Cytokines and Cytokine Receptors Flashcards
Hematopoietic, lymphoid, and inflammatory cells communicate via the production and synthesis of -?
Cytokines
Cytokines are low weight ________ or _________, which are produced by lymphocytes.
Proteins or Glycoproteins
Cytokines can be classified as __________ (cytokines produced by leukocytes, of which there are at least 37) or _________ (chemoattractants for chemotaxis).
Interleukins
Chemokines
True or False: The binding of interleukines along general receptors of cells can initiate or suppress signals.
False, must be to their specific receptors on cells
In the presence of a small concentration of cytokines, will they be able to bind to their receptors in order to initiate cell signaling?
Yes, as cytokines have a high affinity for their specific receptors
Define autocrine signaling.
The production of a cytokine by a cell, for it to only bind to its specific receptor on the same cell for stimulation
Define paracrine signaling.
The production of a cytokine by a cell, for it to bind to its specific receptor on nearby cell
Define endocrine signaling.
The production of a cytokine by a cell, for it to bind to its specific receptor on a cell in a distant part of the body
If IL-4 can lead to activation and differentiation of B cells, class switching of plasma cell immunoglobulins, and activate Mast cells to proliferate, what biological effect is this?
Pleiotropy
If both IL-10 and IL-4 are able to suppress inflammatory mechanisms to terminate those processes by binding to Macrophages and inducing the same response, what is this biological effect called?
Redundancy
If both IL-4 and IL-5 are required for B cell proliferation, what biological effect is this?
Synergism
If IFN gamma can be secreted to inhibit and block the binding of IL-4 to B cells, what is this biological effect called?
Antagonism
True or False: Viral proteins that share similar, if not exact, chemical characteristics to cytokines, can bind to those specific cytokine receptors along any cell.
True
Why are cytokines capable of binding to any cell?
They will have a high affinity for their specific receptors, which could be produced on any number of cells in the body
Of the three - Growth factors, Cytokines, Hormones - which of the following are produced based on external stimuli?
Cytokines and Hormones
Of the three - Growth factors, Cytokines, and Hormones - which of the following are able to participate in autocrine, paracrine, and endocrine signaling?
Cytokines
Of the three - Growth factors, Cytokines, and Hormones - which of the following can be produced by a variety of tissues, and are produced continuously?
Growth factors
Of - the three - Growth factors, Cytokines, and Hormones - which of the following is produced by specialized glands and are long-lived?
Hormones
What are some functions associated with cytokines?
Cellular and humoral immunity, Inflammatory induction, Hematopoietic regulation, Regulation of cells, Regulation of inflammatory responses (time and intensity), and Wound healing
IFN alpha, TGF beta, TNF alpha, IL-1, IL-6, and IL-12, are produced by -?
Macrophages
Th2 cells are responsible for the production of what cytokines?
IL-4 and IL-5
Dendritic cells produce this cytokine, which activates NK cells, and influences the adaptive immune response, to promote Th1 cells?
IL-12
IFN alpha is associated with inducing an _______ state, and promoting B cell proliferation and differentiation, after production from ____________.
Antiviral
Macrophages
What cytokines are released into circulation to induce increased liver production of acute phase proteins during the inflammatory response?
TNF alpha, IL-1, and IL-6
What cytokine, produced from macrophages and other cell types, is associated with inhibiting T cell and B cell proliferation, as well as inhibiting macrophages?
TGF beta
What interleukin acts as an eosinophil activator? What cells produce this cytokine?
IL-5 by Th2 cells
T cells produce IL-2, which has a variety of functions. What are some of those functions?
T and B cell proliferation, and NK cell activation
While both IFN alpha and IFN beta promote the expression of MHC __ receptors, IFN gamma is associated with promoting the expression of -?
IFN alpha/ IFN beta = MHC I molecules
IFN gamma = MHC I and II molecules
Which of the following cells does not secrete cytokines capable of activating NK cells? A) T cells B) Th2 cells C) Fibroblasts D) Macrophages
B) Th2 cells
What functions are associated with the cytokine produced by both Th2 cells and Mast cells?
IL-4 = Promotes Th2 differentiation and isotype switching to IgE
What cytokine is produced by endothelial cells in response to inflammatory processes? A) IL-6 B) TNF alpha C) IFN beta D) IL-1 E) Two of the above
E) Two of the above (both IL-1 and IL-6)
What protein groups are associated with cytokines?
Hematopoietins, Interferons, Chemokines, and TNF Family
How many protein families of receptors are associated with cytokines? What are they?
4
Ig Superfamily, Class I (hematopoietin), Class II (interferon), and TNF receptors
IL-1 will travel to the liver and bind to hepatocytic receptors, which are members of what protein family?
Ig Superfamily protein receptors
Expressed on the cell surface, this family of receptors will be recognized by IL-2, IL, 12, G-CSF, GH, and Prolactin, among other ligands? What subfamilies are associated with this class?
Class I (hematopoietin) protein receptors
GM-CSF receptor subfamily (common beta subunit)
IL-2 receptor subfamily (common gamma subunit)
IL-6 receptor subfamily (common gp130 subunit)
IL-10 will recognize protein receptors of what family? What other cytokines will be associated with this protein receptors family as well?
Class II (interferon) protein receptors IFN alpha, beta, and gamma,
What receptor family will be associated with TNF alpha and TNF beta?
TNF protein receptors
True or False: Composed of several subunits, cytokine receptor subunits will have separate functions for cytokine binding recognition and initiating intracellular signaling pathways.
False, as most cytokine receptors have only a few subunits, not several
Will a cytokine have a strong or weak affinity for a double signaling subunit, cytokine receptor?
Weak, and only upon binding will it have an increased affinity
True or False: A common signaling subunit is likely the cause for both redundancy and synergism.
False, it is either redundancy (binding with the second common subunit leads to the same signal produced) or antagonism (cytokine competition for the same subunit)
If IL-3, IL-5 and GM-CSF are able to affect hematopoiesis, induce proliferation of neutrophils and degranulation of basophils, then they would act in a _______ manner.
Redundant
IL-2 subfamily receptors have _ chains. What are they?
3
Alpha, beta, and gamma
How many forms of the IL-2 receptors are there? Which form will have the highest affinity for IL-2?
3
Monomeric (lowest affinity), Dimeric, and Trimeric (highest affinity)
Chemokines, which are small __________, regulate the adhesion process and chemotaxis during inflammation, as well as during _________ conditions.
Polypeptides
Homeostatic
Chemokines, which are made in peripheral _______ ______ cells, the _____ _______, or even other tissues, will be induced by the presence of TNF ______.
Peripheral Lymphoid Tissue cells
the Bone Marrow
TNF alpha
What other roles, beside regulation of leukocyte extravasation and chemotaxis, are chemokines associated with?
Wound healing, angiogenesis, and cardiac and neural tissue development
What subfamilies are there for chemokines?
C, CC, CXC, CX3C chemokine superfamilies
How are the subfamilies or branches of chemokines divided?
Based on their cysteine motif, or the pattern of cysteine residues in the ligands
C chemokines are associated with what structure?
2 cysteines bound side by side via disulphide bonds
CC chemokines are associated with what structure?
2 cysteines are bound one after another, with their own side chains
CXC chemokines are associated with what structure?
2 cysteines are separated by a single aa between them
CX3C chemokines are associated with what structure?
2 cysteines are separated by 3 aa’s between them, as well as with a mucin domain attached
Chemokine receptors are similar in structure to _ ______ __________ receptors, that are composed of _ transmembrane units and 3 intracellular subunits (alpha, beta, and gamma)
G couples protein (GPCRs)
What chemokine is produced as a result of the interaction between IL-1 and IL-6 during inflammatory processes?
IL-8
What type of chemokine receptor will bind CXC chemokines?
CXCR, or CXC receptors
What type of chemokine receptor will bind CX3C chemokines?
CX3CR, or CX3C receptors
chemokines?
CCR, or CC receptors
What pro-inflammatory chemokines are associated with binding to CCRs?
MIP-1 alpha and MIP-1 beta, to CCL3 and CCL4 respectively
What pro-inflammatory chemokine is associated with binding to CX3CRs?
IL-8, to CX3CL8
