Abstract: Pattern recognition receptors (PRRs) play key roles in the innate immune system and are important host sensors that can recognize pathogen-associated molecular patterns (PAMPs) displayed by invading pathogens. PAMP is an independent immunomodulator with a variety of biochemical components and special structures, and it is gradually considered as the key component of many modern vaccines. Toll-like receptor (TLR) 3 agonist is a synthetic double-stranded RNA (dsRNA) that activates various pathways of host immune defense in a pattern like viral infection. When properly combined with an antigen, TLR3 agonist can be used as a PAMP-adjuvant to regulate and optimize antigen-specific immune response. Based on this, the mechanisms of action of TLR3 and its agonist were mainly discussed, as well as the application progress of TLR3 agonist in vaccine adjuvant, so as to provide new ideas for the research of animal vaccines.

Key words: adaptive immunity, adjuvant, innate immunity, polyI:C, TLR3

摘要： 模式识别受体（pattern recognition receptor，PRR）在先天免疫系统中起着至关重要的作用，是重要的宿主传感器，可识别入侵病原体所显示的病原体相关分子模式（pathogen-associated molecular pattern，PAMP）。PAMP是独立的免疫调节剂，且具有多种生化成分和特殊结构，逐渐被认为是许多现代疫苗的关键成分。Toll样受体（Toll-like receptor，TLR）3激动剂是一种合成的双链RNA（double-stranded RNA，dsRNA），能够以与病毒感染相似的模式激活宿主免疫防御的多种通路。当与抗原适当混合时，TLR3激动剂可以用作PAMP-佐剂，以调节和优化抗原特异性免疫应答。基于此，主要讨论了TLR3及其激动剂的作用机制以及TLR3激动剂在疫苗佐剂中的应用进展，以期为动物疫苗的研究提供新的思路。

关键词: 适应性免疫, 佐剂, 先天免疫, poly I:C, Toll样受体3