Marcinkiewicz Janusz, Witkowski Jacek M, Olszanecki Rafał
Chair of Immunology, Faculty of Medicine, Jagiellonian University Medical College, Krakow, Poland.
Department of Pathophysiology, Medical University of Gdańsk, Poland.
Cent Eur J Immunol. 2021;46(1):1-9. doi: 10.5114/ceji.2021.105240. Epub 2021 Apr 18.
COVID-19 is a highly contagious respiratory disease caused by the novel coronavirus SARS-CoV-2. Since October 2020 the second wave of the pandemic has been observed around the world, as pathogen specific herd immunity has not been built yet. Moreover, the current, more contagious pathogen carrying the D614G mutation has become the globally dominant form of SARS-CoV-2. In this article we present the current state of knowledge on the impact of ACE2 and the reninangiotensin system (RAS) and the innate immune system on different outcomes of COVID-19. Especially, we point out the dual role of the immune system and ACE2 in pathogenesis of the disease. Namely, at the initial stage of the infection anti-viral activity of innate immunity is responsible for inhibition of SARS-CoV-2 replication. On the other hand, a dysregulated immune response may cause the detrimental hyperinflammation ("cytokine storm") responsible for the severe course of the disease. Concomitantly, we analyse the roles of ACE2 in both facilitation of infection and abrogation of its effects, as the major cellular entry receptor for SARS-CoV-2 and an important enzyme responsible for tissue protection, respectively. Finally, we discuss the dominant impact of aging on the fatal outcome of COVID-19.
COVID-19是一种由新型冠状病毒SARS-CoV-2引起的高传染性呼吸道疾病。自2020年10月以来，全球观察到第二波疫情，因为尚未建立针对病原体的群体免疫。此外，目前携带D614G突变的更具传染性的病原体已成为SARS-CoV-2在全球的主要形式。在本文中，我们介绍了关于血管紧张素转换酶2（ACE2）、肾素-血管紧张素系统（RAS）和先天免疫系统对COVID-19不同结局影响的当前知识状态。特别是，我们指出了免疫系统和ACE2在该疾病发病机制中的双重作用。也就是说，在感染初期，先天免疫的抗病毒活性负责抑制SARS-CoV-2复制。另一方面，失调的免疫反应可能会导致有害的过度炎症（“细胞因子风暴”），这是该疾病严重病程的原因。同时，我们分析了ACE2在促进感染和消除其影响方面的作用，ACE2分别作为SARS-CoV-2的主要细胞进入受体和负责组织保护的重要酶。最后，我们讨论了衰老对COVID-19致命结局的主要影响。
