quiz 2 Flashcards
Which of the following interactions is NOT part of the cSMAC (central supramolecular activation complex) between a T-helper cell and an antigen presenting cell?
Question 1 Answer
a.
CD4 co-receptor bound to HLA-II
b.
T-cell Receptor bound to HLA-II
c.
An integrin bound to a cellular adhesion molecule
d.
CD28 bound to CD80
c.
An integrin bound to a cellular adhesion molecule
Choose the protein that is needed to help translocate an antigenic peptide into the rough endoplasmic reticulum via the endogenous pathway.
Question 2 Answer
a.
CLIP
b.
HLA-DM2
c.
Immunoproteosome
d.
TAP
d.
TAP
Choose the protein that prevents a cytosolic (intracellular) antigen from being loaded onto an HLA-II in the rough endoplasmic reticulum.
Question 3 Answer
a.
TAP
b.
HLA-DM2
c.
CD28
d.
Invariant chain
d.
Invariant chain
Which cell is UNABLE to present antigen via HLA-I?
Question 4 Answer
a.
Endothelial cells
b.
Dendritic cells
c.
Red blood cells
d.
Macrophages
c.
Red blood cells
Which of the following is TRUE regarding the endogenous pathway of antigen presentation?
Question 5 Answer
a.
The antigenic peptide is degraded in a proteosome.
b.
Antigenic peptides are phagocytosed.
c.
The antigenic peptide is translocated into the rough endoplasmic reticulum with the help of CLIP.
d.
The antigenic peptide is loaded onto an HLA-II.
a.
The antigenic peptide is degraded in a proteosome.
A naive helper T cell interacts with an APC presenting an antigen. The TCR binds to the antigen on the HLA, the co-receptor binds to the HLA, but there is no CD28 costimulator interaction. What will the helper T-cell do?
Question 6 Answer
a.
The helper T cell becomes a partially-activated effector T cell
b.
The helper T cell will rearrange its TCR to increase its specificity
c.
The helper T cell is rendered anergic.
d.
Its activity will not change, and it will remain naive.
c.
The helper T cell is rendered anergic.
Which of the following statements about follicular T-cells (Tfh) are FALSE?
Question 7 Answer
a.
Tfh cells typically remian in secondary lymphoid organs after activation to interact with B-cells
b.
The polarizing cytokine is IL-12
c.
B cell maturation and development in the germinal zone is dependent on CD40L and IL-21 from Tfh cells
d.
Tfh cell differentiation is dependent on high IL-12 and IL-2 concentrations
d.
Tfh cell differentiation is dependent on high IL-12 and IL-2 concentrations
Choose the TRUE statement regarding IL-2.
Question 9 Answer
a.
IL-2 is the polarizing cytokine that converts a naive Th into a Th2 cell.
b.
IL-2 can provide autocrine stimulation (stimulates that cell that produced IL-2).
c.
High levels of IL-2 are necessary for the development of all helper T-cells
d.
IL-2 is synthesized predominantly by naive T-cells
b.
IL-2 can provide autocrine stimulation (stimulates that cell that produced IL-2).
What cytokine, produced by Th1 cells, inhibits the differentiation of Th2 cells?
Question 8 Answer
a.
TNF-alpha
b.
IL-4
c.
IFN-γ
d.
IL-8
c.
IFN-γ
Choose the cytokine that is NOT associated with polarization of a naive T helper cell to a Th17 cell?
Question 10 Answer
a.
IL-23
b.
IL-6
c.
TGF-beta
d.
IL-4
d.
IL-4
Which part of the respiratory system is least likely to contain natural microbiota?
Question 11 Answer
a.
primary bronchi
b.
laryngopharynx
c.
respiratory bronchioles
d.
trachea
c.
respiratory bronchioles
As a fastidious microorganism, in order to survive in culture, Haemophilus influenzae requires all of the following EXCEPT:
Question 12 Answer
a.
Chocolate agar
b.
X factor
c.
V factor
d.
Blood agar
d.
Blood agar
Why is the production of a vaccine for the common cold so difficult?
Question 13 Answer
a.
Our immune system does not respond to cold viruses.
b.
Cold viruses rapidly mutate
c.
Cold viruses infect cells of the immune system.
d.
The common cold is caused by many different viruses from very different viral families.
d.
The common cold is caused by many different viruses from very different viral families
Which of the following is NOT a mechanism through which rhinoviral infections can make hosts more susceptible to secondary bacterial infections?
Question 14 Answer
a.
Promoting the endocytosis of S. aureus in pneumocytes
b.
Increasing the concentration of binding proteins for S. pneumoniae on epithelial cells
c.
Reducing host immune response through the inhibition of B cells
d.
Disrupting the tight junctions that hold together respiratory mucosal epithelial cells
c.
Reducing host immune response through the inhibition of B cells
Which virulence factors are expressed by group A Streptococcus?
Question 15 Answer
a.
Pathogenic streptococci will produce beta-lactamases, while others will not.
b.
Pathogenic streptococci will be beta-hemolytic, while others will not.
c.
Pathogenic streptococci will produce coagulase, while others will not
d.
Pathogenic streptococci will be catalase positive, while others will not.
b.
Pathogenic streptococci will be beta-hemolytic, while others will not.
