Which of the following statements regarding neutrophils is false?
a.Neutrophils are mobilized from the bone marrow to sites of infection when needed.
b.Neutrophils are active only in aerobic conditions.
c.Neutrophils are phagocytic.
d.Neutrophils form pus, which comprises dead neutrophils.
e.Dead neutrophils are cleared from sites of infection by macrophages.
Plasma cells and memory B cells differentiate most immediately from _____.
a.centrocytes
b.centroblasts
c.B-1 cells
d.IgG-secreting B cells.
The progenitors of macrophages are _____.
a.megakaryocytes
b.dendritic cells
c.monocytes
d.neutrophils
e.erythrocytes
f.M cells.
The process by which cytotoxic T cells kill their targets involves _____. (Select all that
apply.)
a.inducing the target cell to undergo necrosis
b.inducing apoptosis (programmed cell death) in the cytotoxic T cell
c.DNA fragmentation in lengths of multiples of 200 base pairs in the target cell
d.shedding of membrane-bound vesicles and shrinking of the target cell
e.release of granzyme, perforin, and granulysin by the cytotoxic T cell.
Which of the following processes is not dependent on an interaction involving MHC class
I or class II molecules? (Select all that apply.)
a.positive selection of T cells
b.intracellular signaling by pre-T-cell receptors
c.negative selection of T cells
d.peripheral activation of mature naive T cells
e.positive selection of T cells.
Which of the following is consistent with a recently antigen-activated mast cell?
a.high levels of MHC class II molecules on the cell surface
b.the absence of prepackaged granules
c.the absence of IgE on the cell surface
d.high concentrations of C3b on the cell surface
e.the induction of antibody-dependent cell-mediated cytotoxicity.
If a non-professional antigen-presenting cell that lacks co-stimulatory molecules presents
peptide:MHC complexes to a T cell specific for that peptide, then _____.
a.the T cell delivers a signal to the non-professional antigen-presenting cell to activate the
expression of co-stimulatory molecules.
b.the T cell begins to express the chain of the IL-2 receptor.
c.the T cell differentiates into a TH1 cell.
d.T-cell tolerance occurs as a result of anergy.
e.the T cell is more heavily reliant on signals transmitted through CD4 or CD8 in order to
become activated.
Which of the following statements about the production and use of monoclonal antibodies
is incorrect?
a.Production of monoclonal antibodies requires a purified form of antigen.
b.A monoclonal antibody has specificity for only one epitope of an antigen.
c.B cells are fused with a tumor cell called a myeloma, to immortalize the resulting
hybridoma.
d.Monoclonal antibodies made in mice have limited therapeutic potential.
e.Humanized monoclonal antibodies reduce complications associated with using mouse
monoclonal antibodies.
Paroxysmal nocturnal hemoglobinuria is caused by _____.
a.a profound deficiency of neutrophils
b.leukocytosis
c.immune-complex deposition in tissues
d.defects in recruitment of phagocytes to infected tissues
e.complement-mediated lysis of erythrocytes.
A.What mechanism of self-tolerance is broken in the autoimmune syndrome APECED?
B.What is the underlying genetic defect in APECED? Explain why it leads to a reduction
in self-tolerance.
Prostaglandin D2 (PGD2) enhances all of the following except _____.
a.smooth muscle contraction
b.chemotaxis of neutrophils
c.increased vascular permeability
d.vasodilation.
What is the fate of centrocytes in which somatic hypermutation has resulted in
high-affinity receptors for antigen? (Select all that apply.)
a.They die by apoptosis.
b.They express Bcl-xL.
c.They process antigen and present it to TFH cells.
d.CD40 on the centrocyte engages with CD40 ligand on TFH cells.
e.They undergo phagocytosis by tingible body macrophages.
It is believed that the allotype DRB1*_____ may confer protection against rheumatoid
arthritis because it contains _____ amino acid residues at positions 70 and 71 that bind to
different subsets of peptides compared with the allotypes that confer susceptibility to this
disease.
a.04:01; acidic
b.04:02; acidic
c.04:04; basic
d.04:05; basic
e. 04:08; acidic.
Mucosae of a healthy intestinal tract _____. (Select all that apply.)
a.have a large number of activated T and B cells
b.harbor T cells bearing a very wide diversity of antigen specificities
c.contain intraepithelial lymphocytes
d.have large numbers of resident neutrophils
e.are populated with both and effector T cells.
Indicate whether each of the following statements is true (T) or false (F).
A-Describe in chronological order the steps of the antigen-processing and
antigen-presentation pathways for extracellular pathogens.
B-What would be the outcome (i) if invariant chain were defective or missing, or (ii) if
HLA-DM were not expressed?
Match the cell type in column A with its description in column B.
Characterize two properties of endocrine glands that render them susceptible to
autoimmune attack.
Explain why the DTP vaccine stimulates a much stronger protective immunity than does
the DT vaccine.
Explain how mycobacteria avoid immune recognition by T cells during infection.
After the bone marrow transplant, the patient’s entire immune system, including T cells
and dendritic cells, will become reconstituted from hematopoietic stem cells in the donor
bone marrow. Donor-derived T cells developing in the recipient’s thymus will, however, be
positively selected on the recipient’s HLA molecules, and will only recognize antigen in
that context. If the donor and recipient do not share any HLA molecules, these T cells will
not be able to recognize antigen presented by the donor-derived dendritic cells or
macrophages and will not be activated in response to pathogens. Because T-cell activation
is central to all adaptive immune responses, the recipient will remain severely
immunodeficient and unable to make adaptive immune responses to pathogens. In
addition, HLA matching reduces the severity of graft-versus-host disease (GVHD), in
which mature T cells in the donor graft respond to the allogeneic MHC class I and II
molecules of the recipient and attack host tissue.
To which domain of MHC class I does CD8 bind?
The most variable parts of the T-cell receptor are