L6-Exam 2 Flashcards
The typical virus replication cycle has both ___ and ___ phase
extracellular and intracellular phase
Can antibodies gain access to the intracellular environment?
No - it is the job of the T-Lymphocyte system to recognize intracellular antigens
In order for T cells to recognize antigens derived from within a host cell, what must happen to the antigen first?
Antigen must be processed
The exogenous antigen processing pathway involves ____ molecules and activation of ___ cells
-HLA Class II molecules
-CD4+ T Helper cells
The endogenous antigen process pathway involves ___ molecules and activation of ___ cells
-HLA Class I molecules
-CD8+ cytotoxic T cells
Nearly every vertebrates has an MHC that encodes genes responsible for determination of ___
self and non-self
MHC Class I and II genes encode ____ class I and II
HLA Class I and II
Genes for MHC are closely linked on chromosome __
Chromosome 6 (there are 6 main loci)
What are the three loci that make up HLA Class I? Class II?
HLA Class I: HLA-A, B, and C
HLA Class II: HLA-DP, DQ, and DR
True or False: Genetic polymorphisms exist in the MHC complex genes
True - each gene has multiple alleles
How many sets of MHC genes does each person have? How are they inhertited?
two sets of MHC
inherited en bloc
What family does the MHC complex belong to?
IgG Superfamily Gene
Based on the structure, label these as either HLA Class I or HLA Class II:
HLA Class I (left) and HLA Class II (right)
What are three features shared by HLA Class I and HLA Class II molecules?
1) Peptide binding groove
2) Binding site for co-receptor on T cell
3) Transmembrane glycoproteins (activates signaling molecules)
What are three features not shared by HLA Class I and HLA Class II molecules?
1) Structure
- HLA Class I is a monomer
- HLA Class II is a dimer
2) T Cell Interaction
- HLA Class I has a CD8 binding site
- HLA Class II has a CD4 binding site
3) Expression
- MHC I is expressed on all nucleated cells
- MHC II expressed on APC (dendritic cells)
Which of the following associations are correct:
A. MHC I - endogenous
B. MHC II - endogenous
C. MHC I - exogenous
D. MHC II - exogenous
A and D
Which of the following associations are correct?
A. HLA-A - exogenous
B. HLA-DQ - exogenous
C. HLA-DP - endogenous
D. HLA-C - exogenous
B. HLA-DQ - exogenous
Which side is peroxidase independent vs. peroxidase dependent?
Left side (peroxidase independent) while right side (peroxidase dependent)
In processing of an exogenous antigen, HLA class II molecules are made in the ___
ER
What are the two roles of the invariant chain in processing of exogenous antigen?
1) Blocks peptide binding groove
2) Ensures alpha and beta stay in right configuration
Once a microbe gets phagocytose in exogenous antigen processing, a ___ fuses with the phagocytic vesicle and the proteins are broken down
granule
Once HLA Class II molecules are formed and have invariant chain added (in exogenous antigen processing) - they move to the ___ for further processing
Golgi
The endosome fuses with what was phagocytosed to create the ___ endosome. In this endosome, ____ cleaves the invariant chain, leaving a ___
late; proteolytic activity; clip
____ is the site of diversity in processing of exogenous antigens, as it is where peptides with the most affinity for the peptide binding groove site bind
Late endosome
Once processing of exogenous antigens has occurred, HLA molecule fuses with the lipid bilayer and presents to ___
CD4
If the cell can express HLA Class II, it can process and present intracellular __ to _____
Ag to CD4+ T Helper Cells
HLA Class II cells are constitutively expressed on what three cell types?
1) Dendritic cells (spleen/lymph nodes)
2) Thymic epithelial cells
3) B cells
Expression of HLA Class II can be induced on what three cell types?
1) Macrophages
2) Fibroblasts
3) Endothelial cells
If CLIP bound to MHC II irreversibly, what would happen?
A. Self peptides would be presented
B. Exogenous peptides would be presented
C. No peptides would be presented
C. No peptides would be presented
When an endogenous antigen, such as a virus, enters a cell, viral nucleic acid is made in the nucleus then made into a protein, which is ____
ubiquinated (targets protein for recycling)
During endogenous antigen processing, then antigen is broken down into peptides via the ______. Once made, peptides enter the ER via ___
proteosome; TAP1 and TAP2
During endogenous antigen processing, MHC Class I chains and B2m are made in the ___ and assembled with ____
ER; caparones
What type of cells can process endogenous Ag?
All nucelated cells (exception: neutrophils)
Peptides generated within the cytosol of a host cell are likely to become associated with which of the following MHC-encoded molecules?
A. HLA Class I
B. HLA Class II
C. Both HLA Class I and HLA Class II
D. Neither HLA Class I or HLA Class II
A. HLA Class I
Which of the following MHC-encoded molecules are responsible for presenting antigenic peptides that are derived from phagocytosis or endocytosis?
A. HLA Class I
B. HLA Class II
C. Both HLA Class I and HLA Class II
D. Neither HLA Class I or HLA Class II
B. HLA Class II
Influenza vaccine contains dead virus particles. Antigens in this vaccine will most likely activate?
A. CD3+/CD8+ Cytotoxic T Lymphocytes
B. CD16 / CD56 NK cells
C. CD3+ and CD4+ Helper T Cells
C. CD3+ and CD4+ Helper T Cells
