Adaptive Immunity: Cell-mediated Response Flashcards
MHC class involving cytotoxic or CD8 T cells
MHC class I
MHC class involving helper or CD4 T cells
MHC class II
MHC class that deals with extracellular pathogens
MHC class II
MHC class that deals with intracellular pathogens
MHC class I
What are the 4 differences of T cell receptors with antibodies?
- TCRs only recognize short peptides
- short peptides are presented by MHC
- TCRs do not undergo differentiation or hypermutation
- TCRs do not have a free-floating form
The alpha and beta chains of the T cell receptor are similar to the ____ fragment of antibodies
Fab
What gene segments code for the α chain?
V and J
What gene segments code for the β chain?
V, D, and J
T/F: T cell receptor diversity also involves RAGs and DNA recombinations
True
T/F: T cell receptors have C genes that are NOT functionally identical
False
enzymes which cut transposons and copy + paste them to other parts of DNA
transposases
support proteins of T cell receptor complex that function in transducing signals
CD3δ, CD3γ, CD3ε, ζ chain
Which class of T cell receptors is similar in all jawed vertebrates?
α:β
MHC class II molecules are found on what types of cells?
macrophages, dendritic cells, B cells
MHC class I molecules are found on what types of cells?
almost all nucleated cells except for erythrocytes
potential to bind to different peptides
promiscuous binding specificity
In MHC class I, foreign proteins are loaded into the _____.
endoplasmic reticulum
In MHC class II, foreign proteins are loaded into the _____.
endosomes
large barrel-shaped protein complex that degrades damaged, misfolded, or unneeded proteins in the cytosol
proteasome
proteasome that produces peptides that bind to MHC class I molecules
immunoproteasome
interferon that induces formation of immunoproteasomes
IFN-γ
form of proteasome present in the absence of infection and IFN-γ
constitutive proteasome
protein that transports broken down peptides from the cytosol into the endoplasmic reticulum
TAP (transporter associated with antigen processing)
chaperone protein that attaches β2 microglobulin to 3α domain proteins in MHC class I
calnexin
proteins that help in peptide bonding
calreticulin and ERp57
brings MHC I closer to TAP
tapasin
shortens peptides so that it may fit better in MHC I
endoplasmic reticulum aminopeptidase (ERAP)
MHC class II chain that is identical in all individuals and prevents molecules of ER from binding
invariant chain
covers binding site on MHC class II
class II-associated invariant chain peptide (CLIP)
removes CLIP for proper loading of antigen
human leukocyte antigen - DM (HLA-DM)
enables extracellular antigens to be presented by MHC class I
cross-presentation
highly polymorphic HLA-I which present antigen to CD8 T cells + ligands of NK cells
HLA-A, HLA-B, HLA-C
oligomorphic HLA-I which present antigen to ligands of NK cells
HLA-E, HLA-G
monomorphic HLA-I which acts as chaperone to MHC class I molecules
HLA-F
highly polymorphic HLA-II which present antigen to CD4 T cells
HLA-DP, HLA-DQ, HLA-DR
oligomorphic HLA-II which aids loading onto HLA-DP, HLA-DQ, HLA-DR
HLA-DM, HLA-DO
region in chromosome 6 responsible for mostly MHC-related or antigen presentation-related genes
class I
region in chromosome 6 responsible for genes related to TAPs, tapasins, and immunoproteasomes
class II
region in chromosome 6 responsible for proteins not related to MHC
class III
interferon that activates CIITA (MHC class II transactivator) and MHC class II molecules
IFN-γ
give 4 reasons why HLA class I most likely evolved first
- Most of HLA-II genes code for proteins strictly for antigen presentation to T cells, while HLA I genes contain proteins with other functions
- HLA-I related genes are found in other chromosomes
- HLA-II is more compact compared to HLA-I
- Some organisms such as Atlantic cod survive with only HLA-I
different sides of antigen bind to MHC and T cell receptor
MHC restriction
MHC diversity results from ____
natural selection by infectious disease
occurs when recombination combines segments with point mutations to homologous segments
interallelic conversion / segment exchange
