005 Flashcards
The ability of a single cytokine to alter the expression of several genes is called
a. redundancy.
b. pleiotropy.
c. autocrine stimulation.
d. endocrine effect.
b. pleiotropy.
Which of the following can be attributed to IL-1?
a. Mediator of the innate immune response
b. Differentiation of stem cells
c. Halts growth of virally infected cells
d. Stimulation of mast cells
a. Mediator of the innate immune response
Which of the following are target cells for IL-3?
a. Myeloid precursors
b. Lymphoid precursors
c. Erythroid precursors
d. All of the above
d. All of the above
A lack of IL-4 might result in which of the following?
a. Inability to fight off viral infections
b. Increased risk of tumors
c. Lack of IgE
d. Decreased eosinophil count
c. Lack of IgE
Which of the following is also known as the T-cell growth factor?
a. IFN-
b. IL-12
c. IL-2
d. IL-10
c. IL-2
Which chemokine receptor does HIV need for cellspecific binding?
a. CCR1
b. CCR3
c. CCR4
d. CCR5
d. CCR5
IFN-α and IFN-β differ in which way from IFN-у?
a. IFN- α and IFN-β are called immune interferons, and IFN- у is not.
b. IFN- α and IFN-β primarily activate macrophages, while IFN-у halts viral activity.
c. They are made primarily by activated T cells, while IFN-у is made by fibroblasts.
d. IFN-α and IFN-β inhibit cell proliferation, while IFN- β stimulates antigen presentation by class II MHC molecules.
d. IFN-α and IFN-β inhibit cell proliferation, while IFN- β stimulates antigen presentation by class II MHC molecules.
A patient in septic shock caused by a gram-negative bacterial infection exhibits the following symptoms:
high fever, very low blood pressure, and disseminated intravascular coagulation. Which cytokine is the most likely contributor to these symptoms?
a. IL-2
b. TNF
c. IL-12
d. IL-7
b. TNF
IL-10 acts as an antagonist to what cytokine?
a. IL-4
b. TNF- α
c. IFN- у
d. TGF-β
c. IFN- у
Which would be the best assay to measure a specific cytokine?
a. Blast formation
b. T-cell proliferation
c. Measurement of leukocyte chemotaxis
d. ELISA testing
d. ELISA testing
The classical complement pathway is activated by
a. most viruses.
b. antigen–antibody complexes.
c. fungal cell walls.
d. All of the above
b. antigen–antibody complexes.
All of the following are characteristic of complement components except
a. normally present in serum.
b. mainly synthesized in the liver.
c. present as active enzymes.
d. heat-labile.
c. present as active enzymes.
All of the following are true of the recognition unit except
a. it consists of C1q, C1r, and C1s.
b. the subunits require calcium for binding together.
c. binding occurs at the FC region of antibody molecules.
d. Clq becomes an active esterase.
d. Clq becomes an active esterase.
Which is referred to as C3 convertase?
a. C4b2a
b. C3bBb
c. iC3Bb
d. All of the above
d. All of the above
Mannose-binding protein in the lectin pathway is most similar to which classical pathway component?
a. C3
b. C1rs
c. C1q
d. C4
c. C1q
Which of the following describes the role of properdin in the alternative pathway?
a. Stabilization of C3/C5 convertase
b. Conversion of B to Bb
c. Inhibition of C3 convertase formation
d. Binding to the initiating antigen
a. Stabilization of C3/C5 convertase
Which best characterizes the membrane attack complex?
a. Each pathway utilizes different factors to form it.
b. C5 through C9 are not added in any particular order.
c. One MAC unit is sufficient to lyse any type of cell.
d. C9 polymerizes to form the transmembrane channel.
d. C9 polymerizes to form the transmembrane channel.
All of the following represent functions of the complement system except
a. decreased clearance of antigen–antibody complexes.
b. lysis of foreign cells.
c. increase in vascular permeability.
d. migration of neutrophils to the tissues.
a. decreased clearance of antigen–antibody complexes.
Which of the following is true of the amplification loop in complement activation?
a. It is found in the alternative pathway.
b. iC3 binds factor B to generate amplification.
c. C3b is the product that is increased.
d. All of the above
d. All of the above
Factor H acts by competing with which of the following for the same binding site?
a. Factor B
b. Factor D
c. C3B
d. Factor I
a. Factor B
A lack of CR1 receptors on red blood cells would result in which of the following?
a. Decreased binding of C3b to red blood cells
b. Lack of clearance of immune complexes by the spleen
c. Increased breakdown of C3b to C3d and C3dg
d. All of the above
b. Lack of clearance of immune complexes by the spleen