Cytokines Flashcards
1. 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
- Which of the following effects can be attributed to IL-1?
a. Mediation of the innate immune response
b. Differentiation of stem cells
c. Halted growth of virally infected cells
d. Stimulation of mast cells
A
3. Which of the following precursors are target cells for IL-3? a. Myeloid precursors b. Lymphoid precursors c. Erythroid precursors d. All of the above
D
A lack of IL-4 may result in which of the following effects?
a. Inability to fight off viral infections
b. Increased risk of tumors
c. Lack of IgM
d. Decreased eosinophil count
D
- Which of the following cytokines is also known as the T-cell growth factor?
a. IFN-γ
b. IL-12
c. IL-2
d. IL-10
C
- Which of the following represents an autocrine effect of IL-2?
a. Increased IL-2 receptor expression by the Th cell
producing it
b. Macrophages signaled to the area of antigen
stimulation
c. Proliferation of antigen-stimulated B cells
d. Increased synthesis of acute-phase proteins
throughout the body
A
- IFN-α and IFN-β differ in which way from
IFN-gamma?
a. IFN-α and IFN-β are called immune interferons,
and IFN-gamma is not.
b. IFN-α and IFN-β primarily activate macrophages,
whereas IFN-gamma halts viral activity.
c. IFN-α and IFN-β are made primarily by
activated T cells, whereas IFN-gamma is made
by fibroblasts.
d. IFN-α and IFN-β inhibit cell proliferation, whereas
IFN-gamma stimulates antigen presentation by
class II MHC molecules.
D
- 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
- IL-10 acts as an antagonist to what cytokine?
a. IL-4
b. TNF-α
c. IFN-gamma
d. TGF-β
C
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
- Selective destruction of Th cells by the human
immunodeficiency virus contributes to immune
suppression by which means?
a. Decrease in IL-1
b. Decrease in IL-2
c. Decrease in IL-8
d. Decrease in IL-10
B
Why might a colony stimulating factor be given to a cancer patient?
a. Stimulate activity of NK cells
b. Increase production of certain types of leukocytes
c. Decrease the production of TNF
d. Increase production of mast cells
B
- Which of the following would result from a
lack of TNF?
a. Decreased ability to fight gram-negative bacterial
infections
b. Increased expression of class II MHC molecules
c. Decreased survival of cancer cells
d. Increased risk of septic shock
A
14. Which cytokine acts to promote differentiation of T cells to the Th1 subclass? a. IL-4 b. IFN-α c. IL-12 d. IL-10
C
- What is the major function of T regulatory cells?
a. Suppression of the immune response by
producing TNF
b. Suppression of the immune response by
inducing IL-10
c. Proliferation of the immune response by
producing IL-2
d. Proliferation of the immune response by
inducing IL-4
B
16. Th17 cells affect the innate immune response by inducing production of which cytokines? a. IFN-γ and IL-2 b. IL-4 and IL-10 c. IL-2 and IL-4 d. TNF-α and IL-6
D
(i.e., affecting the same cell
that secreted it)
autocrine stimulation
(i.e., affecting a target cell in
close proximity) activities.
paracrine
(i.e., systemic)
endocrine
cytokines released from lymphocytes were called
lymphokines,
cytokines released from monocytes and macrophages were
called
monokines
cytokines secreted by leukocytes that
mainly act on other leukocytes were called
interleukins
means that a single
cytokine can have many different actions
Pleiotropy
When different cytokines
activate some of the same pathways and genes, it is
called
redundancy.
IL-6 and IL-11 use the gp130 subunit as part of their
receptors
EXAMPLE OF REDUNDANCY
Cytokines often act in networks; if the effects complement
and enhance each other, these are called
synergy
one cytokine may counteract
the action of another cytokine is called
antagonism
cytokine secreted by a specific type of cell can activate target cells to produce additional cytokines. For example, activated T helper (Th) cells secrete IFN-gamma, which in turn activates macrophages to secrete IL-12, which then activates The cells to produce other cytokines.
Cascade induction
In extreme circumstances, massive overproduction and
dysregulation of cytokines produce hyperstimulation of the immune
response or , _______________, a condition commonly referred
to as cytokine storm.
hypercytokinemia
The main function of the innate
the immune response is to recruit effector cells to the area.
True
Cytokines involved in triggering this response are interleukin-1 (IL-1), TNF-α, interleukin-6 (IL-6), chemokines, transforming
growth factor-β, and interferons α and (β.
TRUE
IL-1α and IL-1β are proinflammatory cytokines
produced by monocytes, macrophages, and dendritic cells
true
IL-1α and IL-1β exhibit the same activities
in many test systems and share about 25% sequence
homology
TRUE
IL-1α remains within the cells that produce
it and is rarely found outside these cells. IL-1α can be released after cell death and can help attract inflammatory cells to areas
where cells and tissues are being killed or damaged.
TRUE
IL-1 induces the production of __________ molecules as well as _____________. These chemokines and cell-adhesion
molecules attract and assist leukocytes to enter the inflamed area through a process known as ______, which is the passage
of leukocytes through the walls of the blood vessels into the tissues
vascular cell-adhesion, chemokines, and IL-6, diapedesis
induced lysis in tumor cells
Tumor Necrosis Factors
TNF-α production is the presence of lipopolysaccharide,
which is found in gram-_______ bacteria.
negative
decrease in blood pressure
reduced tissue perfusion and disseminated intravascular
coagulation AND uncontrolled bleeding
large amounts of TNF secreted in response to gramnegative
bacterial infections
TNF-α, in particular, causes the blood vessels to become more permeable, resulting in dangerously low blood pressure. As the platelet count drops, excessive bleeding occurs from every orifice in the body.
The Role of Cytokine Storm
in Ebola Virus Infection
It is the primary mediator of
TNF-α signal transduction in most cell types
TNFR1 (TNF receptor 1)
is usually
expressed in epithelial cells and cells of the immune system and
is activated by the membrane-bound form of TNF-α.
TNFR2
_______ are a family of cytokines that enhance motility
and promote migration of many types of white blood cells
(WBCs) toward the chemokine source via a process known as
chemotaxis.
Chemokines
The first group—the
alpha, or _____, chemokines—contains a single amino acid
between the first and second cysteines.
CXC
The second group—
the beta, or ______, chemokines—has adjacent cysteine residues
CC
The third group—the ______chemokines—lacks one of the cysteines.
C
______, the last major group, has three amino acids
between the cysteines
CX3C
The transforming growth factor- (TGF- ) superfamily is
composed of three isoforms: _______________
TGF-β1, TGF-β2, and TGF-β3.
it acts as a control to help downregulate the
inflammatory response when no longer needed
Transforming Growth Factor-β
interfere
with viral replication
Interferon-α and Interferon-β
There
are three main subclasses of Th cells: __________________________AND ________________
T helper 1 (Th1),
T helper 2 (Th2), and T regulatory (Treg) cells.
