MONOCLONAL ANTI-IGM REGULATION OF HUMAN B CELL FUNCTION

单克隆抗 IGM 对人 B 细胞功能的调节

• 批准号: 3287458
• 负责人: Patricia K. Mongini
• 金额: $ 19.32万
• 依托单位: HOSPITAL FOR JOINT DISEASES ORTHO INST
• 依托单位国家: 美国
• 财政年份: 1984
• 资助国家: 美国
• 起止时间: 1984-12-01 至 1993-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3287458
• 关键词: B lymphocyte; T lymphocyte; antiantibody; antigen presentation; binding proteins; biological signal transduction; calcium flux; cell adhesion; cell cell interaction; cell differentiation; cell membrane; crosslink; flow cytometry; histocompatibility antigens; human subject; immunoelectron microscopy; immunoglobulin M; interferons; interleukin 4; laboratory mouse; leukocyte activation /transformation; membrane proteins; monoclonal antibody; radiotracer; tissue /cell culture

This project will evaluate the impact of membrane IgM:ligand affinity on the mechanism by which human s cells undergo clonal expansion. The studies will assess the affinity requisites for mIgM to function in three capacities: (1) transducer of mitogenic signals for B cell S phase entry in the absence of T cell accessory signals, (2) transducer of signals for the partial activation of B cells, and (3) mediator of ligand internalization for processing and presentation to T cells. The research will directly test the hypothesis that the amount of T cell help required for expansion of ligand-specific B cell clones is indirectly related to the affinity of the ligand:mIgM interaction. The studies should enhance our understanding of the affinity constraints determining the immunoregulatory potential of foreign ligands, autologous rheumatoid factors, and anti-idiotype Abs under varying physiological conditions, and in so doing, should aid in the design of more optimal vaccines for B cell clonal expansion. The studies will utilize a large group of mouse anti-human IgM MoAbs that bind to bivalently expressed epitopes on mIgM with a wide range of affinities (Ka = 2x105 to 6x108). The work will have four major aims: (1) Establish that the pronounced T cell and T cell factor independent (TI) signaling potential of certain anti- IgM MoAb mixtures is due to an enhanced functional affinity for mIgM, and assess whether different phases of the prolonged signaling period needed for TI ligand-induced B cell DNA synthesis have distinct affinity requirements. This will be addressed by in vitro culture experiments, immunoelectron microscopy, and cellular equilibrium binding analyses. (2) Evaluate the minimal binding affinity for ligand induction of certain pre-S phase phenomena. This will involve Indo 1 analysis of intracellular free Ca2+ and FACS analysis of the membrane expression of class II MHC and activation-associated molecules. (3) Assess the minimal ligand affinity requirement for signaling B cell S phase entry in the presence of IFN-gamma, IL4, or low MW BCGF. (4) Evaluate the minimal ligand affinity for B cell proliferation with linked, cognate T cell help. This will involve B cell culture with MoAb Fab fragments and mouse Ig specific human T cell clones. Results from these in vitro studies with polyclonally-reactive, affinity diverse ligands should provide a unifying explanation for the apparently diverse functions attributed to mIgM in facilitating B cell clonal expansion.

该项目将评估膜IGM的影响：配体 对人类细胞经历克隆的机制的亲和力 扩张。 研究将评估亲和力要求 MIGM在三个容量中发挥作用：（1）有丝分裂的传感器 在没有T细胞附件的情况下，B细胞S相进入的信号 信号，（2）信号的传感器，用于部分激活 B细胞和（3）配体内在化的介体 并呈现给T细胞。 该研究将直接测试 假设扩展所需的T细胞帮助量 配体特异性B细胞克隆与 配体的亲和力：migm相互作用。 研究应该 增强我们对确定亲和力约束的理解 外国配体的免疫调节潜力，自体配体 类风湿因子和抗IDiotype ABS在不同 生理条件以及这样做应该有助于设计 B细胞克隆膨胀的最佳疫苗。 研究将利用大量小鼠抗人IgM 与A在MIGM上结合二人表达的摩押 广泛的亲和力范围（KA = 2x105至6x108）。 工作将有 四个主要目的：（1）确定明显的T细胞和T 细胞因子独立（Ti）信号传导潜力 IGM Moab混合物是由于对功能亲和力的增强所致 MIGM，并评估延长的不同阶段是否延长 Ti配体诱导的B细胞DNA合成所需的信号传导周期 有不同的亲和力要求。 这将由 体外培养实验，免疫电子显微镜和细胞 平衡结合分析。 （2）评估最小结合 对某些s相位现象的配体诱导的亲和力。 这将涉及Indo 1分析细胞内游离Ca2+和 II类MHC和 激活相关的分子。 （3）评估最小配体 信号传导B细胞S相进入的亲和力要求 IFN-GAMMA，IL4或低MW BCGF的存在。 （4）评估 与链接的B细胞增殖的最小配体亲和力， 同源T细胞帮助。 这将涉及MoAb的B细胞培养 Fab片段和小鼠IG特异性人类T细胞克隆。 结果 从这些对多克隆反应性，亲和力的体外研究中 不同的配体应为 显然，在促进B中归因于MIGM的多种功能 细胞克隆膨胀。