Thesis Format
Integrated Article
Degree
Master of Science
Program
Physiology and Pharmacology
Supervisor
Feng, Qingping
Abstract
COVID-19 is caused by SARS-CoV-2 and has led to over seven million deaths worldwide. It can lead to severe complications like ARDS and sepsis with a systemic inflammatory response. The N-protein is a key structural protein of SARS-CoV-2 and is critical for viral replication and genome packaging. However, its role in COVID-19 induced inflammation remains controversial. One aspect that has been largely overlooked is the consideration of residual endotoxins in recombinant proteins when conducting in vitro immune response studies. We hypothesized that the N-protein will be proinflammatory in endothelial cells and monocytes, independent of potential endotoxin contamination. Our results showed that endotoxin depleted N-proteins did not lead to an increase in inflammatory response in these cells. Furthermore, any inflammatory effects seen were reduced to control levels with polymyxin B treatment. Overall, this showed that the inflammatory effects of recombinant N-proteins that have been observed in current literature may be due to endotoxin contamination, suggesting that it does not directly induce inflammation.
Summary for Lay Audience
COVID-19 is caused by the SARS-CoV-2 virus and has led to over seven million deaths worldwide. The disease can cause severe respiratory problems and widespread infection, which can lead to inflammation throughout the body. SARS-CoV-2 consists of several key proteins, including the nucleocapsid protein (N-protein), which is crucial for viral replication and genome packaging. The N-protein is undoubtedly vital for the virus, but its role in inflammation in the body is still unclear. An important factor that many studies have not considered is the presence of endotoxins in recombinant proteins used for experiments. Endotoxins are contaminants that arise from bacteria during the production of recombinant proteins and can also lead to a strong inflammatory response. Our study aimed to investigate if the N-protein itself causes inflammation in certain types of cells, separate from any effects of contaminants. We found that the recombinant N-protein induced inflammation in endothelial cells and monocytes. However, when we treated cells with polymyxin B, a drug that neutralizes endotoxins, any inflammatory effects observed with the recombinant N-protein were eliminated. This suggests that N-protein does not directly lead to inflammation and some of the reported effects may be due to endotoxin contamination.
Recommended Citation
Tufail, Mehreen, "The Nucleocapsid Protein of SARS-CoV-2 Does Not Induce Inflammation in Endothelial Cells or Monocytes" (2024). Electronic Thesis and Dissertation Repository. 10457.
https://ir.lib.uwo.ca/etd/10457
Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.
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