Targeting EndoS to auto-antibodies

将 EndoS 靶向自身抗体

基本信息

批准号：
10195779
负责人：
ERIC JOHN SUNDBERG
金额：
$ 19.53万
依托单位：
EMORY UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2021
资助国家：
美国
起止时间：
2021-02-18 至 2023-01-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10195779
关键词：
Address Affect Animal Model Antibodies Antigens Arthritis Autoantibodies Autoantigens Autoimmune Autoimmune Diseases Autoimmunity Binding Chimeric Proteins Chronic Clinical Collagen Complement Complement Activation Complex Development Disease Disease model Endoglycosidases Engineering Ensure Enzyme Kinetics Enzymes Epidermolysis Bullosa Acquisita Fc Receptor Glycoproteins Immune response Immune signaling Immune system Immunity Immunoglobulin G Immunologics Immunosuppression Immunosuppressive Agents In Vitro Infection Inflammation Injections Lead Learning Length Link MS4A1 gene Malignant Neoplasms Mass Spectrum Analysis Measures Mediating Methods Mus N-terminal Neuromyelitis Optica Pathologic Pharmaceutical Preparations Polysaccharides Population Property Protein Engineering Proxy Purpura Risk Specificity Streptococcus pyogenes Symptoms System Systemic Lupus Erythematosus Testing Therapeutic Therapeutic Uses Thrombocytopenia Tissues Translating design diagnostic biomarker expectation experimental study in vivo mouse model preclinical development protein function receptor receptor binding reduce symptoms rituximab side effect sugar therapeutic development

项目摘要

Autoantibodies, which recognize autoantigens (i.e., self-antigens), serve as both hallmarks and diagnostic markers of autoimmune diseases. Although autoimmune disease mechanisms are complex and involve various humoral and cellular immune responses, some are exclusively dependent on the presence of autoantibodies. Upon binding to their cognate autoantigens, self-reactive antibodies induce effector mechanisms of immunity through complement activation and/or Fc receptor binding. The resulting autoantibody-mediated effector mechanisms lead to chronic inflammation and the eventual tissue damage symptomatic of autoimmune disease. The effector functions mediated by IgG antibodies, whether they recognize self or foreign antigens, are entirely dependent on the presence of an N-linked complex type glycan on Asn297 of the IgG Fc region, which enables the antibody to bind Fc γ receptors (FcγRs) and activate complement, endowing the antibody with immune signaling capabilities. Endoglycosidases (i.e., enzymes that remove glycans from glycoproteins) can remove the glycan molecule linked to Asn297 and render IgG antibodies immunologically inert. Of all the known endoglycosidases, Endoglycosidase S (EndoS) is unique in that it removes only the Asn297-linked glycan from IgG antibodies. Due to its IgG-specific properties, EndoS pretreatment of pathological autoantibodies and/or injection of purified EndoS in animal models of autoimmunity has been shown to protect against or alleviate the symptoms of many autoimmune diseases. Although EndoS is exquisitely specific to IgG antibodies, it has no capacity to discriminate between antibodies with different antigen specificities. Instead, EndoS deglycosylates all IgG antibodies, including those that keep cancer in check, as well as those that are specific to foreign antigens that provide defense from infections. Engineering EndoS such that it recognizes and deglycosylates only autoantibodies, as opposed to all IgG antibodies, is essential for making a truly specific autoimmunity drug. We hypothesize that we can translate EndoS from an autoimmune disease therapeutic of great potential to one of actual clinical utility by constructing fusion proteins of EndoS linked to autoantigens (EndoS-autoAg) that will drive the targeted deglycosylation and inactivation of pathological autoantibodies, while leaving the remainder of the immune system functionally intact. We will provide proof-of-principle for this concept by: (1) optimizing EndoS-autoAg fusion protein properties for specificity and activity in vitro; and (2) investigating EndoS-autoAg fusion protein efficacy and specificity in vivo using a mouse model of autoimmune epidermolysis bullosa acquisita (EBA).

自身抗体可识别自身抗原（即自身抗原），既可作为标志又可作为诊断尽管自身免疫性疾病的机制很复杂并且涉及多种因素。体液和细胞免疫反应，有些完全依赖于自身抗体的存在。与其同源自身抗原结合后，自身反应性抗体会诱导免疫效应机制通过补体激活和/或 Fc 受体结合产生的自身抗体介导的效应物。机制导致慢性炎症和最终的自身免疫性疾病症状的组织损伤。 IgG 抗体介导的效应功能，无论是识别自身抗原还是外来抗原，都完全是由 IgG 抗体介导的。依赖于 IgG Fc 区 Asn297 上 N 连接复合型聚糖的存在，这使得抗体结合 Fc γ 受体 (FcγR) 并激活补体，赋予抗体免疫功能内切糖苷酶（即从糖蛋白中去除聚糖的酶）可以去除与 Asn297 连接的聚糖分子使 IgG 抗体具有免疫惰性。糖苷内切酶，糖苷内切酶 S (EndoS) 的独特之处在于它仅去除 Asn297 连接的聚糖由于其 IgG 特异性，EndoS 可以预处理病理性自身抗体和/或在自身免疫动物模型中注射纯化的 EndoS 已被证明可以预防或减轻尽管 EndoS 对 IgG 抗体具有高度特异性，但它并没有。 EndoS 能够区分具有不同抗原特异性的抗体。所有 IgG 抗体，包括那些控制癌症的抗体，以及那些针对外来抗原的抗体对 EndoS 进行工程设计，使其仅识别和去糖基化。与所有 IgG 抗体不同，自身抗体对于制造真正特异性的自身免疫药物至关重要。我们可以将 EndoS 从一种具有巨大潜力的自身免疫性疾病治疗方法转化为一种通过构建与自身抗原连接的 EndoS 融合蛋白 (EndoS-autoAg) 来实现实际临床应用驱动病理性自身抗体的靶向去糖基化和失活，同时留下剩余的我们将通过以下方式为这个概念提供原理验证：（1）优化。 EndoS-autoAg 融合蛋白的体外特异性和活性特性；以及 (2) 研究 EndoS-autoAg 使用自身免疫性大疱性表皮松解症小鼠模型研究融合蛋白的体内功效和特异性（欧洲银行管理局）。