Biomarkers of Inflammation and Vaso-occlusion in Sickle Cell Disease

项目摘要 为了确定新的生物标志物来评估镰状细胞病(SCD)患者的状态，我们 已经组建了一个由5名主要调查员组成的团队，他们拥有涵盖临床调查的专业知识， 免疫学、生物医学工程和微血管成像。我们最重要的假设是 提出SCD组织损伤的严重程度与炎症和血管状态有关 灌流。我们的目标是应用微创技术敏感地评估炎症和 微血管闭塞对小鼠和人SCD的分析：1)患者外周血的流式细胞术 测量iNKT细胞的激活；以及2)对比增强超声(CEU)测量血管 小鼠和人的原位体积/灌注量。这些是从以下领域借用的经过验证的安全技术 免疫学和心脏病学。我们会将这些措施与其他疾病指标联系起来，例如 人和小鼠的肺功能和活体显微镜。我们最近发现iNKT细胞， 它可以通过激活腺苷A2a受体(A2AR)来抑制，在小鼠或患有 SCD。我们启动了一项正在进行的临床研究(NIH RC2HL101367)，这是由 FDA批准的A2AR激动剂药物瑞格腺苷。另一项正在进行的SCD临床试验是评估GMI-1070， 一种泛选择素抑制剂，可减少白细胞与内皮细胞(EC)的黏附和血管闭塞事件。 为了更深入地研究白细胞与内皮细胞的相互作用，我们招募了一位研究黏附分子和 活体显微镜。为了研究小鼠和人的微血管灌注，我们招募了一位 CEU技术在小鼠和人体研究中测量血管灌注量。数百万的患者 行CEU检查，测量心脏和其他组织的血管灌注量。这些方法将用于 在小鼠身上评估三种SCD候选药物，并在可能的情况下进行人体研究。这些是瑞格腺苷；GMI- 1070；以及ATL-801，一种临床前A2BR拮抗剂，可抑制RBC镰状。经过验证后，我们的目标是 将这些技术转移到SCD临床试验地点。我们假设识别新的 生物标志物，如流式细胞仪和CEU，将成为比目前使用的更有用的药物疗效指标 临床结果测量。此外，这些研究将提供关于细胞和 触发SCD血管闭塞和组织缺血的分子事件。

Project Summary In order to identify new biomarkers to assess the status of patients with sickle cell disease (SCD) we have assembled a team of 5 principal investigators with expertise encompassing clinical investigation, immunology, biomedical engineering and microvascular imaging. The overarching hypothesis underlying our proposal is that the severity of tissue injury in SCD is related to the state of inflammation and vascular perfusion. Our goals are to apply minimally invasive techniques for sensitively assessing inflammation and microvascular occlusion to the analysis of mouse and human SCD: 1) flow cytometry of patient blood to measure iNKT cell activation; and 2) contrast enhanced ultrasound (CEU) to measure vascular volume/perfusion in situ in mice and people. These are validated safe techniques borrowed from the fields of immunology and cardiology. We will relate these measures to other disease indices such as clinical status in people and pulmonary function and intravital microscopy in mice. We recently discovered that iNKT cells, which can be inhibited by activation of adenosine A2A receptors (A2ARs), are activated in mice or persons with SCD. We initiated an ongoing clinical investigation (NIH RC2HL101367) facilitated by the availability of the drug regadenoson, an FDA approved A2AR agonist. Another ongoing SCD clinical trial is evaluating GMI-1070, a pan-selectin inhibitor, to reduce leukocyte adhesion to endothelial cells (EC) and vaso-occlusive episodes. To study leukocyte-EC interactions in greater depth we recruited an authority on adhesion molecules and intravital microscopy. In order to study microvascular perfusion in mice and people we recruited an expert in the technique of CEU to measure vascular perfusion in mouse and human studies. Millions of patients have undergone CEU to measure vascular perfusion in heart and other tissues. These methods will be used to assess three SCD drug candidates in mice and when possible, human studies. These are regadenoson; GMI- 1070; and ATL-801, a preclinical A2BR antagonist that inhibits RBC sickling. After they are validated, our goal is to transfer these techniques to SCD clinical trial sites. We hypothesize that the identification of new biomarkers, flow cytometric and CEU, will be more useful indices of drug effectiveness than currently used clinical outcome measures. In addition, these studies will provide new information about the cellular and molecular events that trigger vaso-occlusion and tissue ischemia in SCD.