WSU VM 534 - VETERINARY
IMMUNOLOGY - EXAM 2 QUESTIONS
AND ANSWERS
What are two main types of T-lymphocytes? - Correct Answers -CD8 Cytotoxic T
Lymphocytes
CD4 Helper T Lymphocytes
What antigen presenting cell is required to activate a naive T-Cell? What are the
costimulatory molecules involved and why are they important? - Correct Answers -
Dendritic cell
CD 80/86 on APC & CD 28 on T-Cell
Important because costimulation decreases the number of TCRs that must engage an
antigen. This is referred to as "serial triggering". Each MHC-peptide complex triggers
about 200 TCRs on the T-cell. It also increases the signal transduction through the TCR
by lowering the time needed for a trigger and by lowering the threshold for triggering.
What are the different types of T-Helper cells? - Correct Answers -TH1, TH2, TH17
What cytokines induce the different types of Helper T-Cells? - Correct Answers -IL-12
induces TH1 production
Lack of IL-12 stimulation induces TH2 production
What cytokines are produced by TH1 cells and what are their effects? - Correct
Answers -IFN-gamma: Activates macrophages to kill phagocytes microbes. Also
stimulates cytolytic activity in other cells (NK, CTL). Finally, it promotes further TH1
differentiation.
IL-2: This is the primary growth factor for T-Cells. It is also responsible for proliferation
of antigen specific T Cells (helper and cytotoxic T-cells)
IL-3: Stimulates bone marrow (heme=3)
What cytokines are produced by TH2 cells and what are their effects? - Correct
Answers -IL-4: Simulates B-Cell to produce certain antibodies (IgG1 & IgE). Further
promotes TH2 differentiation. Inhibits the effects of IFN-gamma.
,IL-10: Inhibits IL-12 production by dendritic cells and macrophages. Also inhibits the
expression of MHC & costimulatory molecules on dendritic cells & macrophages.
OVERALL - it inhibits cell mediated immunity.
Compare the activation differences between HTL & CTL. - Correct Answers -HTL:
Activated by MHC II - Extracellular pathogen presented
CTL: Activated by MHC I - Intracellular pathogen presented
How is the activity of CD8 CTLs enhanced? - Correct Answers -CD8 CTL cells
recognized antigen and costimulators on dendritic cell. When bound, the dendritic cell
releases IL-12 onto the CTL which stimulates it to start releasing IL-2 (growth factor).
CD4 Helper T-cell can bind to dendritic cell too and release IL-2 & IFN-gamma (growth
& differentiation)
Or, a HTL can bind the dendritic cell first to activate it via CD40. This up regulates MHC
expression, cytokine, & costimulatory signals. The activated dendritic cell will stimulate
a faster activation/differentiation in the naive CTL.
How do CTLs recognize and kill infected cells? - Correct Answers -Binds to target cell
displaying an MHC I complex. When bound, it releases enzymes (perforin & granzyme)
that kill the cell.
What does "MHC Restriction" mean? - Correct Answers -T cells only recognize peptides
presented to them by the animal's own MHC molecules. They cannot recognize antigen
that has not been processed and presented.
Describe the structure of an immunoglobulin. - Correct Answers -
, What are the different immunoglobulin isotypes? - Correct Answers -
Define epitope. - Correct Answers -The "minimal" binding site or antigenic determinant
for an individual antibody.
Define antigen specificity. - Correct Answers -The ability of an antibody to discriminate
between two different epitopes.
Define antibody affinity. - Correct Answers -The strength with which an antibody
molecule binds an epitope.
What is cross-reactivity? - Correct Answers -When an antibody can bind epitopes from
other species as it is very similar to its own antigenic target.
T cell becomes activated only if it binds to the foreign antigen and at the same time
receives a second signal, a process known as:
A- Costimulation
B- Antigen proliferation
C- T cell proliferation
D- Clonal selection - Correct Answers -A
Which of the following statements is false about IL-2
A- IL-2 is a dispensable cytokine
B- IL-2 is secreted by T cells
C- IL-2 binds to IL-2 receptors on T cells
D- Animals with no IL-2 cannot respond to infections - Correct Answers -A
In the majority of viral infections, CD8 T-cell activation requires CD4 T-cell help
A- True B- False - Correct Answers -True
What is the difference between secreted Ig molecules & surface bound BCRs? - Correct
Answers -The mu heavy chain of membrane-bound Ig has an amino acid sequence at
its carboxy- terminal end which anchors the molecule into the membrane; the secreted
form of Ig has a different C-terminal sequence which lacks a membrane anchoring
region.
IMMUNOLOGY - EXAM 2 QUESTIONS
AND ANSWERS
What are two main types of T-lymphocytes? - Correct Answers -CD8 Cytotoxic T
Lymphocytes
CD4 Helper T Lymphocytes
What antigen presenting cell is required to activate a naive T-Cell? What are the
costimulatory molecules involved and why are they important? - Correct Answers -
Dendritic cell
CD 80/86 on APC & CD 28 on T-Cell
Important because costimulation decreases the number of TCRs that must engage an
antigen. This is referred to as "serial triggering". Each MHC-peptide complex triggers
about 200 TCRs on the T-cell. It also increases the signal transduction through the TCR
by lowering the time needed for a trigger and by lowering the threshold for triggering.
What are the different types of T-Helper cells? - Correct Answers -TH1, TH2, TH17
What cytokines induce the different types of Helper T-Cells? - Correct Answers -IL-12
induces TH1 production
Lack of IL-12 stimulation induces TH2 production
What cytokines are produced by TH1 cells and what are their effects? - Correct
Answers -IFN-gamma: Activates macrophages to kill phagocytes microbes. Also
stimulates cytolytic activity in other cells (NK, CTL). Finally, it promotes further TH1
differentiation.
IL-2: This is the primary growth factor for T-Cells. It is also responsible for proliferation
of antigen specific T Cells (helper and cytotoxic T-cells)
IL-3: Stimulates bone marrow (heme=3)
What cytokines are produced by TH2 cells and what are their effects? - Correct
Answers -IL-4: Simulates B-Cell to produce certain antibodies (IgG1 & IgE). Further
promotes TH2 differentiation. Inhibits the effects of IFN-gamma.
,IL-10: Inhibits IL-12 production by dendritic cells and macrophages. Also inhibits the
expression of MHC & costimulatory molecules on dendritic cells & macrophages.
OVERALL - it inhibits cell mediated immunity.
Compare the activation differences between HTL & CTL. - Correct Answers -HTL:
Activated by MHC II - Extracellular pathogen presented
CTL: Activated by MHC I - Intracellular pathogen presented
How is the activity of CD8 CTLs enhanced? - Correct Answers -CD8 CTL cells
recognized antigen and costimulators on dendritic cell. When bound, the dendritic cell
releases IL-12 onto the CTL which stimulates it to start releasing IL-2 (growth factor).
CD4 Helper T-cell can bind to dendritic cell too and release IL-2 & IFN-gamma (growth
& differentiation)
Or, a HTL can bind the dendritic cell first to activate it via CD40. This up regulates MHC
expression, cytokine, & costimulatory signals. The activated dendritic cell will stimulate
a faster activation/differentiation in the naive CTL.
How do CTLs recognize and kill infected cells? - Correct Answers -Binds to target cell
displaying an MHC I complex. When bound, it releases enzymes (perforin & granzyme)
that kill the cell.
What does "MHC Restriction" mean? - Correct Answers -T cells only recognize peptides
presented to them by the animal's own MHC molecules. They cannot recognize antigen
that has not been processed and presented.
Describe the structure of an immunoglobulin. - Correct Answers -
, What are the different immunoglobulin isotypes? - Correct Answers -
Define epitope. - Correct Answers -The "minimal" binding site or antigenic determinant
for an individual antibody.
Define antigen specificity. - Correct Answers -The ability of an antibody to discriminate
between two different epitopes.
Define antibody affinity. - Correct Answers -The strength with which an antibody
molecule binds an epitope.
What is cross-reactivity? - Correct Answers -When an antibody can bind epitopes from
other species as it is very similar to its own antigenic target.
T cell becomes activated only if it binds to the foreign antigen and at the same time
receives a second signal, a process known as:
A- Costimulation
B- Antigen proliferation
C- T cell proliferation
D- Clonal selection - Correct Answers -A
Which of the following statements is false about IL-2
A- IL-2 is a dispensable cytokine
B- IL-2 is secreted by T cells
C- IL-2 binds to IL-2 receptors on T cells
D- Animals with no IL-2 cannot respond to infections - Correct Answers -A
In the majority of viral infections, CD8 T-cell activation requires CD4 T-cell help
A- True B- False - Correct Answers -True
What is the difference between secreted Ig molecules & surface bound BCRs? - Correct
Answers -The mu heavy chain of membrane-bound Ig has an amino acid sequence at
its carboxy- terminal end which anchors the molecule into the membrane; the secreted
form of Ig has a different C-terminal sequence which lacks a membrane anchoring
region.
