PROTEOLYTIC ANTIBODIES FOR TREATMENT OF PSORIASIS

用于治疗牛皮癣的蛋白水解抗体

• 批准号: 7611956
• 负责人: ROBERT F BALINT
• 金额: $ 29.98万
• 依托单位: CYTODESIGN, INC.
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-02-15 至 2010-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7611956
• 关键词: AREG gene; Accounting; Address; Affect; Amphiregulin; Animals; Antibodies; Antibody Formation; Antigens; Binding; Cell Culture Techniques; Cells; Characteristics; Chronic; Cleaved cell; Clinic; Clinical Trials; Collaborations; Complementarity Determining Regions; Cultured Cells; Disease; Dose; Engineering; Enzyme Kinetics; Escherichia coli; Fab Immunoglobulins; Factor VIII; Goals; Human; Hydrolysis; Immunocompromised Host; Immunoglobulin Variable Region; In Vitro; Kinetics; Lesion; Libraries; Light; Link; Mediating; Modality; Monoclonal Antibodies; Mus; Passive Immunotherapy; Pathogenesis; Pharmacologic Substance; Phase; Phenotype; Psoriasis; Reporter; Resistance; Role; Safety; Serine Protease; Skin; Specificity; Structure; System; Therapeutic; Therapeutic Uses; Time; Transgenic Mice; Transplantation; Triad Acrylic Resin; Universities; Variant; antibody engineering; authority; base; cooking; human monoclonal antibodies; humanized antibody; keratinocyte; keratinocyte growth factor; neutralizing antibody; novel therapeutics; pre-clinical; public health relevance; research clinical testing; sensor; skin disorder; therapeutic target; tool

DESCRIPTION (provided by applicant): Proteolytic antibodies are a novel therapeutic modality that has the potential to revolutionize antibody-based therapeutics. The overall goal of this project is to develop potent proteolytic human monoclonal antibodies (mAb) against a new target for treatment of psoriasis. Several recent studies demonstrate a key role for the keratinocyte growth factor amphiregulin (AR) in the pathogenesis of psoriasis. AR-neutralizing antibodies given at high doses alleviate some of the characteristic lesions in human psoriatic skin transplanted onto immunocompromised mice. However, grams of passively administered antibodies will be required for chronic therapy, a serious limitation of the traditional monoclonal antibody approach. We hypothesize that a proteolytic anti-AR antibody can provide comparable benefit at a dose 3-4 logs below that of conventional antibodies. Proteolytic antibodies have been observed naturally, and certain disease states provoke the formation of antibodies with physiologically significant proteolytic activities. For example, Factor VIII hydrolysis by proteolytic antibodies accounts for Factor VIII resistance in many hemophiliacs. Such effects suggest the potential efficacy of proteolytic antibodies in the clinic. It has been estimated that a proteolytic antibody with a modest turnover rate of 0.1/min could inactivate over 2000 times much antigen as an antibody that binds stoichiometrically. A third of the human antibody kappa light chain variable domain (V() germline repertoire contain canonical serine protease-like catalytic triads in their complementarity-determining regions (CDR), and some have detectable peptidolytic activity. The tools of antibody engineering allow the construction of large libraries based on these human V: structures, which may contain effective proteolytic activities against a broad spectrum of therapeutic targets. What is lacking is a robust system for direct selection of desired activities from such libraries. To address this need, we have developed a proprietary cell-based system for the selection of target-specific proteolytic activities with potentially unprecedented catalytic efficiencies from large libraries of antibody Fab fragments containing proteolytic V( domains. The selection system comprises a proteolytic activity sensor in which an auto-inhibited reporter is linked to the target in such a way that cleavage of the target leads to activation of the reporter. When the sensor is expressed in E. coli cells along with a proteolytic V(-containing antibody library, cells expressing antibodies with target-cleaving V( domains can be identified by the selectable phenotype conferred on the cells by the activated reporter. The system will be used to select and optimize human antibody Fab fragments containing V( domains with high proteolytic activity against human amphiregulin. The most active proteolytic Fab(s) will be characterized in vitro with respect to enzyme kinetics, specificity, and the ability to neutralize AR bioactivity on cultured cells. In Phase II, the most promising molecules will be subjected to pre-clinical evaluation in animals, pursuant to submission of an IND application for clinical trials. PUBLIC HEALTH RELEVANCE: Monoclonal antibodies have shown great promise for the treatment of psoriasis, but frequent administration of prohibitively large doses would be required. Proteolytic antibodies are a novel therapeutic modality that has the potential to provide a comparable or better benefit with much smaller doses. In this project, a system which has been developed for engineering proteolytic activity into antibodies will be applied to developing proteolytic antibodies against amphiregulin, a promising new target for the treatment of psoriasis.

描述（由申请人提供）：蛋白水解抗体是一种新的治疗方式，有可能彻底改变基于抗体的治疗方法。该项目的总体目标是开发针对银屑病治疗新靶点的有效蛋白水解人单克隆抗体（mAb）。最近的几项研究表明角化细胞生长因子双调节蛋白（AR）在牛皮癣的发病机制中起关键作用。高剂量的ar中和抗体可减轻人类银屑病皮肤移植到免疫功能低下小鼠身上的一些特征性病变。然而，被动给药抗体的克数将需要用于慢性治疗，这是传统单克隆抗体方法的严重限制。我们假设一种蛋白水解抗ar抗体可以在比常规抗体低3-4倍的剂量下提供类似的益处。蛋白水解抗体已经在自然界中被观察到，某些疾病状态会引发具有显著蛋白水解活性的抗体的形成。例如，蛋白水解抗体对因子VIII的水解是许多血友病患者对因子VIII耐药的原因。这些作用提示了蛋白水解抗体在临床中的潜在功效。据估计，一个周转率为0.1/min的蛋白水解抗体可以灭活超过2000倍的抗原，作为一个化学计量结合的抗体。三分之一的人抗体kappa轻链可变结构域(V（）种系库在其互补决定区（CDR）含有典型丝氨酸蛋白酶样催化三联体，其中一些具有可检测的肽水解活性。抗体工程工具允许基于这些人类V：结构构建大型文库，这些文库可能含有针对广泛治疗靶点的有效蛋白水解活性。缺少的是从这些库中直接选择所需活动的健壮系统。为了满足这一需求，我们开发了一种专有的基于细胞的系统，用于从含有蛋白水解V(结构域的大量抗体Fab片段库中选择具有潜在前所未有的催化效率的靶向蛋白水解活性。所述选择系统包括蛋白水解活性传感器，其中自动抑制的报告基因以这样一种方式与目标相连接，即目标的切割导致报告基因的激活。当传感器与含有蛋白水解V（）的抗体文库一起在大肠杆菌细胞中表达时，表达具有靶向切割V（）结构域的抗体的细胞可以通过激活的报告细胞赋予细胞的可选择表型来识别。该系统将用于选择和优化含有V(结构域的抗人双调节蛋白高蛋白水解活性的人抗体Fab片段。最具活性的蛋白水解Fab将在体外根据酶动力学、特异性和在培养细胞上中和AR生物活性的能力进行表征。在第二阶段，最有希望的分子将根据提交临床试验IND申请进行动物临床前评估。