Midterm Flashcards
A vaccine is a product that produces immunity from a disease and can be administered through needle injections, by mouth, or by aerosol. The following properties render a substance immunogenic:
a. high molecular weight
b. chemical complexity
c. sufficient stability and persistence after injection
d. all of the above
e. all of the above are essential but not sufficient
e. all of the above are essential but not sufficient
Smallpox vaccine, the first successful vaccine to be developed, was introduced by Edward Jenner in 1796. He followed up his observation that milkmaids who had previously caught cowpox did not later catch smallpox by showing that inoculated cowpox protected against inoculated smallpox. The protection against smallpox afforded by prior infection with cowpox represents
a. antigenic specificity
b. antigenic cross-reactivity
c. enhanced viral uptake by macrophages
d. innate immunity
e. passive protection
b. antigenic cross-reactivity
A 22-year-old man was treated for acute myeloid leukemia (AML) with cyclical combination chemotherapy, and complete clinical remission was obtained after three courses. However, remission in AML is generally short; half the patients relapse within a year and second remissions are difficult to achieve. Bone marrow transplantation after high-dose chemoradiotherapy is therefore considered in young patients with suitable family members. Which of the following does not apply to bone marrow as a primary lymphoid organ?
a. cellular proliferation
b. differentiation of lymphocytes
c. cellular interaction
d. antigen-dependent response
e. none of the above
d. antigen-dependent response
Lymph nodes are tiny, bean‐shaped organs that filter lymph fluid. They are located throughout the body, but particular collections are found just under the skin in the neck, under the arms, and in the groin area. Lymph nodes are part of the lymphatic system, which is one of the body's defense mechanisms against the spread of infection and cancer. Which of the following apply uniquely to secondary lymphoid organs? A. presence of precursor B and T cells B. circulation of lymphocytes C. terminal differentiation D. cellular proliferation E. All of the above.
C. terminal differentiation
To elicit an immune response, a compound must contain an antigenic determinant or epitope and must be of sufficient size to initiate lymphocyte activation necessary for an antibody response. In practice, small chemical compounds called haptens are generally not good immunogens. Which of the following is correct about properties of haptens?
A. They require carrier molecules to be immunogenic.
B. They react with specific antibodies when homologous carriers are not employed.
C. They interact with specific antibody even if the hapten is monovalent.
D. They cannot stimulate secondary antibody responses without carriers.
E. All of the above.
E. All of the above.
The concept of adjuvants arose in the 1920s from observations that horses that developed an abscess at the inoculation site of diphtheria toxoid generated higher specific antibody titers. What is the major property of immunologic adjuvants?
A. They reduce the toxicity of the immunogen
B. They enhance the immunogenicity of haptens
C. They enhance hematopoiesis
D. They enhance the immune response against the immunogen
E. They enhance immunologic cross‐reactivity
D. They enhance the immune response against the immunogen
The lymphoid system is made up of a network of lymph fluid, lymphocytes, lymph vessels, lymph nodes and the lymphatic organs. These organs are the spleen, thymus, tonsils, adenoid and bone marrow. Lymphatic tissue is also found in other parts of the body, including the stomach, intestines and skin. Which of the following is the major function of the lymphoid system? A. innate immunity B. inflammation C. phagocytosis D. acquired immunity E. None of the above
D. acquired immunity
The innate immune system provides first‐line defenses in response to invading microorganisms and endogenous danger signals (damaged tissues) by triggering robust inflammatory and antimicrobial responses. Which of the following does not apply to innate immune mechanisms? A. absence of specificity B. activation by a stimulus C. involvement of multiple cell types D. a memory component
D. a memory component
Which of the following pairs is mismatched?
A. lymphocytes: innate immune response
B. natural killer cell: kills virus‐infected cells
C. macrophage: phagocytosis and killing of microorganisms
D. erythrocyte: oxygen transport
E. eosinophil: defense against parasites.
A. lymphocytes: innate immune response
White blood cells are part of the body’s immune system. They help the body fight infection and
other diseases. Types of white blood cells are granulocytes (neutrophils, eosinophils, and basophils) and mononuclear cells (monocytes and T and B lymphocytes). Checking the number of white blood cells in the blood is usually part of a complete blood cell (CBC) test. It may be used to look for conditions such as infection, inflammation, allergies, and leukemia. What is the term generally used to describe all white blood cells?
A. hematopoietic cells
B. myeloid progenitor
C. dendritic cells
D. monocytes
E. leukocytes
E. leukocytes
The most abundant type of leukocyte in human peripheral blood is: A. eosinophil B. basophil C. neutrophil D. monocyte E. lymphocyte
C. neutrophil
A workup on an ill child revealed low levels of complement C3 in her blood. Which one of the following presentations did this child most likely manifest?
A. Chronic eczema
B. Immune hemolytic anemia
C. Incomplete recovery from viral infections
D. Poor response to vaccination
E. Recurrent infections with extracellular bacteria
E. Recurrent infections with extracellular bacteria
Activation of macrophages is best achieved by which cytokine?
A. Interferon gamma (IFN‐gamma)
B. Granulocyte monocyte colony‐stimulating factor (GM‐CSF)
C. Interleukin‐1
D. Macrophage chemotactic protein (MCP)
E. Transforming growth factor beta (TGF‐beta)
A. Interferon gamma (IFN‐gamma)
Toll‐like receptors (TLRs) are a family of homologous receptors expressed on many cell types and are involved in innate immune responses. Ten different mammalian TLRs have been identified, and several ligands for many of these receptors are known. Which of the following is a TLR ligand? A. Single‐stranded RNA B. Transfer RNA C. Double‐stranded DNA D. Unmethylated CpG DNA E. Heterochromatin
D. Unmethylated CpG DNA
Which of the following is a receptor on macrophages that is specific for a structure produced by bacteria but not by mammalian cells?
a. CD36 (scavenger receptor)
b. Fc receptor
c. Complement receptor
d. Mannose receptor
e. ICAM‐1
d. Mannose receptor
Which one of the following cells is the major source of tumor necrosis factor alpha (TNF‐), interleukin‐1, and interleukin‐12?
a. B cells
b. Macrophages
c. Mast cells
d. Th1 cells
e. Th2 cells
b. Macrophages
Activation of the complement system, directly results in which one of the following outcomes?
A. Enhanced phagocytosis
B. Expression of Toll‐like receptors on phagocyte cell surface
C. Enhancement of immune‐mediated neutralization
D. Interaction of Fc receptors with antibodies bound to antigens on the pathogen cell surface
E. Proliferation of T cells
A. Enhanced phagocytosis
Septic shock may develop when bacterial components are recognized by macrophages. Which two proinflammatory cytokines are rapidly elevated during early phases of bacterial septic shock? A. TNF‐α and IL‐1β B. IL‐2 and TNF‐β C. IL‐4 and IL‐5 D. TNF‐β, TGF‐β
A. TNF‐α and IL‐1β
Several of the complement components are: A. Glycolipids B. Cytokines C. Enzymes D. Hormones E. Antibodies
C. Enzymes
NK cells are activated by several cytokines that are produced by specific cell types including which of the following?
A. IL‐12 which is produced by macrophages.
B. IL‐12 which is produced by virally infected cells.
C. IFN‐gamma and IFN‐beta which are produced by virally infected cells.
D. Answers A and C are correct.
E. Answers B and C are correct.
A. IL‐12 which is produced by macrophages.
Complement lyses cells by:
A. enzymatic digestion of the cell membrane.
B. activation of adenylate cyclase.
C. insertion of complement proteins into the cell membrane.
D. inhibition of elongation factor 2.
E. activation of TLR‐4.
C. insertion of complement proteins into the cell membrane.
When the innate immune system encounters a foreign antigen, what cell‐surface molecule plays the role of recognizing the presence of a foreign antigen?
A. Antibody
B. T cell receptor
C. The membrane attack complex of complement
D. HLA Class II
E. Toll‐like receptor
E. Toll‐like receptor
You have a patient who makes autoantibodies against his own red blood cells, leading to their hemolysis. Which one of the following mechanisms is MOST likely to explain the hemolysis?
A. Perforins from cytotoxic T cells lyse the red cells.
B. Neutrophils release proteases that lyse the red cells.
C. Interleukin‐2 binds to its receptor on the red cells, which results in lysis of the red cells.
D. Complement is activated, and membrane attack complexes lyse the red cells.
D. Complement is activated, and membrane attack complexes lyse the red cells.
Cells of the innate immune system are triggered by the binding of surface receptors. In general, the action taken is determined by
A. a single receptor per cell.
B. a single type of receptor found on all cells.
C. the integration of signals generated by multiple receptors on single cells.
D. multiple receptors that bind soluble ligands only.
E. nonspecific receptors capable of binding a wide array of ligands.
C. the integration of signals generated by multiple receptors on single cells.
Neutrophils are attracted to the sites of extracellular bacterial infections by which two important chemotactic substances?
A. Bacterial mannose and lipopolysaccharide
B. Complement C5a and interleukin‐8 (CXCL‐8)
C. Histamine and complement C3b
D. lnterleukin‐7 and interleukin‐16
E. Leukotriene B4 and granulocyte colony‐stimulating factor (G‐CSF)
B. Complement C5a and interleukin‐8 (CXCL‐8)
Which of the following about NK cells is correct?
A. NK cells proliferate in response to antigen
B. NK cells kill their target cells by phagocytosis and intracellular digestion
C. NK cells are a subset of polymorphonuclear cells
D. NK‐cell killing is extracellular
E. NK cells are particularly effective against certain bacteria
D. NK‐cell killing is extracellular
A patient is admitted to your hospital with multiple bacterial infections. He is found to have a complete absence of C3 component of complement. Which complement‐mediated function would remain intact in such a patient?
A. lysis of bacteria
B. opsonization of bacteria
C. generation of anaphylatoxins
D. generation of neutrophil chemotactic factors
E. None of the above.
E. None of the above.
