it's inside you all along ...

topic of the day 053 & video of the day 048

could you be immune to everything?

Youtube channel: It's Okay to be Smart

What, who, when, how, why? Then, so?

Even if you don't remember every time you got sick or got flu shot going back to your childhood, your body does.

Each of this is a time when you faced some germy invader and after you fought them off, your body stored in memory so it would recognize these threats if they showed up again. A cellular memory in your immune system.

The immune system is so adaptable and long-lasting that we would be able to engineer our bodies and become immune to germs we've never met or even give ourselves a universal immunity.

The first level of defense is physical i.e. our skin.

When something leaks through, our second level of defense will come to confront it: our white blood cells.

They attack these biohazards with chemical weapons and call in reinforcements to engulf them, and triggering an alarm system called inflammation.

This is your innate immune system at work, billions of cellular soldiers that have been protecting you since birth.

When the threats are much more serious, just like how some bacteria and viruses could double in your body every twenty minutes, our adaptive immune response is there as a capable foe.

These antibodies/ protein carries a unique region with a special shape that allows it to latch onto one particular enemy, like a lock that fits a single key. When one finds its match, it can coordinate all your body's defense to fight this one intruder.

Your immune system learns from this fight so it can attack even stronger if you ever meet the germ again in the future. This is called being immune.

Antibodies stick like Velcro to tiny shapes or handles on the surface of the enemy. Your body is full of different shaped antibodies, all waiting to run into their perfect target.

How does the immune system make the right antibodies for germs you've never met? Look in the DNA, you won't find specific blueprints for the flu or cold virus for example, but their rather unique shape is built from random shuffling. The strategy is to make enough combinations that there's a chance that one will fit that key.

Deep in the bone marrow, there are B-cells destined to carry antibody armours and each of them has the power to make an exorbitant number of unique antibody shapes by shuffling just three sets of genetic instructions.

For example and making it clearer, these cells have three gene decks to work with to start building an antibody. By picking one card from each deck, they can make about 10,000 genetic hands. Next, random DNA letters are inserted in between these genes, adding another layer of variety up to ten million times more possible combinations.

After being sent out to patrol your body and fight germs, these antibodies will continue to mutate and tweak their shape to stay a step ahead of the enemy. When a B-cell locks into a match, it clones itself and some of these new soldiers become little factories, shooting thousands of identical antibodies at the invader every minute. They can neutralize the threat on their own or wait for the rest of the body's immune army to arrive. 

When the battle is over, a few of the clones hang back and become the body's immune system memory, carrying a copy of the unique antibody while remain in patrol for the rest of their lives and being ready to return to action when the threat returns.

This is what vaccine do: showing the immune system what a germ looks like to create a memory without you getting sick in the first place which can last a lifetime. For example, the 1918 Spanish flu survivors still have the antibodies to the virus in their blood today and being used to keep healthy people safe when it came back in 2009.

Unfortunately, germs are always mutating and evolving as well and this game of cat and mouse is why we face new versions of germs like Influenza each year and we need new vaccines to help fight them.

Scientists have found however that some rare antibodies bind to every version of a virus which could be used to get closer to a universal flu treatment

Even if you do not pay attention to your body, your immune system does.

~ Joe Hanson, a Ph.D. biologist ~