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: 3287455
• 负责人: Patricia K. Mongini
• 金额: $ 13.1万
• 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 1988-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3287455
• 关键词: B lymphocyte; blocking antibody; cell differentiation; cell membrane; crosslink; histocompatibility antigens; human tissue; hybridomas; immunoglobulin M; immunoglobulins; ion exchange chromatography; leukocyte activation /transformation; monoclonal antibody; radioimmunoassay; radiotracer; rheumatoid factor; stoichiometry

The proposed study will investigate the nature of the ligand interaction with membrane IgM which is needed for B lymphocyte stimulation. This will be accomplished through the use of a panel of anti-human IgM monoclonal antibodies (MoAbs) which differ in affinity and/or epitope specificity. Using these defined anti-Ig ligands, an explanation for the diverse regulatory effects of anti-Ig ligands which have been observed in the past will be sought. These studies may elucidate the factors that determine whether or not autologous anti-Ig constant region antibodies (rheumatoid factors) can regulate the function of B cells to which they bind. The different mouse anti-human IgM MoAbs will be compared in their ability to a) induce resting B cells to proliferate, b) affect the proliferation and differentiation of B cells stimulated with other mitogens, and c) stimulate early changes in B cells which precede the S phase of the cell cycle. Once sets of stimulatory and non-stimulatory (perhaps inhibitory) MoAbs have been identified, explanations for the functional differences in these ligands will be sought. This will involve comparing stimulatory and non-stimulatory MoAbs and their F(ab')2 fragments for a) affinity and stoichiometry of binding to IgM and b) epitope specificity. The epitope specificity of the MoAbs will be investigated by competitive inhibition studies and by analysis of the ability of each MoAb to bind to chemically modified IgM, IgM fragments, and synthesized peptides which have been predicted by hydrophilicity and conformational analysis as likely to constitute immunogenic epitopes on the human IgM molecule. In addition, the nature of membrane molecule crosslinkage which is necessary to stimulate B cell proliferation will be studied. This will involve comparing the mitogenic capacity of a divalent anti-IgM MoAb to a hybrid antibody which consists of one F(ab') arm directed to IgM and one F(ab') arm directed to a human major histocompatibility (MHC) antigen.

拟议的研究将调查配体相互作用的性质 具有刺激 B 淋巴细胞所需的膜 IgM。 这将 通过使用一组抗人 IgM 单克隆抗体来完成 亲和力和/或表位特异性不同的抗体 (MoAb)。 使用这些定义的抗 Ig 配体，可以解释多种 过去观察到的抗 Ig 配体的调节作用 将被寻求。 这些研究可能会阐明决定因素 是否有自体抗 Ig 恒定区抗体（类风湿 因子）可以调节与其结合的 B 细胞的功能。 将比较不同的小鼠抗人 IgM MoAb 的能力 a) 诱导静息 B 细胞增殖，b) 影响增殖 和用其他有丝分裂原刺激的 B 细胞的分化，以及 c) 刺激 B 细胞进入 S 期之前的早期变化 循环。 一旦设置刺激性和非刺激性（也许是抑制性） MoAb 已被鉴定，解释了其中的功能差异 将寻找这些配体。 这将涉及比较刺激和 非刺激性 MoAb 及其 F(ab')2 片段的 a) 亲和力和 与 IgM 结合的化学计量和 b) 表位特异性。 表位 MoAb 的特异性将通过竞争性抑制进行研究 研究并分析每种 MoAb 的化学结合能力 修饰的 IgM、IgM 片段和合成肽 通过亲水性和构象分析预测可能 构成人类 IgM 分子上的免疫原性表位。 此外，膜分子交联的性质是 将研究刺激 B 细胞增殖所必需的。 这将 涉及比较二价抗 IgM MoAb 与 混合抗体，由一个针对 IgM 的 F(ab') 臂和一个 F(ab') 臂针对人类主要组织相容性 (MHC) 抗原。