Manufacturing secret: What is a messenger RNA?📃 🏭
The originals remain at the trunk, the copies are transmitted to the factory!Message RNA (or mRNA) are like these copies, molecules responsible for transmitting the information coded in our precious genome, to allow the synthesis of the proteins necessary for the functioning of our cells.Please note, this message will quickly self -destroy: messengers are indeed very fragile molecules.
Our genome contains the manufacturing plan for each of the proteins that our cells may need to exist, operate...And make us live!These plans - our genes - are therefore kept well safe, inside the cell nucleus.But factories that synthesize proteins - ribosomes - are located outside this nucleus.Consequently, the manufacture of proteins is not carried out from the original plans, but by relying on their "duplicate": messengers (for ribonucleic acid messenger).
Thus, without going into details, when a cell needs a protein, the latter's manufacturing plan is "photocopied" - scientists say that its "gene" is "transcribed".The copy thus generated - a messenger RNA - is then exported outside the nucleus and joins the ribosomes where it allows the synthesis of the requested protein.Very unstable and fragile, this copy is then quickly destroyed.
Researchers had the idea of diverting this system to develop vaccines.Classically, vaccination is based on the administration of an attenuated or inactivated infectious agent or on that of its proteins.The objective is to trigger an immune response directed against pathogen, associated with the production of memory cells which will protect us in the event of subsequent infection.With messenger RNA vaccines, the idea is to let our cells make the component against which our organism will learn to defend themselves.
Concretely, it is therefore a question of administering a messenger RNA which corresponds to the manufacturing plan of a protein of the targeted microbe, which is not likely to make us sick but against which the organism will train to fight.Addressed directly to the ribosomes, without going through the nucleus of the cells, this molecule can in no case interact with our genome or lead to its alteration: nothing to do with gene therapy or the creation of an GMO!The advantage of this approach is that RNAs are much simpler and faster to produce than the components of "classic" vaccines.Its defect: the fragility of these small ribonucleic acid molecules requires keeping vaccination preparations at an extremely low temperature.As for the efficiency and safety of this new type of vaccine, although there is little data and hindsight, the information available to date is reassuring, even exciting!
To find out more about messengers and their role in the expression of our genome:
To read also, about the RNA vaccine against the COVVI-19 whose use has just started in the United Kingdom: How does the PFIZER RNA vaccine work?, By Bruno Pitard (The Conversation, 25.11.20)