Bioengineering of a New Antibody Drug Delivery Technology

描述（由申请人提供）：单克隆抗体（MAb）是许多脑疾病的潜在新疗法，包括阿尔茨海默病（AD）、帕金森病、疯牛病、西尼罗河脑炎、神经艾滋病、脑损伤、脑癌或多发性硬化症。在几乎所有情况下，给予血液的单克隆抗体治疗剂必须能够进入脑内的靶位点。然而，MAb是不穿过血脑屏障（BBB）的大分子药物。血脑屏障问题阻碍了抗体药物的脑药物开发。这项研究将开发一种新的技术，将抗体药物输送到大脑，也可用于其他器官。这项工作是基于由2种抗体组成的融合蛋白的基因工程。一种抗体是治疗性抗体，另一种抗体是药物递送系统。这种新技术的原型是新型融合蛋白，其通过将单链Fv（ScFv）抗体融合到针对人胰岛素受体（HIR）的基因工程单抗的两条重链的羧基末端而产生。抗HIR的MAb确实通过内源性胰岛素受体上的BBB转运穿透脑。可行性研究表明，融合蛋白在基因工程和COS细胞中瞬时表达后保留了其双功能特性：融合抗体既结合HIR，使其能够在体内转运穿过BBB，又结合Abeta斑块，引起AD转基因小鼠脑中的淀粉样蛋白解聚。这些I期研究的目的是（1）对表达异源四聚体融合蛋白的串联载体进行遗传工程改造，（2）对在无血清培养基中表达高水平融合抗体的永久转染的宿主细胞系进行工程改造，（3）对融合抗体进行生物化学和功能表征，以及（4）测定所述融合蛋白在成年恒河猴中的血浆药代动力学和脑摄取。如果成功，这项研究将开发一种新的抗体治疗药物输送技术。 公共卫生相关性：单克隆抗体是生物技术的强大的新治疗产品。抗体药物可以应用于许多严重的脑部疾病，如阿尔茨海默病、帕金森病、疯牛病、西尼罗河脑炎、神经艾滋病、脑损伤、脑癌或多发性硬化症。然而，不能开发用于这些疾病的抗体药物，因为抗体药物不能穿过血脑屏障（BBB）。本研究将开发一种用于大脑的抗体药物给药新技术，该技术可应用于其他器官。

DESCRIPTION (provided by applicant): Monoclonal antibodies (MAb) are potential new therapeutics for many brain diseases, including Alzheimer's disease (AD), Parkinson's disease, mad cow disease, West Nile encephalitis, neuro-AIDS, brain injury, brain cancer, or multiple sclerosis. In almost all cases, it is necessary that the MAb therapeutic that is administered into the blood be able to access target sites within the brain. However, MAb's are large molecule drugs that do not cross the blood-brain barrier (BBB). The BBB problem prevents the brain drug development of antibody drugs. The proposed research will develop a new technology for antibody drug delivery to brain, which could also be used for other organs. This work is based on the genetic engineering of a fusion protein comprised of 2 antibodies. One antibody is the therapeutic antibody, and the other antibody is a drug delivery system. The prototype of this new technology is novel fusion protein, which is created by fusion of a single chain Fv (ScFv) antibody to the carboxyl terminus of both heavy chains of a genetically engineered MAb against the human insulin receptor (HIR). The MAb against the HIR does penetrate brain via transport across the BBB on the endogenous insulin receptor. Feasibility studies show the fusion protein retains its bi-functional properties following genetic engineering and transient expression in COS cells: the fusion antibody both binds the HIR, to enable transport across the BBB in vivo, and binds Abeta plaque, to cause amyloid disaggregation in AD transgenic mouse brain. The purpose of these Phase I studies is (1) genetically engineer a tandem vector expressing the hetero-tetrameric fusion protein, (2) to engineer a permanently transfected host cell line that expresses high levels of the fusion antibody in serum free medium, (3) to biochemically and functionally characterize the fusion antibody, and (4) determine the plasma pharmacokinetics and brain uptake of the fusion protein in the adult Rhesus monkey. If successful, this research will develop a new technology for the drug delivery of antibody therapeutics. Public Health Relevance: Monoclonal antibodies are powerful new therapeutic products of biotechnology. Antibody drugs could be applied to many serious brain disorders, such as Alzheimer's disease, Parkinson's disease, mad cow disease, West Nile encephalitis, neuro-AIDS, brain injury, brain cancer, or multiple sclerosis. However, antibody drugs cannot be developed for these disorders, because the antibody drugs do not cross the blood-brain barrier (BBB). The present research will develop a new technology for the drug delivery of antibody drugs for the brain, which could be applied to other organs.