cytokines - new.imunologie.upol.cz · regulatory role of chemokin-like molecules • darc (duffy...
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Cytokines
Cytokines
• small secreted proteins
• they mediate and regulate
immunity, inflammation, and
hematopoiesis.
Cytokines
• Cytokines - heterogenous group of
polypeptides → acting on distinct cell
populations → coordination and
amplification of immune responses
• many cytokines exhibit many functions
• activity of some cytokines is overlapping
(IL-4 a IL-13)
cytokines act
• autocrine (IL-2)
• paracrine (IL-4, IFN-γ, IL-10, TGF-β)
• endocrine (IL-1, IL-6, TNF-α)
pleiotropy of cytokines
• one cytokine exerts multiple actions
• one cytokine interacts with several receptors (chemokines)
• affects the activity of multiple cell types
cytokines and their receptors -
high redundancy
• shared biological actions
• many cytokines interact with single receptors
• many receptor forms can exist for a single cytokine
• promiscuity of receptors
Synergy and antagonism
Cytokines
• activation and inhibition (IFN-γ, IL-10, IL-4, TGF-β)
• stimulation of proliferation (IL-2, IL-7, GM-CSF)
• induction of differentiation (IL-3, IL-4, IL-5, IL-6, RANK-L)
• enhance resistance to viruses (IFN-I)
• antitumor effect (oncostatin, TNF-β)
• co-stimulation (B7.1, B7.2, 4-1BB, OX40, BAFF, APRIL)
• endothelial cell activation (TNF-α, TNF-β, IL-17)
Cytokines - classification
1. lymphokine (cytokines made by lymphocytes)
2. monokine (cytokines made by monocytes)
3. interleukin (cytokines made by one leukocyte
and acting on other leukocytes)
4. chemokine (cytokines with chemotactic
activities)
Receptor-based cytokine classification
• Class I cytokines
• (IL-2, IL-15, IL-4, IL-13, IL-7, IL-9, IL-21; IL-3, IL-5,
GM-CSF; IL-6, IL-11, IL-27, OSM, LIF; Epo, G-CSF;
IL-1, IL-18, IL-33; IL-12, IL-23, IL-27; IL-16)
• Class II cytokines
• Interferons (IFN-I, IFN-γ)
• IL-10 (IL-10, IL-22, IL-28)
• Imunoglobulin family (B7.1, B7.2)
• TNF family (TNF-α, TNF-β, CD40L, FasL, CD27L,
CD30L, 4-1BBL, OX40L, RANKL, APRIL, BAFF)
• IL-17 family (IL-17, IL-25)
Cells producing
cytokines
Innate immunity Macrophages
Endothelial cells
Epithelial cells
Fibroblasts
Specific immunity T, B lymfocytes
Macrophages
NK cells
Hematopoesis
SCF (Stem cell factor)
GM-CSF (Granulocyte-macrophage colony-stimulating factor)
IL-3
IL-5
IL-7
Th1 – Th2
subsets
Th1 immune response: IL-2, IL-12, IFN
gamma a TNF
Th2 immune response: IL-4, IL-5, IL-13
Sakaguchi et al Cell 2008
Tregs
Distinct function of interferons
•IFN-β
•regulation of nonspecific humoral responses and responses to
viral infections and tumor development
•induces negative immune regulating molecules IL-10, PD-L1
which suppress T cell responses
•IFN-α
•antiviral, antiparasitic, and antiproliferative activities
•IFN-γ
•inhibits growth of B-cells induced by IL-4
•growth-promoting factor for T cells
•induces secretion of TNF-α in monocytes and MФ
•in MФ stimulates release of ROS, antiviral and antiparasitic activities
•inhibits proliferation of normal and transformed cells
The molecular basis of interferon action
Inhibition of virus RNA
replication
Inhibition of expression of
virus receptors
Induction of lytic activity of
NK cells
Cytokines are sensed by receptors
Cytokines are sensed by receptors
Receptors -signaling
Viral mimics of cytokines and receptors
Chemokines
Chemokines
• a group of molecules which function in
the recruitment and activation of
leukocytes and other cells at sites of
inflammation, possess the properties of
both chemo attractants and cytokines
• other functions (tissue remodeling,
mucin production etc.)
Many functions of chemokines
Li, 2004, 1(2) Cellular & Molecular Immunology
Chemotaxis
Chemokines • chemokines small proteins (8 – 15 kDa)
• families CCL, CXCL, CX3CL, XCL and number (CCL1, CXCL1, CX3CL1,
XCL1), in the text CXC chemokines
• receptors are designated as CCR, CXCR, CX3CR, XCR and number (CCR1,
CXCR1, CX3CR1, XCR1)
• CC chemokines → 28 members
• CXC chemokines → 16 members
• CX3C chemokin → 1 member
• XC chemokines → 2 members
• receptors → 20 members
Chemokine receptors and ligands
Expression on all cells
Interaction of chemokine - receptor
Ono et al, 2003, 111 J Allergy Clin Immunol
chemokine
receptor
Signalization of chemokines
• GPCR – G-protein-coupled receptor
Endothel-fixed chemokines activate
leukocytes transmigration
Ransohoff, 2009, 31 Immunity
By acting of membrane bound chemokines integrins
are activates → enhanced affinity and avidity →
extravasation
Neutrophiles change their morphology after exposing to
chemoattractant (EM)
Baggiolini, 1998 392(9) Nature
Other chemotactic molecules • C3a, C5a complement components
• leukotrien B4
• PAF (platelet-activating factor)
• expressed by platelets, endothelial cells, neutrophils,
monocytes, and macrophages
• platelets aggregation
• inflammation
• anaphylaxis
• activates β2 integrin
• bacterial factors
Von Adrian et al, 2003, 3 Nature reviews Immunology
Regulatory role of chemokin-like molecules
• DARC (Duffy antigen receptor for chemokines), D6, CCXCKR,
CCRL2, CXCR7
• are not GPCR, do not induce changes in intracellular Ca+
• internalize extravasal chemokines to be presented on luminal part
of endothelium
• on erythrocytes surface DARC allow entrapment of surrounding
chemokines and thus regulate their activity
• effect detectable after blood transfusion → loss of DARC’s
scavenging activity on banked erythrocytes → posttransplantation
pneumonia
Ransohoff, 2009, 31 Immunity
Regulatory role of chemokine receptor-like molecules (D6)
Chemokines in therapy
• Allosteric antagonist of CCR5 (Maraviroc)
• inhibition of HIV-1 infection
• CXCR4 partial agonist (Mozobil, AMD3100)
• originally for HIV-1 infection
• approved for hematopoietic stem cell mobilization
• Antagonist of CCR9 (CCX-282, Traficet-EN)
• IBD, Crohn diseas, celiac disease therapy ???????
Adhesion
molecules
Adhesion molecules
• adhesion molecules are involved in cell-to-cell and cell-
to-matrix interactions
• immunologically competent cells use:
• during all intercellular contacts – activation,
inhibition, survival
• for targeted migration across endothelial layer
• for targeted migration to and resting in individual
immunologically important sites
• some microorganisms utilize for adhesion to target cells
(HIV utilizes α4β7 on T cells for transport to lamina
propria mucosae)
Adhesion molecules
1. addressins → glycan components O- and N-linked to
protein backbone, recognized by selectins
2. selectins → bind glycan moiety of extracellular matrix
or membrane glycoproteins (addressins)
3. integrins → bind CAM, extracellular matrix, fibrinogen
4. immunoglobulin molecules ICAM → ligands for β2, β4,
and some β1 integrins, glycan moiety of CAMs serve
as some addressins
Adhesion molecules - four classes
Leukocyte migration
Lymphocyte migration to LN
Lymphocyte migration to LN
Von Adrian et al, 2003, 3 Nature reviews Immunology
Neutrophils migration to inflammed tissues
Addressins
Lewis – terminal oligosaccharides Symbol Structure Note
Lea Galβ1-3(Fucα1-4)GlcNAc-R blood group antigen
organogenesis
Leb Fucα1-2Galβ1-3(Fucα1-4)GlcNAc-R blood group antigen
organogenesis
Sialyl-Lea NeuAcα2-3Galβ1-3(Fucα1-4)GlcNAc-R binds E-selectin
Lex Galβ1-4(Fucα1-3)GlcNAc-R blood group antigen
organogenesis
Ley Fucα1-2Galβ1-4(Fucα1-3)GlcNAc-R blood group antigen
organogenesis
Sialyl-Lex NeuAcα2-3Galβ1-4(Fucα1-3)GlcNAc-R binds L- E-selectin
Sulfo sialyl-Lex high affinity binding
to E-selektin
Selectins
Naive T cell migration to LN
Mature T cell – cell interaction
integrin old names expressed on ligand functions
α1β1 VLA-1,
CD49a/CD29 activated T cells
collagen, laminin
contact with extracellular
matrix
α2β1 VLA-2, GPIa
CD49b/CD29
B cells, platelets
monocytes, collagen, laminin
contact with extracellular
matrix
α3β1 VLA-3,
CD49c/CD29
B ly,
adherent cells
collagen, laminin,
entaktin, invazin
contact with extracellular
matrix
α4β1 VLA-4,
CD49d/CD29
B ly, thymocytes,
monocytes,
granulocytes, DC
fibronectin
MAdCAM-1,
VCAM-1
contact with extracellular
matrix,
nosal mucosa
αLβ2 LFA-1 leukocytes ICAM-1, 2, 3 leukocyte integrins
αMβ2 CR3, MAC-1
CD11b/CD18
myeloid cells
NK
ICAM-1, 2, 3
iC3b, fibrinogen
LPS, β-glucans
leukocyte integrins
αXβ2 CR4, p150
CD11c/CD18
myeloid cells
DC
ICAM-1,
fibrinogen leukocyte integrins
αIIβ3 gp IIb/IIa
CD41/CD61 platelets
fibrinogen,
fibronectin
platelets entrapment in the
site of injury
αVβ3 vintronectin
CD51/CD61
endotelie,
platelets,
fibroblasty
fibrinogen,
fibronectin
platelets entrapment in the
site of injury
α4β7 LPAM-1 T cells VCAM-1
MAdCAM-1
homing to mucosal tissue
of GIT, respiratory tract
αEβ7 HML-1 interstic. T cells E-cadherin targeting to epithelia
Integrins
Immunoglobulin superfamily CAM
Various differentiation stages are
associated with different AM
expression
APC - T cells interaction
APC - T cells interaction
Targeted anti-cytokine therapy
Mechanismus:
1) Antigonists of cytokine
receptors (IL-1 receptor
antagonist IL-1Ra)
2) Soluble cytokine receptors
3) Anti-cytokine antibodies
anti-TNF antibodies
(Infliximab-antibody,
Etanercept-circulating receptor)
•reumatoid arthritis
•Crohn disease
•sarcoidosis
•autoimune and inflammatory diseases
Reumatoid arthritis
Increased
inflammation
Increased production
of MMP
Increased cytokine
production (IL-1, IL-6)
Increased adhesion
molecules
Cell migration
into joints
Tissue
remodeling
B cell
Macrophage
T cell
Synoviocyte
Cytokines
TNFa
RF
Autoantibodies
Activates
Activates Activates Inflammation
Joint damage
B B
T
T T
T
FLS
PC
PC
FLS
MΦ MΦ
T T
APC/DC
Mechanismus of Etanercept
action
Etanercept
X
Cytokines
Cell – cell communication
Stimulus - Cytokin – Receptor - binding – effect
Promiscuity, redundancy, synergy, networks
In health and disease
Targeted biological therapy