Cytokines Flashcards
small soluble proteins that regulate the
immune system, orchestrating both innate immunity and the adaptive response to infection.
Cytokines
effects of cytokines in vivo
regulation of
growth, differentiation, and gene expression
induced in response to specific
stimuli—such as bacterial lipopolysaccharides,
flagellin, or other bacterial products— through the
ligation of cell adhesion molecules or through the
recognition of foreign antigens by host lymphocytes.
cytokines
important in the 1st
step during hematopoiesis
interleukin 3
single cytokine has many different actions
Pleiotropism
They have the same receptor found
on B cells during proliferation process.
IL 2, IL-4, IL-5
Massive uncontrolled overproduction and
dysregulation of cytokines (“cytokine storm”) may
lead to
- shock
- mutliorgan failure
- death
cytokines will also exert
systemic activities.
endocrine
affecting the same cell that secreted it
Autocrine
cytokines that released by a cell affecting
a target cell in close proximity
paracrine
cooperative effect of multiple cytokines
Synergy
two or more cytokines has the same receptor found on that same cell.
redundancy
acts in synergy with IL-12 to promote growth
of T cytotoxic cells (CD8+ T cell)
IL-2
acts synergy with IL-18 to stimulate INF
gamma production
IL-12
inhibition of one cytokine effects by another cytokine
Antagonist
can act as an antagonist to INF
gamma.
IL-10
this characteristic is usually needed to inhibit other cytokines to avoid overactive overproduction of
cytokines.
antagonist
Do not act alone
Act in networks
modulate the number and composition of cells
Act as growth factors for hematopoietic cells
Families of Cytokines
TNF (Tumor necrosis factor)
IFN (interferon)
Chemokines
TGF (transforming growth factor)
CSF (colony stimulating factor)
IL (interleukins)
are unrelated cytokines that must
satisfy three criteria in order to be classified
interleukins: they must have had their genes
cloned, they must be inducible in leukocytes,
and their biological activities in inflammatory
processes must be catalogued.
interleukin
responsible for many of the physical symptoms
attributed to inflammation, such as fever, swelling,
pain, and cellular infiltrates into damaged tissues
IT is the overall reaction of our body due to injury or trauma.
Cytokines in the Innate Immune Response
pro-inflammatory agent
IL-1,
IL-6,
IL-8, AND TNF-α
Cytokines involved in triggering response of recruiting effector cells to the area
IL-1
IL-6
TNF-a
TGF - b
IFN a, IFN b
Chemokines
Mediator of the innate immune response.
IL-1
Types of IL-1
IL-1 a
IL-1 b
as an endogenous pyrogen
IL-1a
responsible for most of the systemic
activity attributed to IL-1
IL1-b
considered as a
proinflammatory cytokines produce by
monocyte and macrophage.
IL-1a
IL-1b
IL-1RA
This acts as an antagonist to IL-1 alpha and
beta by blocking the IL-1 receptor and limiting
the availability of the receptor for IL-1.
IL-1 RA
Principal mediator of the acute inflammatory
response to gram negative bacteria and other
infectious microbes
TNF
Stimulates gene transcription or induces apoptosis or
programmed cell death
TNF
presence
of lipopolysaccharide, found in gram-negative
bacteria.
TNF-a
enhance motility and promote migration of many types of white blood cells toward the source of the chemokine
chemokines
exists in both membrane-bound and soluble
forms and causes vasodilation and increased
vasopermeability
TNF-a
single protein produced by both lymphoid and
nonlymphoid cell types
IL-6
primarily triggers the secretion of IL-6
IL-1
expressed by a variety of normal and
transformed cells, including T cells, B cells,
monocytes and macrophages, fibroblasts,
hepatocytes, keratinocytes, astrocytes, vascular
endothelial cells, and various tumor cells
IL-6
Pleomorphic activities of IL-6
Inflammation
Acute phase reactions
Immunoglobulins synthesis
Activation states of B cells and T cells
Proliferation and differentiation of B cells into Plasma
cells
induce chemokine production in the inflammatory
response.
TNF- α and IL-6
chemokines family
alpha, or CXC, chemokine
Beta or CC, chemokines:
C chemokines
o CX3C:
: contains a single
amino acid between the first and second
cysteines.
alpha, or CXC, chemokine
has adjacent
cysteine residues.
Beta or CC, chemokines
lacks one of the cysteines.
C chemokines
has three amino acids between the
cysteines.
CX3C
was originally characterized as a factor that
induced growth arrest in tumor cells. Later it was identified as a factor that induces antiproliferative activity in a wide variety of cell types
TGF-b
Were originally named because they literally interfere
with viral replication process in an infected cell.
interferon
Takes part in the process of immunoregulation
interferon a.b
produced primarily during initial innate response to viral infection
Type 1 IFN: or non-immune IFN
produce by mononuclear phagocytes
IFN-α:
produce by fibroblast
IFN-β
considered as immune IFN
IFN- γ
Adaptive immune response is mainly secreted by
T cells, especially T helper (Th) cells, and affect T- and B-cell function more directly.
regulate the activities of Th1 and Th2 cells
T-reg / t-regulatory cell
regulate activities of IL-2, IFN-γ
Th1 cytokines
IL-4, IL-5, IL-10
TH2 cytokines
Dendritic cells in damaged tissues produce what interleukin in response to certain stimuli such as mycobacteria, intracellular bacteria, and viruses.
IL-12
Acts in synergy with IL-2 to promote growth of Tcytotoxic T cells or CD8+ T cell
Th1 Cytokines
Activation of _____ cells induces high level of
expressions of IFN-ɣ
Th1
Produced mainly by Th1 cells
IFN-ɣ
Stimulates antigen presentation by Class II MHC
molecules that will presented to CD4+ T-cells.
IFN-ɣ
Th1 cells, CD8+ cytotoxic lymphocytes, NK cells,
bactericidal activities, IL-12R (IL-12 Receptor) and IL18R are all regulated by
IFN-ɣ
act synergistically to
stimulate IFN-ɣ production
IL-12 and IL-18
also known as the T-cell growth factor.
IL-2
It drives the growth and differentiation of both T and
B cells and induces lytic activity in NK cells
IL-2
cells are primarily responsible for antibodymediated immunit
Th2 Cytokines
Th2 Cytokines Induces the production of
o IL-4
o IL-5
o IL-10
Triggers activation, proliferation and differentiation of
B-cells
IL-4
Responsible in allergic reactions, parasitic infections
and autoimmune diseases
IL-4
Increases expression of MHC-II on resting B cells
IL-4
Inhibits the accessory functions of mononuclear
phagocytes for T-cell activation
IL-10
Acts as an antagonist to INF-gamma
IL-10
important in first stage of hematopoiesis, where
HSC’s will differentiate into lymphoid stems cells or myeloid stem cells.
multilineage
differentiation of t cell and b cell
IL-3
regulate immune activities
IL-4
produce wide variety of infection
IL-4
platelet lineage
Megakaryocyte-CSF
main function is to differentiate WBC
GM-CSF
secrete neutrophil. Enhance function of matured neutrophil - affects survival, proliferation
neutrophil lineage
G-CSF
associated with platelet production
produced within the liver
TPO
it has a normal serum EPO for about 5-28 microns per liter
EPO
used for patients that decrease hemoglobin
EPO-alpha
