MBI 414/514 - Immunology Principles
MBI 415/515 - Immunology Principles and Practice

Sample Questions for Exam 1

MULTIPLE CHOICE: Choose the letter corresponding to the ONE answer for each question.

comment-out some of these MC questions!
1. Which statement concerning innate host defense mechanisms is correct?
a. Host resistance mechanisms are said to be highly specific in their activities because they do not affect a broad range of microbes.
b. Chemical host defense factors include enzymes, complement, salts, fatty acids, and mucus (which is also a physical host defense factor).
c. Peristalsis functions only as an internal host defense mechanism by dissolving infectious agents while they are in our intestines.
 
2. Which statement concerning immune system cells is correct?
a. Neutrophil, but not macrophage, activity is augmented by opsonization due to antibody and/or complement.
b. The myeloid lineage of cells includes B and T lymphocytes as well as erythrocytes, but does not include granulocytes such as neutrophils, eosinophils or basophils.
c. Mast cells are important in inflammation because they release histamine upon membrane damage or when stimulated by activated complement components C3a or C5a.
 
3. Which statement about pattern recognition receptors (PRRs) is correct?
a. To be accessible and to function in innate immune system cellular responses to infection, TLRs must be anchored in the cytoplasmic membrane.
b. PRRs are so-named because they recognize conserved chemical motifs or chemical "patterns" that are found in a wide variety of infectious agents.
c. NOD1 and NOD2 are intracellular PRRs that bind a wide variety of microbial motifs, leading to IkB signaling to genes in the nucleus of the cell.
4. Which statement concerning antigen-antibody interactions is correct?
a. Avidity is the strength of binding of one determinant to its antibody combining site, whereas affinity is the strength of interaction of multivalent antigen binding to more than one antibody combining site.
b. Antigens interact with antibodies via covalent bonds, especially those formed between sulfur or nitrogen atoms that are adjacent to one another.
c. Linear antigenic determinants depend on directly on the primary sequence of subunits, whereas conformational determinants depend on secondary, tertiary or quaternary structure.
1. Which statement about B cell receptors is correct?
a. The B cell coreceptor is comprised of CD3 together with CD19 and CD22, and these molecules work together to enhance B cell signaling by removing inhibitory phosphates from the ITAMs of the PTKs.
b. BCRs are expressed together with Igα/Igβ, which are necessary for signal transduction after binding of antigen by BCRs because they possess ITAMs.
c. B cell receptors signal the nucleus as a result of activation of G proteins such as ras or rac, and the final product of the MAP kinase pathway that they activate generates NFAT for use as a transcription factor.

2. During B cell activation:
a. Syk activates phospholipase C (PLC) to cleave phosphatidylinositol (PIP2) forming DAG, which then activates NF-AT via protein kinase C (PKc).
b. CD45 removes the inhibitory phosphates from Blk, Lyn and Fyn so they can phosphorylate ITAMs of Igα/Igβ subunits, leading to activation of Syk via phosphorylation.
c. Rac-mediated release of Mg2+ from the endoplasmic reticulum activates IP3 to trigger calmodulin-dependent generation of AP-1.

MATCHING MULTIPLE CHOICE: Choose the BEST answer. An answer may be used more than once within a set of questions.

Answers to questions 4-5:
a. IgM
b. IgD
c. IgA
d. IgG
e. IgE

4. _____ is frequently a dimeric immunoglobulin that does not bind complement well but is found in high concentrations in mucous secretions.

5. _____ is the class of antibody that is present at very low levels concentration in serum and is able to bind to basophils and mast cells to initiate allergic reactions.

TRUE FALSE: If a statement is TRUE, print T in the blank; if it is FALSE, print F.

comment-out one of these TF questions!

6. The hemostasis observed in acute inflammatory responses results from constriction of the arteries and dilation of the veins in the immediate area, and results in the exudation of fluid, but not cells, into an area where cell damage has occurred.

7. Bone marrow hematopoietic stem cells are self-renewing pluripotent cells that can differentiate into lymphoid or myeloid progenitor cells under the influence of various combinations of growth factors and cytokines to which they are exposed in these tissues.

8. Experiments have shown that T cell signaling resulting from TCR binding to MHC-antigen is different than B cell signaling resulting from BCR binding to antigen, although the basic set of processes is similar and uses the same types of molecules for similar purposes.

ESSAY and/or PROBLEM-SOLVING QUESTION:

9. Explain how inflammation develops at a site of infection in the tissues, being sure to discuss all the types of cells and molecules that are involved in this process, then discuss how it can foster delivery of immune system cells and chemical factors to a site of infection.

10. Define each of these terms, then briefly discuss the relationships among them. a. phagocytosis - b. C3b - c. oxygen-dependent intracellular killing mechanisms - d. relationships -

11. Draw a series of four diagrams that depicts the events involved in margination and diapedesis of PMNs. In your diagrams, be sure to include not only cell surface molecule interactions, but also molecules that influence these interactions and the process of diapedesis. Also, be sure to label every component and to include short descriptions of what is occurring in each diagram.

12. For each of the major advances listed below, name the immunologist(s) responsible and briefly explain how the experiment leading to the discovery was done. (Note: it is not necessary to explain the mechanisms of the methods used).
a. IgG antibody molecules possess 2 different kinds of polypeptides.
b. When comparing antibodies specific for different antigens, the N-terminal half light chain is highly variable, whereas the C-terminal half is relatively constant in its amino acid sequence.
c. Amino acids in the hypervariable regions mediate the direct contact of the antibody combining site with an antigenic determinant.
d. Three-dimensional structure of immunoglobulin.
e. Each IgG antibody molecule is made up of 2 heavy and 2 light chains.
f. Primary amino acid sequence of IgG.

13. Using an integrated one-page answer, discuss all of the following questions:
a. What is the Ig-fold?
b. How is the Ig-fold related to the overall structure of antibody molecules?
c. How is the Ig-fold related to variable domain structure?
d. How is the Ig-fold related to antibody specificity?

14. Draw a "stick" model of IgG, being certain to label all the parts.

Sample Questions for Exam 2

MULTIPLE CHOICE: Choose the letter corresponding to the ONE answer for each question.

1. Which statement about antigen processing is correct?
a. Exogenous antigens are processed via cytosolic fragmentation and presented on the cell surface in association with MHC-II molecules.
b. Proteosomes are important as chaperones that help position and stabilize MHC-I molecules on the inner surface of the endoplasmic reticulum as they are being assembled.
c. Endogenous antigens are processed via cytosolic fragmentation and presented on the cell surface in association with MHC-I molecules.

2. Which statement about generation of TCR diversity is correct?
a. To form a functional β-chain gene, both TCR α-gene and β-gene segments undergo gene rearrangement.
b. TCR diversity is determined solely by combinatorial joining of multiple germ-line V, D, J and C gene segments.
c. Sequences between the "chosen" TCR V-gene segment and the "chosen" J-gene segment are excised during the process of generating α-chain genes.

3. Which statement concerning generation of diversity in B cells is correct?
a. The so-called "N" diversity generated by mistakes made during Ig gene rearrangement during B cell maturation is important for antibody diversity.
b. TdT (terminal deoxynucleotidyl transferase) is not important in generating antibody diversity, especially in CDR3.
c. RAG1 and RAG2 are recombination activation genes, but do not appear to be associated with the recombinase activity needed for Ig gene rearrangement.

MATCHING MULTIPLE CHOICE: Choose the BEST answer. An answer may be used more than once within a set of questions.

Answers to questions 4-5:
a. TCR
b. MHC class II molecules
c. BCR
d. MHC class I molecules
e. more than one of these
4. ______ participate in the presentation of antigen peptides following partial antigen degradation in phagolysosomes.

5. Cell surface structures which recognize a peptide derived from a foreign protein antigen, together with a "self" molecule are _____.

TRUE FALSE: If a statement is TRUE, print T in the blank; if it is FALSE, print F.

6. Because primary TCR gene transcripts include both introns and exons, their processing to form functional mRNA includes removal of introns by SNRPs as well as capping and addition of a poly-A tail.

7. As demonstrated by Kruisbeek's experiment involving knockout mice, negative selection during T cell development involves recognition of MHC molecules, since MHC-1 knockout mice failed to develop CD4+ T cells and MHC-2 knockout mice failed to develop CD8+ T cells.

8. Using affinity labeling techniques, Wu and Kabat showed that the hypervariable regions of antibody molecules contain contact residues (amino acids that actually form noncovalent bonds with the antigenic determinants) and are therefore considered to be the CDRs.

ESSAY and/or PROBLEM-SOLVING:

9. Generate a diagram that depicts the fine details of MHC1 structure in the region that binds peptides, then explain how it facilitates MHC1-Ag binding.
 
10. Outline the classical pathway of complement activation, then discuss how it is negatively regulated.

11. Compare and contrast the manner in which B cells and T cells rearrange their receptor genes as they mature.

12. Compare and contrast the mechanisms used for positive and negative selection during development of B cells and T cells.

Sample Questions for Exam 3

MULTIPLE CHOICE: Choose the letter corresponding to the ONE answer for each question.

  1. Which statement about cytokines and immune responses is correct?
    a. Th2 cell generation is fostered by production ofIFN-gamma, whereas IL-12 is the preferred signal for triggering proliferation of B cells.
    b. In response to T cell cytokine signals, B cells switch isotype by excising "unwanted" intervening sequences of DNA, then ligating the "wanted" exons to form a functional transcriptional unit (gene).
    c. IL-10 is a cytokine produced by macrophages that can stimulate the development of Th1 cells, thus fostering a cell-mediated immune response.

  2. Which statement related to antibody responses is correct?
    a. Signal 2 for B cells is generated as a result of cytoking binding and leads to expression of CD40L which provides survival signaling.
    b. Switch sequences for class switch recombination areactivated by AID, which attacks regions that are being transcribed.
    c. Signal 2 for T cells is generated as a result of CD40 interaction with CD40L and results in cytokine synthesis and secretion.
  3. Which statement related to cell mediated immune responses is correct?
    a. CTLs form antigen-specific conjugates with target cells via interaction of TCRs with processed Ag on target cell surfaces and non-antigen-specific intercellular adhesion molecules enhance the stability of the cell-cell interaction.
    b. Granules containing lytic mediators are transported to CTL cytoplasmic membrane along microtubules, before these cells orient their microbule organizing centers (MTOCs) towards the bound target cell.
    c. As macrophages are activated, they undergo a respiratory burst that results in increased production of reactive oxygen intermediates, including nitric oxide, peroxynitrite and nitrogen dioxide.

TRUE FALSE: If a statement is TRUE, print T in the blank; if it is FALSE, print F.

4. NK cells are quite important during the early phases of immune responses to viruses and facultative intracellular parasites because they generate cytokines that help initiate these adaptive immune responses.

5. Macrophages, eosinophils, basophils and NK cells can all participate in antibody-dependent cellular cytotoxicity (ADCC) by virtue of having FcR and granules containing factors that can damage target cells.

6.The CD40 generated on T cells as a result of interaction of CD80 or CD86 with CTLA-4 on their surfaces is needed for isotype switching and affinity maturation.


Although the following questions may not be in the exact format as you might see them on the exam, answering them will lead you to a better understanding of the concepts they embody.

7. Outline the steps in the interactions between B cells and T cells in the paracortex and in germinal centers of lymph nodes during secondary antibody responses, paying attention to both signal 1 and signal 2 generation and transmission.

8. Discuss the process of affinity maturation and isotype switching as they occur in germinal centers during antibody responses. (Be sure to explain all cellular events in detail; it is not necessary, however, to discuss intracellular signaling events in this answer.)

9. ITAMs, found in the cytoplasmic tails of NK cell activating receptor molecules, assist in production of nuclear factors that help activate genes as a result of being dephosphorylated by protein tyrosine phosphatases.

10. Describe the mechanisms involved in class-switching in B cells during maturation of a T-dependent antibody response.

11. Discuss CD4+ T cell subsets (both helper and regulator), being sure to include the signature cytokines and master transcription factors as well as the cytokines that induce each of these cell types.

12. Using a graph that indicates the relative timing, isotype diversity, affinity and amounts of antibody produced, compare and contrast the primary and secondary antibody responses to a T-dependent antigen.

Sample Questions for Exam 4

MULTIPLE CHOICE: Choose the letter corresponding to the ONE answer for each question.

  1. Which statement about hypersensitivity is correct?
    a. Type III and type II hypersensitivity are similar, but differ in that type III reactions involve responses to self antigens and type II reactions do not.
    b. Histamine and leukotrienes, both released by mast cells, are mediators of inflammation, but not hypersensitivity reactions.
    c. Mediators of type IV hypersensitivity include IFN-gamma as well as factors that affect macrophage chemotaxis or migration.

  2. Which statement related to vaccines and vaccination is correct?
    a. The main strategy in immunization against viral diseases is to generate as many memory B cells as possible, so responses to infection will be quicker.
    b. Current vaccines used to prevent diseases caused by toxins generally contain chemically-inactivated toxin, referred to as toxoid.
    c. Research has shown that both DNA vaccines and plants genetically-engineered to contain antigens induce tolerance rather than stimulating immune responses when ingested.

MATCHING MULTIPLE CHOICE: Choose the BEST answer. An answer may be used more than once within a set of questions.

Answers to questions 3-4:
a. CTLs
b. Macrophages
c. Eosinophils
d. NK cells
e. More than one of these
  1. Immunity against the larval forms of certain intestinal parasites can involve the participation of _____, which also accumulate at sites where atopic hypersensitivity reactions are occurring so this effect is often used by pathologists as indicators of atopic hypersensitivity reactions.

  2. _____ participate in antibody-dependent cellular cytotoxicity (ADCC) by virtue of having FcR and granules containing factors that can damage target cells.

TRUE FALSE: If a statement is TRUE, print T in the blank; if it is FALSE, print F.

  1. Arthus reactions are typified by formation of soluble immune complexes in the kidneys, lungs or joints, whereas serum sickness is typified by formation of large, insoluble immune complexes at a local site of administration of the eliciting dose of antigen.

  2. The hemostasis observed in acute inflammatory responses results from constriction of the arteries and dilation of the veins in the immediate area, and results in the exudation of fluid, but not cells, into an area where cell damage has occurred.

Answering the following essay questions correctly will lead you to a better understanding of the concepts we covered during this course ... and at least two of them will be on the final exam.

Discuss these four features of antigens in general, then relate each of them to principles of vaccine design:
a. Foreigness
b. Size
c. Composition and complexity
d. Determinants

The mythical Gram-negative extracellular bacterium, Stevensonella pulmonensis, causes a disease called acute miamiosis as the result of its thick capsule and production of a toxin that causes buildup of fluid in the lungs. Which immune mechanism(s) would be most effective against this bacterium... How and why?
a. Antibody specific for the toxin would be helpful because it might neutralize the toxin by preventing its interaction with cellular targets.
b. Activated macrophages would be required because these cells would be able to prevent intracellular multiplication of this parasite
c. Opsonizing antibody specific for capsular antigens might be helpful because it would be able to enhance phagocytosis of the bacterium by neutrophils, which could then kill it intracellularly.
d. ADCC mediated by NK cells would be a primary line of defense against this pathogen because it would provide for its complement mediated lysis.

Define each of these terms, then briefly explain the relationships among them:
a. Lymphocyte -
b. Natural killer (NK) cell -
c. Cytotoxic T lymphocyte (CTL) -
d. Relationships -

Generate a single overview diagram that shows how Th1 and Th2 cells interact with APCs, B cells, Tc cells, and macrophages to assist in generation of antibody responses, CTL responses and activated macrophage responses, respectively. (Note: Be certain to label each of the cells, indicate the cytokines involved, and provide brief descriptions of the processes that occur as a result of each of the interactions.)

Generate a diagram that depicts the events in T cell intracellular signaling (signals 1, 2 and 3), then compare and contrast (in words) this pathway with the events that occur in B cell signaling (signals 1, 2 and 3).

Generate a diagram that depicts the events in T cell development in the thymus, then compare and contrast (in words) this pathway with the events that occur in B cell development in the bone marrow.

Describe the process of apoptosis, then explain how it is induced and carried out in each of these instances:
a. Positive and negative selection in either T or B cell development
b. Regulation of T cell responses
c. NK cell and CTL function
d. Eosinophil function in ADCC

Discuss, at the mechanistic level, the role of antigen processing and presentation in determining the outcome of an immune response against each of these types of parasite:
a. Extracellular parasite
b. Obligate intracellular parasite
c. Facultative intracellular parasite.
(To answer this question, you will need to choose a specific microbe that is applicable to each of these situations, and you will need to explain, in detail, how the antigen processing pathways used in each instance function and how they influence the subsequent immune response.)

Discuss how receptors function vis-à-vis binding of ligand and initiation of intracellular signaling, in general, then explain how this works in detail for each of these:
a. IFN-gamma receptor
b. TCR
c. BCR and B cell coreceptor

Describe, in detail, the mechanisms involved in generating TCR diversity, then compare and contrast these mechanisms with those involved in generating:
a. BCR diversity
b. MHC diversity

Discuss the relationships between immunoglobulin structures of all five classes (IgG, IgM, IgA, IgD, IgE) of antibody and the functions that each of these types of antibody can carry out in antibody mediated immunity, including complement interactions.

Discuss the mechanisms of activation and regulation of the classical, MBL and alternative complement activation pathways we discussed in class, then explain why all the negative regulatory processes in each are necessary to prevent immunopathologic reactions.

Draw a series of four diagrams depicting the events involved in margination and extravasation of neutrophils into inflammatory sites. In your diagrams, be sure to include cell surface molecule interactions, chemokines that influence these interactions, and the process of diapedesis. Also, be sure to label every component and to include short descriptions of what is occurring in each diagram. Finally, compare and contrast this series of events with those that occur during emigration of lymphocytes from the bloodstream into lymphoid tissue via HEVs.

Generate a series of diagrams (one for each major step) depicting the sequence of interactions involved in activation of a B cell by a T helper cell, starting with binding antigen to BCRs, and finishing with activation of the B cell by cytokines secreted by the Th cell. Explain how (and where) this sequence of events is important in antibody responses in germinal centers of lymph nodes. (Be certain that your diagrams are clearly labeled, and complete your answer by adding a text description that outlines the mechanisms involved in each step.)
Describe the mechanisms involved in class-switching in B cells during maturation of a T-dependent antibody response.

Compare and contrast the structure and cellular architecture of a lymph node with that of a Peyer's patch, then compare and contrast mechanisms of antigen capture by cells in lymph nodes with those in the mucosal immune system of the small intestine.


Discuss CD4+ T cell subsets (both helper and regulator), being sure to include the signature cytokines and master transcription factors as well as the cytokines that induce each of these cell types and the intracellular signaling pathways that each cytokine triggers.

Describe the mechanisms involved in somatic hypermutation and class-switching in B cells during maturation of a T-dependent antibody response in germinal centers of secondary lymphoid tissues.

Discuss the potential problems vis-a-vis autoimmune disease that could lead to imperfect deletion of self-reactive (autoreactive) T cells as they develop and mature in thymus and B cells as they develop and mature in bone marrow, then splee, then discuss how these errors could lead to generation of autoimmune disease.

Using a graph that indicates the relative timing, isotype diversity, affinity and amounts of antibody produced, compare and contrast the primary and secondary antibody responses to a T-dependent antigen, then explain, in detail, how each of these factors relates to maturation of these antibody responses.


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© 1996-2013 John R. Stevenson. All Rights Reserved

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email questions and comments to:
John R. Stevenson, Ph.D.
Associate Professor
Department of Microbiology
Miami University
Oxford, Ohio 45056
USA
This document was last modified on Monday, 25-Nov-2013 13:52:28 EST