GINGIVA DERIVED MSCS: ROLE IN IMMUNOMODULATION AND TISSUE REGENERATION

描述（由申请人提供）：再生医学的一个主要障碍是解决疾病相关炎症和优化组织再生能力以防止继发于炎症或瘢痕的进一步组织破坏的能力。最近，间充质干细胞（MSCs）研究的重大突破确定了MSCs在免疫调节功能中的内在作用。我们已经证明，促炎细胞因子是通过趋化因子和一氧化氮的协同作用来实现MSC的免疫抑制功能所必需的，并且活化的T细胞可以通过Fas/Fas L途径诱导MSC的凋亡。我们的研究还表明，皮肤来源的MSC的免疫抑制特性受到自分泌/旁分泌IL 17/IL 6轴介导的局部炎症小生境的严格调节，并且靶向这些不同小生境组分的治疗方法导致过度瘢痕形成的抑制。基于这些观察结果，我们探讨了从人牙龈（hGMSCs）中分离MSCs的可行性，人牙龈是一种独特的口腔组织，既可作为生物粘膜屏障，又可作为口腔粘膜免疫的一个组成部分。有趣的是，hGMSC不仅表现出多能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Tcl 3扩增和抑制Th 17细胞，具有上级免疫抑制作用，因此，在我们的炎症相关组织损伤/骨坏死模型中，抑制由双膦酸盐（BRONJ）诱导的组织破坏。我们假设，GMSC能够发挥双重作用，在组织修复中，包括作为免疫调节剂的保护作用，以抑制组织损伤和组织再生的作用，通过其多能分化能力。在这项申请中，我们的跨学科团队在干细胞生物学、免疫学、组织修复/再生和临床治疗方面具有先进的专业知识，提出了阐明炎症相关组织损伤/变性的分子机制，并开发了一种使用GMSC抑制炎症并促进患病和受伤的口腔和颅面组织再生/重建的新治疗方法。我们的目的将使用三个综合的具体目标来解决：1）进一步描述单集落水平上hGMSC的干细胞特性; 2）确定hGMSC是否能够免疫调节和潜在的机制;和3）探索靶向GMSC以减少炎症和促进炎症相关的口腔病症/疾病的动物模型中的组织再生的可行性。这项研究将大大扩展目前对GMSC免疫调节功能的认识，并提供关键的临床前数据，以测试使用GMSC来利用炎症和增强炎症相关或损伤的口面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：本研究将探索利用牙龈干细胞抑制炎症及其组织破坏，以开发修复和恢复受损口面组织的最佳方法。

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.