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RESEARCH ARTICLE (Open Access)

Cellular signalling by SARS-CoV-2 spike protein

Nicholas P. Gracie https://orcid.org/0000-0001-9843-367X A # , Lachlan Y. S. Lai https://orcid.org/0000-0002-0753-1168 A # and Timothy P. Newsome https://orcid.org/0000-0002-2193-596X A B *
+ Author Affiliations
- Author Affiliations

A School of Life and Environmental Sciences, The University of Sydney, Camperdown, Sydney, NSW, Australia.

B Sydney Institute for Infectious Diseases (Sydney ID), The University of Sydney, Camperdown, Sydney, NSW, Australia.




Nicholas Gracie is a 3rd Year PhD candidate in the Newsome Lab at The University of Sydney. His research involves poxviruses, SARS-CoV-2 and cell signalling.



Lachlan Lai is a 1st Year PhD candidate in the Newsome Lab at The University of Sydney. His research involves poxviruses with a focus on Monkeypox.



Timothy Newsome is an Associate Professor of The University of Sydney. His research interests lie at the intersection of virology and cell signalling.

* Correspondence to: timothy.newsome@sydney.edu.au
# These authors contributed equally to this paper

Microbiology Australia 45(1) 13-17 https://doi.org/10.1071/MA24005
Submitted: 18 January 2024  Accepted: 7 March 2024  Published: 22 March 2024

© 2024 The Author(s) (or their employer(s)). Published by CSIRO Publishing on behalf of the ASM. This is an open access article distributed under the Creative Commons Attribution 4.0 International License (CC BY)

Abstract

Following the release of the SARS-CoV-2 genome, the spike protein was identified as the key viral protein mediating cell entry. In addition to its critical function in delivering the viral genome to the host cytoplasm, the spike protein is able to activate diverse cell signalling pathways, leading to notable cellular responses, including inflammation, cellular remodelling, and immune evasion. The spike protein is associated with the induction of a ‘cytokine storm’ characterised by elevated levels of proinflammatory cytokines like IL-6 and IL-1β. Moreover, the spike protein deregulates TGF-β and E-selectin, leading to fibrotic injury and tissue scarring in cellular remodelling, notably in pulmonary tissues. Finally, the spike protein plays a role in immune evasion, disrupting Type I interferon responses. Understanding these diverse interactions and effects is crucial for comprehending the pathogenesis of COVID-19 and developing effective therapeutic strategies.

Keywords: ACE2, Angiotensin Converting Enzyme Receptor 2, cellular signalling, COVID-19, cytokine storm, fibrosis, spike protein, TGF-β, transforming growth factor-beta.

Biographies

MA24005_B1.gif

Nicholas Gracie is a 3rd Year PhD candidate in the Newsome Lab at The University of Sydney. His research involves poxviruses, SARS-CoV-2 and cell signalling.

MA24005_B2.gif

Lachlan Lai is a 1st Year PhD candidate in the Newsome Lab at The University of Sydney. His research involves poxviruses with a focus on Monkeypox.

MA24005_B3.gif

Timothy Newsome is an Associate Professor of The University of Sydney. His research interests lie at the intersection of virology and cell signalling.

References

Barthe M et al. (2023) Receptors and cofactors that contribute to SARS-CoV-2 entry: can skin be an alternative route of entry? Int J Mol Sci 24, 6253.
| Crossref | Google Scholar | PubMed |

Hikmet F et al. (2020) The protein expression profile of ACE2 in human tissues. Mol Syst Biol 16, e9610.
| Crossref | Google Scholar | PubMed |

Jackson CB et al. (2022) Mechanisms of SARS-CoV-2 entry into cells. Nat Rev Mol Cell Biol 23, 3-20.
| Crossref | Google Scholar | PubMed |

Lim S et al. (2022) ACE2-independent alternative receptors for SARS-CoV-2. Viruses 14, 2535.
| Crossref | Google Scholar | PubMed |

Martínez-Baz I et al. (2023) Risk reduction of hospitalisation and severe disease in vaccinated COVID-19 cases during the SARS-CoV-2 variant Omicron BA.1-predominant period, Navarre, Spain, January to March 2022. Eurosurveillance 28, pii=2200337.
| Crossref | Google Scholar | PubMed |

Andrews N et al. (2022) Covid-19 vaccine effectiveness against the Omicron (B.1.1.529) variant. N Engl J Med 386, 1532-1546.
| Crossref | Google Scholar | PubMed |

Grgič Vitek M et al. (2022) mRNA vaccine effectiveness against hospitalisation due to severe acute respiratory infection (SARI) COVID-19 during Omicron variant predominance estimated from real-world surveillance data, Slovenia, February to March 2022. Eurosurveillance 27, pii=2200350.
| Crossref | Google Scholar |

Cevik M et al. (2020) Virology, transmission, and pathogenesis of SARS-CoV-2. BMJ 371, 3862.
| Crossref | Google Scholar | PubMed |

Hoffmann M et al. (2020) SARS-CoV-2 cell entry depends on ACE2 and TMPRSS2 and is blocked by a clinically proven protease inhibitor. Cell 181, 271-280.e8.
| Crossref | Google Scholar | PubMed |

10  Zhang J et al. (2021) Structural impact on SARS-CoV-2 spike protein by D614G substitution. Science 372, 525-530.
| Crossref | Google Scholar | PubMed |

11  Coutard B et al. (2020) The spike glycoprotein of the new coronavirus 2019-nCoV contains a furin-like cleavage site absent in CoV of the same clade. Antiviral Res 176, 104742.
| Crossref | Google Scholar | PubMed |

12  Hsu R-J et al. (2022) The role of cytokines and chemokines in severe acute respiratory syndrome coronavirus 2 infections. Front Immunol 13, 832394.
| Crossref | Google Scholar |

13  Halajian EA et al. (2022) Activation of TLR4 by viral glycoproteins: a double-edged sword? Front Microbiol 13, 1007081.
| Crossref | Google Scholar | PubMed |

14  Zhao Y et al. (2021) SARS-CoV-2 spike protein interacts with and activates TLR41. Cell Res 31, 818-820.
| Crossref | Google Scholar | PubMed |

15  Aboudounya MM et al. (2021) SARS-CoV-2 spike S1 glycoprotein is a TLR4 agonist, upregulates ACE2 expression and induces pro-inflammatory M1 macrophage polarisation. bioRxiv 2021.08.11.455921 [Preprint, published 11 August 2021].
| Crossref | Google Scholar |

16  Shirato K, Kizaki T (2021) SARS-CoV-2 spike protein S1 subunit induces pro-inflammatory responses via toll-like receptor 4 signaling in murine and human macrophages. Heliyon 7, e06187.
| Crossref | Google Scholar | PubMed |

17  Negron SG et al. (2021) Selectively expressing SARS-CoV-2 spike protein S1 subunit in cardiomyocytes induces cardiac hypertrophy in mice. bioRxiv 2021.06.20.448993 [Preprint, published 20 June 2021].
| Crossref | Google Scholar |

18  Khan S et al. (2021) SARS-CoV-2 spike protein induces inflammation via TLR2-dependent activation of the NF-κB pathway. eLife 10, e68563.
| Crossref | Google Scholar |

19  Jones SA, Hunter CA (2021) Is IL-6 a key cytokine target for therapy in COVID-19? Nat Rev Immunol 21, 337-339.
| Crossref | Google Scholar | PubMed |

20  Gu T et al. (2020) Cytokine signature induced by SARS-CoV-2 spike protein in a mouse model. Front Immunol 11, 621441.
| Crossref | Google Scholar | PubMed |

21  Patra T et al. (2020) SARS-CoV-2 spike protein promotes IL-6 trans-signaling by activation of angiotensin II receptor signaling in epithelial cells. PLoS Pathog 16, e1009128.
| Crossref | Google Scholar | PubMed |

22  Rose-John S et al. (2023) Targeting IL-6 trans-signalling: past, present and future prospects. Nat Rev Immunol 23, 666-681.
| Crossref | Google Scholar | PubMed |

23  Heinz FX, Stiasny K (2021) Distinguishing features of current COVID-19 vaccines: knowns and unknowns of antigen presentation and modes of action. NPJ Vaccines 6, 104.
| Crossref | Google Scholar | PubMed |

24  Swank Z et al. (2023) Persistent circulating severe acute respiratory syndrome coronavirus 2 spike is associated with post-acute coronavirus disease 2019 sequelae. Clin Infect Dis 76, e487-e490.
| Crossref | Google Scholar | PubMed |

25  Karadeniz H et al. (2022) The prognostic value of lung injury and fibrosis markers, KL-6, TGF-β1, FGF-2 in COVID-19 patients. Biomark Insights 17, 117727192211354.
| Crossref | Google Scholar |

26  Willis BC et al. (2005) Induction of epithelial–mesenchymal transition in alveolar epithelial cells by transforming growth factor-β1. Am J Pathol 166, 1321-1332.
| Crossref | Google Scholar | PubMed |

27  Zhang T et al. (2020) Comparison of clinical and pathological features between severe acute respiratory syndrome and coronavirus disease 2019. Zhonghua Jie He He Hu Xi Za Zhi 43, 496-502.
| Crossref | Google Scholar | PubMed |

28  Biering SB et al. (2022) SARS-CoV-2 spike triggers barrier dysfunction and vascular leak via integrins and TGF-β signaling. Nat Commun 13, 7630.
| Crossref | Google Scholar |

29  Biering SB et al. (2021) Structural basis for antibody inhibition of flavivirus NS1-triggered endothelial dysfunction. Science 371, 194-200.
| Crossref | Google Scholar | PubMed |

30  Kumar N et al. (2021) SARS-CoV-2 spike protein S1-mediated endothelial injury and pro-inflammatory state is amplified by dihydrotestosterone and prevented by mineralocorticoid antagonism. Viruses 13, 2209.
| Crossref | Google Scholar | PubMed |

31  Jana S et al. (2021) Cell-free hemoglobin does not attenuate the effects of SARS-CoV-2 spike protein S1 subunit in pulmonary endothelial cells. Int J Mol Sci 22, 9041.
| Crossref | Google Scholar | PubMed |

32  Meyer K et al. (2021) SARS-CoV-2 spike protein induces paracrine senescence and leukocyte adhesion in endothelial cells. J Virol 95, e00794-21.
| Crossref | Google Scholar | PubMed |

33  Fountain JH et al. (2023) Physiology, Renin Angiotensin System. StatPearls Publishing, Treasure Island, FL, USA. https://www.ncbi.nlm.nih.gov/books/NBK470410/

34  Gao X et al. (2022) Spike-mediated ACE2 down-regulation was involved in the pathogenesis of SARS-CoV-2 infection. J Infect 85, 418-427.
| Crossref | Google Scholar | PubMed |

35  Lei Y et al. (2021) SARS-CoV-2 spike protein impairs endothelial function via downregulation of ACE 2. Circ Res 128, 1323-1326.
| Crossref | Google Scholar | PubMed |

36  Pires De Souza GA et al. (2021) Angiotensin II receptor blockers (ARBs antihypertensive agents) increase replication of SARS-CoV-2 in Vero E6 cells. Front Cell Infect Microbiol 11, 639177.
| Crossref | Google Scholar | PubMed |

37  Sui Y et al. (2021) SARS-CoV-2 spike protein suppresses ACE2 and type I interferon expression in primary cells from macaque lung bronchoalveolar lavage. Front Immunol 12, 658428.
| Crossref | Google Scholar |

38  Zhang Q et al. (2021) Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) membrane (M) and spike (S) proteins antagonize host type i interferon response. Front Cell Infect Microbiol 11, 766922.
| Crossref | Google Scholar |

39  Csordas BG et al. (2022) Is IFN expression by NK cells a hallmark of severe COVID-19? Cytokine 157, 155971.
| Crossref | Google Scholar | PubMed |

40  Ferreira-Gomes M et al. (2021) SARS‐CoV‐2 in severe COVID‐19 induces a TGF‐β‐dominated chronic immune response that does not target itself. Nat Commun 12, 1961.
| Crossref | Google Scholar |

41  Freitas RS et al. (2022) SARS-CoV-2 spike antagonizes innate antiviral immunity by targeting interferon regulatory factor 3. Front Cell Infect Microbiol 11, 789462.
| Crossref | Google Scholar | PubMed |

42  Palakkott AR et al. (2023) The SARS-CoV-2 spike protein activates the epidermal growth factor receptor-mediated signaling. Vaccines 11, 768.
| Crossref | Google Scholar | PubMed |

43  Kucia M et al. (2021) An evidence that SARS-Cov-2/COVID-19 spike protein (SP) damages hematopoietic stem/progenitor cells in the mechanism of pyroptosis in Nlrp3 inflammasome-dependent manner. Leukemia 35, 3026-3029.
| Crossref | Google Scholar | PubMed |

44  Ratajczak MZ et al. (2021) SARS-CoV-2 entry receptor ACE2 is expressed on very small CD45 precursors of hematopoietic and endothelial cells and in response to virus spike protein activates the Nlrp3 inflammasome. Stem Cell Rev Rep 17, 266-277.
| Crossref | Google Scholar | PubMed |

45  Ogata AF et al. (2022) Circulating severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine antigen detected in the plasma of mRNA-1273 vaccine recipients. Clin Infect Dis 74, 715-718.
| Crossref | Google Scholar | PubMed |