Module 2 Lesson 2: Cytokines

cytokine

chemical messangers that regulate the immune system

cytokine storm

overproduction or dysregulation of cytokines; can be fatal

autocrine

cytokine affects the cell that it was secreted from

paracrine

cytokines affects a cell that is close by 

endocrine

cytokine that has a systemic effect; enters the bloodstream and affects things far away

plietropy

one cytokine having multiple functions

redundancy

many cytokines having the same functions

antagonism

one cytokine counteracts another cytokine

synergy

cytokines enhance/compliments another

cascade induction

When many cytokines induce the actions of other cytokines or produce more cytokines

rapid 

induces the innate and adaptive immunity

what are the steps of the cascade induction

1. Bacterial exposure induces TNF-α

2. TNFa induces IL-1B

3. everything else induces IL-6

innate cytokines functions

recruit effector cells to infection site

induce acute phase reactants

considered non-specific effects

what symptoms do innate cytokines induce?

fever, swelling, pain

all of the innate cytokines

TNF (mainly TNF-a)

IL-1 and IL-6

chemokines

TGF-B

INF-a and INF-B

function of adaptive cytokines

cell mediated immunity

antibody mediated immunity 

continue inflammatory processes

regulation and suppression 

all of the adaptive cytokines

IFN-gamma

IL-2

IL-4 and IL-10

IL-17

TGF-B

pro inflammatory cytokines

TNF-a

IL-1

IL-6

IFN-gamma

anti inflammatory cytokines

TGF-B

IL-10

IL-13

IL-35

producers of IL-1

monocytes, macrophages, and dendritic cells

inducers of IL-1

microbial pathogens

LPS

cytokines

functions of IL-1

pro-inflammatory

acts on the hypothalamus 

produces cell adhesion molecules (diapedisis)

stimulates production of new phagocytes 

IL-1a

internal

IL-1b

endogenous pyrogen

creates fevers 

main role is diapedisis

producers of IL-6

T and B cells

macrophages

monocytes

vascular endothelial cells

tumor cells

inducers for IL-6

IL-1 cascade

functions of IL-6

stimulates APR production

Ig synthesis

activate T and B cells

producers of IL-2

Th1 cells

functions of IL-2

acts as a T cell growth factor

promotes T and B cell differentiation 

promotes more Th1 cells

enhancers NK activity 

stimulates Ig in B cells

produers of IL-4 and IL-5

Th2 cells

functions of IL-4 and IL-5

downregulates Th1

promotes more Th2

IgG class switching

IgE promotion

allergic and parasitic reactions

producers of IL-10

Th2

functions of IL-10

downregulate Th1

inhibits antigen presentation by macros and DC

IgG class switching 

suppresses IL-12 synthesis 

IFN-gamma antagonist 

functions of IL-12

responds to intracellular bacteria/viruses

stimulates naive CD4+ cell to become Th1 by stimulating IFN-gamma

produced by APC 

functions of TNF-a

vasodilation

chemokine expression 

induce MHC class II and IL-1B

septic shock caused by decreased blood pressure and uncontrolled bleeding

functions of TGF-B

regulation of the immune response

primary cytokine for growth, proliferation, differentiation, and apoptosis

inhibits macrophages 

establish tolerance to normal flora in oral cavity

downregulates inflammation

functions of INF-a and B

protect against viruses by inhibiting viral replication activate NK cells 

increase MHC I expression 

functions of INF-gamma

enhance MHC class I and II expression

create supermacrophages 

enhance phagocytic and cytotoxic abilities

regulate Th1, CD8 cells, and NK cells

what do chemokines do for inflammation?

they promote migration of WBCs to the site of infection or injury 

produced by immune cells at the site 

what cytokines do Th1 cells produce?

INF-gamma and IL-2

what cytokines do Th2 cells produce?

IL-4 and IL-10

what cytokines do Th17 cells produce?

IL-17 which recruits the PMN

function of hematopoietic stem cells?

stimulate proliferation and differentiation of progenitor cells 

what are the colony stimulating factors (CSF)?

IL-3

EPO

granulocyte colony stimulating factor (G-CSF)

macrophage colony stimulating factor (M-CSF)

granulocyte-macrophage colony stim factor (GM-CSF)

function of IL-3

get stem cells to form T and B cells (alone)

activate different pathways for RBCs, platelets, and WBCs (syn)

function of EPO

regulate RBC production

can treat anemia and offset chemo

function of G-CSF

promotes maturation of neutrophils

function of M-CSF

promotes maturation of macrophages

promotes more phagocytosis and cytokine secretion in macrophages and monocytes

function of GM-CSF

maturation of granulocytes and macros/monos

IL-3: basos and mast cells

IL-3, IL-5: eosinophils

what is the point of cytokine and anti-cytokine therapy?

decrease chronic inflammation through stopping the interactions between cytokines and their receptors 

examples of cytokine and anti-cytokine therapy?

infliximab

etancercept

what does infliximab do

anti-INF-a

creates less immunogenic monoclonal antibodies 

what does etanercept do

TNF-a and IgG hybrid

cytokine receptor attached to C region of and Ig

what are the ways serum cytokines are used?

report exposure and responses to infectious diseases

Detect autoimmune and allergies 

immunoassays

ELISAs

determine previous exposures