MONOCLONAL ANTIBODY-TOXIN CONJUGATES FOR TUMOR THERAPY IN VIVO

用于体内肿瘤治疗的单克隆抗体-毒素缀合物

• 批准号: 3860822
• 负责人: R J YOULE
• 金额: --
• 依托单位: NATIONAL INSTITUTE OF NEUROLOGICAL DISORDERS AND STROKE
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/3860822
• 关键词: CD4 molecule; HIV infections; Macaca mulatta; antiantibody; binding proteins; brain neoplasms; cerebellar Purkinje cell; cytotoxicity; drug administration routes; genetic manipulation; guinea pigs; helper T lymphocyte; human immunodeficiency virus; human subject; human tissue; immunoconjugates; laboratory rat; molecular cloning; monoclonal antibody; neoplasm /cancer immunotherapy; protein engineering; toxin; tumor antigens

Monoclonal antibodies selectively bind tumor cell differentiating antigens in vitro and in vivo. Natural effector mechanisms often do not mediate killing of monoclonal antibody bound cells so we have devised methods of linking extremely toxic proteins to the antibodies to selectively kill tumor cells. Two methods of coupling toxic proteins, like ricin to antibodies, have been used to kill antigen-positive cells in vitro. Ricin has two subunits: the A subunit blocks protein synthesis when in the cytosol and the B subunit binds galactose groups on all cell surfaces but also facilitates the transport of ricin A chain to the cytosol. 1) Linkage of the ricin A chain to antibodies yields reagents with low nontarget toxicity but target cell toxicity too slow for in vivo applications; 2) Linkage of intact ricin to antibodies results in very potent target cell toxicity but the nontarget cell killing must be prevented by a ligand which blocks ricin B chain binding to cells. This has limited its application to in vitro situations where 100 mM lactose can block ricin binding. We have succeeded in developing several new approaches to apply immunotoxins in vivo. 1) Cloning of toxins, then altering their structure at the gene level to decrease non-target cell toxicity; 2) intrathecal administration of immunotoxins for therapy of brain tumors that kill 2-5 logs of tumor cells in animal models; 3) preparation of genetically engineered immunotoxins for clinical trials of human brain tumor patients; 4) prevention of immune response against immunotoxin with anti-CD4 antibodies; S) construction of HIV-infected cell immunotoxins; 6) specific deletion of Purkinje cells in rats, guinea pigs and rhesus monkeys; and 7) Use of human cytotoxic proteins such as RNase linked to antibodies will selectively target cells.

单抗选择性结合肿瘤细胞分化 体外和体内的抗原。自然效应器机制通常不会 介导对单抗结合细胞的杀伤，所以我们设计了 将剧毒蛋白与抗体连接起来的方法 选择性地杀死肿瘤细胞。 将有毒蛋白质，如蓖麻毒素与抗体偶联的两种方法 在体外被用来杀死抗原阳性细胞。蓖麻毒素有两种 亚基：A亚基在胞浆中阻止蛋白质合成， B亚基与所有细胞表面的半乳糖基团结合，但也 促进了蓖麻毒素A链向胞浆的运输。1)链接 与抗体结合的蓖麻毒素A链产生非靶向性低的试剂 毒性，但靶细胞毒性太慢，无法在体内应用；2) 完整的蓖麻毒素与抗体的连接导致非常有效的靶细胞 毒性，但非靶细胞杀伤必须通过配基来防止 它阻断了蓖麻毒素B链与细胞的结合。这限制了它的 应用于体外100 mM乳糖可阻断蓖麻毒素的情况 有约束力的。 我们已经成功地开发了几种新的方法来应用 体内的免疫毒素。1)克隆毒素，然后改变其结构 在基因水平上降低非靶细胞毒性；2)鞘内 免疫毒素治疗可杀死2-5人的脑肿瘤 动物模型中肿瘤细胞的记录；3)遗传学制备 人脑肿瘤临床试验中的工程免疫毒素 患者；4)预防免疫毒素的免疫反应 抗CD_4抗体；S)构建HIV感染细胞免疫毒素； 6)大鼠、豚鼠和恒河猴浦肯野细胞的特异性缺失 猴子；以及7)使用人类细胞毒性蛋白，如与 抗体将选择性地以细胞为靶标。