreased proliferation and MMP production. Unlike THP-1 cells, primary monocytes expressed mRNA for MKP1 and did not have constitutively activated c-Myc or NF-kB. Additionally, primary monocytes required stimulation to produce MMPs. Furthermore, in parallel experiments with primary monocytes and inhibitors of MEK12 and phosphatase, we demonstrate an intrinsic balance between phosphatase activity and phosphorylation of ERK12. These findings indicate that MKP1 may function as a putative tumor suppressor. Urokinase plasminogen activator (uPA) and plasmin, in addition to their role in fibrinolytic activity and activation of pro-matrix metalloproteinases (MMPs), have been shown to transduce intracellular signals through specific receptors. We hypothesized that components of the urokinase system may induce signals that regulate the production of MMPs by monocytes. We speculated that binding of uPA to the uPA receptor (uPAR) andor plasmin to specific receptors would induce signaling leading to MMP production. In a submitted manuscript we show that catalytically active high molecular weight uPA (HMW-uPA), which binds to the uPAR, and low molecular weight uPA (LMW-uPA), which does not bind uPAR, both significantly enhanced MMP-1 by activated primary human monocytes. In contrast, the amino terminal fragment of uPA (ATF-uPA) which lacks the catalytic site but binds to uPAR failed to induce MMP-1 production, indicating that uPA-stimulated MMP-1 synthesis was plasmin-dependent and independent of uPAR binding. Plasmin generated endogenously by the action of uPA or exogenously added plasmin increased MMP-1 by signaling through annexin A2. This was demonstrated by inhibition of uPA or plasmin-induced MMP-1 production with antibodies against annexin A2 and S100A10, a dimeric protein associated with annexin A2, as well as by inactive plasmin. Interaction of plasmin with annexin A2 resulted in the stimulation of ERK12 and p38 MAPKs, cyclooxygenase-2 and PGE2 leading to increased MMP-1 production. These findings demonstrate that the urokinase plasminogen activation system, in addition to activating pro-MMPs, directly regulates the production of MMP-1 by activated monocytes and thus plays a major role in the turnover of connective tissue at an inflammation site. Furthermore, the inhibition of plasmin induction of MMP-1 by inactive plasmin as a result of its binding to annexin A2 suggests that inactive-plasmin may useful in suppressing inflammatory responses. Polyreactive antibodies bind to a variety of structurally unrelated antigens, however their function has remained an enigma and because of their low binding affinity their biological relevance has been questioned. We have collaborated with investigators in the Experimental Medicine Section of the Oral Infection and Immunity Branch who are examining the functional role of polyreactive antibodies. Through the use of a panel of monoclonal polyreactive antibodies it was shown that these antibodies: bind to both gram-negative and gram-positive bacteria and acting through the classical complement pathway inhibit bacterial growth by lysis; enhance phagocytosis; and neutralize endotoxin as shown by the ability of these antibodies to block LPS induction of MMP-1 in monocytes. From these findings it is concluded that polyreactive antibodies are a major contributor to the broad anti-bacterial activity of the natural antibody repertoire.

免疫病理学部分的研究重点是调节人单核细胞功能的生物学介质和信号转导途径，这些途径可能有助于与各种炎症性病变相关的免疫病理学。结缔组织破坏与多核噬细胞是一个突出细胞的许多疾病有关。这些慢性炎症性病变的例子包括牙周疾病和类风湿关节炎，其中结缔组织的破坏会导致结构完整性和动脉粥样硬化的丧失，其中脆弱斑块中结缔组织的降解会导致破裂和随后的缺血性事件。另外，单核细胞噬细胞与癌细胞的相互作用有可能通过诱导结缔组织降解酶来调节或促进转移。由于基质金属蛋白酶（MMP）和MMPS（TIMP）的组织抑制剂被认为在结缔组织的破坏和重塑中起主要作用，因此已经将这些酶和抑制剂在人类单细胞和单细胞细胞中如何调节的细胞类型的其他细胞类型的主要重点放在了如何调节这些酶和抑制剂上。确定导致单核细胞产生MMP的炎症剂和信号转导途径对于潜在的治疗干预很重要。信号蛋白的磷酸化和去磷酸化由与上游激酶的精确相互作用控制，也可以受磷酸酶的强烈调节。我们已经研究了MAPK磷酸酶1（MKP1）（双特异性蛋白磷酸酶之一）在单核细胞信号传导和MMP的产生中的潜在作用。为了进行这项研究，将Thp-1细胞（人类急性单核细胞细胞系）与人类原代单核细胞进行了比较。发现THP-1细胞缺乏MKP1 mRNA，从而导致转录因子C-MYC和NF-KB的组成性激活，最终导致这些细胞的增殖并增加了MMP的产生。用MKP1转染THP-1细胞抑制了C-MYC和NF-KB的本构激活，导致增殖和MMP产生降低。与THP-1细胞不同，原代单核细胞表达了MKP1的mRNA，并且没有组成激活的C-MYC或NF-KB。另外，一级单核细胞需要刺激才能产生MMP。此外，在与MEK12和磷酸酶的原代单核细胞和抑制剂的并行实验中，我们证明了磷酸酶活性和ERK12磷酸化之间的内在平衡。这些发现表明MKP1可能起到推定的肿瘤抑制作用。尿激酶纤溶酶原活化剂（UPA）和纤溶酶在纤维蛋白溶解活性和丙糖金属蛋白酶（MMP）的活化中的作用外，还显示出通过特定受体转导细胞内信号。我们假设尿蛋白酶系统的成分可能诱导通过单核细胞调节MMP产生的信号。我们推测，UPA与UPA受体（UPAR）Andor纤溶酶与特定受体的结合将诱导信号传导，从而导致MMP产生。在提交的手稿中，我们表明，与UPAR结合的催化活性高分子量UPA（HMW-UPA），而低分子量UPA（LMW-UPA）（LMW-UPA）不结合UPAR，两者都通过活化的原代人单细胞显着增强了MMP-1。相反，缺乏催化位点但与UPAR结合的UPA（ATF-UPA）的氨基末端片段未能诱导MMP-1产生，这表明UPA刺激的MMP-1合成是纤溶酶依赖性的，并且独立于UPAR结合。纤溶酶通过UPA或外源添加的纤溶酶的作用而产生的纤溶酶通过通过膜联蛋白A2发出信号而增加了MMP-1。通过抑制UPA或纤溶酶诱导的MMP-1产生的抗体抗体A2和S100A10的抗体，这是一种与膜联蛋白A2以及无活性纤溶酶相关的二聚体蛋白，这证明了这一点。纤溶酶与膜联蛋白A2的相互作用导致ERK12和p38 MAPK，环氧合酶-2和PGE2的刺激导致MMP-1产生增加。这些发现表明，除激活ProMMP外，尿蛋白酶纤溶酶原激活系统还直接通过活化的单核细胞来调节MMP-1的产生，因此在炎症部位的结缔组织营业层中起着重要作用。此外，由于非活性纤溶酶与膜联蛋白A2的结合，对MMP-1诱导纤溶酶诱导的抑制作用表明非活性 - 质蛋白可能有助于抑制炎症反应。多反应性抗体与各种结构无关的抗原结合，但是它们的功能仍然是一个谜，由于它们的生物学相关性较低，因此受到了质疑。我们已经与研究人员在口腔感染和免疫分支的实验医学部分合作，他们正在研究多反应性抗体的功能作用。通过使用一组单克隆多反应性抗体，这些抗体表明：与革兰氏阴性和革兰氏阳性细菌结合并通过经典补体途径抑制细菌生长，以通过裂解来抑制细菌的生长；增强吞噬作用；如这些抗体阻止单核细胞中MMP-1诱导LPS诱导的能力所示，并中和内毒素。从这些发现得出的结论是，多反应性抗体是自然抗体库的广泛抗细菌活性的主要因素。