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bioRxiv · 10.1101/2021.09.13.460185

Effect of ORF7 of SARS-CoV-2 on the chemotaxis of monocytes and neutrophils in vitro

Wang, G.·Guan, J.·Li, G.·Wu, F.·Yang, Q.·Huang, C.·Shao, J.·Xu, L.·Guo, Z.·Zhou, Q.·Zhu, H.·Chen, Z.
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Abstract

Coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is currently the most significant public health threats in worldwide. Patients with severe COVID-19 usually have pneumonia concomitant with local inflammation and sometimes a cytokine storm. Specific components of the SARS-CoV-2 virus trigger lung inflammation, and recruitment of immune cells to the lungs exacerbates this process, although much remains unknown about the pathogenesis of COVID-19. Our study of lung type II pneumocyte cells (A549) demonstrated that ORF7, an open reading frame (ORF) in the genome of SARS-CoV-2, induced the production of CCL2, a chemokine that promotes the chemotaxis of monocytes, and decreased the expression of IL-8, a chemokine that recruits neutrophils. A549 cells also had an increased level of IL-6. The results of our chemotaxis transwell assay suggested that ORF7 augmented monocyte infiltration and reduced the number of neutrophils. We conclude that the ORF7 of SARS-CoV-2 may have specific effects on the immunological changes in tissues after infection. These results suggest that the functions of other ORFs of SARS-CoV-2 should also be comprehensively examined.

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Wang, G., Guan, J., Li, G., Wu, F., Yang, Q., Huang, C., Shao, J., Xu, L., Guo, Z., Zhou, Q., Zhu, H., Chen, Z.. 2021-09-14. Effect of ORF7 of SARS-CoV-2 on the chemotaxis of monocytes and neutrophils in vitro. https://doi.org/10.1101/2021.09.13.460185

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