Study your flashcards anywhere!

Download the official Cram app for free >

  • Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off

How to study your flashcards.

Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key

Up/Down arrow keys: Flip the card between the front and back.down keyup key

H key: Show hint (3rd side).h key

A key: Read text to speech.a key


Play button


Play button




Click to flip

34 Cards in this Set

  • Front
  • Back
What is the protein that is lateral to the TCR and is responsible for signal transduction?
What is the structure of MHCI's?
alpha chain with 3 external domains, 1 transmembrane domain, and 1 cytoplasmic tail. Beta 2 microglobulin chain with one external domain. Beta 2 is not encoded in MHC gene
What is the structure of MHC2's?
alpha chain has 2 external domains, 1 transmembrane, and 1 cytoplasmic tail. Beta chain has the same number and type domains as alpha. All are encoded in the MHC gene.
where is the peptide Ag binding cleft in MHC1's and MHC2's?
1: between alpha 1 and alpha2
2: between alpha 1 and beta 1
What are the three gene regions that encode MHC2's?
DP, DQ, and DR. (each contains an alpha and beta chain)
What are the three regions in the MHC1 gene?
B, C, A (only alpha chains).
which cells can present intracellular protein Ag or extracellular protein Ag to either MHC class (it breaks the rules)?
dendritic cells
what are the protein transporters that transport intracellular Ag from the proteosome to the ER to be presented on MHC1's?
tap1 and tap2
what part of the CD3 protein is responsible for signal transduction?
alpha chains on the TCR have what DNA segments? beta chains??
alpha: V and J
beta: V,D, and J
Where are the gamma and delta loci for g-d TCR?
gamma: different chrom (chrom 7)
delta: in between V-alpha and J-alpha
What are two examples of non specefic adhesion molecule interactions seen when the TCR and MHC associate?
LFA1 (on T cell) binds ICAM1
CD2 (on T cell) binds LFA3
In the thymus, corticoepithelial cells mediate positive selection in what type of immature T cells?
double positive thymocytes (have both CD4 and CD8)
In the thymus, dendritic cells in the cortico-medullary junction mediate negative selection in what stage of T cell maturation?
double positive thymocytes (CD4 and CD8 positive) OR mature (either CD8+ OR CD4+) thymocytes
What is the progression of CD44 and CD25 seen in maturing double negative thymocytes before they enter the double positive stage?
CD44+, CD25-
CD44+, CD25+
CD44low, CD25+
CD44-, CD25-
In terms of TCR receptor alpha chain and beta chain DNA rearrangement, which one rearranges 1st and what DNA regions does it rearrange first?
B chain rearranges first. It rearranges segments DJ first then V.
The mature TCR is seen first at what maturation stage of the T cell?
the double positive stage
Why can't T cells bind free Ag?
Because positive selection makes them bind self MHC + peptide
T cell maturation looks a lot like B cell maturation except for what process?
B cells undergo somatic hypermutation to change their binding speceficities, whereas T cells do not.
What is the main co-stimulatory signal seen in T cell activation?
Association of CD28 on T cell with its ligand, B7
What are the 2 competence signals in T cell activation and what is the progression signal?
competence signals are the TCR engagement and the co-stimulatory signal. The progression signal is IL-2R and IL-2.
What is the signalling pathway activated by the competence signal in T cell activation?
CD45 (membrane protein) de-Pi's SARC family kinase (Fyn or LCK) which Pi ITAMs (docking sites on CD3) which $'s ZAP70 which $'s PLC. DAG $'s PKC which removes IK-B from txn factor NF-KB. IP3 releases Ca2+ which $'s calmodulin which de-Pi's NF-ATc thus activating this txn factor. The genes upregulated are for IL-2 and IL-2R
If a naive T cell encounters an APC with MHC + Ag but NO co-stimulatory signal, what happens?
The T cell becomes anergic leading to tolerance to that Ag.
What are the cytokines secreted by the TH1 cells?
IL-2, IFN-y, TNF-B, GM-CSF, IL-3
What two cytokines promote TH1 formation?
IL-12 from dendritic cells exposed to bacteria and viruses and IFN-y from NK cells which make IFN-y in presence of IL-12
What cytokine promotes TH2 formation and what conditions promote its release?
IL-4, which is secreted from NK cells in absence of dendritic cells.
TH1's secrete what to prevent TH2 formation, and TH2's secrete what to prevent TH1 formation?
TH1's secrete IFN-y
TH2's secrete TGF-B and IL-10
What do these cytokines do? (answers in the same order)
IFN-y, TNF-B or FASL, IL-3 + GM-CSF, TNF-a and TNF-B.
activates macs, kills chronically infected cells and macs to release contents to new macs, induces mac differentiation in bone marrow, and upregulate adhesion molecules in the endothelium for diapdesis of macs
B cells present antigen to T cells via which MHC class?
TH2's activate B cells via what signalling molecules?
CD40 on B cell and CD40L on T cell
If a CD4 T cell does not assist the APC in activating a naive T cell to become a CD8, what is the consequence?
There will be no memory cells from this event
Graft rejections are what kind of response?
Delayed type hypersensitivity response or type 4 response
Where do super antigens bind on MHC II's? On TCR?
alpha 1 chain on MHC and V beta section of TCR
What is a genetic advantage some people have over toxic shock syndrome toxin (a super antigen)?
They do not have V beta2 regions on their TCR where this toxin binds.