A.Describe two ways in which the immunoglobulins acting as antigen receptors on the
surface of a mast cell differ from the immunoglobulins acting as the antigen receptors on
the surface of a B cell.
B.What is the essential difference in response of these two cell types when antigen binds to
these surface immunoglobulins.
Which of the following best describes the function of tapasin?
a.Tapasin is an antagonist of HLA-DM and causes more significant increases in MHC
class I than MHC class II on the cell surface.
b.Tapasin is a lectin that binds to sugar residues on MHC class I molecules, T-cell
receptors, and immunoglobulins and retains them in the ER until their subunits have
adopted the correct conformation.
c.Tapasin is a thiol-reductase that protects the disulfide bonds of MHC class I molecules.
d.Tapasin participates in peptide editing by trimming the amino terminus of peptides to
ensure that the fit between peptide and MHC class II molecules is appropriate.
e.Tapasin is a bridging protein that binds to both TAP and MHC class I molecules and
facilitates the selection of peptides that bind tightly to MHC class I molecules.
Imagine a situation in which an individual who has a latent cytomegalovirus (CMV)
infection receives a hematopoietic stem-cell transplant. Which of the following is likely to
occur?
a.The memory T cells present at the time of transplantation would inhibit activation of
newly generated naive T cells.
b.The CMV viral load would increase exponentially, overcoming the host and causing
death.
c.The transplant-derived naive T cells would be activated and give rise to memory T cells
that would persist and control viral load.
d.There would be a rapid increase in CMV viral load and expansion of T cells bearing
CD45RA.
_____ express a limited range of diversity in their antigen receptors yet can still bind to
large groups of pathogens expressing common chemical entities. (Select all that apply.)
a. cells
b. cells
c.NK cells
d.NKT cells
e.B-1 cells.
Which of the following determines the isotype of an immunoglobulin?
a.the composition of the hypervariable regions
b.whether the immunoglobulin is membrane-bound or secreted
c.its light chain
d.its heavy chain
e.the composition of the cytoplasmic tails of Ig± and Ig²
MHC class II molecules are made up of two chains called _______, whose function is to
bind peptides and present them to _______ T cells:
a.alpha ( ) and beta ( ); CD4
b.alpha ( ) and beta2-microglobulin ( ); CD4
c.alpha ( ) and beta ( ); CD8
d.alpha ( ) and beta2-microglobulin ); CD8
e.alpha ( ) and beta ( ); T cells.
All of the following are associated with Goodpasture€s syndrome except _____. (Select all
that apply.)
a. chain of type IV collagen
b.inflammation
c.extracellular matrix antigen
d.neutropenia
e.renal tubules and glomeruli
f.type III hypersensitivity reaction.
Identify which of the following statements is true regarding the transporter associated with
antigen processing (TAP).
a.TAP is a homodimer composed of two identical subunits.
b.TAP transports proteasome-derived peptides from the cytosol directly to the lumen of the
Golgi apparatus.
c.TAP is an ATP-dependent, membrane-bound transporter.
d.Peptides transported by TAP bind preferentially to MHC class II molecules.
e.TAP deficiency causes a type of bare lymphocytes syndrome resulting in severely
depleted levels of MHC class II molecules on the surface of antigen-presenting cells.
Indicate which of the following statements is true (T) or false (F).
a.__ Immature T cells failing to successfully recombine a -chain locus die by apoptosis.
b.__ Apoptotic T cells are ingested by medullary epithelial cells.
c.__ Allelic exclusion of the T-cell receptor and chains is effective; therefore, all T
cells express only one T-cell receptor on the cell surface.
d.__ T-cell receptor rearrangements have many features in common with immunoglobulin
rearrangement, including the use of the RAG-1 and RAG-2 genes.
e.__ The expression of the pre-T-cell receptor is required in order to halt
-chain rearrangements.
Which of the following types of immune response are most beneficial in clearing helminth
infections in the intestinal tract? (Select all that apply.)
a.production of IgG2 antibodies
b.production of IgE antibodies
c.complement fixation
d.eosinophil activation
e.antibody-dependent cell-mediated cytotoxicity
f.IFN- -induced production of mucus
g.TH1-derived cytokines.
Which of the following is an accurate description of how centroblasts differ from
centrocytes?
a.Centroblasts cease their expression of cell-surface immunoglobulins.
b.Centroblasts divide more slowly than centrocytes.
c.Centroblasts express CD44 but centrocytes do not.
d.Centrocytes, but not centroblasts, initiate the process of isotype switching.
e.Centroblasts participate in affinity maturation.
In contrast with leader peptides and the C regions, the V regions in immunoglobulin
heavy-chain genes
a.encode hydrophobic amino acids that anchor the immunoglobulin chains to B-cell
membranes
b.comprise the smallest number of gene segments in the human immunoglobulin loci
c.are composed of V, D, and J gene segments that must undergo gene rearrangement to
generate a transcribable exon
d.do not undergo somatic hypermutation
e.are not subject to allelic exclusion.
Examples of rheumatic diseases caused by autoimmune responses include _____. (Select
all that apply.)
a.rheumatoid arthritis
b.acute rheumatic fever
c.multiple sclerosis
d.autoimmune hemolytic anemia
e. ‘s syndrome
f.systemic lupus erythematosus.
A characteristic of the human eye that enables the cornea to be transplanted with a 90%
success rate is that _____. (Select all that apply.)
a. antigen-presenting cells in the eye do not express the co-stimulatory molecule B7
b. the cornea is not vascularized
c. anterior-chamber-associated immune deviation (ACAID) establishes a state of tolerance
in the eye
d. only regulatory T cells express the adhesion molecules necessary to enter the cornea
e. the aqueous humor of the anterior chamber contains TGF , which downregulates
CD40 and inhibits IL-12 secretion.
A.Deficiencies in antibody production can be due to a variety of underlying genetic
defects. Name two immunodeficiency diseases, other than the severe combined
immunodeficiencies, in which a defect in antibody production is the cause of the disease,
and for which the underlying genetic defect is known. For each disease, say (i) how
antibody production is affected, and (ii) what the underlying defect is and why it has this
effect.
B.What is the main clinical manifestation of immunodeficiency diseases in which antibody
production is defective but cell-mediated immune responses are intact?
As an adaptive immune response progresses, the production of variant antibodies that
compete more effectively for antigen occurs, and B cells producing these antibodies are
preferentially selected on the basis of their improved binding to antigen. This phenomenon
is referred to as _______.
a.isotype switching
b.neutralization
c.allelic exclusion
d.affinity maturation
e.somatic rearrangement.
Anita Garcia, 17 years old, and her roommate Rosa Rosario were celebrating a friend’s
birthday at a dessert buffet at a local restaurant when Anita developed acute dyspnea, and
angioedema. She complained of an itchy rash, and then had difficulty swallowing. Rosa
drove Anita to the emergency room two blocks away rather than wait for an ambulance. As
they approached the hospital, Anita lost consciousness. This medical emergency would
most probably result in immediate _____ before any subsequent treatment.
a.subcutaneous injection of epinephrine
b.intravenous injection of corticosteroids
c.intravenous injection of antihistamine
d.intravenous injection of antibiotics
e.intravenous injection of a nonsteroidal anti-inflammatory drug.
Mutagens that increase one€s predisposition to developing cancer are called _____.
a.carcinogens
b.tumor antigens
c.neoplastic mutagens
d.oncogenes
e.proto-oncogenes.