Faculty of Dentistry, Sir John Walsh Research Institute, University of Otago, Dunedin, New Zealand.
Int Endod J. 2011 Feb;44(2):87-99. doi: 10.1111/j.1365-2591.2010.01817.x. Epub 2010 Nov 17.
Bacteria are the prime cause of periapical diseases and root canal microbiology is a well-researched area of endodontics. Antigen-presenting cells (APCs) are present in periapical lesions of endodontic origin and play a substantial role in recognizing, processing and presenting pathogenic antigens to the adaptive immune system such as an effective and long-lasting immune response is generated against the specific pathogens. Toll-like receptors (TLRs) are germ-line encoded pathogen recognition receptors (PRR) expressed by various APCs which induce their maturation, lead to gene transcription in the nucleus and the production of several pro- and anti-inflammatory cytokines. Thirteen TLRs have been discovered, 10 of which have been identified in humans so far. Preliminary studies of dental pulp tissue have demonstrated various cell types expressing different TLRs in response to commonly encountered microorganisms. However, there is little information available regarding the expression and function of the various TLRs in human periapical lesions. This review discusses the interactions of various APCs in periapical lesions and the possible roles of different TLRs and APCs in pulp/periapical pathogen recognition and presentation to the adaptive immune system in the initiation and sustaining of periapical diseases.
细菌是根尖周病的主要原因，根管微生物学是牙髓学中一个研究充分的领域。抗原呈递细胞（APC）存在于牙髓来源的根尖周病变中，在识别、加工和向适应性免疫系统呈递病原性抗原方面发挥着重要作用，例如针对特定病原体产生有效且持久的免疫反应。Toll 样受体（TLR）是由各种 APC 表达的胚系编码的病原体识别受体（PRR），诱导其成熟，导致核内基因转录和多种促炎和抗炎细胞因子的产生。目前已经发现了 13 种 TLR，其中 10 种已经在人类中被鉴定出来。对牙髓组织的初步研究表明，各种细胞类型在响应常见微生物时表达不同的 TLR。然而，关于人类根尖周病变中各种 TLR 的表达和功能的信息很少。本文综述了根尖周病变中各种 APC 的相互作用，以及不同 TLR 和 APC 在牙髓/根尖周病原体识别和向适应性免疫系统呈递中的可能作用，以启动和维持根尖周疾病。
