Engineered biomaterials modulating inflammatory T cells in rheumatic arthritis

项目摘要 免疫耐受是通过许多分子和细胞机制介导的，包括调节性T细胞 （Treg）。这种免疫耐受性的破坏导致衰弱的自身免疫性疾病，其中类风湿性关节炎 关节炎（RA）是示例性的。与免疫信号相关的等位基因多态性可使 个体对RA的发展。蛋白酪氨酸磷酸酶非受体2的遗传变异 PTPN 2基因座是这样一组突变，其被充分表征为有助于疾病发病机制 和类风湿关节炎的严重程度。这种改变的信号传导导致了细胞内 免疫景观，特别是影响抗炎Treg和促炎Treg之间的平衡。 炎症性T辅助17（Th 17）细胞参与RA的发展。PTPN 2功能结果减弱 在Treg不稳定性中，其中Treg在炎性关节炎中转化为致病性“Th 17样”效应T细胞。 微环境，导致严重炎症的自我持续循环。然而，目前没有 靶向Treg不稳定性的治疗，以挽救Treg功能并促进免疫稳态， 炎症环糊精/全反式视黄酸复合物（CAC）是一种很有前途的工具， 在PTPN 2单倍不足（PTPN 2 +/-）中恢复和维持Treg功能的临床可转化疗法 在某些情况下，CAC能够预防个体中的Treg不稳定，因为CAC能够预防炎症条件下的Treg不稳定。但 全身性给予CAC以促进Treg不是一种可行的策略，因为这可能会产生全身性的风险。 免疫抑制可能会增加严重感染和癌症的风险。为了解决这个问题， 假设在关节处局部持续递送CAC将增强Treg稳定性并改善 PTPN 2受损内型的临床结局。为了实现长期的、部位特异性免疫， 在调节中，用于释放CAC的可注射生物材料系统是必要的。该项目的目标是 (i)开发和表征用于持续递送CAC的可注射生物材料系统，以及（ii）阐明 CAC介导的Treg稳定的功效、机制和特异性。这将通过以下方式实现： 具体目标：目标1。一种微粒制剂（CAC-MP），其包含由聚（乳酸-共-丙交酯）包封的CAC。 羟基乙酸（PLGA）将被表征并优化用于体内释放动力学。随后，剂量 将进行研究以检查不同剂量的CAC-MP在RA的Ptpn 2 +/- SKG模型中的功效。目的 2.将阐明CAC-MP介导Ptpn 2 +/- SKG关节炎改善的作用机制， 并检测CAC-MP对全身免疫应答的影响。这个项目的直接结果 将确定局部免疫调节的可行性，以挽救Treg不稳定性，以改善治疗结果。 使用临床批准的材料明确定义的RA患者子集。此外，可注射生物材料 本文开发的平台将具有更广泛的适用性，作为介导局部免疫调节的工具， 可以用来探测免疫耐受和耐受破坏的问题。

PROJECT SUMMARY Immune tolerance is mediated via a number of molecular and cellular mechanisms, including regulatory T cells (Treg). Breakdown of this immune tolerance leads to debilitating autoimmune disease, of which rheumatoid arthritis (RA) is exemplary. Polymorphisms in alleles associated with immune signaling can predispose individuals to the development of RA. Genetic variants at the protein tyrosine phosphatase non-receptor 2 (PTPN2) locus are one such set of mutations that are well characterized to contribute to disease pathogenesis and RA severity in a well-established subset of patients. This altered signaling results in changes to the immunological landscape, and particularly influences the balance between anti-inflammatory Treg and the pro- inflammatory T helper 17 (Th17) cells that are involved in RA development. Diminished PTPN2 function results in Treg instability, in which Treg convert to pathogenic “Th17-like” effector T cells in the inflammatory arthritic microenvironment, leading to self-perpetuating cycle of severe inflammation. However, currently there are no therapies that target Treg instability to rescue Treg function and promote immune homeostasis to help resolve inflammation. Cyclodextrin/all-trans retinoic acid complexes (CAC) are a promising tool to address the need for a clinically translatable therapy to restore and maintain Treg function in PTPN2 haploinsufficient (PTPN2+/-) individuals, as CAC are capable of preventing Treg destabilization in inflammatory conditions. However, the systemic administration of CAC to promote Treg is not a feasible strategy, as this may run the risk of systemic immune suppression that could increase the risk of serious infection and cancer. To address this, it is hypothesized that the local, sustained delivery of CAC at the joint will enhance Treg stability and improve clinical outcomes in the PTPN2 compromised endotype. To achieve prolonged, site specific immune modulation, an injectable biomaterial system for the release of CAC is necessary. The goal of this project is to (i) develop and characterize an injectable biomaterial system for the sustained delivery of CAC and (ii) elucidate the efficacy, mechanisms, and specificity of CAC-mediated Treg stabilization. This will be achieved in the following Specific Aims: Aim 1. A microparticle formulation (CAC-MP) comprising CAC encapsulated by poly (lactic-co- glycolic) acid (PLGA) will be characterized and optimized for in vivo release kinetics. Subsequently, a dosage study will be conducted to examine efficacy of CAC-MP at different doses in the Ptpn2+/- SKG model of RA. Aim 2. The mechanism of action by which CAC-MP mediate improvement in Ptpn2+/- SKG arthritis will be elucidated, and the impact of CAC-MP on systemic immune response will be examined. The immediate results of this project will determine the feasibility of localized immune modulation to rescue Treg instability to improve outcomes in a well-defined subset of RA patients using clinically approved materials. Additionally, the injectable biomaterial platformed developed herein will have broader applicability as a tool to mediate local immune modulation and may be used to probe questions of immune tolerance and tolerance breakdown.