Viral Replication of the SARS-CoV-2 virus - NanoBiology Course 2020 - Tuesday Group
Channel: Maastricht4Imaging
Date: 2020-11-02

In this video students of the Maastricht Science Program NanoBiology Course 2020, show their explanation of the SARS-CoV-2 viral replication. Using CellPAINT, UCFS Chimera and their creativity they explain the nanobiology of how the SARS-CoV-2 virion can replicate within a cell. 

Viruses are not living things. They are just complicated assemblies of molecules, in particular macromolecules such as proteins, oligonucleotides, combined with lipids and carbohydrates. A virus cannot function or reproduce by itself. It needs a host cell.  

After a virus entered the host cell, a series of chemical reactions occur that lead to the production of new viruses. A virus particle has to disassemble, uncoat and release its genetic material. New viral particles will need to have new genetic material: the Replication of the viral genome is crucial within the Viral Life Cycle. How this replication works depends on the class of virus: David Baltimore classified viruses into one of seven groups depending on a combination of their nucleid acid (DNA or RNA), strandedness (single-stranded or double-stranded), sense, and method of  replication. SARS-CoV2 belongs to the class of Positive-strand RNA virus, where the  positive-sense genome can act as  messenger RNA (mRNA) and can be directly translated into viral proteins by the the host cell's ribosomes.

Interfering with steps within the Replication process could be a very efficient way to treat a viral disease. Lots can be learned from other viruses, for example from Influenza Virus, which causes the common flu. Influenza viruses are RNA viruses which makes use of an RNA Polymerase to replicate and transcribes each negative-sense viral RNA genome segment. The influenze polymerase has an active site where it performs a template directed nucleotide addition, a Cap domain and an endonuclease domain. Replication of influenza virus can be attenuated by, among others, Cap-binding inhibitors, Endonuclease inhibitors, as well as RNA synthesis active site inhibitors. The latter include nucleoside analogues such as Favipiravir, β-d'n4-hydroxycytidine, and Remdesivir. Remdesivir was initially developed for the treatment of Ebola virus, and has recently been admitted by the FDA and EMA for the treatment of COVID-19.