Question 1
1.
The figure depicts an experiment conducted in the 1950s that was used to discover a key
component of the immune response to a virus. This experiment was performed by infecting nonimmune cells in culture with an inactive form of the influenza virus. After incubation with the
inactive virus, the cells and virus were removed and the culture media is transferred to a second
culture of cells. The media alone from the initial culture was able to prevent influenza virus
replication in the second culture. What factor in the immune response to viruses was identified in
this experiment?

[x]

Answer
2 points

Question 2
1.
Many viruses produce proteins that evade the interferon response. Match the viral protein with
its mechanism of inhibiting the interferon response.
Answer

InfluenzaAnswer
A Pseudo substrate for PKR
NS1
.
B. Activates cellular phosphatase that
Vaccinia
dephosphorylates eIF2a
virus
C. Binds dsRNA and prevents PKR activation
K3L
D Interferon receptor analog that bnds

HSV
ICP34.5
EBV
Bcrf1

.

interferon and prevents activation of cellular
interferon receptor
E. Interleukin analog that inhibits production of
interferons

Vaccinia
Virus
B18R
2 points

Question 3
1.
Match the following pattern recognition receptors with the viral component they recognize
Answer

Toll-like
Receptor 3
Toll-like
Receptor 4
Toll-like
Receptor 7

Answer
A Viral glycoproteins
.
B. Unmethylated CpG

DNA
C. ssRNA
D
.

dsRNA

Rig-I
Toll-like
Receptor 9
2 points

Question 4
1.
Match the labled boxes in the figure below with the correct....

Answer
Answer
A RIG-I
.
B. Mx
C. Interferon

Receptor
D NFkB
.
E. TLR9
F.
G
.
H
.
I.
J.

TLR3
eIF2alpha
PKR
TRIM5-alpha
RNase L
TLR4

K
.
L. TLR7

12 points

Question 5
1.
The data below is recent data that a colleague of mine generated who obviously has not taken BIOL 513. RNA
aptamers are short RNA oligonucleotides (~80 nucleotides) that can be selected with high affinity to a specific
protein. A RNA aptamer was identified that binds specifically to one of the viral X proteins and inhibits a
protein/protein interaction essential for replication of Virus X. The idea of the experiment below was to see if the
aptamer would inhibit replication of the viruses in cells by measuring the cytopathic effect. The colleague
transfected the virus X aptamer into cells. As he had hoped, the aptamer inhibits the virus cytopathic effect. As a
control, the colleague also transfected a random aptamer that does not bind to any of the viral proteins and should
not inhibit replication. To his surprise, the random aptamer is just as effective as the viral aptamer at inhibiting viral
replication. What did the colleague fail to take into account when designing this experiment (3-4 sentences max)?

Answer
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