TeachableMedicalNews article 03172023

Teachable moment in classrooms:

  1. chemical basis of life chapter – proteins can be cut by hydrolysis using proteases
  2. cellular basis of life chapter – transmembrane proteins can serve as receptors
  3. cellular basis of life chapter – RNA is translated into proteins on ribosomes
  4. microbiology – lifecycle of RNA viruses

The news item:  Recently this news appeared online

 

https://www.washingtontimes.com/news/2022/jul/23/bidens-health-improving-after-second-day-paxlovid-/

The article states that President Biden received Paxlovid treatment after his diagnosis of COVID infection. The article doesn’t explain anything about Paxlovid itself.

So, Why Do I Care??  At the time of writing this blog post the number of COVID infections numbered 765 million with 6.78 million deaths worldwide.  There is a small number of people (less than 1% of infections) who suffer serious health consequences, and even die because of this virus. Early intervention, such as the use of oral antiviral drugs is a promising way to prevent the development of serious illness.  The way Paxlovid acts may provide a template on how antiviral drugs may treat other virus-borne illnesses.

Plain English, Please!!!

First, let’s talk about why corona viruses can cause so much damage to our bodies. Corona viruses is an organism that can not multiply without a cell hosting it. In order to multiply, corona viruses hijack the RNA making and the protein-making capacities of the host cell.  Viral hijacking means that the host cell can not make RNA and proteins for the host’s own use, and the host cell dies as a consequence of the infection. Therefore, the main direct damage from corona virus infection is the killing of our own cells.

Second, let’s talk about how Sars-CoV-2 hijacks cells. Once a corona virus enters a living host cell, the long RNA of the virus snatches the ribosomes of the host cell, and is transcribed into a long, viral polyprotein.  Think about this polyprotein as long toolbelt with several tools attached to it. Each tool is a unique protein that helps making more viral RNA, and improves the quality of the viral RNA. Before those tools can be used, however, they have to be freed from the polyprotein, and this is done by cutting the toolbelt into smaller pieces. The cutting of the toolbelt, the polyprotein, is done by protease enzymes. Once the polyprotein is cut, the host cell is flooded by viral enzymes that create many new viral RNA.

Third, let’s talk about how Paxlovid acts. Because the cutting of the viral polyprotein is essential for making many new viruses, drugs blocking this cutting can be effective in stopping the infection.  The main ingredient in Paxlovid is doing exactly that.  Imagine that pair of scissors is used to cut the toolbelt, but taping together the scissor blades would stop the cutting. The scissors are protease enzymes, and the Nimatlervir component in Paxlovid tapes shut the scissors, inhibits the protease enzymes, and, thus, the polyprotein remains in one piece, and without the separated tools the corona virus can not make new viruses inside the host cell.