Transboundary Animal Diseases Centre, Joint Faculty of Veterinary Medicine, Kagoshima University, Kagoshima 890-0065, Japan.
Department of Microbiology and Public Health, Faculty of Animal Science and Veterinary Medicine, Patuakhali Science and Technology University, Barishal 8210, Bangladesh.
Viruses. 2021 Nov 18;13(11):2302. doi: 10.3390/v13112302.
The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has led to coronavirus disease (COVID-19), a global health pandemic causing millions of deaths worldwide. However, the immunopathogenesis of COVID-19, particularly the interaction between SARS-CoV-2 and host innate immunity, remains unclear. The innate immune system acts as the first line of host defense, which is critical for the initial detection of invading pathogens and the activation and shaping of adaptive immunity. Toll-like receptors (TLRs) are key sensors of innate immunity that recognize pathogen-associated molecular patterns and activate downstream signaling for pro-inflammatory cytokine and chemokine production. However, TLRs may also act as a double-edged sword, and dysregulated TLR responses may enhance immune-mediated pathology, instead of providing protection. Therefore, a proper understanding of the interaction between TLRs and SARS-CoV-2 is of great importance for devising therapeutic and preventive strategies. The use of TLR agonists as vaccine adjuvants for human disease is a promising approach that could be applied in the investigation of COVID-19 vaccines. In this review, we discuss the recent progress in our understanding of host innate immune responses in SARS-CoV-2 infection, with particular focus on TLR response. In addition, we discuss the use of TLR agonists as vaccine adjuvants in enhancing the efficacy of COVID-19 vaccine.
严重急性呼吸综合征冠状病毒 2（SARS-CoV-2）的出现导致了冠状病毒病（COVID-19），这是一种全球性的健康大流行，在全球范围内造成数百万人死亡。然而，COVID-19 的免疫发病机制，特别是 SARS-CoV-2 与宿主固有免疫之间的相互作用，仍不清楚。固有免疫系统作为宿主防御的第一道防线，对于初始检测入侵病原体以及激活和塑造适应性免疫至关重要。Toll 样受体（TLR）是固有免疫的关键传感器，可识别病原体相关分子模式，并激活下游信号转导，以产生促炎细胞因子和趋化因子。然而，TLR 也可能是一把双刃剑，失调的 TLR 反应可能会增强免疫介导的病理，而不是提供保护。因此，正确理解 TLR 与 SARS-CoV-2 的相互作用对于制定治疗和预防策略非常重要。TLR 激动剂作为人类疾病疫苗佐剂的使用是一种很有前途的方法，可应用于 COVID-19 疫苗的研究。在这篇综述中，我们讨论了宿主固有免疫反应在 SARS-CoV-2 感染中的最新研究进展，特别关注 TLR 反应。此外，我们还讨论了 TLR 激动剂作为疫苗佐剂在增强 COVID-19 疫苗功效方面的应用。
