In this video, Attack of the Clones, we will be discussing the initiation of the adaptive immune response,
which unlike the innate response outlined in the previous video, takes longer to kick in but is
much more specific to the individual threats being encountered by the body.
In our Star Wars system, a pocket of Imperial troops have unfortunately gone
undetected from the earlier battle and they have dug themselves into the
reinforced defensive position of the Death Star. In immunological terms the Death
Star represents an area of persistent inflammation or infection that the innate
immune system has not been able to deal with. These Super Battle Droids have
become battle-hardened and as a result are going to be much
tougher to destroy than their weaker droid counterparts. These Super Battle
Droids could represent bacteria that have become resistant to certain
antibiotics or pathogens that have found other ways to evade the innate immune
system. The Super Battle Droids wage war across the galaxy, which represents our
body or a specific site of immune challenge, often leaving immense damage
and destruction in their wake. The only option to rid the galaxy of these
hostile invaders for good and restore balance is to call in the strength of
the Jedi Army, which represents the adaptive immune system. Fortunately for
the Jedi Army, Chewbacca and R2D2 have been on a daring mission behind enemy
lines gathering intelligence on the new threat and bringing key information
about these new droids to present to the Jedi commanders. Chewbacca and R2D2
represent two types of cells called macrophages and dendritic cells, these
cells are professional antigen presenting cells and are able to educate
the adaptive immune system about the nature of the threat being
encountered. They do this by presenting small pieces of the threat in a molecule
called MHC class 2 that they have on their surface and they present this to other
cells of the adaptive immune system. In Star Wars terms think of this as R2D2
presenting a holographic image of the Super Battle Droid to help the young
commanders of the Jedi Army identified the threat they are about to encounter.
These Jedi Army commanders include Admiral Yularen, who represents a naive
B-lymphocyte, Princess Leia Organa, a naive CD4+ T-lymphocyte or helper T-cell and
Luke Skywalker, a naive CD8+ T-lymphocyte, or cytotoxic, killer T-cell.
These cells are called naive because they have yet to encounter an immune threat in a
similar way that Leia and Skywalker, who is still new to his training in the ways
of the Force, may be unsure how best to attack the Super Battle Droid invader
having never seen one before.
Fortunately, the immune system also has something called immune memory.
These naive T and B lymphocytes when they
encounter a threat for the first time, can become long-lived memory cells that
remembered the threat they have encountered and are able to respond
more quickly and efficiently.
This is the basis of vaccination where a version of
the pathogen that cannot cause disease, is introduced into the body to allow
the naive immune system to learn about a specific threat. This is called the
primary immune response, if the same threat is ever encountered again, the
immune system mounts a secondary immune response, which is much more robust and
helps eliminate a pathogen before it can cause any harm.
The memory T-cells in Star Wars can be represented by the Jedi Masters Yoda, as a memory CD4+ helper
T-cell, who takes on this role as he is not often directly involved in the battle itself
but instead directs the shots from behind the lines and Obi-Wan Kenobi, as a memory CD8+
killer T-cell, who is often leading the charge to eliminate the dark side threat
and restore balance to the force.
Our naive commanders, Leia and Luke are able to
consult with these wiser Jedi Masters to see if they have any insight from
previous battles. Fortunately, Yoda and Obi-Wan have
encountered a similar battle droid before and are able to offer advice
and guidance to their younger, more naive counterparts on how best to attack this
new threat. Armed with this new information from R2D2 and the Jedi Masters and
backed by the might of the
Jedi Army, Luke and Leia begin to plan their assault.
In the next episode of Immunology Wars, The Host Strikes Back we will look at just how
Luke and Leia carry out their attack to eliminate the threat and restore peace to the galaxy.
Join us then for more Immunology Wars.
