Contribution of B cells to human cardiac allograft vasculopathy

B 细胞对人心脏同种异体移植血管病的作用

• 批准号: 9114457
• 负责人: Emmanuel Zorn
• 金额: $ 40.25万
• 依托单位: COLUMBIA UNIVERSITY HEALTH SCIENCES
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-08-01 至 2020-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9114457
• 关键词: Alloantigen; Antibodies; Antigen Presentation; Antigen Targeting; Antigen-Antibody Complex; Antigen-Presenting Cells; Antigens; Apoptotic; Autoantigens; B cell repertoire; B-Lymphocytes; Biological Assay; Biopsy Specimen; Blood; Blood specimen; Canada; Cardiac; Cell physiology; Cells; Cellular Assay; Clonality; Complement; Complication; Coronary artery; Development; Enzyme-Linked Immunosorbent Assay; Fc Immunoglobulins; Flow Cytometry; Functional disorder; Graft Rejection; Health; Heart Transplantation; Heavy-Chain Immunoglobulins; Human; Humoral Immunities; Immunofluorescence Immunologic; Immunoglobulin G; In Situ; In Vitro; Inflammation; Inflammatory; Location; MS4A1 gene; Molecular; Monoclonal Antibodies; Morbidity - disease rate; Multi-Institutional Clinical Trial; Mus; Patients; Phenotype; Preventive; Process; Property; Protein Microchips; Research; Rheumatoid Factor; Role; Sampling; Sequence Analysis; Series; Somatic Mutation; Source; Specificity; Specimen; T cell response; T-Lymphocyte; Techniques; Testing; Therapeutic Agents; Time; Tissue Grafts; Tissues; Transplant Recipients; Transplantation; United States National Institutes of Health; Vascular Diseases; base; cytokine; deep sequencing; graft function; heart allograft; macrophage; mortality; nonhuman primate; prevent; research study; response; rituximab; uptake

 DESCRIPTION (provided by applicant): CAV is almost invariably associated with B cell infiltrates in or around coronary arteries as well as in endomyocardial tissue (quilty effect). It s assumed that these cells participate in the rejection process, although a formal demonstration of such contribution is still lacking. On the whole, infiltrating B cells are loosely defined. Their eact phenotype, antigen specificity and possible function are currently unknown. Understanding how B cells contribute to mechanisms of graft rejection would undoubtedly facilitate the development of therapeutic agents to target them and treat rejection. Studies in humans are challenging due to the limited source of samples and the difficulty of setting up techniques to study primary B cells retrieved directly from tissue. For these reasons, the assessment of human graft infiltrating B cells has been limited thus far and most studies have focused on humoral immunity using blood samples. We have begun collecting fresh cardiac graft specimens rejected because of CAV and explanted for re-transplantation through a collaborative network of transplant centers in the USA and Canada. Preliminary experiments using deep sequencing to analyze rearranged immunoglobulin heavy chain repertoire in situ demonstrated the massive expansion and somatic mutation of B cell clones in 4 cardiac allografts. We have also started immortalizing B cell clones directly from these cardiac allograft specimens. Our proposed research will characterize these cells, uncover their main function and evaluate their participation in the pathophysiology of CAV. Aim 1. To characterize the phenotype, clonality and specificity of graft infiltrating B cells during CAV: We will first assess the distribution and phenotype of B cells within the rejected graft tissue. B cell repertoire analyses will then identify predominant B cell clones expanded in situ. In parallel, B cells isolated from explanted grafts will be immortalized and cultured in vitro. Selected clones corresponding to B cells expanded in situ will be further characterized. Aim 2. To identify the function of antibodies secreted by graft infiltrating B cells during CAV: Monoclonal antibodies secreted by immortalized clones found to be expanded in situ in aim 1, will be assessed for their capacity to form immune complexes and induce cytokine secretion by macrophages in situ as well as facilitate antigen presentation to T cells. Aim 3. To determine the function of graft infiltrating B cells during CAV: Aside from their capacity to secrete pathogenic antibodies, we will examine whether graft-infiltrating B cells during CAV can uptake and present antigens to T cells. We will also investigate whether B cells can polarize T cell responses in situ. Lastly, we will also examine the role of the complement to modulate these responses.