Active Immunity Targeted at PCSK9 for the Treatment of Hypercholesterolemia

描述（由申请方提供）：本提案的长期目标是设计和开发抑制/减少PCSK 9作用的新策略。这是一个潜在的强大的新的治疗目标，以调节LDL胆固醇和降低心血管疾病的负担。 PCSK 9（Proprotein convertase subtilisin/kexin type 9）是新近发现的一种基因，它通过与LDL受体结合，作为分子伴侣，介导LDL受体进入溶酶体降解，从而对LDL胆固醇水平产生深远影响。人体研究表明，总PCSK 9缺乏症的LDL胆固醇水平非常低（14-16 mg/dl），无不良临床后果。因此，PCSK 9将是治疗高胆固醇血症的极好靶点。此外，他汀类药物可增加PCSK 9转录，导致血浆PCSK 9水平升高。然后，他汀类药物和PCSK 9抑制剂的联合治疗将提供降低LDL胆固醇的更好疗法。 在本申请中，我们建议通过产生刺激针对PCSK 9的免疫系统的疫苗来使用主动免疫治疗策略。蛋白质是独特的生物分子，它们展开和折叠，产生不同构象异构体的混合物。我们开发了一种二硫键加扰技术，允许在天然异构体和不同的变性异构体之间进行可逆转化。我们的初步结果表明，这些异构体诱导对天然蛋白质的免疫原性和降低血浆胆固醇水平。这是一种使用二硫键加扰产生Pcsk 9的构象异构体（X-Pcsk 9）以诱导针对天然Pcsk 9的免疫原性的新方法。这一过程将阻断PCSK 9与LDL受体的相互作用，从而降低LDL胆固醇，用于治疗高胆固醇血症。此外，针对氧化LDL或载脂蛋白B肽的动脉粥样硬化疫苗已经显示出一些成功。因此，开发针对PCSK 9的疫苗以调节LDL胆固醇的提议是令人兴奋且可行的方法。在本申请中，我们将产生并生产一组X-Pcsk 9异构体疫苗，其将与天然Pcsk 9交叉反应。我们建议评估这些疫苗在体内降低胆固醇水平以及调节动脉粥样硬化发展的效力。总之，本研究将提供降低LDL水平和减轻心血管疾病负担的新型治疗方法。 公共卫生相关性：动脉粥样硬化是心血管疾病的主要原因之一。大多数患者患有LDL胆固醇升高。目前，这种疾病的治疗选择仅限于手术和他汀类药物的终身治疗，并且他汀类药物通常对某些患者不起作用。我们的研究旨在研究一个新的基因PCSK 9，并开发新的治疗方法来降低LDL胆固醇，阻止和逆转动脉粥样硬化。这项研究的成功将导致临床上适用的治疗方法来调节LDL和动脉粥样硬化的发展。

DESCRIPTION (provided by applicant): The long-term objective of this proposal is to design and develop novel strategies to inhibit/reduce PCSK9 action. This is a potential powerful new therapeutic target to regulate LDL cholesterol and reduce the burden of cardiovascular disease. PCSK9 (Proprotein convertase subtilisin/kexin type 9) is a newly discovered gene that has a profound effect on LDL cholesterol levels by binding to LDL receptor and acts as a chaperon, mediates LDL receptor to lysosome for degradation. Studies in Humans demonstrated that total PCSK9 deficiency had very low LDL cholesterol (14-16 mg/dl) with no adverse clinical consequences. Thus, PCSK9 would be an excellent target for the treatment of hypercholesterolemia. Moreover, it has been shown that statins increase PCSK9 transcription, resulting in higher plasma PCSK9 levels. Then, a combination treatment of statins and PCSK9 inhibitor(s) would provide a better therapy to reduce LDL cholesterol. In this application, we propose to use an active immunotherapy strategy by generating a vaccine that stimulates the immune system against PCSK9. Proteins are unique bio-molecules, they unfold and refold, generate a mixture of diverse conformational isomers. We developed a technique of disulfide scrambling permits reversible conversion between the native and diverse denatured isomers. Our preliminary results have shown that these isomers induced immunogenicity towards native protein and decreased plasma cholesterol levels. This is a novel approach to use disulfide scrambling to generate conformational isomers of Pcsk9 (X- Pcsk9) to induce immunogenicity towards native Pcsk9. This process will block the interaction of PCSK9 and LDL receptor to decrease LDL cholesterol for the treatment of hypercholesterolemia. Moreover, Vaccine for atherosclerosis towards oxidized LDL or apolipoprotein B peptide has shown some success. Thus, the proposal of developing vaccine against PCSK9 to regulate LDL cholesterol is an exciting and feasible approach In this application, we will generate and produce a panel of X-Pcsk9 isomers vaccines, which will cross- react with native Pcsk9. We propose to evaluate the potency of these vaccines on decreasing cholesterol levels as well as modulating atherosclerosis development in vivo. In summary, this study will provide novel therapeutic treatment for decreasing LDL levels and reducing the burden of cardiovascular disease. PUBLIC HEALTH RELEVANCE: Atherosclerosis is one of the leading causes for cardiovascular disease. Most patients suffer from elevated LDL cholesterol. Currently the treatment options for this disease are limited to surgery and life-long therapy on the statin drug, and statin often does not work well for certain patients. Our study seeks to study a new gene PCSK9 and develop novel therapeutics to decrease LDL cholesterol, and to stop and reverse atherosclerosis. The success of this study would lead to the development of clinically applicable therapeutics to modulate LDL and atherosclerosis.