IIIR3b Flashcards
Where do NK cells come from?
bone marrow from a common NK and T cell progenitor
What interferons activate NK cells?
interferon alpha/beta: augments cytolytic activity
What interleukins activate NK cells?
- IL-15: needed for development and is constantly needed, increases cytotoxicity
- IL-12/18: augments INF-gamma production
- IL-2: induces proliferation, increases cytotoxicity
What are NK cells especially good at?
fighting viruses
What will make an NK cell kill another cell?
- The absence of an MHCI receptor, and
2. An activating reaction from the other cell
What are Id2, MCM4 and TF Nfil3 (E4B4) for?
They are all important in T cell development.
How do NK cells indirectly participate in fighting viral infections?
IFN-alpha/gamma activates them, as do cytokines released from infected cells.
How do NK cells directly participate in fighting viral infections?
KIR (Ly49 in mice) helps the NK cell recognize infected cells. If MHCI is absent, KIR helps NK to bind and kill. If MHCI is present, KIR inhibits the attack.
What is an NKG2D ligand?
It is a “kill me” signal put up by infected cells. NK cells have NKG2D receptors.
What must NKG2D pair up with in order to work?
DAP10.
What type of cell does HIV target?
CD4+ T lymphocytes
What are the 3 steps of entry for HIV?
- bind to CD4
- bind co-reeptor, either CCR5 or CXCR4
- fuze membrane
Where does HIV turn RNA into DNA?
cytoplasm
What is the role of integrase?
It brings the viral DNA into the nucleus to be inserted into the host DNA
How many HIV clades are there?
A-O. B is common in US, C is common in Africa.
What is normal CD4 levels? When does a person have AIDS?
normal = 450-500 CD4 cells per microliter AIDS = <200 CD4 cells per microliter
What HLA type do elite controllers have?
HLAB57
Whys is HIV so hard to fight?
B cells can make Abs, and CTL cells will attack, but CD4+ cells are the ones that regulate the B cell and CTL cells. Also, rapid mutation rates.