Background The release of neutrophil extracellular traps (NETs) is associated with inflammation, coagulopathy, and organ damage found in severe cases of COVID-19. However, the molecular mechanisms underlying the release of NETs in COVID-19 remain unclear. Objectives We aim to investigate the role of the Gasdermin-D (GSDMD) pathway on NETs release and the development of organ damage during COVID-19. Methods We performed a single-cell transcriptome analysis in public data of bronchoalveolar lavage. Then, we enrolled 63 hospitalized patients with moderate and severe COVID-19. We analyze in blood and lung tissue samples the expression of GSDMD, presence of NETs, and signaling pathways upstreaming. Furthermore, we analyzed the treatment with disulfiram in a mouse model of SARS-CoV-2 infection. Results We found that the SARS-CoV-2 virus directly activates the pore-forming protein GSDMD that triggers NET production and organ damage in COVID-19. Single-cell transcriptome analysis revealed that the expression of GSDMD and inflammasome-related genes were increased in COVID-19 patients. High expression of active GSDMD associated with NETs structures was found in the lung tissue of COVID-19 patients. Furthermore, we showed that activation of GSDMD in neutrophils requires active caspase1/4 and live SARS-CoV-2, which infects neutrophils. In a mouse model of SARS-CoV-2 infection, the treatment with disulfiram inhibited NETs release and reduced organ damage. Conclusion These results demonstrated that GSDMD-dependent NETosis plays a critical role in COVID-19 immunopathology and suggests GSDMD as a novel potential target for improving the COVID-19 therapeutic strategy.

Vaccination with flagellin fused L2 multimers provided lasting (>1year) immunity without the need for an exogenous adjuvant. Inclusion of the L2 amino acid 17-38 region in such multi-HPV type fusions expanded the spectrum of protection.

The release of neutrophil extracellular traps (NETs) is associated with inflammation, coagulopathy, and organ damage found in severe cases of COVID-19. However, the molecular mechanisms underlying the release of NETs in COVID-19 remain unclear. Using a single-cell transcriptome analysis we observed that the expression of GSDMD and inflammasome-related genes were increased in neutrophils from COVID-19 patients. Furthermore, high expression of GSDMD was found associated with NETs structures in the lung tissue of COVID-19 patients. The activation of GSDMD in neutrophils requires live SARS-CoV-2 and occurs after neutrophil infection via ACE2 receptors and serine protease TMPRSS2. In a mouse model of SARS-CoV-2 infection, the treatment with GSDMD inhibitor (disulfiram) reduced NETs release and organ damage. These results demonstrated that GSDMD-dependent NETosis plays a critical role in COVID-19 immunopathology, and suggests that GSDMD inhibitors, can be useful to COVID-19 treatment.

Neutrophil extracellular traps (NETs) are an important mechanism for defense against pathogens. Their overproduction can be harmful since excessive NET formation promotes inflammation and tissue damage in several diseases. Nucleases are capable to degrade NET on basis of their DNA hydrolysis activity, including the CdcPDE, a nuclease isolated from Crotalus durissus collilineatus snake venom. Here, we report a new finding about CdcPDE activity, demonstrating its efficiency in degrading cell-free DNA from NETs, being a potential candidate to assist in therapies targeting inflammatory diseases.