Project 3: Immune regulation by cellular glycosylation for the inhibitory antibody development to factor VIII in hemophilia

项目3：总结 治疗血友病A的一个主要障碍是约25%的患者产生高滴度、中和的抗第VIII因子 (Fviii)蛋白质替代疗法后的抗体(抑制物)。预计这一问题还将 在至少一部分患者中，在基因治疗后发生。治疗血友病尤其具有挑战性。 已经产生抑制性抗体的患者。绕过用来治疗这些患者的疗法 有时疗效有限，而且成本很高。抗FVIII抑制抗体的形成是由 涉及遗传和环境风险因素的复杂的多方面免疫反应。几个“危险” 信号“已被证明与抑制剂形成的风险有关。然而，潜在的 激活抗FVIII反应的触发因素尚不完全清楚。例如，具有相同突变的患者 在蛋白质替代治疗后，FVIII基因在抑制物的发展中具有不同的风险。 此外，不同的FVIII产品可能表现出不同程度的抑制作用 风险。近年来，已有研究表明，葡聚糖对免疫系统至关重要，因为一些 免疫系统与病毒或细菌之间最重要的相互作用或外源添加 蛋白质是通过蛋白质-糖链相互作用来调节的。几乎每一步都涉及糖基化。 免疫激活途径。葡聚糖是识别非我事件和改变糖蛋白的关键 可导致免疫反应的激活。糖基化也参与了细胞机制， 控制TCR激活阈值，免疫细胞转运，TCR和BCR信号，抗体功能，以及 更多。我们假设，多糖在诱导免疫反应或对FVIII的耐受中的影响可以 有两个方面：一是糖基化的FVIII抗原与宿主免疫系统的相互作用 在确定诱导抗FVIII免疫反应的风险方面，糖链图谱可能是重要的；以及 其次是对外源添加的蛋白质或基因的识别和随后的免疫激活 FVIII糖基的不同程度或模式可以改变其表达。因此，为了更充分地 了解潜在糖基化对抗FVIII抑制剂开发的影响 ，我们建议首先研究宿主多糖谱在抗FVIII抗体形成中的影响 在不同背景的人和老鼠身上都有反应。接下来，我们将描述免疫的特征 不同程度或不同糖基化模式的FVIII分子的免疫应答 探讨免疫激活的机制。从这项研究中，我们希望定义特定的免疫学 由糖基化及其相关机制触发，导致预防或消除FVIII抑制剂。

PROJECT 3: SUMMARY A major obstacle in treating hemophilia A is that ~25% of patients develop high-titer, neutralizing anti-factor VIII (FVIII) antibodies (inhibitors) following protein replacement therapy. It is also anticipated that this problem will occur following gene therapy in at least a subset of patients. It is particularly challenging to treat hemophilia patients who have developed inhibitory antibodies. Bypassing therapies that are used to treat these patients sometimes have limited efficacy and are very costly. The anti-FVIII inhibitory antibody formation results from a complex multifaceted immune response involving both genetic and environmental risk factors. Several “danger signals” have been demonstrated to be associated with risks of inhibitor formation. However, the potential triggers to activate anti-FVIII responses are not fully understood. For example, patients with identical mutations in FVIII gene can have differential risks in inhibitor development following protein replacement therapy. Moreover, there were some implications that different FVIII products may exhibit different degrees of inhibitor risks. In recent years, it has been demonstrated that glycans are crucial for the immune system, as some of the most important interactions between the immune system and viruses or bacteria or exogenously added proteins are mediated by protein-glycan interactions. Glycosylation is involved in almost every step of the immune activation pathway. Glycans are a key in the recognition of non-self events and an altered glycome can lead to activation of immune responses. Glycosylation is also involved in the cellular mechanisms that control the threshold of TCR activation, immune cell trafficking, TCR and BCR signaling, antibody function, and more. We hypothesize that the impact of glycans in the induction of immune response or tolerance to FVIII can be twofold: one is that the interaction of glycosylated FVIII antigens and host immune system with specific glycan profiles can be significant in determining the risk of inducing anti-FVIII immune response; and the second is that the recognition of and ensued immune activation by exogenously added protein or gene expression can be altered by different extent or patterns of FVIII glycomes. Therefore, in order to more fully understand the spectrum of potential glycosylation influence on the development of anti-FVIII inhibitor responses, we propose to first look into the influence of host glycan profiles in the development of anti-FVIII response both in humans and mice with different backgrounds. Next we will characterize the immune responses elicited by delivery of FVIII molecules with different extent or patterns of glycosylation and investigate the mechanism of immune activation. From this study, we wish to define specific immunologic trigger by glycosylation and its associated mechanisms, leading to prevention or elimination of FVIII inhibitors.