RESUMEN
SARS-CoV-2 triggers inflammasome-dependent release of pro-inflammatory cytokine IL-1ß and pyroptosis, therefore, contributes to the huge inflammatory response observed in severe COVID-19 patients. Less is known about the engagement of inflammasome in neutrophils, main players in tissue injury and severe infection. We studied the activation of the inflammasome in neutrophils from severe COVID-19 patients and assessed its consequence in term of cells contribution to disease pathogenesis. We demonstrated that NLRP3 inflammasome is dramatically activated in neutrophils from severe COVID-19 patients and that the specific inhibition of NLRP3 reverts neutrophils' activation. Next, the stimulation of severe patients' neutrophils with common NLRP3 stimuli was not able to further activate the inflammasome, possibly due to exhaustion or increased percentage of circulating immature neutrophils. Collectively, our results demonstrate that the NLRP3 inflammasome is hyperactivated in severe COVID-19 neutrophils and its exhaustion may be responsible for the increased susceptibility to subsequent (and possibly lethal) infections. Our findings thus include a novel piece in the complex puzzle of COVID-19 pathogenesis.
Asunto(s)
COVID-19 , Inflamasomas , Humanos , Proteína con Dominio Pirina 3 de la Familia NLR , Neutrófilos , SARS-CoV-2 , Interleucina-1betaRESUMEN
OBJECTIVE AND DESIGN: The heterogeneity of response to SARS-CoV-2 infection is directly linked to the individual genetic background. Genetic variants of inflammasome-related genes have been pointed as risk factors for several inflammatory sterile and infectious disease. In the group of inflammasome receptors, NLRP1 stands out as a good novel candidate as severity factor for COVID-19 disease. METHODS: To address this question, we performed an association study of NLRP1, DPP9, CARD8, IL1B, and IL18 single nucleotide variants (SNVs) in a cohort of 945 COVID-19 patients. RESULTS: The NLRP1 p.Leu155His in the linker region, target of viral protease, was significantly associated to COVID-19 severity, which could contribute to the excessive cytokine release reported in severe cases. CONCLUSION: Inflammasome genetic background contributes to individual response to SARS-CoV-2.
Asunto(s)
COVID-19 , Inflamasomas , Humanos , Inflamasomas/genética , Inflamasomas/metabolismo , Proteínas Adaptadoras Transductoras de Señales/genética , Proteínas Adaptadoras Transductoras de Señales/metabolismo , COVID-19/genética , Proteínas NLR/genética , SARS-CoV-2/metabolismo , Proteínas de Neoplasias/genética , Proteínas Adaptadoras de Señalización CARD/genéticaRESUMEN
The formation of microthrombi in lung autopsies indicates the involvement of NETs in the immunopathogenesis of severe COVID-19. Therefore, supplements inhibiting NET formation, in association with drugs with fewer adverse effects, should be a relevant strategy to attenuate the disease. Resveratrol (RESV) is a natural polyphenol with an important antiviral and antioxidant role. To modulate neutrophils from patients infected with SARS-CoV-2, we evaluated the in vitro effect of RESV on NET formation. Herein, we investigated 190 patients hospitalized with moderate, severe, and critical symptoms at Hospital das Clínicas, Brazil. We observed that neutrophilia in patients with severe COVID-19 infection is composed of neutrophils with activated profile able to release NET spontaneously. Notably, RESV decreased the neutrophil-activated status and the release of free DNA, inhibiting NET formation even under the specific PMA stimulus. At present, there is no evidence of the role of RESV in neutrophils from patients with COVID-19 infection. These findings suggest that adjunctive therapies with RESV may help decrease the inflammation of viral or bacterial infection, improving patient outcomes.
RESUMEN
Zika virus (ZIKV) infection has been associated with the development of Neuromyelitis Optica Spectrum Disorder (NMOSD). ZIKV-induced antibodies that putatively cross-react to aquaporin-4 (AQP4) protein are suggested to cause inflammation of the optic nerve. A region of similarity between AQP4 and the ZIKV NS2B protein was identified. Our data showed that ZIKV-associated NMOSD patients develop anti-AQP4 antibodies, but not anti-ZIKV NS2B antibodies, revealing that cross-reacting antibodies are not the underlying cause of this phenotype. ZIKV infection in mice showed persistent viral replication in the eye tissue, suggesting that NMOSD symptoms are consequence of viral infection of the optic nerve cells.