Neutrophil virucidal activity against SARS-CoV-2 is mediated by NETs

Cícero José Luíz Dos Ramos Almeida; Flávio Protásio Veras; Isadora Marques Paiva; Ayda Henriques Schneider; Juliana da Costa Silva; Giovanni Freitas Gomes; Victor Ferreira Costa; Bruna Manuella Souza Silva; Diego Brito Caetite; Camila Meirelles Souza Silva; Ana Caroline Guerta Salina; Ronaldo Martins; Caio Santos Bonilha; Larissa Dias Cunha; Maria Célia Jamur; Luís Lamberti Pinto da Silva; Eurico Arruda; Dario Simões Zamboni; Paulo Louzada-Junior; Renê Donizeti Ribeiro de Oliveira; José Carlos Alves-Filho; Thiago Mattar Cunha; Fernando de Queiroz Cunha

doi:10.1093/infdis/jiad526

Neutrophil virucidal activity against SARS-CoV-2 is mediated by NETs

J Infect Dis. 2023 Nov 28:jiad526. doi: 10.1093/infdis/jiad526. Online ahead of print.

Authors

Cícero José Luíz Dos Ramos Almeida^{1

2}, Flávio Protásio Veras^{1

2

3}, Isadora Marques Paiva^{1

2}, Ayda Henriques Schneider^{1

2}, Juliana da Costa Silva^{1

2}, Giovanni Freitas Gomes^{1

2}, Victor Ferreira Costa^{1

2}, Bruna Manuella Souza Silva^{1

2}, Diego Brito Caetite^{1

2}, Camila Meirelles Souza Silva^{1

2}, Ana Caroline Guerta Salina⁴, Ronaldo Martins^{4

5}, Caio Santos Bonilha^{1

2}, Larissa Dias Cunha⁴, Maria Célia Jamur⁴, Luís Lamberti Pinto da Silva^{4

5}, Eurico Arruda^{4

5}, Dario Simões Zamboni⁴, Paulo Louzada-Junior^{1

2}, Renê Donizeti Ribeiro de Oliveira^{1

2}, José Carlos Alves-Filho^{1

2}, Thiago Mattar Cunha^{1

2}, Fernando de Queiroz Cunha^{1

2}

Affiliations

¹ Center of Research in Inflammatory Diseases, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, 14049-900, Brazil.
² Department of Pharmacology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, 14049-900, Brazil.
³ Department of BioMolecular Sciences, School of Pharmaceutical Sciences of Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo, 14049-900, Brazil.
⁴ Department of Cellular and Molecular Biology and Pathogenic Bioagents, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, 14049-900, Brazil.
⁵ Virology Research Center, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil.

PMID: 38015657
DOI: 10.1093/infdis/jiad526

Abstract

Background: The inflammation in the lungs and other vital organs in COVID-19 are characterized by the presence of neutrophils and high concentration of neutrophil extracellular traps (NETs), which also seems to mediate host tissue damage. However, it is not known whether NETs could have virucidal activity against SARS-CoV-2.

Methods: We investigated whether NETs could prevent SARS-CoV-2 replication in neutrophils and epithelial cells, and what the consequence of NETs degradation in K18-humanized ACE2 transgenic mice infected with SARS-CoV-2.

Results: Here, by immunofluorescence microscopy we observed that viral particles co-localize with NETs in neutrophils isolated from COVID-19 patients or from healthy individuals and infected in vitro. The inhibition of NETs production increased virus replication in neutrophils. In parallel, we observed that NETs inhibited virus abilities to infect and replicate in epithelial cells after 24 h of infection. Degradation of NETs with DNase I prevented their virucidal effect in vitro. Using K18-humanized ACE2 transgenic mice we observed a higher viral load in animals treated with DNase I. On the other hand, the virucidal effect of NETs was not dependent on neutrophil elastase or myeloperoxidase activity.

Conclusion: Our results provide evidence of the role of NETosis as a mechanism of SARS-CoV-2 viral capture and inhibition.

Keywords: COVID-19; SARS-CoV-2; neutrophil extracellular traps; neutrophils.