How a Tiny Messenger Powers Your Body and Fuels a Revolution in Medical Science

Hello there—allow me to introduce myself. I’m mRNA, a tiny but vital messenger inside your cells. Every single moment, I work behind the scenes, carrying essential instructions from your DNA to the part of the cell that builds proteins. Without proteins, your body couldn’t do the countless tasks that keep you alive, from delivering oxygen through your bloodstream to defending against harmful invaders.

I can tell you’re the curious type. I like that! Here’s a little more insight into what I do… Think of your DNA as the master blueprint, safely stored in the nucleus (like the control centre) of each cell. This blueprint has all the instructions your body needs, but it can’t leave the nucleus for safety reasons. So, when your body needs a specific protein, it copies a section of the DNA, the protein’s blueprint, into mRNA—that’s me! Once I’m made, I leave the nucleus and move into the cell’s main area, the cytoplasm, where ribosomes—tiny machines that build proteins—wait patiently for my instructions.

When I arrive at a ribosome, it's like stepping onto a construction site with blueprints at the ready. My instructions tell the ribosome exactly how to assemble the amino acids that make up the protein, like the bricks and beams of a building. Just as a foreman guides the crew on how to lay each brick in the right order to construct a sound and sturdy structure, the ribosome follows my directions to assemble the amino acids and build a specific protein. Without my guidance, the cell would have no clear roadmap for building the proteins it needs. These proteins then go on to perform various essential jobs, keeping everything in your body running smoothly.

But why are proteins such a big deal? Well, take haemoglobin, for example. Its name sounds like a character you might encounter in a fantasy story, but haemoglobin is a crucial protein in your red blood cells. It carries the oxygen from the air you breathe to all other parts of your body, including your organs! Without it, your body wouldn’t get the oxygen it needs to survive.

And then there are antibodies, an important part of your body’s personal defence force. These protective proteins are produced by your immune system. They track down and neutralize nasty invaders like viruses and bacteria.

Scientists have been learning the language that cell DNA uses to write my instructions since the 1970s—'the language of the cell' if you will. And throughout the years, they’ve used it to successfully create synthetic proteins for a range of treatments. Practice makes perfect, so it’s no surprise that the understanding of DNA and RNA has improved greatly in the last 50-odd years.

With this intimate knowledge of our language, humans are not just listening to our conversations—you’re actively sending messages. Humans have figured out how to create custom mRNA messages to guide cells in new ways. By the way, this is why mRNA vaccines were such a breakthrough during the COVID-19 pandemic.

We were able to give cells the right instructions, helping the body recognize and fight off the virus effectively. You see, COVID-19 vaccines work by instructing cells to produce a harmless piece of the spike protein found on the surface of the SARS-CoV-2 virus. This, in turn, prompts an appropriate immune response.

And this is just the beginning. Think about what we can do next—using mRNA as messengers to treat, or even cure, diseases that have affected people for generations. The ultimate goal is to create new and improved mRNA instructions for different treatments, giving your body the ability to produce medicines on its own. That’s what makes mRNA technology so impressive.

I’m excited and extremely proud to play my part. At times, it sounds like something out of a science fiction film. But thankfully, it’s become very much science non-fiction!

Curious about what else mRNA can do? A close colleague of mine—a human cell—can tell you more about how we’re helping unlock new potential in regenerative medicine, autoimmune diseases, metabolic disorders, and many other important fields.