Supramolecular hydrogels for localized delivery of immunomodulatory enzymes

项目摘要。先天免疫系统通过以下方式在保护宿主组织功能中起重要作用： 根除病原体和其他外来因素，促进适当的伤口愈合，并保持组织 体内平衡然而，由于异常的自我导向免疫系统， 免疫应答可导致慢性局部炎症状态，其诱导组织损伤或功能障碍。 慢性炎症性疾病通常是不可治愈的，因此目前的护理标准包括： 通过抑制促炎细胞因子或其受体的药物来管理疼痛或发烧。虽然有效， 这些治疗方式可抑制免疫系统功能， 机会性感染相反，炎症的自然消退部分由酶介导 锚定在细胞膜上，将免疫刺激信号转化为非活性的，或在某些情况下， 免疫抑制形式。例如，细胞外ATP（eATP）由自身受损或死亡释放 细胞作为激活炎症的“危险信号”，eATP免疫刺激活性在局部 由膜锚定酶调节，该酶将ATP脱磷酸化为腺苷（Ado）， 免疫抑制信号。受这些观察的启发，一种ATP去磷酸化酶，腺苷三磷酸双磷酸酶， 目前作为免疫生物学研究，并已证明有效抑制 临床前模型中的炎症。然而，通过胃肠外途径递送的可溶性腺苷三磷酸双磷酸酶的临床疗效不佳。 生物药物典型的短有效半衰期很可能阻碍了这一途径。为了解决这一限制， 拟议的研究计划将开发具有整合的ATP去磷酸化酶的生物材料， 免疫治疗剂可以局部递送至特定组织部位以抑制异常炎症。 为此，拟议的研究计划将创造自组装的水合聚合物凝胶（即“水凝胶”）。 组装的肽纳米纤维与整合的酶，去磷酸化ATP腺苷。具体来说，我们将 调整我们建立的平台，基于充电互补性的联合组装标签（“CATCH”），以创建 含有腺苷合酶A（AdsA）的水凝胶，所述腺苷合酶A是一种将ATP脱磷酸化为Ado的酶。通过 这项资助，我们将（i）通过材料重新设计优化CATCH-AdsA水凝胶酶活性，（ii）评估 CATCH-AdsA水凝胶使用体外和体内模型用于免疫调节的功效，和（iii）建立CATCH-AdsA水凝胶用于免疫调节的有效性。 通过评估宿主先天性和适应性免疫反应， CATCH水凝胶及其单个组分。这项研究的成功将带来新的 本发明涉及一种生物材料，其可通过呈递免疫调节酶来局部抑制炎症， 将为未来开发新的免疫治疗剂以解决慢性炎症提供基础。 更一般地说，具有可互换的整合酶组分的生物材料平台可能使 利用天然酶机制治疗各种免疫相关疾病的新机会。

Project summary. The innate immune system plays an essential role in protecting host tissue function by eradicating pathogens and other foreign elements, promoting proper wound healing, and maintaining tissue homeostasis. However, dysregulated innate immune system activation resulting from aberrant self-directed immune responses can lead to states of chronic local inflammation that induce tissue damage or dysfunction. Chronic inflammatory diseases are often incurable, and therefore the current standard of care involves managing pain or fever via drugs that inhibit pro-inflammatory cytokines or their receptors. Although effective, these treatment modalities can suppress immune system function and render patients susceptible to opportunistic infections. In contrast, natural resolution of inflammation is mediated in part by enzymes anchored to the cell membrane that convert immunostimulatory signals to an inactive, or in some cases immunosuppressive, form. For example, extracellular ATP (eATP) released by one’s own damaged or dying cells acts as a ‘danger signal’ that activates inflammation, and eATP immunostimulatory activity is locally regulated by membrane-anchored enzymes that dephosphorylate ATP to adenosine (Ado), an immunosuppressive signal. Inspired by these observations, an ATP dephosphorylating enzyme, apyrase, is currently investigated as an immunotherapeutic biologic, and has demonstrated efficacy for suppressing inflammation in pre-clinical models. However, clinical efficacy of soluble apyrase delivered via parenteral routes is likely to be hindered by the short effective half-life typical of biologic drugs. To address this limitation, the proposed research program will develop biomaterials with integrated ATP dephosphorylating enzymes as immunotherapeutics that can be locally delivered to specific tissue sites to suppress aberrant inflammation. Toward this end, the proposed research program will create hydrated polymeric gels (i.e. “hydrogels”) of self- assembled peptide nanofibers with integrated enzymes that dephosphorylate ATP to Ado. Specifically, we will adapt our established platform, Co-Assembly Tags based on CHarge complementarity (“CATCH”), to create hydrogels harboring Adenosine Synthase A (AdsA), an enzyme that dephosphorylates ATP to Ado. Through this grant, we will (i) optimize CATCH-AdsA hydrogel enzymatic activity through material redesign, (ii) assess CATCH-AdsA hydrogel efficacy for immunomodulation using in vitro and in vivo models, and (iii) establish a pre-clinical safety profile for these biomaterials by assessing host innate and adaptive immune responses to CATCH hydrogels and their individual components. Success of the proposed research will lead to new biomaterials that can locally suppress inflammation via presentation of an immunomodulatory enzyme, which will provide the basis for future efforts to develop new immunotherapeutics to resolve chronic inflammation. More generally, a biomaterial platform with interchangeable integrated enzyme components is likely to enable new opportunities to harness natural enzymatic mechanisms to treat various immune-related pathologies.