Immune System
Tour of the System
By taking an imaginary tour of the Immune System, we’ll get a better idea of how it
works and what it does.
When a virus invades the body, it first attacks a single cell. From there,
...
Immune System
Tour of the System
By taking an imaginary tour of the Immune System, we’ll get a better idea of how it
works and what it does.
When a virus invades the body, it first attacks a single cell. From there, the virus
cop- ies itself repeatedly until much of the body is affected--and INfected.
This is where the Immune System takes action. First, it sends a spy known as a
mac- rophage. The macrophage figures out that the virus is an enemy and does
not belong. After the tiny spy moves toward the virus, it devours it, shredding it.
The macrophage next displays antigens on its surface. Antigens are just tiny
fragments of the virus. This macrophage could continue seeking out the original
virus’s offspring, but it would take too long. Instead, it goes for help. This help
comes from a T Cell. Specifically, the macrophage finds T cells that recognize
fragments from the virus on the surface of the macrophage. When the macrophage
meets a T cell and the T cell recog-nizes traces of the virus on its surface, the T
cell and macrophage physically unite.
This connecting of the cells creates a chain reaction that leads to the destruction of
all copies of the virus inside the body.
How did this happen? When the T cell and macrophage connected, they released
chemi-cals which stimulate production of more helper T cells and more
macrophages. Even better, they stimulate production of a “killer” T cell.
This new killer T cell tracks do
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