牙周组织再生是口腔科学的工作和研究中心之一，牙周膜干细胞被认为是牙周组织再生的最佳种子细胞，给牙周组织再生带来了新的希望。机体的免疫包括固有免疫和适应性免疫，适应性免疫可分为细胞免疫和体液免疫，本课题组已经完成了牙周膜干细胞对机体细胞免疫(T淋巴细胞)和体液免疫(B淋巴细胞)影响的研究，发现牙周膜干细胞能抑制T淋巴细胞和B淋巴细胞的功能，异体移植后不会引起细胞免疫和体液免疫介导的排斥反应。在此基础上，本申请研究牙周膜干细胞与机体固有免疫的重要组成部分——巨噬细胞之间的相互作用，探讨牙周膜干细胞对同种异体巨噬细胞表型、吞噬功能和分泌功能的影响，研究牙周膜干细胞同种异体移植后受体巨噬细胞体内功能的变化、巨噬细胞对牙周膜干细胞介导的牙周炎治疗的影响以及巨噬细胞对牙周膜干细胞生物学特性的影响。通过本研究可得到人牙周膜干细胞与巨噬细胞相互作用的特性，为异体牙周膜干细胞应用于牙周组织再生提供科学依据。

Regeneration of periodontal tissue is one of the key issues in dental clinic and research. Currently, periodontal ligament stem cells (PDLSCs) is regarded as the best seed cell resource for the regeneration of periodontal tissue and provide great hope for the periodontitis treatment strategy. Immunity consists of inherent immunity and adaptive immunity, and adaptive immunity includes cellular immunity and humoral immunity. Our group completed the study of PDLSCs’ effect on cellular immunity(T lymphocytes) and humoral immunity(B lymphocytes), and found that PDLSCs are capable of inhibiting the functions of T lymphocytes and B lymphocytes, and allogeneic transplantation of PDLSCs could not induce the rejection responses mediated by cellular immunity and humoral immunity. Based on these studies, we intend to examine the effect of PDLSCs on macrophage, which is an important part of inherent immunity. We plan to explore the effect and the underlying mechanisms of PDLSCs on the immunophenotype, phagocytosis, and secretion function of macrophage, study the in vivo function alteration of macrophage after allogeneic transplantation of PDLSCs, and examine the influence of macrophage on the PDLSCs-mediated periodontitis therapy. Thus, we can acquire the properties of the interaction of PDLSCs and macrophage, offering evidence for application of allogeneic PDLSCs in periodontal regeneration.