The Cloning, Optimization, and Validation of Caninized-Phage Monoclonal Antibody Library For Regulation of Cancer Responses in Canus lupus

癌症已经成为狗发病和死亡的主要原因，估计发病率为1 / 4。尽管传统的化疗和放疗取得了进步，但对大多数癌症类型的完全治愈仍然是难以捉摸的，挑战在于开发出高度靶向的治疗方法，既能杀死癌细胞，又能让正常细胞保持健康。同样的看似无法克服的问题也适用于人类癌症的治疗。在过去的20年里，肿瘤学的一个巨大进步是发现和应用单克隆抗体作为新的治疗工具来改善癌症患者的治疗。事实上，制药行业最大的研发领域之一就是单克隆抗体的开发。什么是单克隆抗体（MAb’s）？这些是我们身体产生的蛋白质，是健康免疫系统的正常组成部分，是大自然帮助我们清除体内外来病毒和致病菌的方式，也能最大限度地减少疾病的发展。事实上，当我们变老时，疾病会发展，或者当我们变老时，我们对病毒更敏感，其中一个原因基本上是由于免疫系统的“破坏”。然而，科学家们已经发现了利用免疫系统力量的惊人方法，首先克隆MAb，然后激活MAb来治疗特定疾病。MAb就像“灵丹妙药”，因为它们可以特异性地瞄准不良细胞并治愈疾病。然而，使用单克隆抗体作为灵丹妙药的一个主要障碍是，免疫系统可以将任何看起来与体内正常蛋白质不同的颗粒识别为外来颗粒；即使是给病人注射的单克隆抗体也可能看起来是外来的，在单克隆抗体有机会起作用并引发治愈之前就被从体内清除了。为了克服这一障碍，科学家们又开创了一种“定制”单克隆抗体的方法，使其对人体免疫系统不可见，并能循环并靶向疾病细胞。这种针对人类的单克隆抗体被称为“人源化”单克隆抗体，这种方法为未来治疗复杂疾病提供了进一步的希望。尽管取得了这些进展，但原则上可以像治疗人类一样治疗狗的癌症，但还没有使用单克隆抗体进行任何重大尝试。主要原因是“狗化”单克隆抗体必须使用不能被狗的免疫系统识别为入侵者的单克隆抗体，而狗化单克隆抗体还没有被开发出来，这将大大促进这一过程。在我们的研究项目中，我们开发了新的方法来捕获和克隆狗的免疫系统可以产生的大部分单克隆抗体。我们的应用程序旨在优化我们的狗化单抗库，并通过分离潜在的狗化“灵丹妙药”来验证它，这些灵丹妙药可用于抑制与导致狗癌症有关的特定受体蛋白。这些狗化单克隆抗体的成功验证将导致临床试验，有望改善患有癌症的狗的健康和寿命，但也会为如何开发狗化单克隆抗体来治疗狗的其他年龄相关疾病提供路线图。

Cancer has emerged as a major cause of morbidity and mortality in the dog, with an estimated incidence of 1 in 4. Despite advances in conventional chemotherapy and radiation, complete cures for most cancer types remains elusive, the challenge being to develop highly targeted therapies that kill cancer cells but leave normal cells healthy. The same seemingly insurmountable problem holds true for the treatment of human cancer and a big advance in oncology in the past 20 years has been the discovery and application of monoclonal antibodies as novel therapeutic tools to improve cancer treatments in patients. In fact, one of the biggest areas of R and D in the pharmaceutical industry is now in the development of monoclonal antibodies. What are monoclonal antibodies (MAb's)? These are proteins made by our bodies that form a normal part of a healthy immune system and is the way nature helps to rid our bodies of foreign viruses, pathogenic bacteria, and also minimize disease development. Indeed, one reason why disease develops when we age or why we are more sensitive to viruses when we are older is essentially due to a "broken" immune system. However, scientists have discovered spectacular ways to harness the power of the immune system, by first cloning MAb's and then turning the MAb's on to treat particular diseases. The MAb's then act essentially like "magic bullets" as they can specifically hone in on rogue cells and cure disease. However, a major obstacle in this strategy of using MABs as magic bullets is that the immune system can recognize as foreign any particle that looks in any way different from normal proteins in the body; even a MAb given to patients with disease can paradoxically look foreign and be eliminated from the body before the MAb has a chance to act and elicit a cure. To overcome this obstacle, scientists in turn have pioneered a way to "tailor" the MAb so that it appears invisible to the body's immune system and can circulate and target disease cells. This tailoring of a MAb to treat humans is called "human-izing" the MAb and this approach provides further hope that complex diseases can be treated in the future. Despite these advances, the treatment of dog cancer, though in principle could be carried out like that in humans, has not been attempted in any significant way using MAb's. The main reason is that "dog-ized" MAb's would have to be used that are not recognized as invaders by the dog's immune system and dog-ized MAb's have not been developed that would greatly facilitate this process. In our research programme, we have developed novel methods to capture and clone the large majority of MAb's that can be made by the dog's immune system. Our application aims to optimize our dog-ized MAb library and validate it by isolating potential dog-ized "magic bullets" that can be used to inhibit specific receptor proteins that are implicated in causing dog cancers. The successful validation of these dog-ized MAb's will lead to clinical trials that would hopefully improve the health and longevity of dogs with cancer, but also produce a road map on how to develop dog-ized MAb's to treat other age related diseases in the dog.