SYSTEMATIC STUDY OF BORON RICH ANTIBODY CONJUGATES

本提案中所述研究的广泛、长期目标 是开发一种方法， 中子俘获反应[10 B（n，alpha）7 Li]用于癌症治疗，使用 单克隆抗体作为选择性递送硼-10的载体 从原子到肿瘤 据计算，为了使这种方法 为了成功，大约10/3的硼-10个原子必须连接到每个 免疫蛋白，而不损害其有效定位于 肿瘤 尽管有几个小组已经证明了 抗体与所需量的硼，在每一个案件肝脏摄取 的免疫缀合物已经大大增加， 肿瘤靶向 本建议描述了一个成熟的系统 解决这一问题的办法涉及协调和整合 研究化学和免疫学。 本研究中所用的硼化合物是均相低聚物 富含硼的磷酸二酯衍生物（富含硼的“trailers”）。 这类化合物衍生自简单的前体，并且可以是 使用自动化DNA合成简单有效地组装 仪器. 各种结构性影响的表征 改变（单体几何形状、硼含量和亲水性; 大分子连接性;电荷和电荷分布） 富含硼的拖车将有利于选择只有最 有前途的拖车试剂（非常亲水，低非特异性结合， 蛋白质，在肝脏以及其他器官中的最小摄取）用于缀合 免疫蛋白。 抗体工程将用于产生免疫蛋白递送 用于富硼拖车试剂的车辆。 全抗体以及 其免疫反应性片段（通过抗体工程产生） 特异性针对肿瘤相关癌胚抗原（CEA）将是 研究了 这些蛋白质中的每一种都会被赋予暴露的，反应性的 用于与富硼尾部位点特异性缀合的巯基 分子。 这些免疫蛋白上的巯基与 适当官能化的富硼低聚磷酸盐将提供广泛的 各种富含硼的免疫缀合物，以及 这些新化合物将被广泛地表征。 的 生物分布和肿瘤靶向能力的最佳表现的富硼 免疫缀合物将被彻底评估，最有前途的 免疫偶联物最终将在设计为 证明其在BNCT中的有效性。 这些系统的研究将导致 富硼尾试剂的优化， 化学，和免疫蛋白运载工具，并将最终 证明了免疫缀合物方法对硼的可行性 中子俘获治疗癌症

The broad, long-term objective of the research described in this proposal is to develop the means to apply the high linear energy transfer boron-10 neutron capture reaction [10B(n,alpha)7Li] to cancer therapy, using monoclonal antibodies as vehicles for the selective delivery of boron-10 atoms to tumors. It has been calculated that in order for this approach to be successful about 10/3 boron-10 atoms must be attached to each immunoprotein without compromising its ability to localize efficiently in tumor. Although several groups have demonstrated the conjugation of antibodies with the required amount of boron, in every case liver uptake of the immuno-conjugates has been greatly increased at the expense of tumor targeting. The present proposal describes a mature systematic approach to this problem that involves the coordination and integration of research in chemistry and immunology. The boron compounds to be used in this research are homogeneous oligomeric boron-rich phosphate diester derivatives (boron-rich 'trailers'). Compounds of this class are derived from simple precursors and can be simply and efficiently assembled using automated DNA synthesis instruments. Characterization of the effects of various structural alterations (monomer geometry, boron content, and hydrophilicity; macromolecular connectivity; charge and charge distribution) upon the boron-rich trailers will facilitate the selection of only the most promising trailer reagents (very hydrophilic, low non-specific binding to protein, minimal uptake in liver as well as other organs) for conjugation to immunoproteins. Antibody engineering will be used to generate immunoprotein delivery vehicles for the boron-rich trailer reagents. Whole antibodies as well as their immunoreactive fragments (generated via antibody engineering) specific for the tumor-associated carcinoembryonic antigen (CEA) will be studied. Each of these proteins will be endowed with exposed, reactive thiol groups for site-specific conjugation with boron-rich trailer molecules. The reaction of the thiol groups on these immunoproteins with appropriately functionalized boron-rich oligophosphates will afford a wide variety of boron-rich immunoconjugates, and the in vitro properties of these novel compounds will be extensively characterized. The biodistribution and tumor-targeting ability of the best behaved boron-rich immunoconjugates will be thoroughly evaluated, and the most promising immunoconjugates will be ultimately examined in studies designed to demonstrate their efficacy in BNCT. These systematic studies will lead to the optimization of the boron-rich trailer reagents, the conjugation chemistry, and the immunoprotein delivery vehicles, and will ultimately demonstrate the viability of the immunoconjugate approach to the boron neutron capture therapy of cancer.