Developing a Rat Analogue of a Human Transglutaminase 2 Inhibitory Antibody to Facilitate Preclinical Testing in Treating Kidney Fibrosis

开发人转谷氨酰胺酶 2 抑制抗体的大鼠类似物，以促进治疗肾纤维化的临床前测试

• 批准号: MR/K00770X/1
• 负责人: Timothy Johnson
• 金额: $ 68.21万
• 依托单位: University of Sheffield
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2012
• 资助国家: 英国
• 起止时间: 2012 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=MR%2FK00770X%2F1
• 关键词: Developing; Rat; Analogue; Human; Transglutaminase

Fibrosis, or scarring, is a frequent feature of a number of relatively common, usually chronic, diseases. These include many types of lung, liver and heart disease and essentially all forms of chronic kidney disease. Studies of the mechanisms underlying the scarring process is an area of intense activity given that currently there is no recognized anti-scarring / anti-fibrotic therapy available for a condition that is ultimately fatal for millions of people each year. Subsequently the potential therapeutic benefits offered by the development of agents able to block or reduce the impact of scarring are considerable. Cumulative data from a range of different groups and experimental designs have highlighted tissue transglutaminase (transglutaminase type 2 ,TG2) as a key effector of the scarring process. Transglutaminases are a family of closely related enzymes that all catalyze the crosslinking of peptide chains via covalent epsilon (gamma-glutamyl) lysine bonds. It is this peptide crosslinking activity of TG2 that acts to produce the increased deposition and stabilization of extracellular matrix observed in chronic scarring. Knockdown of TG2, either genetically, or through the use of small molecule inhibitors, has been shown to have clear beneficial effects in animal models of chronic kidney disease (CKD). Scarring & fibrosis is reduced and kidney function preserved by up to 80% over the timescale of the experiments. Translation of these results into the patient setting would have profound therapeutic application in the area of CKD, and possibly other diseases that feature chronic scarring. Prolonging kidney function and delaying the requirement for dialysis or renal transplantation would offer a substantial increase in the quality of life of CKD patients and have major cost implications for the health service. Given the clear case for the development of TG2 inhibitors, there is much interest in this area of research. Development of inhibitors have been hampered by the degree of structural conservation between the 8 different members of the TG family. The catalytic site, or 'core', is highly conserved and all existing small molecule candidates have exhibited prohibitive levels of cross reactivity with other related enzymes. This is particularly important in the case of TG1 and TG3, which are critical to maintaining integrity of the dermis, and factor XIIIa, a major component of the clotting process. Inhibition of these related TG molecules produces serious side effects that would preclude a therapeutic role for existing small molecule inhibitors. A monoclonal antibody approach to this problem offers the potential to overcome these specificity issues due to the very precise nature of antibody targeting.Using an innovative immunization approach we have successfully generated a series of TG2-specific inhibitory monoclonal antibodies. All are specific for human TG2 and show no cross reactivity to other members of the enzyme family. We have established the inhibitory potential of these mAbs in different in vitro systems and derived IC50 data. The most effective of these antibodies has been humanised, with the affinity and inhibitory activity being preserved. The next stage in the development of this potential therapeutic is to generate preclinical data in FDA approved animal models of chronic fibrosis. The most effective monoclonal, AB1, and the other candidates, are all specific for human TG2, and lack significant inhibitory action against mouse or rat TG2. Accordingly, the aim of this project is to allow us to generate orthologous inhibitory antibodies against rat and mouse TG2, in order that we can gather this crucial preclinical data, attract downstream commercial partners, and accelerate the development of this potentially new class of therapeutic agents.

纤维化或疤痕是许多相对常见（通常是慢性）疾病的常见特征。其中包括多种类型的肺病、肝病和心脏病，以及基本上所有形式的慢性肾病。鉴于目前还没有公认的抗疤痕/抗纤维化疗法可用于每年最终导致数百万人死亡的疾病，因此对疤痕形成过程背后机制的研究是一个活跃的领域。随后，开发能够阻止或减少疤痕影响的药物所提供的潜在治疗益处是相当大的。来自一系列不同组和实验设计的累积数据强调组织转谷氨酰胺酶（2 型转谷氨酰胺酶，TG2）是疤痕形成过程的关键效应物。转谷氨酰胺酶是一系列密切相关的酶，它们都通过共价ε（γ-谷氨酰）赖氨酸键催化肽链交联。正是 TG2 的这种肽交联活性起到了在慢性疤痕形成中观察到的细胞外基质沉积增加和稳定的作用。 TG2 的敲低（无论是通过基因敲除还是通过使用小分子抑制剂）已被证明对慢性肾病 (CKD) 动物模型具有明显的有益作用。在实验期间，疤痕和纤维化减少，肾功能保留高达 80%。将这些结果转化为患者环境将在 CKD 领域以及可能在其他以慢性疤痕为特征的疾病领域产生深远的治疗应用。延长肾功能并延迟透析或肾移植的需要将显着提高 CKD 患者的生活质量，并对卫生服务产生重大成本影响。鉴于 TG2 抑制剂开发的明确案例，人们对这一研究领域产生了浓厚的兴趣。 TG 家族 8 个不同成员之间的结构保守程度阻碍了抑制剂的开发。催化位点或“核心”高度保守，所有现有的小分子候选物都表现出与其他相关酶的交叉反应性水平。这对于维持真皮完整性至关重要的 TG1 和 TG3 以及凝血过程的主要组成部分 XIIIa 因子而言尤其重要。抑制这些相关的 TG 分子会产生严重的副作用，从而妨碍现有小分子抑制剂的治疗作用。由于抗体靶向的非常精确的性质，解决这个问题的单克隆抗体方法有可能克服这些特异性问题。使用创新的免疫方法，我们成功地产生了一系列 TG2 特异性抑制性单克隆抗体。所有这些都对人类 TG2 具有特异性，并且与酶家族的其他成员没有交叉反应性。我们已经确定了这些 mAb 在不同体外系统中的抑制潜力并得出了 IC50 数据。这些抗体中最有效的已经被人源化，并保留了亲和力和抑制活性。这种潜在疗法开发的下一阶段是在 FDA 批准的慢性纤维化动物模型中生成临床前数据。最有效的单克隆抗体 AB1 和其他候选药物均对人 TG2 具有特异性，并且对小鼠或大鼠 TG2 缺乏显着的抑制作用。因此，该项目的目的是让我们能够生成针对大鼠和小鼠 TG2 的直系同源抑制抗体，以便我们能够收集这一关键的临床前数据，吸引下游商业合作伙伴，并加速这一潜在新型治疗剂的开发。