ANTIBODY FUSION PROTEINS FOR THE THERAPY OF CANCER

描述：(申请人摘要)微小残留病是一种 许多常见恶性肿瘤的治疗中存在严重问题，包括 乳腺癌、肺癌、卵巢癌和胃肠癌。更有效 治疗需要针对最小的残留疾病和 微转移。申请人认为，合并招聘和 使用抗体融合蛋白的共刺激作用可能协同作用于 放大宿主对肿瘤的反应。申请者将合成抗体 靶向肿瘤相关基因的可变区融合分子 抗原，如CEA或HER2/neu，与编码 趋化因子RANTES和/或B7.1 T细胞胞外区 共刺激配体。Rantes，一种C-C趋化因子，作用于招募T细胞 和其他免疫效应细胞转移到炎症部位。B7.1， CD28共刺激受体的配体作用于传递第二个 T细胞参与后激活T细胞所需的信号 受体(TCR)。与RANTES的融合旨在提高 免疫效应细胞的跨内皮迁移和募集， 而与B7.1的融合预计会激活特定的宿主反应 从效应细胞群转移到肿瘤。申请者将建造和 提纯肿瘤相关新抗体融合蛋白 抗原HER2/neu和CEA与趋化因子RANTES和/或 B7.1共刺激配体的胞外区。两个有希望的人 已经构建了与RANTES和B7.1的融合，并正在 被积极刻画的。他将评估免疫反应性， 融合蛋白的受体结合特性及生物活性 在试管中。将研究RANTES融合的抗原结合、结合 细胞受体，以及诱导趋化性的能力。B7.1融合 蛋白质的特征是能够与抗原、同源物结合 细胞受体(CTLA4和CD28)，并提供共刺激 在体外发出信号。他将描述重组体的特性 体内融合蛋白及其致癌作用 拒绝。放射性标记融合蛋白在体内的定位 在植入HER2/neu或CEA的SCID小鼠中进行研究，表达和 不表达的肿瘤。表达靶抗原的肿瘤模型 将在具有免疫能力的同基因小鼠身上进行研究。聚变 将测试蛋白质在引发肿瘤排斥反应和 一种细胞溶解的T细胞反应。CEA和HER2/neu均低表达 在某些正常组织中的含量。因此，申请者将成为 抗CEA融合蛋白对小鼠的治疗效果和潜在毒性 转基因CEA小鼠。抗体融合蛋白的使用可能克服 基因转移和/或标准抗体治疗的局限性和 是解决最小残差问题的一种很有前途的方法。 疾病。

DESCRIPTION: (Applicant's Abstract) Minimal residual disease is a serious problem in the therapy of many common malignancies including breast, lung, ovarian and gastrointestinal cancer. More effective therapies are required to target minimal residual disease and micrometastases. The applicant believes that combined recruitment and costimulation using antibody fusion proteins may act synergistically to amplify host response to tumors. The applicant will synthesize antibody fusion molecules with variable domains directed against tumor associated antigens, such as CEA or her2/neu, linked to sequences encoding the chemokine RANTES and/or to the extracellular domain of the B7.1 T-cell costimulatory ligand. RANTES, a C-C chemokine acts to recruit T-cells and other immune effector cells to sites of inflammation. B7.1, the ligand for the CD28 costimulatory receptor acts to deliver a second signal required for T-cell activation following engagement of the T-cell receptor (TCR). Fusion with RANTES is designed to increase transendothelial migration and recruitment of the immune effector cells, while fusion with B7.1 is expected to activate a specific host response to tumor from effector cell population. The applicant will construct and purify novel antibody fusion proteins specific for the tumor-associated antigens, her2/neu and CEA, linked to the chemokine RANTES and/or the extracellular domain of the B7.1 costimulatory ligand. Two promising fusions to RANTES and to B7.1 have already been constructed and are being actively characterized. He will evaluate the immunoreactivity, receptor binding properties and biological activity of fusion proteins in vitro. RANTES fusions will be studied for antigen binding, binding to cellular receptors, and for ability to elicit chemotaxis. B7.1 fusion proteins will be characterized for ability to bind to antigen, cognate cellular receptors (CTLA4 and CD28), and to deliver a co-stimulatory signal in vitro. He will characterize the properties of the recombinant fusion proteins in vivo and their effectiveness in causing tumor rejection. Localization of radiolabelled fusion proteins in vivo will be studied in SCID mice implanted with her2/neu or CEA expressing and non-expressing tumors. Tumor models that express the target antigens will be studied in immunologically competent syngeneic mice. Fusion proteins will be tested for efficacy in eliciting tumor rejection and a cytolytic T-cell response. Both CEA and her2/neu are expressed at low levels in certain normal tissues. Therefore, the applicant will model efficacy and potential toxicity of anti CEA fusion proteins in a transgenic CEA mouse. The use of antibody fusion proteins may overcome limitations of gene transfer and/or standard antibody therapy and represents a promising approach to the problem of minimal residual disease.