Targeting EndoS to auto-antibodies

将 EndoS 靶向自身抗体

• 批准号: 10356157
• 负责人: ERIC JOHN SUNDBERG
• 金额: $ 23.48万
• 依托单位: EMORY UNIVERSITY
• 依托单位国家: 美国
• 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/10356157
• 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

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).

识别自动抗原（即自我抗原）的自身抗体既是标志和诊断 自身免疫性疾病的标记。尽管自身免疫性疾病机制很复杂，并且涉及各种 体液和细胞免疫反应，有些仅取决于自身抗体的存在。 与其同源自身抗原结合后，自反应抗体会影响免疫的效应机制 通过完成激活和/或FC受体结合。由此产生的自身抗体介导的效应子 机制导致慢性感染和事件组织损害自身免疫性疾病的症状。 IgG抗体介导的效应器功能，无论它们是识别自我还是外国抗原，都是完全 取决于IgG FC区域ASN297上N连接的复合型聚糖的存在，这可以实现 结合Fcγ受体（FCγR）并激活完成的抗体，使抗体具有免疫 信号功能。内糖苷酶（即从糖蛋白中去除糖的酶）可以去除 与ASN297相关的聚糖分子并使IgG抗体具有免疫学惰性。所有已知的 内糖苷酶，内糖苷酶S（endos）是独一无二的，因为它仅从ASN297链接的聚糖中去除。 IgG抗体。由于其IgG特异性，病理自身抗体和/或 在自身免疫动物模型中注射纯化的胚胎已被证明可以防止或减轻 尽管胚胎完全特定于IgG抗体，但没有 区分不同抗原规格的抗体的能力。相反，内糖糖基元 所有IgG抗体，包括控制癌症的抗体以及针对外国抗原的抗体 这提供了免受感染的防御。工程胚胎仅识别和脱糖基元 与所有IgG抗体相反，自身抗体对于制造真正特定的自身免疫药物至关重要。我们 假设我们可以将恩托斯从具有巨大潜力的自身免疫性疾病疗法转化为一种 通过构建与自动抗原（Endos-AutoAg）的内生的融合蛋白来构建实际临床实用性 驱动靶向脱糖基化和病理自身抗体的失活，同时离开其余部分 免疫系统功能完整。我们将通过以下方式为此概念提供原则证明 内托斯-AutoAg融合蛋白特性的特异性和活性； （2）调查endos-autoag 融合蛋白的效率和特异性在体内使用自身免疫性表皮分解的小鼠模型 （EBA）。