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1. The anatomic location in mammals where pluripotent stem cells differentiate into B cells is:
A. the bone marrow.
B. the Bursa of Fabricius.
C. the spleen.
D. the thymus. |
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Definition
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2. The first step in differentiating a B cell from the pluripotent stem cell is:
A. creating a surrogate light chain from germline DNA.
B. rearranging germ-line DNA to create a functional kappa-chain.
C. rearranging germ-line DNA to create a functional lambda-chain.
D. rearranging germ-line DNA to create a functional mu-chain. |
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Definition
| D. rearranging germ-line DNA to create a functional mu-chain. |
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3. The difference between an immature B cell and a mature B cell is that:
A. the immature B cell has IgD on its surface and the mature B cell has IgM on its surface.
B. the immature B cell has IgM in the endoplasmic reticulum but not on its surface and the mature B cell has IgM on its surface.
C. the immature B cell has IgM on its surface and the mature B cell has IgG on its surface.
D. the immature B cell has only IgM on its surface and the mature B cell has both IgM and IgD. |
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Definition
| D. the immature B cell has only IgM on its surface and the mature B cell has both IgM and IgD. |
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4. The “Pre-BCR” surface receptor on a large pre-B cell consists of:
A. mu chains and no light chains at all.
B. mu chains plus kappa light chains.
C. mu chains plus lambda light chains.
D. mu chains plus surrogate light chains. |
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Definition
| D. mu chains plus surrogate light chains. |
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5. A developing B cell that cannot rearrange its light-chain genes to produce either a functional kappa or lambda light chain:
A. becomes anergized.
B. remains an undifferentiated pluripotent stem cell.
C. survives but is never released into the circulation from the bone marrow.
D. undergoes apoptosis. |
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6. An immature B cell that is self-reactive to multivalent self–antigens (e.g., self-antigens on the surface of cells):
A. becomes anergized.
B. remains an undifferentiated pluripotent stem cell.
C. survives but is never released into the circulation from the bone marrow.
D. undergoes apoptosis unless it can edit its specificity. |
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Definition
| D. undergoes apoptosis unless it can edit its specificity. |
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7. An immature B cell that is self-reactive to a soluble self-antigen (e.g., serum albumin):
A. becomes anergized.
B. remains an undifferentiated pluripotent stem cell.
C. survives but is never released into the circulation from the bone marrow.
D. undergoes apoptosis unless it can edit its specificity. |
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8. It has been observed that 75% of a person’s antibody molecules have kappa light chains and only 25% have lambda light chains. An explanation for this observation is that:
A. At this time, there is no satisfactory explanation for this observation.
B. B-cell differentiation is programmed to attempt rearrangement of the kappa light-chain germline DNA first and only if attempts at rearrangement of that DNA on both chromosomes is unsuccessful is lambda light-chain DNA rearrangement attempted.
C. B-cell differentiation is programmed to attempt rearrangement of the lambda light-chain germline DNA first but rearrangement of that DNA on both chromosomes is successful only 25% of the time, leading to attempts to rearrange the kappa light-chain germline DNA and that attempt is successful 75% of the time.
D. Rearrangement of the lambda light-chain germline DNA leads to self-reactive immunoglobulin molecules 75% of the time and such cells are prevented from maturing. |
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Definition
| B. B-cell differentiation is programmed to attempt rearrangement of the kappa light-chain germline DNA first and only if attempts at rearrangement of that DNA on both chromosomes is unsuccessful is lambda light-chain DNA rearrangement attempted. |
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9. Mature B cells, once released from the bone marrow, enter the circulation and enter the cortex of lymph nodes via:
A. high endothelial venules (HEVs).
B. migration through the walls of capillaries (a phenomenon called diapedesis).
C. the afferent lymphatic vessel.
D. the efferent lymphatic vessel. |
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Definition
| A. high endothelial venules (HEVs). |
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10. The encounter of naïve B cell with specific antigen and CD4 T-helper cells in secondary lymphoid organs leads to:
A. apoptosis of such B cells.
B. differentiation of such B cells into antibody-secreting plasma cells.
C. further heavy-chain and light-chain rearrangements in such B cells.
D. the anergic state in such B cells. |
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Definition
| B. differentiation of such B cells into antibody-secreting plasma cells. |
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11. The body site where T cells differentiate is:
A. the bone marrow.
B. the regional lymph nodes.
C. the spleen.
D. the thymus. |
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Definition
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12. A developing thymocyte, at one stage of its development, is described as “double positive.” This statement means that such a thymocyte:
A. has completed its differentiation process.
B. interacts with only MHC class II antigens.
C. is invariably destined for programmed cell death.
D. is less differentiated than a “single positive” thymocyte. |
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Definition
| D. is less differentiated than a “single positive” thymocyte. |
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13. A “single positive” thymocyte:
A. interacts with both MHC class I antigens and MHC class II antigens.
B. is always selected against by negative selection.
C. is completely differentiated and ready to leave the thymus.
D. is less further along the T cell differentiation path than a “double positive” thymocyte. |
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Definition
| C. is completely differentiated and ready to leave the thymus. |
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Term
14. Thymocytes that cannot make a successful or rearrangement:
A. are subject to positive selection by cortical stromal cells.
B. become B memory cells.
C. die by apoptosis.
D. differentiate into a natural killer (NK) cells. |
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Definition
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15. A “double positive” T cell binds to MHC antigens on a cortical stromal cell and receives a “go” signal to proliferate. This situation is an example of:
A. an event leading to apoptosis of the T cell in question.
B. negative selection.
C. positive selection.
D. somatic hypermutation. |
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16. A particular T cell interacts with MHC class II antigens. This interaction (binding) accounts for the fact that the T cell in question is:
A. a CD4+ T cell.
B. a CD8+ T cell.
C. a natural killer (NK) cell.
D. a self-reactive T cell destined for apoptosis. |
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17. A particular T cell interacts with MHC class I antigens. This interaction (binding) accounts for the fact that the T cell in question is:
A. a CD4+ T cell.
B. a CD8+ T cell.
C. a natural killer (NK) cell.
D. a self-reactive T cell destined for apoptosis. |
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Definition
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18. The TCR of a CD4+ T cell binds very tightly to MHC class II antigens on a dendritic cell. This tight binding results in:
A. development of this T cell into a natural killer (NK) cell.
B. loss of the CD4+ marker from the cell.
C. negative selection against this particular T cell.
D. positive selection for this particular T cell. |
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Definition
| C. negative selection against this particular T cell. |
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19. The TCR of a CD8+ cell binds to MHC class I antigens on a dendritic cell, but the binding is not very strong. This type of binding leads to:
A. development of this T cell into a natural killer (NK) cell.
B. lack of negative selection against this cell; i.e., the cell is allowed to leave the thymus.
C. loss of the CD8+ marker from the cell.
D. negative selection against this particular T cell. |
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Definition
| B. lack of negative selection against this cell; i.e., the cell is allowed to leave the thymus. |
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Term
20. The human thymus:
A. decreases in activity between birth and puberty.
B. does not reach full development until an individual is about 30 years of age.
C. increases in size as an individual ages.
D. is fully developed before birth. |
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Definition
| D. is fully developed before birth. |
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1. Once a CD8+ cytotoxic T cell is activated and leaves the lymph node to perform its effector function, it depends on co-stimulatory molecule signal to kill virally infected cells.
A. True
B. False |
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2. A CD4+ helper T cell that becomes a TH2 cell can function to provide help to this type of cell.
A. Macrophage
B. Naïve B cell
C. Memory B cell
D. Both A and B above
E. Both B and C above |
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3. If a naïve T cell enters a lymph node and does not encounter the Ag:MHC complex it is specific for, which of the following would happen to that naïve T cell?
A. Undergo apoptosis
B. Begin secreting IL-2 to activate other T cells
C. Become activated and start secreting IgE
D. Exit the lymph node to survey other lymph nodes |
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Definition
| D. Exit the lymph node to survey other lymph nodes |
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4. Cytotoxic CD8+ T cells are able to induce apoptosis in virally-infected cells. What molecules are used by the T cell to induce apoptosis in these cells?
A. Granzymes
B. CD40:CD40L interaction
C. Fas:FasL interaction
D. JAK: STAT signaling molecules
E. Both A and B above
F. Both A and C above |
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5. The development of a CD4+ T cell into a Th1 cell is initiated by which of the following?
A. IL-1
B. IFN-?
C. IL-10
D. IL-4 |
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6. Identify the costimulatory molecule on a naïve T cell that is required for its activation.
A. CD28
B. CD4
C. LFA-1
D. MHC class II |
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7. When a T cell binds only the peptide: MHC complex on an APC without any other costimulatory molecules, the state the T cell enters is called what?
A. Activated
B. Anergic
C. Differentiated
D. TH2 |
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8. The area of interaction between the T cell and APC (indicated by the asterisk in the accompanying figure ) is called what?
A. Activation zone
B. Green zone
C. Transient synapse
D. Immunological synapse |
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9. Once activated, T cells secrete this cytokine that provides an additional survival signal. The cytokine can act in an autocrine manner as well as paracrine.
A. IL-2
B. IL-4
C. IL-10
D. IL-1 |
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10. Naive T cells enter a lymph node by which of the following?
A. Nerves
B. High endothelial venules
C. Afferent lymphatics
D. Both B and C above
E. None of the above |
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1. Only memory B cells participate in a secondary immune response. Why?
A. During a primary immune response all antigen specific naïve B cells are deleted by apoptosis
B. Naïve B cells that bind to a pathogen already opsonized with antibody are prevented from being activated by signaling through FcRIIB1
C. Memory B cells send cytokine signals to naïve B cells that prevents them from becoming activated.
D. Memory B cells express a low affinity BCR allowing them to become more easily activated. |
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Definition
| B. Naïve B cells that bind to a pathogen already opsonized with antibody are prevented from being activated by signaling through FcRIIB1 |
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2. Which of the following is a feature of memory B cells?
A. They have lower surface expression levels of MHC class II and co-stimulatory molecules
B. The frequency of antigen specific memory B cells is lower that antigen-specific naïve B cells allowing for a more robust response
C. They process and internalize antigen better because they have undergone somatic hypermutation and affinity maturation.
D. They require more antigen and more time to become activated that naïve B cells |
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Definition
| C. They process and internalize antigen better because they have undergone somatic hypermutation and affinity maturation. |
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3. The main antibody isotype secreted in the mucosal lymphoid tissue is:
A. IgE
B. Poly-Ig receptor
C. IgG
D. Dimeric IgA |
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4. IgM is not easily transported into tissues for the following reason:
A. IgM fixes complement
B. IgM contains a J chain
C. IgM is a small dimeric molecule
D. IgM is a large pentameric molecule |
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Definition
| D. IgM is a large pentameric molecule |
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5. Which of the following influences antibody class switching to IgG, IgA, or IgE in B cells?
A. Fc receptors
B. IFN-, TGF- or IL-4
C. ADCC
D. Follicular dendritic cells |
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6. Activated B cells that enter a germinal center, do not express surface IgM and actively undergo somatic hypermutation are called what?
A. Memory B cells
B. Centroblast
C. Plasma cell
D. Centrocyte |
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1. Antibodies function to neutralize infecting pathogens by which of the following mechanisms?
A. Opsonization facilitating phagocytosis
B. By binding to receptors on the pathogen that prevent it from infecting cells
C. By binding to toxins produced by the pathogen
D. All of the above answers are correct |
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Definition
| D. All of the above answers are correct |
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8. Transcytosis of dimeric IgA from the lamina propria to the lumen of the intestine is mediated by the poly-Ig receptor, which binds to what portion of the IgA dimer?
A. The hinge region
B. The Fc region
C. The J chain
D. The light chain |
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9. The structural difference that defines the IgG subclasses is:
A. The antigen binding region
B. The hinge region
C. The specific amino acid sequence in the Fc portion of the molecule
D. The variable light chain |
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10. Which of the following is NOT a feature of thymus-independent (TI) antigens?
A. TI antigens require T cell help to properly activate B cells
B. TI antigens make up a small amount of antigens that can activate B cells and induce an antibody response
C. TI antigens are divided into two different categories based on how the antigens activate B cells. |
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Definition
| A. TI antigens require T cell help to properly activate B cells |
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