Immunology
MIMG 185A
Midterm examination
04/30/2020
1h 15min
Question 1 __100___/100
Question 2 __100___/100
Question 3 __100___/100
Total: __300___/300
, Question 1 (100 points)
You are a student from an immunology lab. You perform three independent experiments using
different mouse strains and you want to explain your results with what you have learned from
MIMG 185.
a) In the first set of experiments, you infect two strains of mice with extracellular bacteria. You
test their serum cytokine levels and get the following results: +++ (strong response), ++ or +
(lower response), +/- (partial response), - (no response).
Cytokines Strain 1 Mice Th2 Strain 2 Mice Th1 Normal level
+ Extracellular Bacteria + Extracellular Bacteria (uninfected)
IFN -/+ +++ +
IL-4 +++ -/+ +
IL-5 ++ - +
IL-10 ++ - +
TNF - ++ +
Briefly explain (2-3 sentences) what are the differences between strain 1 and strain 2 in
response to the same infection. (15 points)
Serum from strain 1 mice show higher than normal IL-4, IL-5 and IL-10 and lower than normal
IFN and TNF. Serum from strain 2 mice have lower than normal IL-4, IL-5 and IL-10 and higher
than normal IFN and TNF. This suggests an imbalance in the Th1/Th2 response; strain 1
favors Th2 and strain 2 favors Th1.
Which strain of mice will survive better? Explain your answer in no more than 3 sentences. (15
points)
Strain 2, Th2 extracellular response
Th1 activates cellular responses while Th2 activates B cells to produce antibodies.
b) In the second set of experiments, you test the function of lymphocytes from two additional
mouse strains (A and B). You isolate T cells and NK cells, and test their response to cytokine
stimulation. In strain A, T cells and NK cells respond normally to IL-7 and IL-21, however,
their proliferative response to IL-2 and IL-15 is diminished. T cells and NK cells from strain B
respond normally to all cytokines. ++ (strong proliferative response), - (no proliferative
response).
Cell type Cytokine Strain A Strain B Normal mice
T cell IL-2 - ++ ++
IL-7 ++ ++ ++
IL-15 - ++ ++
IL-21 ++ ++ ++
NK cells IL-7 ++ ++ ++
IL-15 - ++ ++
IL-21 ++ ++ ++
MIMG 185A
Midterm examination
04/30/2020
1h 15min
Question 1 __100___/100
Question 2 __100___/100
Question 3 __100___/100
Total: __300___/300
, Question 1 (100 points)
You are a student from an immunology lab. You perform three independent experiments using
different mouse strains and you want to explain your results with what you have learned from
MIMG 185.
a) In the first set of experiments, you infect two strains of mice with extracellular bacteria. You
test their serum cytokine levels and get the following results: +++ (strong response), ++ or +
(lower response), +/- (partial response), - (no response).
Cytokines Strain 1 Mice Th2 Strain 2 Mice Th1 Normal level
+ Extracellular Bacteria + Extracellular Bacteria (uninfected)
IFN -/+ +++ +
IL-4 +++ -/+ +
IL-5 ++ - +
IL-10 ++ - +
TNF - ++ +
Briefly explain (2-3 sentences) what are the differences between strain 1 and strain 2 in
response to the same infection. (15 points)
Serum from strain 1 mice show higher than normal IL-4, IL-5 and IL-10 and lower than normal
IFN and TNF. Serum from strain 2 mice have lower than normal IL-4, IL-5 and IL-10 and higher
than normal IFN and TNF. This suggests an imbalance in the Th1/Th2 response; strain 1
favors Th2 and strain 2 favors Th1.
Which strain of mice will survive better? Explain your answer in no more than 3 sentences. (15
points)
Strain 2, Th2 extracellular response
Th1 activates cellular responses while Th2 activates B cells to produce antibodies.
b) In the second set of experiments, you test the function of lymphocytes from two additional
mouse strains (A and B). You isolate T cells and NK cells, and test their response to cytokine
stimulation. In strain A, T cells and NK cells respond normally to IL-7 and IL-21, however,
their proliferative response to IL-2 and IL-15 is diminished. T cells and NK cells from strain B
respond normally to all cytokines. ++ (strong proliferative response), - (no proliferative
response).
Cell type Cytokine Strain A Strain B Normal mice
T cell IL-2 - ++ ++
IL-7 ++ ++ ++
IL-15 - ++ ++
IL-21 ++ ++ ++
NK cells IL-7 ++ ++ ++
IL-15 - ++ ++
IL-21 ++ ++ ++
