INSTRUCTIONS
Complete this practice exam under “exam-like” conditions

nallow yourself up to 3 hours to complete the exam.

ncomplete the exam without the aid of your notes, the textbook or any other course material

You can compare your answers to those provided.  This practice exam should assist in identifying areas that may need more of a review prior to the final exam in this course.  If you have any questions concerning the practice exam, please contact your instructor.

UNIVERSITY OF WINDSOR

Immunology Practice Exam

55-242

IMPORTANT - Please put your name (last name first), student number, the course number on the answer sheet.  Mark the answer sheet only in pencil.

The final examination is a 3 hour examination that covers the entire course material.  There are three parts in this exam:

Part A- Multiple Choice Questions.  Consists of  30 multiple choice questions.  Please read each question carefully and choose only one answer per question.  The answer selected should be the most correct of the possible choices.  Each question is worth 2 marks for a total of 60  marks.  Additional marks (a penalty) will not be deducted for incorrect answers on the multiple choice question.

Part B-Definitions and short answers. Consists a list of 10 terms which must be defined in the sentence form.  Use examples when applicable.  Each question is worth 4 marks for a total of 40 marks.

Part C-Essay Question.  Consists of 3 essay questions.  Each question is worth 15 marks for a total 45 marks.  Answer the questions to the best of your ability and ONLY in the space provided. Information that you provide outside the allotted space will not be marked.   Please plan your answer and write neatly in complete sentences.  You will be marked on content (10 marks) as well as on the clarity and organization (5 marks).  Make sure you answer the question directly. You may use properly labeled diagrams or tables to answer the questions.

Part A: Multiple Choice Questions

1.  CD8 is a receptor for:

a.  antigen

b.  MHC class II molecules

c.  antibody

d.  TCR

e.  MHC class I molecules

2.  Helper T cells recognize antigen on antigen-presenting cells as antigen

a.  alone

b.  with MHC class I product

c.  with MHC class II product

d.  with both class I and class II products

e.  with complement

3.  The term “MHC restriction” refers to the

a.  inheritance of MHC antigens

b.  need for antigen to be recognized in association with MHC molecules

c.  need for MHC genes to control complement activity

d.  problems associated with allograft rejection

e.  need for MHC molecules in order to reject grafts

4.  Proteasomes play a key role in processing

a.  exogenous antigens

b.  bacterial antigens

c.  cell surface antigens

d.  endogenous antigens

e.  MHC class II peptides

5.  Glycoproteins are proteins that

a.  contain lipids

b.  contain oligosaccharides

c.  contain interchain bonds

d.  stimulate the immune system

e.  are found only in bacteria

6.  Protein molecules that differ in a few amino acid residues are called

a.  polymers

b.  isoforms

c.  glycoforms

d.  heterotypes

e.  isotypes

7.  Which one of the following is not immunogenic?

a.  keyhole limpet hemocyanin

b.  bovine serum albumin

c.  bacterial lipopolysaccharide

d.  glucose

e.  DNA

8.  An antigenic determinant is about the size of

a.  1 amino acid residue

b.  5 amino acid residues

c.  20 amino acid residues

d.  50 amino acid residues

e.  100 amino acid residues

9.  The primary immune response is characterized by

a.  induction by one dose of antigen

b.  a long lag period

c.  low levels of antibody produced

d.  rapid decline

e.  all of the above

10. A secondary immune response

a.  occurs after several months

b.  has a very short lag period

c.  is mediated by cells

d.  only occurs against toxoids

e.  can be induced by one high dose of antigen

11.    The antigen-combining site of an antibody molecule determines its

• a.  isotype

• b.  anti-idiotype

c.  allotype

d.  hypertype

e.  idiotype

12. The process of physiologically mediated cell death is called

a.  necrosis

b.  lysis

c.  hemolysis

d.  apoptosis

e.  osmosis

13. The predominant type of leukocyte in human blood is the

a.  monocyte

b.  eosinophil

c.  basophil

d.  neutrophil

e.  lymphocyte

14. The movement of neutrophils under the influence of external chemical signal is called:

a.  endocytosis

b.  chemotaxis

c.  phagocytosis

d.  chemolysis

e.  exotaxis

15. Following a single intravenous injection of antigen, antibody formation primarily occurs in the

a.  Peyer’s patches

b.  lymph nodes

c.  spleen

d.  thymus

e.  bone marrow

16. The CD4 molecule is

a.  a heterodimer

b.  a receptor for MHC class II molecules

c.  part of the BCR

d.  a complement receptor

e.  a tyrosine kinase

17. Exogenous antigen processing mainly occurs within

a.  T lymphocytes

b.  neutrophils

c.  plasma cells

d.  macrophages

e.  none of the above

18. Class I MHC molecules are found on

a.  B cells and macrophages

b.  erythrocytes, B cells, and T cells

c.  T cells only

d.  all nucleated cells

e.  neutrophils, T cells, and B cells

19. Class II MHC molecules contain

a.  one gamma chain and one light chain

b.  one alpha chain and one Beta chain

c.  two light and two heavy chains

d. one epsilon chain

e.  B2-microglobulin

20. One characteristic that distinguishes the construction of

immunoglobulin heavy chains from that of light chains is

a.  somatic mutation

b.  the use of gene segments

c.  looping out of gene segments

d.  the use of a D gene segment

e.  the use of a J gene segment

21.    The central paradigm of the immune response is called

a.  somatic mutation

b.  antigen presentation

c.  MHC restriction

d.  clonal selection

e.  antigen recognition

22. The insertion of one or more additional bases at a gene splice site is

called

a.  N-region addition

b.  somatic mutation

c.  antigenic variation

d.  sister chromatid exchange

e.  looping out

23. Reaction of antigen with IgE antibodies attached to mast cells causes

a.  Complement fixation.

b.  Agglutination.

c.  Lysis of the cells.

d.  Release of chemical mediators.

e.  None of these.

24. When an antibody combines with an antigen, the Fc region is

exposed to react with

a.  TNF and IL-l.

b.  Macrophages.

c.  B cells.

d.  Other antibodies.

e: none of these.

25. A secondary immune response

a.  occurs after several months

b.  has a very short lag period

c.  is mediated by cells

d.  only occurs against toxoids

e.  can be induced by one high dose of antigen

26. Germinal centers of lymphoid tissues largely contain

a.  macrophages

b.  neutrophils

c.  T-cells

d.  B-cells

e.  plasma cells

 27. Macrophages can be cytotoxic for other target cells as a result of the release of

a.  superantigens

b.  perforins

c.  complement

d.  immunoglobulins

e.  nitric oxide

28. NK cells develop from which cell lineage?

a.  T cell

b.  B cell

c.  myeloid

d.  erythroid

e.  none of the above

29. Which of the following is a potent chemotactic factor for neutrophils?

a.  C-reactive protein

b.  interleukin-8

c.  arachidonic acid

d.  complement

e.  immunoglobulin

30. Bacteria are cleared from the bloodstream mainly by

a.  lung capillaries

b.  spleen and liver macrophages

c.  circulating neutrophils

d.  marginating neutrophils

e.  renal capillaries

Part B: Definitions/ Short Answers

1.  Allergy

2.  Atopy

3.  Anergy

4.  F(ab’)2

5.  Multiple myeloma

6.  C1-INH

7.  MAC

8.  Reverse transcriptase

9.  Integrase

10. Superantigens

Part C: Essay Questions

1.  In the space provided, construct a table comparing the biological characteristics of the five classes of immunoglobulins

2.  Describe and Draw MHC-II molecule.

3. The difficulty in characterizing IL-1 is caused by the fact that it seems to be made in every cell and seems to be able to affect every cell.  Explain.

Answers to multiple choice questions

Answers to definitions/short answer questions

Review Lesson 9 for questions: 1, 2, 3.

nReview Lesson 3 for questions: 4, 5.

nReview Lesson 7 for questions: 6, 7.

nReview Lesson 11 for questions: 8, 9.

nReview Lesson 6 for question: 10.

1.  An allergy is a hypersensitivity reaction or an inappropriate immune response to an antigen.  The reaction can be immediate - Type I, Type II or Type III, or delayed - Type IV.  Allergies are usually associated with an IgE mediated hypersensitivity reaction which leads to inflammation, edema, and to tissue damage.

2.  Atopy refers to the clinical manifestation of Type I hypersensitivity reaction.

Most commonly atopy refers to the reactions of the skin. Examples include hives, rhinitis, eczema and anaphylaxis.  Atopic conditions result when IgE sensitized mast cells are triggered by allergen and release pharmacological mediators, which then cause the inflammatory  response.

3. Anergy is an induced state of unresponsiveness to a particular antigen,  which results from prior exposure of T cells to the antigen.  Its function is to prevent the self destruction.

4.  F(ab’)2 is a product of digestion of IgG with pepsin.  It consists of two Fab fragments held together by disulfide bridges. It is able to visibly precipitate the antigen.

5.  Multiple myeloma is a cancer of antibody producing plasma cells which divides in an unregulated way without antigen activation.  In patients with multiple myeloma, myeloma protein can account for 95% of serum immunoglobulins.

It is also found in the urine of myeloma patients, for example Bence-Jones proteins.   

6.  MAC stands for the membrane-attack complex.  In  a terminal sequence in the Complement pathway, several C9 molecules bind to C5b678 complex creating a large, perforin like molecule (MAC), which inserts to the membrane. Ions and small molecules can diffuse freely through the central channel of the MAC and cause the cell lysis. 

7.  C1-INH stands for C1 inhibitor.  It binds to the C1q complement protein and prevents the formation of the C1r2s2 attachment to the C1q anchor.  The result is a cessation of the complement cascade.

8.  Reverse transcriptase is an enzyme produced by retroviruses, including HIV.  It utilizes the host cell’s nucleotides to produce an RNA-DNA duplex which is then converted to a dsDNA copy of the viral genome to be incorporated into the host genome.

9.  Integrase is an HIV enzyme which allows the integration of viral DNA into the  host cell genome and formation of provirus.  Once integrated, the viral DNA is permanently associated with the host-cell DNA and is passed on to daughter cells as the cell divides.

10.    Superantigens are a group of substances which are very potent T-cell activators.  They bind to residues in the variable regions of T-cell receptor and to residues in the MHC class II molecules outside the antigen binding cleft.  Superantigens can thus nonspecifically cross-link a T cell to MHC class II molecule, and activate all T-cells expressing the identical V domain.  The most common examples are staphylococcal enterotoxin, and toxic shock syndrome.

Answers to Essay Questions

nReview Lesson 3 for question 1.

nReview Lesson 5 for question 2.

nReview Lesson 7 for question 3.

Question 1.

In this question you must use the table format to answer it. Note that the question calls for the comparison of the biological activities only.  Therefore it is not necessary to include all the information on physical and structural features of immunoglobulins.

Question 2.

In this question you are asked to draw and describe the structure of MHC II molecule.  Therefore you have to concentrate on the structural features and details only.  Draw the model of the molecule and label all parts clearly.  Half of the mark on this question will be on the correct drawing and the other half on proper labeling.

Question 3.

Use essay format to answer this question.  The explanation of the stated fact about the difficulty in characterizing IL-1 should include:

nshort definition of IL-1

nexplanation of pleiotropy, redundancy, synergy and antagonism

nexamples of cells producing IL-1 and cells effected by IL-1

Il-1 is a cytokine, produced by various cells of the immune system (monocytes, macrophages, B cells, dendritic cells) and effecting a vide range of target cells (T-helpers, B-cells, macrophages, neutrophils, NK-cells).  By definition cytokines function as intercellular massagers that induce particular biological activities after binding to the receptors on the target cells.  Il-1, among many other cytokines, exhibits many characteristics which allows it to regulate cellular activity in a co-ordinated way.  Such characteristics include pleiotropy which refers to the fact that it has different biological effects on different target cells.  It is also redundant and thus it is difficult to ascribe a particular activity to a single cytokine.  IL-1 can also function through synergic action with another cytokine causing greater combined biological effect than the individual cytokines. In some cases IL-1 exhibits antagonism, when its effects inhibit or offset the effects of another cytokine.  It is for these reasons that it is difficult to pinpoint the effects caused by IL-1 alone.