Week 5 Flashcards
TF of Plasmacells
IRF4, Blimp-1
TF of Bmems
Bach2
What chemokine receptor do B cells use to cycle between LZ and DZ?
CXCR4
Contents of Light Zone of GC
FDCs (appearing light because so much projections from fDC), LZ B cells, Tfh cells
Contents of DZ
Rapidly proliferating B cells
Cell surface markers used to differentiate between LZ and DZ B cells
CD83 and CD86 - high on light zone, low on dark zone
What is the mechanosensor that is responsible for MaDCAM-1 polarization on HEV cells?
Piezo1
How long do tissue-derived macrophages last?
self-renew permanently, tend to not be proliferative. Will renew from local precursors.
What are the four ways that macrophages phagocytose?
complement, antibody, antibody-complement, and apoptotic cells
what processes are efferocytosis critical for?
development, regeneration, apoptotic cell clearance
What are human NK markers?
CD3- CD56+
What are mouse NK markers?
CD3-NK1.1+
Is thymus required for NK cel development?
No
From which common progenitor do NK cells develop?
NK cell/T cell progenitor
What are the lymphocyte percentages of NK cells in the peripheral blood, spleen and liver?
5-20% in peripheral blood
~5% in spleen, abundant in liver
Over 70% in decidual tissue!
What are main roles of NK cells?
Cell-mediated killing (ADCC)
early IFNg production
How do NK cells kill?
predominantly perforin and granzymes, but can also use TNFa, Fas ligand and TRAIL
Which cytokine is required for NK cell development and survival throughout lifespan?
IL-15
Which cytokine augments NK cell cytolytic activity and survival during activation?
Interferon a/B (Type 1)
Which cytokines induce IFNg production in NK cells and are required for their proliferation?
IL-12 and IL-18
Which cytokine induces proliferation, increases cytotoxicity, and is used to grow NK cells in vitro?
IL-2
What types of infections are NK-deficient individuals susceptible to?
viral infections, particularly herpesvirus.
May also be more susceptible to cancers.
What is the “missing self” hypothesis?
NK cells will target cells (tumor cells or infected cells) that are not displaying MHC class I
Why is there such variety in NK cell ‘phenotypes’ in any individual?
NK cells express a variety of activating and inhibitory receptors, which can pair with various adaptors (CD3, ITAMs, etc.) Very promiscuous pairing.