TARGETING ENDOGENOUS ANTIBODIES TO OVARIAN CARCINOMA

针对卵巢癌的内源性抗体

• 批准号: 6623365
• 负责人: MOO J CHO
• 金额: $ 14.78万
• 依托单位: UNIV OF NORTH CAROLINA CHAPEL HILL
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-04-01 至 2004-09-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6623365
• 关键词: antitumor antibody; clone cells; folate; galactose; galactosyltransferases; gene targeting; genetically modified animals; humoral immunity; immunoconjugates; laboratory mouse; neoplasm /cancer immunology; neoplasm /cancer immunotherapy; nonhuman therapy evaluation; ovary neoplasms; receptor binding; vitamin receptor

DESCRIPTION (provided by applicant): Humans and Old World primates naturally produce a significant amount of antibodies which recognize a particular galactosyl epitope, GAL alpha 1-3GAL. We have been interested in testing if these anti-Gal antibodies can be targeted to undesirable cancerous cells. Specifically we wish to explore a possibility of redirecting these endogenous antibodies to ovarian carcinoma cells which overexpress folate receptor isotype alpha (FR-alpha) by means of chemical conjugates of folic acid to the galactosyl epitope. The end result should be the cytolysis of the target cell. Towards this goal, the present application is concerned with the total synthesis of the folate-digalactose conjugates and development of an ovarian cancer model in immune competent mice. Preparation of the conjugate which can mediate anti-Gal binding to FR+ cells with high avidity is the main chemistry goal of the project. Our strategy is to introduce multiple copies, 2 and 4 copies, of the epitopes to one molecule of folic acid at an optimal distance between them. Chemical synthesis will be carried out on a solid-phase support. The conjugates will be tested with FR+/Gal- human nasopharyngeal carcinoma KB cells for their ability of promoting the anti-Gal binding to FR on the cell surface. Specificity of the interaction will be tested in the presence of free folic acid or free disaccharide as well as with a conjugate that contains lactose instead of GAL alpha 1-3GAL. The antibody binding will be conveniently characterized by means of FACS procedure. The biological goal of this project is to develop a mouse model of ovarian cancer that is suitable for testing anti-tumor activity of our folate conjugates in vivo. Since normal mice express the galactosyl epitopes in their tissue, we will have to use alpha 1,3-GALactosyltransferase-knockout (GT/KO) mice. It is known that GT/KO mice produce anti-Gal as in humans. We plan to transform the ovarian epithelial cells harvested from these mice in culture to tumor-forming cell lines following a procedure we have recently developed. They will be then transfected with murine cDNA encoding full length FR-alpha. Finally these GAL-/FR+cells will be introduced into peritoneum of healthy GT/KO mice. Our current approach to immunotherapy of ovarian cancer is unique in that we are using naturally occurring endogenous antibodies. Immune modulators in this application are all small molecules with MW < 3 kDa, rendering pharmacokinetic properties most favorable for sustained activity in peritoneal cavity as well as reduced potential side effects.

描述（由申请人提供）： 人类和旧世界的灵长类动物自然会产生大量 识别特定的半乳糖基表位的抗体，gal alpha 1-3gal。 我们一直对测试这些抗GAL抗体是否可以 针对不良的癌细胞。特别是我们希望探索 将这些内源性抗体重定向到卵巢癌的可能性 通过过表达叶酸受体同种型α（FR-α）的细胞 叶酸的化学结合物与半乳糖基表位。最终结果 应该是靶细胞的细胞解析。朝着这个目标，现在 应用与叶酸 - 二乳糖的总合成有关 免疫能力中的卵巢癌模型的结合和开发 老鼠。 可以介导抗-gal结合到FR+细胞的结合物的制备 高亲和力是该项目的主要化学目标。 我们的策略是 将表位的多个副本（2和4副本）引入一个分子 叶酸之间的最佳距离。化学合成将是 在固相支撑上进行。结合将测试 FR+/Gal-人鼻咽癌KB细胞的促进能力 与细胞表面上的FR结合的抗GAL结合。相互作用的特异性 将在有游离叶酸或游离二糖的情况下进行测试 与含有乳糖代替加仑α1-3Gal的结合物一样。这 抗体结合将通过FACS方便地表征 程序。 该项目的生物学目标是开发卵巢的鼠标模型 适合测试叶酸抗肿瘤活性的癌症 结合体体内。由于正常小鼠在其中表达半乳糖基表位 组织，我们将不得不使用Alpha 1,3-半乳糖基转移酶敲除（GT/KO） 老鼠。众所周知，gt/ko小鼠像人类一样产生抗神经。我们计划 转化从培养中这些小鼠收获的卵巢上皮细胞到 遵循我们最近开发的过程，形成肿瘤的细胞系。 然后将用编码全长fr-α的鼠cDNA转染它们。 最后，这些gal-/fr+细胞将被引入健康的腹膜 GT/KO小鼠。 我们目前对卵巢癌免疫疗法的方法是独一无二的 正在使用天然存在的内源性抗体。免疫调节剂 应用都是小分子，带有MW <3 kDa，渲染药代动力学 最有利于腹膜腔中持续活动最有利的特性 由于潜在的副作用减少。