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Old 07-28-2011
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Default Immunology: Natural Killers

Natural Killer are specific cells that helps to kill any Cell without MHC 1 using grazyme to perform the destruction of any cell.

They are our native immune killers.

IF Natural Killers kill any cell without MHC 1, why they dont kill RBC or Sperm ( which are the only 2 cell without it? )


RBC doesnt have Nucleo, therefore, dont have mitocondria, therefore dont have any HLA antigen, that's why NK dont kill them, because they dont react, or present any reaction to NK.

Another Theory is that Decay-accelerating factor and C1 esterase inhibitors prevent complement activation on self-cell ( RBC ). Preventing any damage to the RBC.

Why dont kill Sperm ?

Answer: Because of the Blood-testi-barrier who prevents the NK to react or cross-contact with them, in any pathology state or trauma, they become in contact with NK and react... then,,, Natural Killer Kill it.. making less sperm available.

Im reviewing Immune chapter on FA right now, and i didnt see a clear answer on the book, i've always known that NK kill all cell without MHC1 and same time i know that RBC doesnt have one... so why ? i think i just explain the answer...

This is an Open topic, if someone have anything to add, please feel free... =)
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The above post was thanked by:
dr_lizard (07-28-2011), dr.muhamad (07-28-2011), Hope2Pass (07-28-2011), jahn77 (07-28-2011), struggle (07-28-2011)


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