GINGIVA DERIVED MSCS: ROLE IN IMMUNOMODULATION AND TISSUE REGENERATION

描述(申请人提供)：再生医学中的一个主要障碍是解决与疾病相关的炎症和优化组织再生能力以防止继发于炎症或疤痕的进一步组织破坏的能力。最近，间充质干细胞(MSCs)研究的一项重大突破确定了MSCs在免疫调节功能中的内在作用。我们已经证明，促炎细胞因子通过趋化因子和一氧化氮的协同作用来发挥MSCs的免疫抑制作用，而活化的T细胞可以通过Fas/Fas L途径诱导MSCs的凋亡。我们的研究还发现，皮肤来源的MSCs的免疫抑制特性受到自分泌/旁分泌IL17/IL6轴介导的局部炎症生态位的严格调控，针对这些不同的生态位成分的治疗方法可以抑制过度的瘢痕形成。在这些观察的基础上，我们探索了从人牙龈中分离间充质干细胞(HGMSCs)的可行性，hGMSCs是一种独特的口腔组织，既具有生物黏膜屏障的功能，又是口腔黏膜免疫的组成部分。有趣的是，hGMSCs不仅表现出多潜能的分化和自我更新能力，而且与骨髓间充质干细胞(BMMSC)相比，通过诱导Tregs的扩张和抑制Th17细胞，具有优越的免疫抑制作用，从而抑制双膦酸盐(BRONJ)诱导的炎症相关组织损伤/骨坏死模型中的组织破坏。我们假设GMSCs能够在组织修复中发挥双重作用，包括作为免疫调节剂的保护性作用，以抑制组织损伤，以及通过其多向分化能力发挥组织再生的作用。在这项应用中，我们的跨学科团队拥有干细胞生物学、免疫学、组织修复/再生和临床治疗方面的先进专业知识，旨在阐明炎症相关组织损伤/退化的分子机制，并开发一种利用GMSCs抑制炎症并促进病变和损伤的口腔和颅面组织的再生/重建的新疗法。我们的目标将通过三个综合的具体目标来实现：1)在单个克隆水平进一步描述hGMSCs的干细胞特性；2)确定hGMSCs是否具有免疫调节能力和潜在的机制；以及3)在炎症相关口腔疾病/疾病的动物模型中探索靶向GMSCs以减少炎症和促进组织再生的可行性。这项研究将大大扩展目前对GMSCs免疫调节功能的了解，并提供关键的临床前数据，以测试使用GMSC治疗炎症和促进炎症相关或受伤的口腔面部组织再生的新治疗方法的可行性和有效性。 公共卫生相关性：这项研究将探索使用从牙龈提取的干细胞来抑制炎症及其组织破坏，以开发修复和修复口腔面部损伤组织的最佳方法。

DESCRIPTION (provided by applicant): A major roadblock in regenerative medicine is the ability to resolve disease-associated inflammation and to optimize tissue regenerative capacity to prevent further tissue destruction secondary to inflammation or scarring. Recently, a major breakthrough in mesenchymal stem cells (MSCs) research identifies an intrinsic role of MSCs in immune-regulatory function. We have demonstrated that pro-inflammatory cytokines are required for immunosuppressive function of MSCs through the concerted action of chemokines, and nitric oxide, and that activated T cells can induce apoptosis of MSCs via the Fas/Fas L pathway. Our studies also have revealed that the immunosuppressive property of skin derived MSCs were tightly regulated by the local inflammatory niche mediated by the autocrine/paracrine IL17/IL6 axis, and therapeutic approaches targeting these distinct niche components resulted in suppression of excessive scar formation. Based on these observations, we explore the feasibility of isolating MSCs from human gingiva (hGMSCs), a unique oral tissue that functions both as a biological mucosal barrier and a component of the oral mucosal immunity. Interestingly, hGMSCs exhibit not only multipotent differentiation and self-renewal capacities but also possess superior immunosuppressive effect as compared to bone marrow mesenchymal stem cells (BMMSC), by inducing Tregs expansion and inhibiting Th17 cells, and consequently, suppress tissue destruction in our inflammation-related tissue injury/osteonecrosis model induced by bisphosphonate (BRONJ). We hypothesize that GMSCs are capable of playing dual roles in tissue repair including a protective role as an immunomodulator to inhibit tissue injury and a tissue regeneration role through their multipotent differentiation capacities. In this application, our interdisciplinary team with advanced specialties in stem cell biology, immunology, tissue repair/regeneration, and clinical therapies, proposes to elucidate the molecular mechanisms of inflammation- related tissue injury/degeneration, and develop a novel therapeutic approach using GMSCs to suppress inflammation and promote regeneration/reconstruction of diseased and injured oral and craniofacial tissues. Our objective will be addressed using three integrated specific aims: 1) To further delineate stem cell properties of hGMSCs at the single colony level; 2) To determine whether hGMSCs are capable of immunomodulation and the underlying mechanisms; and 3) To explore the feasibility of targeting GMSCs to reduce inflammation and promote tissue regeneration in animal models of inflammation- related oral disorders/diseases. This study will substantially extend current knowledge of the immunomodulatory functions of GMSCs and provide critical pre-clinical data to test the feasibility and efficacy of novel therapeutic approach using GMSC to harness inflammation and enhance regeneration of inflammation-related or injured orofacial tissues. PUBLIC HEALTH RELEVANCE: This study will explore the use of stem cells derived from the gingiva, a specialized oral tissue, to inhibit inflammation and its tissue destruction in order to develop an optimal approach for the repair and restoration of the injured orofacial tissues.