Saturday, July 26, 2014

Natural Killer Cell

I chose to do more research on a topic we covered in Module five. I would like to expand your knowledge on the interesting facts of the Natural Killer cell. When the video in module 5, on the YouTube channel Crash Course, briefly talked about the Natural Killer cells it sparked an my interest. Natural Killer cells or NK cells are a part of the innate immune system. This is the immune system that we are born with. The NK cells “play a major role in the host-rejection of both tumors and virally infected cells.” What happens is when the NK cell detects a cell that has become infected?  When this occurs the NK cell will use proteins called granzymes, these proteins eat holes in the cells membrane. When this happens the proteins get into the cell and cause a case of scheduled cell death upon the NK attacking the cell.

The NK cell is a lymphocyte, a form of small leukocyte (white blood cell)
View from a NK from an Electron Microscope
One thing that scientist were trying to unravel was, how the NK cell only kills the targeted cell, with the proteins that the cell spreads to the infected cell. For the NK cell to be signaled to do its job, the interferons or macrophages deliver cytokines needed to signal the immune system. This is how the NK is shown where to go to target and kill the cell. This is just one way that the immune system takes care of infected cells to make sure that you are safe and are able to live a healthy life.
A scientific team looked into what made the NK work as it did. To do so, the team of Sophie Ugolini and other scientist, mutated mice; “To identify the genes responsible for many properties of the NK cell, we induce random mutations in the genome of mice with a chemical agent,” said Sophie Ugolini They did this until they achieved a homozygous mutation; this made it so that the mutation could be carried through generations without losing the mutation. When the team achieved this, they exposed the mice to pathogens to see what the NK cell would do. Upon this action the team was able to determine that a gene called Ncr1, if inactivate, increases the “anti-tumor property,” of NK cells. With Ncr1 being inactive this effects the receptor molecule NKp46. This molecule keeps the NK cell from over reacting to possible stimuli; without the proper amount of this molecule the NK cell becomes extremely active.   
This is just a brief but, deeper look into the Natural Killer cell. I found that this cell is very interesting both by its name and by function. I hope that this small amount of information has given you a look into a small but extremely important part of the immune system. 

Used sources

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