Extracellular matrix and the regulation of adaptive immune responses

描述(申请人提供)：Foxp3+调节性T细胞(T-reg)被认为是免疫耐受的关键仲裁者。不幸的是，成功地在体外诱导FoxP3+调节性T细胞(T-reg)的方案涉及到TGFb和IL-2的水平，如果在体内全身给药，这些水平将是有毒的。然而，我们的初步数据表明，通过将TGFb、IL-2和抗CD3抗体注入由透明质酸(HA)和硫酸肝素(HS)组成的水凝胶平台，以局部方式传递同样的T-reg诱导信号是可能的。这种方法大约是可溶性试剂中FoxP3+细胞数量的两倍。 我的假设是，使用类似的HA/HS水凝胶可以从CD4+FoxP3-前体诱导抗原特异性Treg。我建议从三个方面研究这一假说：1)我将阐明HA和HS以交联体形式促进Treg诱导的机制。2)用HA/HS水凝胶优化多克隆Treg诱导。3)研制HA/HS水凝胶，诱导抗原特异性Treg。 这项工作是我K08资助的HA和促进免疫耐受性研究的高潮。R03可能会为在体内和原位诱导糖尿病小鼠模型中抗原特异性耐受的研究奠定基础，我希望在R01应用中进行这一研究。 这项有计划的工作的意义在于，在组织移植和自身免疫性疾病的治疗中，有可能在没有系统性免疫抑制的情况下诱导抗原特异性耐受。 公共卫生相关性：自身免疫性疾病和器官移植的治疗经常涉及全身免疫抑制剂的管理，往往导致感染或不可接受的毒性。最近诱导FoxP3+调节性T细胞(T-reg)的努力也面临着同样的限制。然而，我们的初步数据表明，通过使用由透明质酸和硫酸肝素组成的水凝胶结构作为平台，有可能局部传递一组先前报道的诱导T-reg的共刺激信号。在这项应用中，我建议开发能够以抗原特异性方式诱导耐受性的水凝胶。这项计划工作的意义在于有可能诱导对特定自身抗原或移植组织的耐受，而不需要全身免疫抑制。

DESCRIPTION (provided by applicant): FoxP3+ regulatory T-cells (T-reg) are thought to be crucial arbiters of immune tolerance. Unfortunately, protocols that have successfully induced FoxP3+ regulatory T-cells (T-reg) in vitro involve levels of TGFb and IL-2 that would be toxic if administered systemically in vivo. Our preliminary data, however, suggests that it is possible to deliver this same set of T-reg induction cues in a local manner by inculcating TGFb, IL-2 and anti-CD3 Ab into a hydrogel platform made of hyaluronan (HA) and heparin sulfate (HS). This approach roughly doubles the number FoxP3+ cells seen with soluble agents. My hypothesis is that antigen specific Treg can be induced from CD4+FoxP3- precursors using similar HA/HS hydrogels. I propose to investigate this hypothesis in three aims: 1) I will elucidate the mechanisms by which HA and HS in crosslinked form promote Treg induction. 2) I will optimize polyclonal Treg induction using HA/HS hydrogels. 3) I will develop HA/HS hydrogels to induce antigen specific Treg. This work is a culmination of my K08 funded research on HA and the promotion of immune tolerance. This R03 will potentially set the stage for studies on the in vivo and in situ induction of antigen specific tolerance in mouse models of diabetes that I hope to pursue in an R01 application. The significance of the planned work lies in the potential to induce antigen specific tolerance without systemic immune suppression in tissue transplantation and in the treatment of autoimmune diseases. PUBLIC HEALTH RELEVANCE: The treatment of autoimmune disease and organ transplantation frequently involves the administration of systemic immunosuppressants, often leading to infection or unacceptable toxicities. Recent efforts at inducing FoxP3+ regulatory T-cells (T-reg), the body's own mediators of immune tolerance, have faced the same limitations. Our preliminary data, however, suggests that it is potentially possible to locally deliver a set of costimulatory cues previously reported to induce T-reg by using hydrogel constructs made of hyaluronan and heparin sulfate as a platform. In this application I propose to develop hydrogels that are capable of inducing tolerance in an antigen specific manner. The significance of this planned work lies in the potential to induce tolerance to specific autoantigens or transplanted tissues without the need for systemic immunosupression.