PMTH Morning Report: NK Cells

Good morning staff, zombies, and minions of Princeton Medbloro Teaching Hospital!

I am a baby medblr here, taking a stab at my first morning report. Today’s topic is…wait for it…my favorite cells…natural killer cells! Those bad ass little buggers whom you can thank your lucky stars for playing a role in keeping you a healthy, and relatively happy, humanoid. 

Give them credit because they truly are:

These lymphocytes don’t get as much credit as their ever so popular B and T cell counterparts, but don’t let the absence of genetic rearrangement deter your from what these gems do. They are a part of the innate immune system, and they are ready for action! Watch out infected cells, watch out neoplasms, NK cells are hunting you down!

How do you identify one of these super duper cells you ask? Well, lucky for us they are waving a giant flag. Thanks CD56! Of course, there are other markers but I like this one the best. Anyway, some NK cells let their CD56 shine more than others. What do I mean by that? You can see it with the use of our friend,flow cytometry!

But don’t think CD56 is all lonely on the surface…oh no. There’s a party going on. We have NKG2D getting all flirty with danger, and revving up the engines. All the while NKG2A is flirting’ with the HLA’s (Human Leukocyte Antigen) on cells passing by, and calming shit down. 

However, our party would not be complete without the KIRs (Killer Cell Immunoglobulin-Like Receptors) making everything more interesting. These aren’t generalists like NKG2D or NKG2A. Oh no, these dudes are picky. KIR2DL1 is looking for HLA-C2, KIR2DL2/3 is looking for HLA-C1, KIR3DL1 is looking for HLA-Bw4. But shhhh there’s a little secret that people don’t like to talk about…these KIRs can be frisky sometimes. I just listed the inhibitory KIRs, but substitute an S for the L (ex. KIR2DS1), and you’ve got yourself an activating KIR!

Yes, Yes, I know there is a lot of random information here. It’s important though because whether or not an NK cell kills, and how activated it is, depends on the BALANCE of those activating and inhibiting signals. 

Why do we give a shit about this? There are lot’s and lot’s of reasons, but I’ll list one. Tumor immunology! Turns out information about somebody’s HLA and KIR genotypes may be able to predict a patient’s response to immunotherapies, and maybe even outcomes in cancer patients. Pretty neat huh? 

Well, that’s all I’ve got. Be sure to grab coffee and an extra doughnut on your way out.