Oral tolerance in enzyme replacement therapy of Morquio A disease

描述（由申请人提供）：Morquio A病（粘多糖病IVA； MPS IVA）是一种常染色体隐性溶酶体贮积症（LSD），由n -乙酰半乳糖胺-6-硫酸盐硫酸酯酶（GALNS）缺乏引起。未降解的硫酸角蛋白（KS）会积聚，特别是在骨骼中，导致系统性骨骼发育不良。自20多年前PI和合作者开始Morquio A研究以来，GALNS的纯化、人类GALNS cDNA的克隆、人类基因组基因的克隆、常见突变的鉴定、小鼠基因的克隆、GALNS的三级结构、Morquio A小鼠模型的建立、ELISA法的KS测定、Morquio的教育CD、CHO生产的重组人类GALNS、串联质谱法的KS测定、国际Morquio登记处的建立、Morquio A基因敲除小鼠首次尝试ERT，并获得Morquio A患者生长图。我们已经在Morquio a上发表了50多篇同行评审文章，申请和/或发布了7项与治疗和诊断相关的专利。我们正在开发新的创新酶替代疗法（ERT）来针对Morquio a的骨骼。同时，重复使用这种酶可能会引起不良的免疫反应。50-90%的lsd患者静脉注射后抗体升高。lsd对ERT的免疫反应已被广泛报道，并被认为是治疗的主要并发症之一。目标：携带者的直接目标是发展对lsd，特别是Morquio A病的ERT免疫反应的“口服耐受性”。长期的载体目标是优化目前的ERT方案，使ERT对lsd的疗效改变更具可行性。我们的目标是：1)建立Morquio A小鼠对人重组GALNS的口服耐受方案；2)比较Morquio A耐受与非耐受小鼠ERT的疗效。研究计划：为了抑制ERT的免疫应答，将设计一种新的口服耐受方案，通过口服给予合成的GALNS肽。将在Morquio a敲除小鼠中通过多次低剂量喂养方案研究合成GALNS肽诱导口服耐受性。在诱导GALNS口服耐受后，我们将对Morquio A小鼠进行ERT，以评估病理病变的改善情况。实验计划是1)合成GALNS多肽，2)在Morquio a小鼠中通过多次低剂量喂养合成GALNS多肽诱导口服耐受性，3)通过流式细胞术测量调节T细胞群的增加来测量炎症反应的抑制，4)测量GALNS抗体的存在或缺失，5)Morquio a小鼠将接受ERT治疗，6)我们通过测量抗体和评估病理改善来评估免疫耐受。实现提出的目标将解决当前ERT未遇到的挑战之一，并可能显著改变治疗效果。

DESCRIPTION (provided by applicant): Morquio A disease (mucopolysaccharidosis IVA; MPS IVA) is an autosomal recessive lysosomal storage disorder (LSD) caused by deficiency of N-acetyl-galactosamine-6-sulfate sulfatase (GALNS). Undegraded keratin sulfate (KS) will be accumulated especially in bone, leading to systemic skeletal dysplasia. Since the PI and co-investigators started Morquio A research over 20 years ago, purification of GALNS, cloning of human GALNS cDNA, cloning of human genomic gene, identification of common mutations, cloning of mouse gene, tertiary structure of GALNS, establishment of Morquio A murine models, KS assay by ELISA, Educational CD for Morquio, recombinant human GALNS produced in CHO, KS assay by tandem mass spectrometry, development of International Morquio Registry, the first attempt of ERT on Morquio A knock-out mouse, and growth chart for Morquio A patients were achieved. We have published over 50 peer-review articles on Morquio A. Seven patents related to therapy and diagnosis were applied and/or issued. We are developing new innovative enzyme replacement therapy (ERT) to target bone for Morquio A. Meanwhile, repeated administration of the enzyme could induce an undesirable immune response. 50-90% patients with LSDs administered intravenously raised antibody against infused enzyme. Immune response to ERT in LSDs has been widely reported and presented as one of the major complications of treatment. Goals: The immediate carrier goal is to develop "oral tolerance" for immune response to ERT of LSDs, in particular, Morquio A disease. The long-term carrier goal is to optimize current ERT regimen and to change efficacy of ERT for LSDs with more feasibility. We will aim: 1) to establish an oral tolerance protocol to the human recombinant GALNS in Morquio A mice; 2) to compare the efficacy of ERT between the tolerized and non-tolerized Morquio A mice. Research Plan: For suppressing the immune response to ERT, a novel oral tolerance protocol will be designed by administering synthetic GALNS peptides orally. Induction of oral tolerance with synthetic GALNS peptides will be investigated by a multiple low-dose feeding regimen in a Morquio A knock-out mouse. After induction of oral tolerance against GALNS, we will perform ERT on Morquio A mouse to assess improvement of pathological lesions. The experimental plan is 1) synthetic GALNS peptides will be made, 2) oral tolerance is induced by a multiple low-dose feeding regimen of synthetic GALNS peptides in Morquio A mouse, 3) the inhibition of an inflammatory response will be measured by the increment of regulatory T cell populations by flow cytometry, 4) the presence or absence of antibodies against GALNS will be measured, 5) Morquio A mice will be treated by ERT, and 6) we assess the immunological tolerance by measuring antibodies and assessing pathological improvement..To accomplish the proposed aims will resolve one of unmet challenges in current ERT and could change efficacy of the therapy dramatically. PUBLIC HEALTH RELEVANCE: Morquio A disease is a rare disorder caused by a deficiency of one of lysosomal enzymes, leading to accumulation of a sugar of chain mainly in bone, and showing systemic skeletal disease with short stature, prominent chest, spinal cord compression, knock-knee, and loose joints. Recent advanced technology has led to development of so-called "enzyme replacement therapy" to make up for the deficient enzyme. To avoid immunological reaction against infused enzyme and resultant unwanted side effect is urgently demanded, therefore, we will develop novel immunological tolerance method to the infused enzyme by oral administration of synthetic peptide for the enzyme.