Novel hematopoietic effects of C5 cleavage fragment

C5 裂解片段的新造血作用

• 批准号: 8628110
• 负责人: Mariusz Z Ratajczak
• 金额: $ 32.9万
• 依托单位: UNIVERSITY OF LOUISVILLE
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-03-01 至 2017-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8628110
• 关键词: Address; Adhesions; Adult; Anaphylatoxins; Blood Vessels; Bone Marrow; Bone Marrow Cells; Bone Marrow Transplantation; CXCR4 Receptors; CXCR4 gene; Cell Adhesion Molecules; Cells; Chemotactic Factors; Circadian Rhythms; Collaborations; Complement; Complement 3a; Complement 5a; Complement Activation; Complement Membrane Attack Complex; Complement component C5; Cytolysis; Data; Defect; Development; Dinoprostone; Distal; Endothelium; Engraftment; Erythrocytes; Exhibits; Fibroblasts; Funding; Generations; Granulocyte Colony-Stimulating Factor; Growth Factor; Hematopoiesis; Hematopoietic; Hematopoietic Stem Cell Mobilization; Hematopoietic Stem Cell Transplantation; Hematopoietic stem cells; Homing; Human; Integrin alpha4beta1; Integrins; Investigation; Lead; Life; Ligands; Light; Link; Lipids; Lytic; Molecular; Mus; Natural Immunity; Nucleotides; Osteoblasts; Patients; Physiological; Plasma; Polysaccharides; Process; Publishing; Role; Stem cells; Syndrome; Testing; Transplantation; Transplantation Conditioning; Umbilical Cord Blood; Vascular Cell Adhesion Molecule-1; Work; base; cathelicidin; ceramide 1-phosphate; chemotherapy; complement C3 precursor; complement C5b; immunodeficient mouse model; leukemia; novel; novel therapeutics; peripheral blood; public health relevance; reconstitution; response; sphingosine 1-phosphate; stem; trafficking

DESCRIPTION (provided by applicant): Both pharmacological mobilization of hematopoietic stem progenitor cells (HSPCs) and myeloablative conditioning for transplantation activate the complement cascade (CC) in bone marrow (BM), and in the previous funding period we focused on the role of the third complement component (C3) in mobilization and homing of HSPCs. In this competing renewal we will focus on the fifth complement component (C5), which is located downstream from C3. C5 cleavage leads to generation of the potent anaphylatoxins C5a and desArgC5a and generation of non-lytic and lytic C5b-C9, known as the membrane attack complex (MAC). Our recently published data support a crucial role for C5a/C5b-C9 in trafficking of HSPCs. In particular, C5-deficient mice are poor mobilizers in response to granulocyte colony stimulating factor (G-CSF) and exhibit delayed hematopoietic reconstitution after transplantation with wild type (WT) BM cells. Based on these findings, the central hypothesis of this competing renewal is that the activation of distal steps of the complement cascade and release of C5a and C5b-C9 (MAC) are important regulators of mobilization and homing of HSPCs. To address this hypothesis, we propose: Specific Aim 1. The molecular basis of the mobilization defect in C5-deficient mice. Based on our observation that C5-deficient mice are poor G-CSF mobilizers, we will address whether C5 cleavage is i) required for circadian HSPC mobilization, ii) mobilization of HSPC induced by other agents and iii) whether C5 activation and S1P plasma level correlates with mobilization efficacy in patients. We will also focus on the role of erythrocyte-released S1P in mobilization by performing mobilization studies in CD55/CD59-deficient mice that are highly sensitive to C5b-C9 (MAC) lysis. Finally, we will focus on the role of C5b-C9-induced release of S1P in mobilization observed in patients with hemolytic syndromes. Specific Aim 2. The molecular basis of the homing defect in C5-deficient mice. We found that the CC is activated in lethally irradiated mice and that C5-deficient mice engraft poorly with WT BM cells. To shed more light on the role of the distal part of the CC (C5a/C5b-C9) in homing/engraftment, we will study whether conditioning for transplantation by chemotherapy also activates the CC in BM and study the effect of C5a/C5b-C9 on expression of i) HSPC chemoattractants in BM, ii) adhesion/tethering molecules for HSPCs on BM endothelium, and ii) on secretion of factors facilitating homing. Specific Aim 3. The C5a/C5b-C9-induced BM stroma-derived cathelicidin (LL-37) as a potent homing sensitizing factor. We found that LL-37, like C3a, is a very strong priming factor for SDF-1 that becomes upregulated in BM stroma after conditioning for transplantation in a C5a/C5b-C9-dependent manner. In an immunodeficient mouse model, we will test whether short exposure of HSPCs to LL-37 before transplantation increases homing of human BM- and umbilical cord blood (UCB)-derived HSPCs. We will also address whether LL-37 also primes the responsiveness of HSPCs to other homing factors and focus on the molecular mechanism of these phenomena.

描述（由申请人提供）：造血干祖细胞（HSPC）的药理动员和移植清髓调理都会激活骨髓（BM）中的补体级联（CC），在之前的资助期间，我们重点研究了第三补体成分（C3）在HSPC的动员和归巢中的作用。在这次竞争性更新中，我们将重点关注位于 C3 下游的第五个补体成分 (C5)。 C5 裂解导致强效过敏毒素 C5a 和 desArgC5a 的生成，以及非裂解性和裂解性 C5b-C9 的生成，称为膜攻击复合物 (MAC)。我们最近发布的数据支持 C5a/C5b-C9 在 HSPC 贩运中的关键作用。特别是，C5 缺陷小鼠对粒细胞集落刺激因子 (G-CSF) 的动员能力较差，并且在移植野生型 (WT) BM 细胞后表现出造血重建延迟。基于这些发现，这种竞争性更新的中心假设是补体级联远端步骤的激活以及 C5a 和 C5b-C9 (MAC) 的释放是 HSPC 动员和归巢的重要调节因子。为了解决这一假设，我们提出： 具体目标 1. C5 缺陷小鼠动员缺陷的分子基础。根据我们对 C5 缺陷小鼠 G-CSF 动员能力较差的观察，我们将探讨 C5 裂解是否是 i) 昼夜 HSPC 动员所必需的，ii) 其他药物诱导的 HSPC 动员，以及 iii) C5 激活和 S1P 血浆水平是否与患者的动员功效相关。我们还将通过在对 C5b-C9 (MAC) 裂解高度敏感的 CD55/CD59 缺陷小鼠中进行动员研究，重点关注红细胞释放的 S1P 在动员中的作用。最后，我们将重点关注 C5b-C9 诱导的 S1P 释放在溶血综合征患者观察到的动员中的作用。具体目标 2. C5 缺陷小鼠归巢缺陷的分子基础。我们发现，CC 在受到致命辐射的小鼠中被激活，而 C5 缺陷的小鼠与 WT BM 细胞的移植效果较差。为了进一步阐明 CC 远端部分 (C5a/C5b-C9) 在归巢/植入中的作用，我们将研究化疗移植条件是否也激活 BM 中的 CC，并研究 C5a/C5b-C9 对 i) BM 中 HSPC 趋化剂、ii) BM 内皮上 HSPC 粘附/束缚分子表达的影响，以及 ii)关于促进归巢的因子的分泌。具体目标 3. C5a/C5b-C9 诱导的 BM 基质来源的导管素 (LL-37) 作为有效的归巢敏化因子。我们发现，LL-37 与 C3a 一样，是 SDF-1 的一种非常强的启动因子，在以 C5a/C5b-C9 依赖性方式进行移植调节后，其在 BM 基质中上调。在免疫缺陷小鼠模型中，我们将测试移植前 HSPC 短暂暴露于 LL-37 是否会增加人骨髓和脐带血 (UCB) 来源的 HSPC 的归巢。我们还将讨论 LL-37 是否也引发 HSPC 对其他归巢因子的反应，并重点关注这些现象的分子机制。