Novel hematopoietic effects of C3 cleavage fragments

C3 裂解片段的新造血作用

• 批准号: 7579931
• 负责人: Mariusz Z Ratajczak
• 金额: $ 28.1万
• 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 2012-02-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7579931
• 关键词: Address; Adhesions; Animals; Antibodies; Apoptosis; B-Lymphocytes; Binding; Biological; Blood; Bone Marrow; Bone Marrow Cells; C3bi; CD34 gene; CSF3 gene; CXCR4 gene; Cell Adhesion Molecules; Cells; Chemotaxis; Cleaved cell; Clinic; Complement; Complement 3 Convertase; Complement 3a; Complement 3b; Complement Activation; Cytostatics; Data; Defect; Deposition; Dose; Engraftment; Exhibits; Exposure to; Generations; Half-Life; Hematopoiesis; Hematopoietic; Hematopoietic stem cells; Homing; Human; Hypoxia; Immunodeficient Mouse; Immunoglobulin M; Immunoglobulins; In Vitro; Inflammation; Infusion procedures; Injury; Laboratories; Lead; Ligands; Link; Liquid substance; Macrophage-1 Antigen; Marrow; Mediating; Membrane Lipids; Membrane Microdomains; Molecular; Mus; NOD/SCID mouse; Organ; Pathway interactions; Patient Care; Patients; Peptides; Phase; Phenotype; Play; Process; Progenitor Cell Engraftment; Proteolysis; Radiation therapy; Radio; Recovery; Reporting; Research; Research Personnel; Role; SCID Mice; Serum; Signal Transduction; Site; Solid; Staging; Stem cells; Stress; Stromal Cell-Derived Factor 1; Stromal Cells; Supplementation; System; Testing; Tissues; Transplantation; Transplantation Conditioning; Umbilical Cord Blood; Work; Zymosan; base; cell motility; chemotherapy; citrate carrier; conditioning; in vivo; in vivo Model; injured; insight; irradiation; mouse model; novel; prevent; progenitor; programs; stem; trafficking

DESCRIPTION (provided by applicant): The preliminary data from our laboratory established a novel and previously underappreciated role of the complement (C) system in modulating SDF-1-CXCR4 axis-dependent homing/retention/mobilization of hematopoietic stem/progenitor cells (HSPC) in bone marrow (BM). We found that C proteins are synthesized in BM and C activation provides one of the earliest signals of BM injury e.g., during conditioning for transplant by irradiation/chemotherapy or G-CSF-induced mobilization. We reported that HSPC express functional C3aR and the iC3b-receptor, CR3, and while C3a and desArgCSa stimulation of HSPC enhances/sensitizes responsiveness of HSPC to SDF-1 gradients, deposition of iC3b on BM stroma tethers early CR3-positive hematopoietic progenitors causing retention in the BM. Four aims are proposed to better elucidate the role of C3 in hematopoiesis during stress situations: 1. The molecular aspects of the C3a-C3aR axis in homing/engraftment of HSPC in bone marrow. Preliminary research points to a crucial role for the C3a-C3aR axis in homing/retention of HSPC in the bone marrow. We will focus on determining the molecular mechanisms of C3aR signaling in HSPC crucial for these processes and test whether priming of HSPC before transplantation with C3 cleavage fragments enhances engraftment of long-term repopulating HSPC in wt mice and human cord blood HSPC engraftment in NOD/SCID mice. 2. Blockade of the C3a-C3aR axis as a new strategy to mobilize stem cells. We reported that the small molecular C3aR antagonist SB2900157 enhances and accelerates G-CSF-induced mobilization. As a continuation of this work we will study the phenotype of mobilized cells and test whether they engraft efficiently after transplantation into syngeneic mice. 3. C3 fragments as modulators of the SDF-1-CXCR4 axis. C3a, desArgCSa and iC3b prime chemotaxis of HSPC to SDF-1. This aim will define the molecular mechanism of this phenomenon and explore the hypothesis that C3 cleavage fragments promote a shift of CXCR4 into membrane lipid rafts which increases their responsiveness to SDF-1. 4. C3 and impaired mobilization in immunodeficient mice. We have observed that immunodeficient RAG2-/- and SCID mice show impaired mobilization of HSPC, which is restored after infusion of immunoglobulins. We will test the hypothesis that this defect is related to the lack of naturally occurring C cascade-activating IgM antibodies.

描述（由申请人提供）：我们实验室的初步数据建立了补体(C)系统在调节骨髓（BM）中造血干细胞/祖细胞（HSPC）的SDF-1-CXCR4轴依赖性归巢/保留/动员中的一个新的和以前未被重视的作用。我们发现C蛋白在骨髓中合成，C激活提供了骨髓损伤的最早信号之一，例如，在照射/化疗或g - csf诱导的动员的移植调节过程中。我们报道了HSPC表达功能性C3aR和iC3b受体CR3，虽然C3a和desArgCSa刺激HSPC增强/增敏了HSPC对SDF-1梯度的反应，但iC3b在BM基质上的沉积会栓住早期CR3阳性造血祖细胞，导致在BM中滞留。为了更好地阐明应激情况下C3在造血中的作用，本文提出了四个目标：1。C3a-C3aR轴在HSPC在骨髓中归巢/植入中的分子方面。初步研究指出，C3a-C3aR轴在HSPC在骨髓中的归巢/保留中起着至关重要的作用。我们将专注于确定对这些过程至关重要的HSPC中C3aR信号的分子机制，并测试在移植前用C3切割片段启动HSPC是否能增强wt小鼠中长期再生HSPC的植入，以及NOD/SCID小鼠中人类脐带血HSPC的植入。2. 阻断C3a-C3aR轴作为动员干细胞的新策略。我们报道了小分子C3aR拮抗剂SB2900157增强和加速g - csf诱导的动员。作为这项工作的继续，我们将研究动员细胞的表型，并测试它们在移植到同基因小鼠后是否有效地移植。3. C3片段作为SDF-1-CXCR4轴的调制器。C3a， desArgCSa和iC3b是HSPC对SDF-1的趋化性。本研究旨在明确这一现象的分子机制，并探讨C3裂解片段促进CXCR4向膜脂筏转移从而增加其对SDF-1的反应性的假设。4. C3和免疫缺陷小鼠的动员受损。我们观察到免疫缺陷的RAG2-/-和SCID小鼠表现出HSPC的动员受损，在输注免疫球蛋白后恢复。我们将检验这种缺陷与缺乏自然发生的C级联激活IgM抗体有关的假设。