Interleukins are a group of cytokines that were first seen to be expressed by white blood cells and act as signaling molecules between immune cells. They promote the development and differentiation of T and B lymphocytes. The majority of interleukins are synthesized by helper T cells, monocytes, macrophages, and endothelial cells. There are several common families of interleukins that play various roles, such as interleukin 1 which participates in immune responses and inflammation, interleukin 2 which induces T cell proliferation, and interleukin 6 which stimulates antibody production.

1. INTERLEUKINS
&
THEIR ROLE
VIPIN MOHAN
2011-09-112
College of Agriculture
Vellayani, TVM

2. • Interleukins are a group
of cytokines (secreted proteins and
signaling molecules) that were first
seen to be expressed by white
blood cells (leukocytes).

3. • the term was coined by Dr Vern
Paetkau, University of Victoria in
1979
• The term interleukin derives from
(inter-) "as a means of
communication", and (-leukin)
"deriving from the fact that many of
these proteins are produced by
leukocytes and act on leukocytes".

4. • The function of the immune system depends
in a large part on interleukins.
• rare deficiencies of a number of them have
been described, all featuring autoimmune
diseases or immune deficiency.
• The majority of interleukins are synthesized
by helperCD4 T lymphocytes, as well as
through monocytes, macrophages, and
endothelial cells.
• They promote the development and
differentiation of T and B
lymphocytes,and hematopoietic cells.

5. Common families of interleukins
– Interleukin 1
– Interleukin 2
– Interleukin 3
– Interleukin 4
– Interleukin 5
– Interleukin 6
– Interleukins 7 and 9
– Interleukin 8
– Interleukin 10
– Interleukin 11
– Interleukin 12
– Interleukin 13
– Interleukin 15
– Interleukin 17
– Interleukin 18
– Interleukin 23

6. • Interleukin 1 alpha and interleukin 1 beta
(IL-1 alpha and IL-1 beta) are cytokines
that participate in the regulation of immune
responses, inflammatory reactions, and
hematopoiesis
• Interleukin 1 also plays a role in
the Central Nervous System.
Interleukin 1

7. Produced by activated Macrophages,
Endothelia Cells, B-Cells, andFibroblast Cells.
L-1 also augments CorticoSteroid release,
induces fever and shivering - useful responses,
because elevated body temperature reduces
Bacterial growth.

8. Interleukin 2
• T Lymphocytes regulate the growth and
differentiation of T cells and certain B cells
through the release of secreted protein factors.
• These factors, which includeinterleukin 2 (IL2),
are secreted by lectin- or antigen-stimulated T
cells, and have various physiological effects.
• IL2 is a lymphokine that induces the
proliferation of responsive T cells.
• In addition, it acts on some B cells, via
receptor-specific binding, as a growth factor
and antibody production stimulant. .

9. Interleukin 3
• Interleukin 3 (IL3) is a cytokine that
regulates blood-cell production by
controlling the production, differentiation
and function of granulocytes and
macrophages.
• The protein, which exists in vivo as a
monomer, is produced in activated T cells
and mast cells,and is activated by the
cleavage of an N-terminal signal
sequence.

10. INTERLEUKIN 4
• Interleukin 4 (IL4) is produced by CD4 T
cells specialized in providing help to B cells
to proliferate and to undergo class switch
recombination and somatic hypermutation.
• Stimulates production of AntiBody-
producing B-Cells, leading to the
production of IgG & IgE.
• IL-4 also promotes CD8+ Cell growth
and promotes TH2 Cell differention.

11. Interleukin 5
• Interleukin 5 (IL5), also known as
eosinophil differentiation factor (EDF), is a
lineage-specific cytokine for
eosinophilpoiesis.
• It regulates eosinophil growth and
activation,and thus plays an important role
in diseases associated with increased
levels of eosinophils, including asthma.

12. Interleukin 6
• Interleukin 6 (IL6), also referred to as B-
cell stimulatory factor-2 (BSF-2) and
interferon beta-2, is a cytokine involved in
a wide variety of biological functions.
• It plays an essential role in the final
differentiation of B cells into IG-secreting
cells, nerve cell differentiation, and, in
hepatocytes.

13. • Is produced by many cell types, including T-
Cells, Macrophages, B-Cells, Fibroblasts,
and Endothelia Cells.
• IL-6 stimulates several types of Leukocytes,
and the production of Acute Phase Proteins in
the Liver.
• IL-6 is particularly important in inducing B-
Cells to differentiate into AntiBody Forming
Cells (Plasma Cells).

14. Interleukin 7
• InterLeukin-7 (IL-7)
• Is made by Bone Marrow Stroma Cells
and acts on Thymocytes.
• IL-7 is a T-Cell growth and activation
factor, and a Macrophage Activation
Factor.
• Interleukin 7 (IL-7) is a cytokine that serves
as a growth factor for early lymphoid cells of
both B- and T-cell lineages.

15. Interleukin 8
• InterLeukin-8 (IL-8)
• Is produced by most cells of the body,
especially Macrophages andEndothelia
Cells.
• IL-8 enhances Inflammation, by enabling
Immune Cells to migrate into tissue, & is
a powerful inducer of
Chemotaxis for Neutrophil Cells.

16. Interleukin 9
• InterLeukin-9 (IL-9)
• Up-regulates Th1 responses (Enhancing
Inflammation) by inhibiting T-
Cell Apoptosis.
• Interleukin 9(IL-9) is a cytokine that
supports IL-2 independent and IL-4
independent growth of helper T cells.
• Interleukin 7 and 9 seems to be evolutionary
related.

17. Interleukin 10
• Interleukin 10 (IL-10) is a protein that
inhibits the synthesis of a number of
cytokines, including IFN-gamma, IL-2, IL-
3, TNF, and GM-CSF produced by
activated macrophages and by helper T
cells.
• TNF-. IL-10 is also very important in B-
Cell activation

18. • Interleukin 11 (IL-11) is a secreted protein
that stimulates megakaryocytopoiesis,
resulting in increased production of platelets,
as well as activating osteoclasts, inhibiting
epithelial cell proliferation and apoptosis, and
inhibiting macrophage mediator production.
• These functions may be particularly important
in mediating the hematopoietic, osseous and
mucosal protective effects of interleukin 11.
• Family members seem to be restricted to
mammals.
Interleukin 11

19. Interleukin 12
• Interleukin 12 (IL-12) is a disulphide-bonded
heterodimer consisting of a 35kDa alpha subunit
and a 40kDa beta subunit.
• It is involved in the stimulation and maintenance
of Th1 cellular immune responses, including the
normal host defence against various intracellular
pathogens, such as Leishmania,
Toxoplasma, Measles virus, andHuman
immunodeficiency virus 1 (HIV).
• IL-12 also has an important role in pathological
Th1 responses, such as in inflammatory bowel
disease and multiple sclerosis.

20. Interleukin 13
• Interleukin 13 (IL-13) is a pleiotropic
cytokine that may be important in the
regulation of the inflammatory and immune
responses.
• It inhibits production of Macrophage
Inflamatory Cytokines.
• with IL-2 in regulating interferon-gamma
synthesis.

21. Interleukin 15
• Interleukin 15 (IL-15) is a cytokine that possesses
a variety of biological functions, including
stimulation and maintenance of cellular immune
responses.
• Shares several biological activities with IL-
2 and is produced by both Epithelial
Cells and Monocytes.
• IL-15 also induces T-Cellproliferation,
enhances NK Cell CytoToxicity and
stimulates B-Cells to proliferate and
secrete ImmunoGlobulins.

22. Interleukin 17
• Interleukin 17 (IL-17) is a potent
proinflammatory cytokine produced
by activated memory T cells.
• The IL-17 family is thought to
represent a distinct signalling
system that appears to have been
highly conserved across vertebrate
evolution.

23. Interleukin 18
• InterLeukin-18 (IL-18)
• Induces Interferon-gamma (IFN-)
production.

24. Interleukin 23
• InterLeukin-23 (IL-23)
• One of the essential factors
required for the expansion of
pathogenic CD4+ T-Cells, which
is characterized by the
production of IL-17, IL-6,
and Tumor Necrosis Factor