Articles, Blog

Virus Wars

December 9, 2019


All might seem outwardly peaceful, but right
now tiny battles are raging inside of you. The battles are being fought for control of
the molecular machinery that runs your cells and keeps them, and you, alive. Who are the
attackers? They are miniscule, yet deadly, viruses. If you’ve ever had chicken pox, the
flu, or the common cold, your cells have fought and defeated viruses. Your cells have factories with the power to
create molecular machines. Viruses need to hijack that factory to copy themselves because
they do not have factories of their own. Each virus is like a little tank that can blast
a hole in the outer cell wall and send its forces in. These intruders change the blueprints
in the factory’s headquarters so the factory starts producing more viral tanks. It doesn’t
stop until it builds so many tanks that the cell bursts right open. This is what a virus attack might look like
if you were the size of a cell. Most viruses are little more than genetic information—-DNA
or RNA—-inside a protein shell. They bind to a cell and inject their genetic code inside.
The invaded cell treats this code as its own and starts making virus protein components
to build new viruses. When enough viruses have been assembled, they burst through the
cell membrane and the whole process starts again. Fortunately, your cells have evolved their
own defenses. When you get sick with the flu, at first the viruses win out, but then your
immune system learns to recognize and destroy the invaders. One immune response, which was only recently
discovered in plants and some animals, is called RNA interference, or RNAi. Cells make
a protein called DICER. It’s always on the lookout for double stranded RNA, which is
used by many viruses but rarely by cells. When DICER finds this RNA, it dices it up.
DICER doesn’t stop all the viral RNA from getting through, but it doesn’t need to because
RNAi has a great trick up its sleeve: it uses those chopped up pieces of RNA as weapons
against the virus. Those chopped up RNAs are shreds of the virus’s
blueprint for copying itself. Now, when that virus tries to hijack the cell’s factory,
RNAi molecules are ready: they check all the protein assembly instructions against the
chopped up virus RNA snippets. Anything that matches is something that the virus is trying
to make, so the cell slices it up before it makes a protein. And just like that, the cell
defeats the virus. RNAi is not only a great natural defensive
weapon, but also a powerful tool for biological research. Scientists can use the same basic
mechanism of RNA interference to turn off one gene at a time and study the effect on
the cell and the organism. For example, turning off one gene may drain all of the pigment
out of a purple flower. Another might prevent a plant from producing a toxic chemical, making
it safe to eat. Scientists have not yet determined whether human cells naturally fight viruses
with RNAi, but it is possible that one day we will be able to use RNAi to deactivate
cancer-causing genes and genetic disorders. Meanwhile, viruses and cells will continue
evolving ingenious weapons to try to gain the upper hand as the Great Virus Wars rage
on.

15 Comments

  • Reply Hunter Miller April 23, 2014 at 3:39 pm

    the animations are very cool, but the information presented is very elementary, i didnt learn anything

  • Reply Chaz Searson April 24, 2014 at 7:39 am

    Awesome. Great concise and clear information with cool animations. I love these videos!

  • Reply jorel777 November 13, 2014 at 4:37 pm

    What about retrovirus? 8 of them inside us?!

  • Reply WhiteIce February 22, 2015 at 9:59 pm

    genes cannot cause cancer. Cancer is mutated DNA, not normal DNA.

  • Reply Burning Experience April 24, 2015 at 2:04 am

    Amazing analogy!

  • Reply Fartonaut February 15, 2017 at 8:16 pm

    At the time of writing this comment, my body isn't just battling, it's fighting a cold war.

    (Pun intended)

  • Reply An An May 15, 2017 at 8:12 am

    it's hard to believe all this complexity and systems resulted from random mutations

  • Reply Rufino Bartolabac August 26, 2017 at 10:42 am

    the RNAis are like a micromari.

  • Reply A . M August 27, 2017 at 11:00 am

    chicken pox is caused by bacteria….

  • Reply Skris the Geek November 1, 2017 at 4:00 am

    WERE RUNNING OUTA CELLS!

  • Reply the strange gentleman 404A December 16, 2017 at 4:45 am

    NOT ENOUGH MINERALS – starcraft

  • Reply Choki Choki May 3, 2018 at 10:15 pm

    Trap trigger ed

  • Reply SpaceSauce December 19, 2018 at 9:30 pm

    Very cool!

  • Reply The Yangem May 17, 2019 at 12:42 am

    there are also polite viruses that are like "hey, can I borrow your factories? I will kill bacteria for you.." and our cells are like "yeah ,sure." and the virus uses our factories and kills some bacteria, and everyone is happy.

  • Reply HeyHannah September 23, 2019 at 6:39 am

    This is so awesome how does this not have more views and comments this is my favorite video of the week

  • Leave a Reply