Lecturer: Ge Jin, Ph.D., [email protected], 3683791 Learning Objectives: 1. describe basic properties...

Lecturer: Ge Jin, Ph.D., [email protected], 3683791

Learning Objectives:

1. describe basic properties of cytokines

2. describe how cytokines regulate immunity (e.g. increase or decrease MHC expression and T cell activation…)

3. cytokine and oral diseases

NOTE: you need to download the PowerPoint file to your computer to read notes.

Slides containing research results from my lab will be added during the lecture.

Cytokines

properties, categories, signaling, function

Body as Host: Immune Molecules

Cytokines

small, secreted, non-antibody proteins

produced by cells involved in both innate & adaptive immunity

mediate and regulate immunity, inflammation, and hematopoiesis

Cytokines Lymphokine: made by activated lymphocytes, especially TH cells, e.g. IL-2

Monokine: made by mononuclear phagocytes, e.g. Mig/CXCL9

Chemokine: chemotactic activity, e.g. IL-8, CXCL12

Interleukin: interaction between leukocytes IL-1, IL-8, IL-10, IL-13……

named by activity: Tumor Necrosis Factor (TNF), Colony Stimulation Factor (CSF), Transforming Growth Factor (TGF)….

Cytokines

grouped by structures into families

interferons (IFN): type I (IFN and IFN), type II (IFN)

Interleukin: IL-1, IL-2

chemokine: CXCL and CCL chemokines

TNF: TNF, FasL, CD40L…

hematopoietin: erythropoietin (EPO), colony- stimulation factors (CSF)

Properties of Cytokines

produced in response to immune stimuli -- not store pre-formed -- synthesis: DNA mRNA protein secretion -- slow cellular response

can act on the cells that produce them (autocrine action)

can act on nearby cells (paracrine action)

can act on distance cells (endocrine action)


can be produced by many cell types and act on many cell types (pleiotropic)

different cytokines can have similar actions (redundant)

-- share receptors

-- defect in a unique cytokine have little effect

-- defect in a share component (common receptor) can have profound effects

e.g. IL-2R defect X- linked SCID

(Severe Combined Immunodeficiency)


can modulate synthesis of other cytokines - cascades: e.g. TNF IL-1 IL-6, IL-8…

- enhance or suppress production of other cytokines: positive or negative

influence the action of other cytokines - antagonistic - additive - synergistic

short half life, low plasma concentration, bind to receptor with high affinity

Immunoglobulin superfamily: IL1R, TLRs…

Cytokine Receptors(grouped by structures into families)

Toll-IL-1 Receptordomain (TIR)

Toll-likereceptors (TLRs)

leucine-richrepeatsimmunoglobulin

domain

IL-1 receptor

cell membrane

TNFR family: TNF, FasL, CD40L…

Cytokine Receptors

Cytokine ReceptorsG

M-C

SF

R

IL-3

R

IL-5

R

GM-CSF

IL-2

IL-3 IL-5

IL-15 IL-7 IL-9

IL-2

R

IL-2

IL-1

5R

IL-2

IL-7

R

IL-9

R

class I receptor family: hematopoietin family

gp130gp130 gp130 gp130

CN

TF

R

cell membrane cell membrane

GM-CSF: Granulocyte macrophage colony-stimulating factorIL: interleukingp130: glycoprotein 130 (m.w. 130 kDa)

IL-6 IL-11

CNTF LIF/OSM

class II receptor family: Interferon , , and

Cytokine Receptors

IFNARI

IFNAR2c

IFNAR2b

IFNR

IFNR

type I IFN receptor type II IFN receptor

cell membrane

type I IFN: IFN and IFN, type II: IFN

chemokine receptor family: CCR1-5, CXCR1-4

NH3

COOH

binding of a ligandto the receptor

Cytokine Receptors

cell membrane

Cytokine Receptors

TGF receptors

TGF receptors have intrinsic kinase activity when interacting with ligands.

Cytokine Signalingcytokines

membrane receptors

phosphorylation cascades

transcription, Ca++…

signal transduction

binding

activation

Cytokine Signaling

NFB signaling pathways

JAK/STAT signaling pathways

Chemokine signaling pathways

Cross-talk between pathways

NFB Signaling

NFB signaling inducers: cytokines: IL-1, TNF,… microbial cell components: Fn cell wall, lipopolysacchrides (LPS),… virus: retroviruses, double-stranded RNA (dsRNA),…

Receptors: IL-1 receptors Toll-like receptors (TLRs, innate immunity) TNF receptors

Nuclear Factor B (NFB): dimeric transcription factors: p65/RelA, c-Rel, RelB, p105/p50, p100/p52 sequestered by inhibitory IB proteins and retained in cytosol in resting cells

NFB

IRAK

TRAF6pp

IRAK

4

pellino1

IB

IBp

p

TF

IRAK pp

p

p

u

u

degradation

u

TAK1

TAK1

activ

atio

n

uu u

u

pp IBIB

ubiquitination&degradation

uu TRAF6

pTAK1

TAB1

TAB3

TAB2Ubc13/Uev1A

complex III

IRAK

TRAF6pp

IRA

K4

pe

llin

o1

TAK1

TAB1

TAB3TAB2

p

complex II

NEMO

IKKIKK

pIK

Kac

tivat

ion

p

u ubiquitination

phosphorylation

IL-1 receptor

IRAK

Tollip MyD88

IRAK4

TRAF6pp

complex I

IL-1

nucleus

cell

mem

bran

e

IL-6IL-8hBD-2….

innate&adaptiveimmunity

p

NFB

activ

atio

n

NFB p

nucl

ear

trans

loca

tion

pTF NFB p

NFB Signaling

Alternative NFB activation pathways of immunity

CD40L, LT-B, BAFF

NIK

IB degradation

NFB activation

CD4/TCR

PKC

UV-light

p38-CKII

JAK/STAT Signaling Pathway

JAK (Janus Kinases): a family of tyrosine kinases, JAK1-3, Tyk2

STAT (Signal Transducers and Activators of Transcription): transcription factors, STAT1-6,…

Cytokines: IFN/, IFN-, Epo, GM-CSF, IL-6, IL-13…

in resting cells, non-phosphorylated, monomeric STATs reside in cytosol

SJ Baker et al, Oncogene (2007) 26, 6724–6737.

IFN/IFN

receptorbind

ing

phos

pho-

ReceptorJAKs

ReceptorJAKsSTATs

DNA STATdimers

target genetranscription

phos

pho-

trans

loca

tion

nucleusbi

ndin

gcdc25a, cyclin D1~3,c-myc, cyclin E, MMP9p21, caspase 3, 1, 8…

Chemokine Signaling

2 major families: the CCL family and CXCL family

CCL1~27, CXCL1~14

receptors: G-protein coupled 7 transmembrane

Gi

SDF

PI-3K MAPK PLC

target genes

Adhesion, polarization, chemotaxis

CCL12 (SDF) signaling

p

p GRK-arrestin

recyclingdegradation

SDF

Cross-talk between CytokineSignaling Pathways

chemokinereceptor

interferonreceptor

IL, TLR, TNFreceptors

STATs NFB

PI-3K

TAK1

TGFreceptor

Cytokines and Immunoregulation

Mediators of Innate Immunity

Mediators of adaptive immunity

Stimulators of hematpoiesis

Cytokines and Immunoregulation


TNF IL-1 IL-10 IL-12 IFN, IFN IFN Chemokines


Stimulators of hematpoiesis

Tumor Necrosis Factor (TNF) Produced by activated macrophages and T cells Most important mediator of acute inflammation in response to microbes, such as LPS Induces production of myeloid CSFs, IFN-, IL-6, IL-8 and other chemokines Mediate recruitment of neutrophils and microphages to site of inflammation by stimulating cells to produce adhesion molecules (e.g. ICAM-1) Stimulates endothelial cells and macrophages to produce chemokines A potent pyrogen causing fever by direct action or via IL-1 Promotes production of acute phase proteins, such as CRP Roles in rheumatoid arthritis, psoriasis, tuberculosis, …

prothrombotic

macrophageactivation

hematopoiesis

lymphocytedevelopment

Interleukin 1 (IL-1)

Produced by activated macrophages, stimulated lymphocytes, keratinocytes, fibroblasts Activates the NFB signaling pathway (similar effects to TNF) Helps activate T cells Can be induced by inflammation, injury, and infection


Produced by macrophages, B cells, Th2 cells

Originally identified as cytokine synthesis inhibitory factor

Suppresses inflammatory responses

Inhibits production of IFN-, IL-2, IL-3, TNF, GM-CSF

Stimulate thymocytes, mast cells, B cells

Limits Th1 response, promotes Th2 cell development, shifts response to Th2 type (phagocytosisAb production)

Inhibits expression of class II MHC and co-stimulatory molecules on macrophages


Produced by macrophages, dendritic cells, Tc cells, NK cells Belongs to the IL-6 cytokine family Has immunoregulatory effect on NK cells and T cells Stimulates production of IFN- Promotes Th cells Th1 Enhances differentiation of Cytotoxic T Lymphocytes (with IL-2) Enhances cytolytic functions of T cells and NK cells

Type I Interferon (IFN-, IFN-)

Produced by macrophages and virus-infected cells

Inhibits viral replication in cells via PKR and RNaseL

Increases expression of MHC I and Tc mobilization

Stimulates production of IFN- by activated T cells

Activate NK cells

Type II Interferon (IFN-)

Produced primarily by Th1

Induce ICAM production in endothelial cells

Activate NK cells

Increase MHC I and MHC II expression to help Th cell and

APC interaction

Promotes B cell differentiation to plasma cell

Promotes cytotoxic T cell differentiation

Chemokines

Produced by many leukocytes and other types of cells

Large family of molecules (over 50)

Have significant structural homology and overlapping functions

Chemotactic for leukocytes, such as PMN, T and B cells

Recruit leukocytes to sites of infection and inflammation

Involved in lymphocytes trafficking, wound healing, metastasis, angiogenesis, lymphoid organ development….

Cytokine in ImmunregulationMediators of Innate Immunity

Mediators of adaptive immunity IL-2 IL-4 IL-5 TGF IL-10 IL-12 IFN-Stimulators of hemotopoesis

Interleukin 2 (IL-2) Produced by lectin- or antigen-activated Th cells Powerfully immunoregulatory lymphokine Main growth factor for both T and B lymphocytes Activates NK cells and monocytes

CTLA-4: Cytotoxic T-Lymphocyte Antigen 4, inhibits T cell function.


Produced by macrophages, Th2 cells, activated B cells Has complex biological actions via cytokine production Enhances antigen-presenting activity of B to T cells Stimulates development of Th2 cells from naïve Th cell Stimulates Ig class switch from IgG1 to IgE (allergy)


Produced by Th2 cells Originally identified as a B cell differentiation factor Aids in the growth and differentiation of eosinophils and

late-developing B cells to plasma cells

Transforming growth factor (TGF)

Produced by T cells, macrophages, other cell types

30 members

Have effect on many cell types

Have pro- and anti-inflammatory effect

Inhibits proliferation of T cells and activation of B cells

Acts on PMNs and endothelial cells to block the effects of pro-inflammatory cytokines

Cytokine and Immunoregulation



Stimulators of hematopoiesis (Colony Stimulating Factors)

GM-CSF: promotes differentiation of bone marrow progenitors

M-CSF: promotes growth and differentiation of monocytes and macrophages

G-CSF: promotes production of PMNs

emdbiosciences.com

Regulation of Immune Responsesregulatory mechanisms: recognition phase

Regulation of Immune Responsesregulatory mechanisms: antibody

antibody competes with B cellsfor antigen

antigen/antibody complexesbinding to Fc receptors sendsan inhibitory signal to B cells

Regulation of Immune Responsesregulatory mechanisms: Tregs

Regulatory T cells (Tregs) do not inhibit initial T cell activation and proliferation They are not Th1 or Th2 cells They can suppress both Th1 and Th2 responses They inhibit a sustained response and prevent chronic and potentially damaging responses


Naturally occurring Tregs

CD4+CD25+Foxp3+ cells derived from thymus

IL-2, cell contact dependent inhibition

Foxp3 is required for Treg development

Foxp3

CD25 (part of IL-2R)CD4


Induced Tregs

CD4+CD25+Foxp3+ cells induced by antigen

CD25 (part of IL-2R)CD4 CD4

T cells

antige+IL-10

TGFFoxp3

Treg cells

Cytokines and Oral Diseasesbacterial colonization

periodontal disease (PD)

bacterial invasion

osteoclast formation/bone loss

host responses

chemokines: bone resorption, osteoclast survival

IL-1: up-regulated, stimulates bone loss

IL-6: proinflammatory to bone resorption

TNF: induces cytokine production, stimulate inflammation and bone loss

RNAKL: inducer of osteoclast formation and activity, bone loss

Colony stimulating factors (CSFs) hematological disorders associated with cancer therapy

Erythropoietin (EPO) anemia associated with kidney disease

IFN- multiple sclerosis

IFN- chronic granulomatous disease (GCD)

IL-2 kidney cancer, melanoma

IL-11 thrombocytopenia following high dose chemotherapy

TNF mAb Infliximab for rheumatoid arthritis and Crohn’s disease

Cytokines and Clinical Applications

Cytokinesproperties, categories, signaling, function

What are cytokine?Interleukines, chemokines, monokines, …cytokine receptorsNFkB, JAK/STATA, chemokine signaling pathwaysrole of cytokines in immunomodulationcytokines and oral diseases (PD)

Lecturer: Ge Jin, Ph.D., [email protected], 3683791 Learning Objectives: 1. describe basic properties...

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Transcript of Lecturer: Ge Jin, Ph.D., [email protected], 3683791 Learning Objectives: 1. describe basic properties...