Biol 430
Question Bank
Components of the Immune System
1. Identify the granulocytes shown to the right.
2. Identify the regions and structures of the lymph node
labeled in this image as A - G :
3. The lymphoid tissue identified as ‘A’ in this
diagram is called a __________________________, which is an
example a secondary lymphoid tissue called ____________.
The structure identified as ‘B’ is called a _________________.
4. Thymectomy (removal of the thymus) in fetal mice causes complete loss of the acquired
immune response when they mature. Explain.
Biol 430
Question Bank
Components
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5. The functions of T-cells and B-cells necessitate that upon activation one type but not the other
must recirculate through the body.
A. Upon activation, Tc-cells become what type of cell? Upon activation, B-cells become
what type of cell?
B. What is the function of Tc effector cells; and how do they recognize target cells?
What is the function of B effector cells; and how do they recognize target antigens?
C. Now explain why is it necessary that upon activation one type recirculates but not the
other.
6. Explain why each of the following statements is false:
A. The HSC is the most abundant cell in the bone marrow.
B. Lymphoid follicles are found in both primary and secondary lymphoid tissue.
C. In adults, all immune cells complete their antigen-independent maturation in the bone
marrow.
D. Most hormonal regulation of the immune system would be described as endocrine.
7. Leukemia is a cancer of the blood in which there is an uncontrolled proliferation of a
particular type (usually) of lymphoid or myeloid cell, which often leads to compromising of the
person’s immune system and other physiological abnormalities. A common treatment for
leukemia is to destroy the bone marrow and circulating immune cells through radiation and
chemotherapy, and then perform a bone marrow transplant from a genetically related individual.
A. Why is it necessary to destroy cells of the bone marrow as a first step toward treating
the disorder; why not simply destroy the abnormal cells circulating in the blood?
B. What would happen if the treatment were stopped before the transplant occurred?
C. Which cell(s) of the bone marrow transplant are most important to the success of the
treatment? Explain.
Biol 430
Question Bank
Components
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8. Identify the stages of
extravasation labeled as A
– E in this diagram, and
briefly explain what is
happening
A. _____________________
B. _____________________
C. _____________________
D. _____________________
E. _____________________
9. Assume that you had mice with mutations that diminished the function of the proteins listed
below. For each, identify and explain whether lymphocyte extravasation, homing and/or
immune responses would be affected.
A. ICAM, a protein required for cell-to-cell adhesion
B. CXCR7, a cytotaxic chemokine receptor
C. TRL3, a toll-like receptor that binds to viral dsRNA
Biol 430
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Components
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10. Match each cell type with its correct description.
a. ___ Mast cell
b. ___ Basophil
c. ___ Lymphocyte
d. ___ Natural Killer cell
e. ___ Hematopoietic stem cell
f. ___ Neutrophil
g. ___ Monocyte
h. ___ T-cell
i. ___ Multipotent progenitor cell
j. ___ Langerhans cell
k. ___ M-cell
l. ___ Macrophage
m. ___ B-cell
n. ___ Granulocyte
o. ___ Dendritic cell
Biol 430
Question Bank
1. Primary mediator of the humoral branch
of the acquired immune system
2. Precursor of all immune cells
3. Immune cell found in tissues and is
involved in inflammation and allergic
reactions
4. Any one of the myeloid lineage cells
holding vasoactive agents in cellular
granules
5. Stem cell that gives rise to lymphoid and
other cell types
6. Myeloid cell that gives rise to
macrophages and certain types of
dendritic cells
7. Phagocytic cell of innate system also
capable of antigen presentation
8. Primary mediator of the cell-mediated
branch of the acquired immune system
9. Principal cells mediating the acquired
immune response
10. Most abundant granulocyte, and which
responds rapidly to infection
11. Phagocytic cell found within the skin
12. Professional antigen-presenting cell
capable of activating naïve T-cells
13. Circulating granulocyte staining with
basic dyes that acts against eukaryotic
parasites and contributs to Type-I
hypersensitivities
14. Antigen-engulfing cell of MALT
15. Lymphoid cell of innate response
recognizing antigens with toll-like
receptors
Components
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11. Unless donor and recipient are genetically identical, following an organ transplant procedure
tissue rejection occurs because the new tissue is perceived as foreign. An axiom of modern
immunology is that tolerance of T-and B-cells toward ‘self’ antigens is not genetically
determined but arises as the cells mature. Suppose that a bone marrow transplant occurs between
two genetically different individuals. Rank the following scenarios from most-likely (1) to leastlikely (3) to occur, and explain each of your rankings.
A. ___ Host-versus-graft rejection, in which the recipient’s immune cells attack the
graft.
B. ___ Graft-versus-host rejection, in which immune cells carried in by the graft attack
the recipient’s cells.
C. ___ Graft-versus-host rejection, in which newly maturing B- and T-cells from the
graft attack the recipient’s cells.
12. Suppose a primary (genetic) immunodeficiency eliminated a particular cell type from the
immune cell repertoire. What type of immune abnormality would be expected if the deficiency
involved:
A. Eosinophils:
B. B-cells:
C. Neutrophils
D. Dedritic cells
Biol 430
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Components
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13. How do immune cells know to which tissue they should travel; or to put the question in different
terms, why do immune cells possess receptors appropriate for the tissue to which they should home?
Mora et al. (2006, Science 314:1157-1160) speculated that following activation, GALT B-cells
home to intestinal tissue because they are biochemically “imprinted” to do so by GALT-DC
(dendritic cells). Previous, it had been shown that T-cells that move into the gut mucosa express
integrin α4β7 and chemokine receptor CCR9. The authors speculated that imprinting of mucosaltropism in B-cells is triggered by retinoic acid (RA), a vitamin A derivative, synthesized by GALTDC (such as from Peyers patches); DC from other tissues (such as lymph nodes) do not produce RA.
The authors also postulated that RA induces expression of α4β7 and CCR9 on the B-cells which
allows them to home to mucosal tissue.
Naïve B-cells were activated in situ by treating with antibodies (αIgM) that bind to the B-cell
receptor (which mimics binding by an authentic antigen). B-cell activation was performed in the
presence of DC from Peyers patch DC (PP-DC) or lymph node (PLN-DC). The cells were then costained with fluorescent antibodies against B220 (a B-cell specific marker) and α4β7, and quantified
via FACS. Their
results are shown
below. The cross hairs
in the plots mark the
fluorescence levels of
B220+cells (to the right
of the vertical line) and
α4β7+ cells (above the
horizontal line).
A. Why are the cells stained with anti-B220 antibodies? Why are the cells also stained
with anti-α4β7 antibodies?
B. What does it mean that a cell is plotted higher along the Y-axis? … farther to the
right along the X-axis?
C. Evaluate the statement “When activated in the presence of PP-DC, the B-cells are
α4β7+ and B220—.”
D. In diagram ‘C’, sketch the appearance of a plot showing cells predominantly α4β7—
and B220+.
Question continued on next page
Biol 430
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Components
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In one set of experiments, B-cells were activated in the presence of PP-DC or PLN-DC and
immunofluorescently stained for B220, and α4β7 or CCR9. The FACS results were quantified
and are shown below. The Y-axis shows Mean Fluorescence Intensity (MFI) for the cells.
E. Why are naïve cells and cells treated with PLN-DC included in the experiment?
F. Do the results of this experiment support the authors’ hypothesis? Explain.
In another set of experiments, B-cell activation was triggered in the presence of spleen-DC (D1DC), and in the presence or absence of added RA, and again the B-cells were then assayed for
α4β7 and CCR9. Their results are shown below:
G. Why are spleen-DC cells used in this experiment instead of GALT-DC?
H. Explain how the results of these experiments support (or not) the authors’ hypothesis.
I. In both of the above experiments, which tissue targeting protein increases most significantly in
response to GALT-DC or RA?
Biol 430
Question Bank
Components
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