ACTIVATION OF INNATE IMMUNITY BY SARS-COV-2

Ciampoli C, Cuccurullo C. Activation of innate immunity by SARS-CoV-2. International Journal of Infection. 2021;5(3):81-90

C. Ciampoli¹ and C. Cuccurullo^2*

¹Dental School, University of Chieti-Pescara, Chieti, Italy.
²Department of Medicine and Ageing Sciences, University “Gabriele d’Annunzio” of Chieti‐Pescara, Chieti, Italy.

*Correspondence to:
Chiara Cuccurullo,
Department of Medicine and Ageing Sciences,
University “Gabriele d’Annunzio” of Chieti‐Pescara,
Chieti, Italy.

ABSTRACT

In some patients with severe coronavirus disease 2019 (COVID-19), both the innate and adaptive immune responses are dysregulated. The activation of innate immunity in response to SARS-CoV-2 is an important early defence mechanism and its dysregulation is responsible for the onset of COVID-19. Innate immune cells, such as macrophages, dendritic cells, and epithelial cells, recognize SARS-CoV-2 that has entered host cells through pattern recognition receptors (PRRs). PRRs detect pathogen-associated molecular patterns (PAMPs), which are molecular structures of the virus. PRRs include Toll-like receptors (TLRs) and NOD-like receptors (NLRs). NLRs and NOD-like receptor protein 3 (NLRP3)s form inflammasomes, which are important for the inflammatory response. The excessive immune response can lead to the increased production of life-threatening inflammatory cytokines, and therefore, it is crucial to prevent the spread of SARS-CoV-2.

KEYWORDS: innate immunity, immunity, SARS-CoV-2, COVID-19, inflammation, cytokine, Toll-like receptor