SARS-CoV-2 spike glycoprotein S1 induces neuroinflammation in BV-2 microglia (preprint)

The emergence of SARS-CoV-2 has resulted in a global pandemic. In addition to respiratory complications as a result of SARS-CoV-2 illness, accumulating evidence suggests that neurological and neuropsychiatric symptoms are associated with the disease caused by the virus. In this study, we investigated the effects of the SARS-CoV-2 spike glycoprotein S1 stimulation on neuroinflammation in BV-2 microglia. Analyses of culture supernatants revealed an increase in the production of TNF, IL-6, IL-1{beta} and iNOS/NO. SARS-CoV-2 spike glycoprotein S1 increased protein expressions of phospho-p65 and phospho-I{kappa}B, as well as enhancing DNA binding and transcriptional activity of NF-{kappa}B. Pro-inflammatory effects of the glycoprotein effects were reduced in the presence of BAY11-7082 (1 M). The presence of SARS-CoV-2 spike glycoprotein S1 in BV-2 microglia increased the protein expression of NLRP3, as well as caspase-1 activity. However, pre-treatment with CRID3 (1 M) or BAY11-7082 (1 M) resulted in the inhibition of NLRP3 inflammasome/caspase-1. It was also observed that CRID3 attenuated SARS-CoV-2 spike glycoprotein S1-induced increase in IL-1{beta} production. Increased protein expression of p38 MAPK was observed in BV-2 microglia stimulated with the spike glycoprotein S1, and was reduced in the presence of SKF 86002. These results have provided the first evidence demonstrating SARS-CoV-2 spike S1 glycoprotein-induced neuroinflammation in BV-2 microglia. We propose that promotion of neuroinflammation by this glycoprotein is mediated through activation of NF-{kappa}B, NLRP3 inflammasome and p38 MAPK. These results are significant because of their relevance to our understanding of neurological and neuropsychiatric symptoms observed in patients infected with SARS-CoV-2.

Rapid expression of COVID-19 proteins by transient expression in tobacco (preprint)

ABSTRACT In 2020 we suffered from a major global pandemic caused by the SARS-CoV-2 coronavirus. Efforts to contain the virus include the development of rapid tests and vaccines, which require a ready supply of viral proteins. Here we report the production of two SARS-CoV-2 proteins by transient transformation of tobacco, leading to high expression within three days, and subsequent purification of the intact proteins. Such efforts may help to develop testing resources to alleviate the major impacts of this global pandemic.