This document provides an overview of cytokines presented in a lecture by Dr. Ge Jin. It defines cytokines as small secreted proteins that mediate and regulate immunity and inflammation. It describes the basic properties, categories and functions of cytokines including their role in innate and adaptive immunity. It also discusses cytokine signaling pathways and the role of cytokines in immunoregulation and oral diseases like periodontal disease.

1. Lecturer: Ge Jin, Ph.D., ge.jin@case.edu, 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.

2. Cytokines
properties, categories, signaling, function
Body as Host: Immune Molecules

3. Cytokines
 small, secreted, non-antibody proteins
 produced by cells involved in both innate & adaptive
immunity
 mediate and regulate immunity, inflammation, and
hematopoiesis

4. 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 a (TNFa),
Colony Stimulation Factor (CSF), Transforming Growth Factor b
(TGFb)….

5. Cytokines
 grouped by structures into families
 interferons (IFN): type I (IFNa and IFNb), type
II (IFNg)
 Interleukin: IL-1, IL-2
 chemokine: CXCL and CCL chemokines
 TNFa: TNFa, FasL, CD40L…
 hematopoietin: erythropoietin (EPO), colony-
stimulation factors (CSF)

6. 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)

7. Properties of Cytokines
 can be produced by many cell types and
act on many cell types (pleiotropic)
 different cytokines can have similar actions
(redundant)

8. -- share receptors
-- defect in a unique
cytokine have little
effect
-- defect in a share
component (common
receptor) can have
profound effects
e.g. IL-2Rg defect X-
linked SCID (Severe Combined Immunodeficiency)

9. Properties of Cytokines
 can modulate synthesis of other cytokines
- cascades: e.g. TNFa 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

10. Immunoglobulin superfamily: IL1R, TLRs…
Cytokine Receptors
(grouped by structures into families)
Toll-IL-1 Receptor
domain (TIR)
Toll-like
receptors (TLRs)
leucine-rich
repeats
immunoglobulin
domain
IL-1 receptor
cell membrane

11. TNFR family: TNFa, FasL, CD40L…
Cytokine Receptors

12. Cytokine Receptors
GM-CSFRa
IL-3R
IL-5R
b b
b
GM-CSF
IL-2
IL-3 IL-5
IL-15 IL-7 IL-9
g
g
g
g
IL-2Ra
IL-2b
IL-15Ra
IL-2b
IL-7R
IL-9R
class I receptor family: hematopoietin family
gp130
gp130 gp130 gp130
CNTFR
cell membrane cell membrane
GM-CSF: Granulocyte macrophage colony-stimulating factor
IL: interleukin
gp130: glycoprotein 130 (m.w. 130 kDa)
IL-6 IL-11
CNTF LIF/OSM

13. class II receptor family: Interferon a, b, and g
Cytokine Receptors
IFNARI
IFNAR2c
IFNAR2b
IFNgRa
IFNgRb
type I IFN receptor type II IFN receptor
cell membrane
type I IFN: IFNa and IFNb, type II: IFNg

14. chemokine receptor family: CCR1-5, CXCR1-4
NH3
binding of a ligand
to the receptor
Cytokine Receptors
cell membrane

15. Cytokine Receptors
TGFb receptors
TGFb receptors have intrinsic kinase activity when interacting with ligands.

16. Cytokine Signaling
cytokines
membrane receptors
phosphorylation cascades
transcription, Ca++…
signal transduction
binding
activation

17. Cytokine Signaling
 NFkB signaling pathways
 JAK/STAT signaling pathways
 Chemokine signaling pathways
 Cross-talk between pathways

18. NFkB Signaling
NFkB signaling inducers:
 cytokines: IL-1, TNFa,…
 microbial cell components: Fn cell wall, lipopolysacchrides (LPS),…
 virus: retroviruses, double-stranded RNA (dsRNA),…
Receptors:
 IL-1 receptors
 Toll-like receptors (TLRs, innate immunity)
 TNFa receptors
Nuclear Factor k B (NFkB):
 dimeric transcription factors: p65/RelA, c-Rel, RelB, p105/p50,
p100/p52
 sequestered by inhibitory IkB proteins and retained in
cytosol in resting cells

19. NFkB
IRAK
TRAF6
p
p
pellino1
IkB
IkB
p
p
TF
IRAK p
p
p
p
u
u
degradation
u
TAK1
u
u u
u
p
p
IkB
IkB
ubiquitination&
degradation
u
u TRAF6
p
TAK1
TAB1
TAB3
TAB2
Ubc13/Uev1A
complex III
IRAK
TRAF6
p
p
IRAK4
pellino1
TAK1
TAB1
TAB3
TAB2
p
complex II
IKKa
IKKb
p
p
u ubiquitination
phosphorylation
IL-1 receptor
IRAK
Tollip MyD88
IRAK4
TRAF6
p
p
complex I
IL-1
nucleus
IL-6
IL-8
hBD-2
….
innate
&
adaptive
immunity
p
NFkB p
p
TF NFkB p

20. NFkB Signaling
Alternative NFkB activation pathways of immunity
CD40L, LT-B, BAFF
NIK
IkB degradation
NFkB activation
CD4/TCR
PKC
UV-light
p38-CKII

21. 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: IFNa/b, IFN-g, Epo, GM-CSF, IL-6, IL-13…
 in resting cells, non-phosphorylated, monomeric STATs
reside in cytosol

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

23. IFNa/b
IFNg
receptor
Receptor
JAKs
Receptor
JAKs
STATs
DNA
STAT
dimers
target gene
transcription nucleus
cdc25a, cyclin D1~3,
c-myc, cyclin E, MMP9
p21, caspase 3, 1, 8…

24. Chemokine Signaling
 2 major families: the CCL family and CXCL family
 CCL1~27, CXCL1~14
 receptors: G-protein coupled 7 transmembrane

25. a
b
g
Gai b
a
g
PI-3K MAPK PLC
target genes
Adhesion, polarization, chemotaxis
CCL12 (SDF) signaling
p
p GRK
b-arrestin
recycling
degradation

26. Cross-talk between Cytokine
Signaling Pathways
chemokine
receptor
interferon
receptor
IL, TLR, TNFa
receptors
STATs NFkB
PI-3K
TAK1
TGFb
receptor

27. Cytokines and Immunoregulation
Mediators of Innate Immunity
Mediators of adaptive immunity
Stimulators of hematpoiesis

28. Cytokines and Immunoregulation
Mediators of Innate Immunity
 TNFa
 IL-1
 IL-10
 IL-12
 IFNa, IFNb
 IFNg
 Chemokines
Mediators of adaptive immunity
Stimulators of hematpoiesis

29. Tumor Necrosis Factor a (TNFa)
 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-g, 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, …

30. prothrombotic
macrophage
activation
hematopoiesis
lymphocyte
development

31. Interleukin 1 (IL-1)
 Produced by activated macrophages, stimulated lymphocytes,
keratinocytes, fibroblasts
 Activates the NFkB signaling pathway (similar effects to TNF)
 Helps activate T cells
 Can be induced by inflammation, injury, and infection

32. Interleukin 10 (IL-10)
 Produced by macrophages, B cells, Th2 cells
 Originally identified as cytokine synthesis inhibitory factor
 Suppresses inflammatory responses
 Inhibits production of IFN-g, IL-2, IL-3, TNFa, GM-CSF
 Stimulate thymocytes, mast cells, B cells
 Limits Th1 response, promotes Th2 cell development,
shifts response to Th2 type (phagocytosisAb production)
 Inhibits expression of class II MHC and co-stimulatory
molecules on macrophages

33. Interleukin 12 (IL-12)
 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-g
 Promotes Th cells  Th1
 Enhances differentiation of Cytotoxic T Lymphocytes (with IL-2)
 Enhances cytolytic functions of T cells and NK cells

34. Type I Interferon (IFN-a, IFN-b)
 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-g by activated T cells
 Activate NK cells

35. Type II Interferon (IFN-g)
 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

36. 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….

37. Cytokine in Immunregulation
Mediators of Innate Immunity
Mediators of adaptive immunity
 IL-2
 IL-4
 IL-5
 TGFb
 IL-10
 IL-12
 IFN-g
Stimulators of hemotopoesis

38. 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.

39. Interleukin 4 (IL-4)
 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)

40. Interleukin 5 (IL-5)
 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

41. Transforming growth factor b (TGFb)
 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

42. Cytokine and Immunoregulation
Mediators of Innate Immunity
Mediators of adaptive immunity
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

43. emdbiosciences.com

44. Regulation of Immune Responses
regulatory mechanisms: recognition phase

45. Regulation of Immune Responses
regulatory mechanisms: antibody
antibody competes with B cells
for antigen
antigen/antibody complexes
binding to Fc receptors sends
an inhibitory signal to B cells

46. Regulation of Immune Responses
regulatory 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

47. Regulation of Immune Responses
regulatory mechanisms: Tregs
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

48. Regulation of Immune Responses
regulatory mechanisms: Tregs
Induced Tregs
CD4+CD25+Foxp3+ cells induced by antigen
CD25 (part of IL-2R)
CD4 CD4
T cells
antige+IL-10
TGFb
Foxp3
Treg cells

49. Cytokines and Oral Diseases
bacterial 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
TNFa: induces cytokine production, stimulate inflammation and bone loss
RNAKL: inducer of osteoclast formation and activity, bone loss

50. Colony stimulating factors (CSFs)
hematological disorders associated with cancer therapy
Erythropoietin (EPO)
anemia associated with kidney disease
IFN-b
multiple sclerosis
IFN-g
chronic granulomatous disease (GCD)
IL-2
kidney cancer, melanoma
IL-11
thrombocytopenia following high dose chemotherapy
TNFa mAb
Infliximab for rheumatoid arthritis and Crohn’s disease
Cytokines and Clinical Applications

51. Cytokines
properties, categories, signaling, function
What are cytokine?
Interleukines, chemokines, monokines, …
cytokine receptors
NFkB, JAK/STATA, chemokine signaling pathways
role of cytokines in immunomodulation
cytokines and oral diseases (PD)