Role Of Monocytes In Immunopathology

单核细胞在免疫病理学中的作用

• 批准号: 7318451
• 负责人: LARRY M WAHL
• 金额: --
• 依托单位: NATIONAL INSTITUTE OF DENTAL & CRANIOFACIAL RESEARCH
• 依托单位国家: 美国
• 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/7318451
• 关键词: Role; Monocytes; Immunopathology; Role; Monocytes; Immunopathology

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 monocyte/macrophage 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 monocytes/macrophages 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. Reactive oxygen species such as hydrogen peroxide (H2O2) have been associated with the initiation or aggravation of diverse pathological states. In a manuscript published this fiscal year we report that addition of H2O2 to LPS activated monocytes, but not alone, caused a significant enhancement of the LPS-induced production of MMP-1, cyclooxygenase-2 (COX-2), and PGE2. The mechanism by which H2O2 increased these mediators was through the enhancement of IkappaB degradation, the inhibitor of the activation of the transcription factor NF-kappaB. The subsequent increase in NF-kappaB activation by H2O2 is responsible for the increase in MMP-1 production. The effect of H2O2 on IkB degradation and NF-kappaB activation was demonstrated through studies of co-immunprecipitation of IkB with p50 and ELISA assay of NF-kappaB p65 activity. The key role for NF-kappaB in this process was demonstrated by the ability of MG-132 or lactacystin (NF-kappaB inhibitors) to block the enhanced production of MMP-1, COX-2 and PGE2. In contrast, indomethacin, which inhibited PGE2 production, partially blocked the enhanced MMP-1 production. Moreover, while PGE2 restored MMP-1 production in indomethacin treated monocyte cultures it failed to significantly restore MMP-1 production in NF-kappaB inhibitor treated cultures. Thus in the presence of LPS and H2O2, NF-kappaB plays a dominate role in the regulation of production of MMP-1, COX-2 and PGE2 as well as in the PGE2 induction of MMP-1. A number of inflammation factors serve as biomarkers for chronic inflammatory diseases. We have investigated how some of these biomarkers interact in the regulation of monocyte MMP production and the potential relationship of these affects on the pathology associated with inflammatory lesions. Our findings have demonstrated that in many cases in order for biomarkers to affect monocyte MMP production there is a requirement that more than one of these inflammatory agents must be present. An example of this requirement is demonstrated in one of our studies published this last year on C reactive protein. We have demonstrated that C reactive protein (CRP), a biomarker of inflammation and cardiovascular disease, enhances MMP-1 production by monocytes only in the presence of activators such as inflammatory cytokines. Augmentation of MMP-1 by CRP occurs, in part, through the induction of an intermediate, monocyte chemotactic protein-1 (MCP-1). The role of MCP-1 in the enhancement by MMP-1 by CRP was demonstrated by suppression of MMP-1 by neutralizing antibodies against MCP-1 and the ability of exogenous MCP-1 to increase MMP-1 production by cytokine stimulated monocytes. In addition to CRP, oxidized LDL (ox-LDL) is another biomarker of atherosclerosis and potentially other diseases. When cytokine activated monocytes were exposed to CRP and ox-LDL there was a synergistic enhancement of MMP-1. The synergistic increase in MMP-1 by CRP and ox-LDL resulted from a differential regulation through MCP-1 and prostaglandin E2, respectively. These findings indicate that multiple biomarkers or risk factors may be involved in the initiation of an inflammatory disease. In a collaborative study with investigators at The Johns Hopkins University School of Medicine we have a manuscript in press that provides evidence for the association of MCP-1 gene polymorphism with increased occult ischemia in individuals when additional risk factors are present. A single nucleotide polymorphism in the MCP-1 gene promoter (-2578A>G) results in greater production of MCP-1 protein. We genotyped 679 apparently healthy siblings of people with premature coronary artery disease (CAD), tested for occult ischemia with exercise treadmill tests and thallium-201 single photon emission computed tomography, and assessed CAD risk factors to calculate the Framingham risk score (FRS). For subjects in the first three quartiles of FRS, the prevalence of occult ischemia did not differ significantly by genotype, but in the highest quartile of FRS, individuals with the -2578A>G MCP-1 polymorphism had a significantly greater prevalence of ischemia (44.4% vs 26.1%, p=0.017). These findings provide further support for the interaction of multiple inflammatory mediators in the pathology associated with inflammatory events.

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。结缔组织破坏与单核细胞/巨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。此外，单核细胞/巨噬细胞与癌细胞的相互作用具有通过诱导结缔组织降解酶来调节或促进转移的潜力。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。 活性氧，例如过氧化氢（H2O2）与多种病理状态的起始或加剧有关。在本财政年度发表的手稿中，我们报告说，将H2O2添加到LPS激活的单核细胞中，但并非孤单，导致LPS诱导的MMP-1，环氧酶-2（COX-2）（COX-2）和PGE2的产生显着增强。 H2O2增加这些介体的机制是通过增强Ikappab降解的增强，这是转录因子NF-kappab激活的抑制剂。随后H2O2激活NF-kappab激活的后续增加导致MMP-1产生增加。 H2O2对IKB降解和NF-kappab激活的影响通过研究IKB与NF-kappab P65活性的P50和ELISA分析的研究证明了。 NF-kappab在此过程中的关键作用是通过MG-132或乳酸（NF-kappab抑制剂）阻断MMP-1，COX-2和PGE2增强产生的能力。相反，抑制PGE2产生的吲哚美辛部分阻断了增强的MMP-1产生。此外，虽然PGE2在吲哚美辛治疗的单核细胞培养物中恢复了MMP-1的产生，但它未能显着恢复NF-kappab抑制剂治疗的培养物中的MMP-1产生。因此，在LPS和H2O2的存在下，NF-KAPPAB在MMP-1，COX-2和PGE2的生产以及MMP-1的PGE2诱导中起着主导作用。 许多炎症因素是慢性炎症性疾病的生物标志物。我们已经研究了这些生物标志物中的一些在单核细胞MMP产生的调节中如何相互作用，以及这些影响对与炎症病变相关的病理的潜在关系。我们的发现表明，在许多情况下，为了使生物标志物影响单核细胞MMP的产生，必须存在这些炎症剂中的多个。去年发表的有关C反应性蛋白质的一项研究证明了这一要求的一个例子。我们已经证明，仅在炎症细胞因子等激活剂的存在下，单核细胞仅在炎症和心血管疾病的生物标志物（CRP）（CRP）中增强了MMP-1的产生。通过诱导中间的单核细胞趋化蛋白-1（MCP-1），通过CRP对MMP-1的增强。通过抑制MMP-1，通过中和对MCP-1的抗体以及外源MCP-1通过细胞因子刺激的单核细胞增加MMP-1产生的能力来证明MCP-1在MMP-1通过CRP增强中的作用。除CRP外，氧化的LDL（OX-LDL）是动脉粥样硬化和潜在其他疾病的另一个生物标志物。当细胞因子活化的单核细胞暴露于CRP和OX-LDL时，MMP-1的协同增强。 CRP和OX-LDL在MMP-1中的协同增加是由于通过MCP-1和Prostaglandin E2的差异调节引起的。这些发现表明，炎症性疾病的开始可能涉及多种生物标志物或危险因素。 在约翰·霍普金斯大学医学院的研究人员的一项合作研究中，我们在新闻界有一个手稿，为MCP-1基因多态性与存在其他危险因素时的神秘性缺血相关的证据提供了证据。 MCP-1基因启动子（-2578a> g）中的单个核苷酸多态性导致MCP-1蛋白的产生更大。我们对679例过早的冠状动脉疾病（CAD）的人的兄弟姐妹进行了基因分型，该兄弟姐妹通过运动跑步机测试和Thallium-2011单光子发射计算机断层扫描进行了神秘性缺血测试，并评估了CAD风险因素以计算Framingham风险评分（FRS）。对于FRS的前三个四分位数中的受试者，基因型的神秘性缺血的流行率并没有显着差异，但是在FRS的最高四分位数中，患有-2578A> G MCP -1多态性的个体具有缺血性的明显更大（44.4％vs 26.1％，P = 0.017）。这些发现为与炎症事件相关的病理学中多个炎症介质的相互作用提供了进一步的支持。