• 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
Reading...
Front

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

image

Play button

image

Play button

image

Progress

1/43

Click to flip

43 Cards in this Set

  • Front
  • Back
When is the adaptive immune response initiated?
When lymphocytes recognize antigens
What must APCs do to activate T-cells?
break down antigen to peptides and present it on MHC molecules in SECONDARY LYMPHOID TISSUES
What is the function of MHC molecules? Where are they expressed?
Present PEPTIDE fragments to helper and cytotoxic T cells. expressed on all somatic cells
T\F MHC molecules are constituitively located on cell surfaces?
false, MHC molecules must be bound to an antigen before they are on the cell surface
What do T cell Receptors bind to?
MHC+antigen
T\F MHC molecule binding groove are specific for a single peptide fragment?
False
Compare the structures of MHCI vs MHCII molecules?
MHCI=One variable α chain and one NON-variable β chain

MHCII=Variable α and β chains
Compare the cells that expresss the different MHC molecules?
All nucleated cells=MHCI

APC's=MHC II
What are the different cells that MHC's are used to present to and where are the peptides take up from?
MHCI= express ENDOGENOUS peptides to Cytotoxic T lymphocytes

MHCII=take up EXOGENOUS peptides and display them to T helper cells
What CD marker can bind to MHC II molecules?
CD4(T helper cells)
What is a function of the MHCI cells?
All nucleated cells use these to express endogenous peptide to CTL when they have iINTRACELLULAR PATHOGENS or TUMOR PEPTIDES
What CD marker can MHC II cells bind to?
CD8=cytotoxic T lymphocyte
Which chromosome is the MHC allele located on?
Chromosome 6
What are the 3 genes in each MHC class?
MHCI:HLA-A\B\C
MHCII: HLA-DP\DQ\DR
Why is the MHC locus considered to be polymorphic and polygenic?
Polygenic because each class contains three genes

Polymorphic because the genes all have multiple alleles
What is a MHC haplotype?
it is the specific combonation of alleles for the genes present on the chromosome 6 MHC locus
Why are MHC molecules usually inherited as a set?
Because recombination at the MHC locus is really low
Why do MHC I molecules have 6 different molecules?
Because each person has 2 alleles for each of the 3 genes
Why do MHC II molecules have more than 6 different molecules?
Because each MHC molecule can have variable α and β units
What types of MHCs do APC's express?
Both MHCI and MHCII
What types of MHC's do all nucleated cells express/?
All MHC I coding regions
Why do individuals have such variety of antigens their T cells can respond to?
Because of variation in MHC alleles and because of the non-specificity of the peptide binding of MHC's
Which MHC gene gives people susceptibility to malaria?
HLA-B53
What determines if Grafts are rejected by the immune system?
When MHC molecules in individual don't match donor tissue: Histocompatible vs histoincompatible
What are the 2 pathways for presentation?
MHCI=cytosolic
and MHCII molecules=endocytic pathway
What are the steps of the cytosolic pathway?
Antigen is broken down in CYTOSOL by proteosome and peptides are tranported to RER by TAP transporter. MHCI made in RER and associated with peptide then transported to the membrane
What is the functional deficiency of a person with TAP deficiency?
Cytotoxic T cell function is dimished because no MHCI presentation, causing decreased cell mediated immune response
What are the steps of MHC II presentation?
Lysosomal degredation of antigen
Synthesis of MHCII+invariant chain(Ii) in RER
Transport of MHCII+invariant to endolysome
Removal and degredation of Ii
Loading of exogenous peptide by DM
Transport to membrane
What is cross presentation of exogenous antigen? What does this allow?
usually presented by MHCII but APCs can present exogenous with MHCI. Allows cells to capture viruses or infected cells and generate CTLs to those infected cells
What types of MHC's do all nucleated cells express/?
All MHC I coding regions
Why do individuals have such variety of antigens their T cells can respond to?
Because of variation in MHC alleles and because of the non-specificity of the peptide binding of MHC's
Which MHC gene gives people susceptibility to malaria?
HLA-B53
What determines if Grafts are rejected by the immune system?
When MHC molecules in individual don't match donor tissue: Histocompatible vs histoincompatible
What are the 2 pathways for presentation?
MHCI=cytosolic
and MHCII molecules=endocytic pathway
What types of MHC's do all nucleated cells express/?
All MHC I coding regions
Why do individuals have such variety of antigens their T cells can respond to?
Because of variation in MHC alleles and because of the non-specificity of the peptide binding of MHC's
Which MHC gene gives people susceptibility to malaria?
HLA-B53
What determines if Grafts are rejected by the immune system?
When MHC molecules in individual don't match donor tissue: Histocompatible vs histoincompatible
What are the 2 pathways for presentation?
MHCI=cytosolic
and MHCII molecules=endocytic pathway
What are the steps of the cytosolic pathway?
Antigen is broken down in CYTOSOL by proteosome and peptides are tranported to RER by TAP transporter. MHCI made in RER and associated with peptide then transported to the membrane
What is the functional deficiency of a person with TAP deficiency?
Cytotoxic T cell function is dimished because no MHCI presentation, causing decreased cell mediated immune response
What are the steps of MHC II presentation?
Lysosomal degredation of antigen
Synthesis of MHCII+invariant chain(Ii) in RER
Transport of MHCII+invariant to endolysome
Removal and degredation of Ii
Loading of exogenous peptide by DM
Transport to membrane
What is cross presentation of exogenous antigen? What does this allow?
usually presented by MHCII but APCs can present exogenous with MHCI. Allows cells to capture viruses or infected cells and generate CTLs to those infected cells