Cytokines Flashcards
How long can cytokines stay in plasma?
Maximum 3 mins
Is cytokine toxic in high doses?
Yes
-> Cytokine storm
- -> Overproduction of IL - 6 ( Pro inflammatory )
- - -> Dies
What is the difference between lymphokines & monokines?
Lymphokines
-> secreted by lymphocytes
Monokines
-> secreted by monocytes / macrophages
Who secretes Interleukins ( IL )?
Leukocytes
-> WBC
What is the difference between autocrine, paracrine & endocrine?
Autocrine
-> Cell A releases substances that acts on itself
Paracrine
-> Cell A releases substances that acts nearby cells
Endocrine
-> Cell A releases substances that acts on distant cell
- -> through circulation
Explain the following features of cytokines
Pleiotropy
Pleiotropy
-> Single cytokine
- -> Works on different cells
Explain the following features of cytokines
Redundancy
Redundancy
-> Multiple cytokines
- -> Having very similar effects on cells
Explain the following features of cytokines
Synergy
Synergy
-> At least 2 cytokines
- -> Works better when present together
Explain the following features of cytokines
Antagonism
Antagonism
-> Cytokines
- -> Competing with other cytokines
Explain the following features of cytokines
Cascading
Cascading
-> Cytokines acting one after another
IL - 1
What is the 2 difference between IL - 1 beta & IL - 1 alpha
IL - 1 beta
-> Produced more
-> Secretory
IL - 1 alpha
-> Produced less
-> Membrane bound
IL - 1
Does IL -1 pro Th2?
Yes
IL - 1
What are the functions of IL - 1 on macrophage?
Induce IL - 6 production
IL - 1
What are the functions of IL - 1 on Th2?
Activation
Proliferation
IL - 1
What are the functions of IL - 1 on endothelial cell?
Increased cell adhesion molecule expression
IL - 1
What are the functions of IL - 1 on hepatocytes?
Synthesis of acute phase protein
IL - 1
What are the functions of IL - 1 on hypothalamus?
Induction of Fever
IL - 4
Does IL - 4 pro Th2?
Yes
IL - 4
What are the functions of IL - 4 on Th2?
Activation
Differentiation
IL - 4
What are the functions of IL - 4 on B cell?
G0 -> G1 phase
MHC - 2 up regulation
Class switch
-> IgG1
-> IgE
IL - 4
What are the functions of IL - 4 on IFN - gamma & IL - 2?
Antagonization
IL - 4
What are the functions of IL - 4 on Th17 activation?
Suppression
IL - 13
What is the function of IL - 13?
Redundancy
-> IL - 4
- -> Weaker than IL - 4 though
IL - 5
Which cells secrete IL - 5
Th2
Mast cell
Eosinophil
IL - 5
What are the functions of IL - 5 on B cell?
G1 => S phase
Class switching
-> IgA
IL - 5
What are the functions of IL - 5 on eosinophil?
Growth
Differentiation
-> Progenital cell => eosinophil
- -> Requires presence of IL - 5
IL - 6
What are the functions of IL - 6 on Th2?
Activation
Differentiation
IL - 6
What are the functions of IL - 6 on B cell?
S phase => plasma cell
IL - 2
What are the functions of IL - 2 on Th1, B cell, Macrophage, NK cells?
Activation
IL - 2 activates many things :D
IL - 2
What are the functions of IL - 2 with IL - 12?
Synergy
IL - 2 + IL + 12
-> Induce T cell => CTL ( Cytotoxic T lymphocyte )
Is T reg Th1, Th2, Th3 or Th17?
Th3
IL - 15
What are the functions of IL - 15 on memory CD8+ cell?
Survival
IL - 15
What are the functions of IL - 15 on IL -2?
Redundancy
IL - 12
What are the functions of IL - 12 on Th1?
Activation
Differentiation
IL - 12
What are the functions of IL - 12 on IL - 2?
Synergy
IL - 2 + IL - 12
-> Induce T cell => CTL
IL - 18
What are the functions of IL - 18 on IL - 12?
Redundancy
IL - 23
What are the functions of IL - 23 on IL - 12?
Sort of redundancy (?
-> Work on Th17
- -> Instead of Th1
IL - 23
What are the functions of IL - 23 on Th17?
Activation
Survive
IL - 21
What are the functions of IL - 21 on activated NK & CD8+ cells?
Enhance
-> cytotoxic activity
-> IFN - gamma production
IL - 21
What are the functions of IL - 21 on germinal centers?
Activation
-> B cell
-> follicular helper T cell
IL - 17
Which cells secrete IL - 17?
CD4+ Th17 cells
IL - 17
What is the function of IL - 17?
Neutrophil - mediated inflammation
What is the difference between IL - 12 & IL - 23?
-> Though closely related
IL - 12
-> Activation of Th1
- -> Secretion of IFN - gamma
- - -> Activation of Macrophage
IL - 23
-> Activation of Th17
- -> Secretion of IL -17
- - -> Neutrophil - mediated inflammation
What is the function of IL - 23 & IL - 21 on ROR gamma T ( Th17 phenotype )?
IL - 23
-> Stabilize ROR gamma t
IL - 21
-> Activation of ROR gamma t
What is the function of IL - 3?
Myeloid progenitor ( Hematopoietic cells )
-> Growth
-> Differentiation
What is the relationship between SCF & C-kit?
SCF ( Stem cell factor )
-> C - kit ligand
C - kit
-> SCF receptor
What is the function of IL - 7?
Lymphoid progenitor
-> Differentiation
What is the function of IL - 11?
Magakaryocyte
-> Differentiate of platelets
What is the function of IL - 8?
Chemotaxis
-> Neutrophil
Which Ths secrete IL - 10?
What is the function?
Th2
-> inhibits Th1
Th3
-> inhibits Th1 & Th2
What causes Crohn’s disease ( Inflammatory bowel disease )?
How to treat it?
Lack of IL - 10
-> Th 1 increases
- -> Constant inflammatory
Treatment
-> Ingestion of parasites egg
- -> IL - 5 increases => Eosinophil activation
- - -> Th2 increase = Th1 decrease
What is the function of IL -16?
Chemotaxis
-> Th
-> Monocyte
-> Eosinophil
Which IFN ( Interferons ) are in Type 1 & Type 2?
Type 1 Interferons
-> IFN - alpha
-> IFN - beta
Type 2 Interferons
-> IFN - gamma
Does IFN - gamma promotes Th1 / Th2?
Th1
Is TGF - beta ( Transforming growth factor - beta ) an activators / inhibitory cytokines?
Inhibitory
Which cell secretes TGF - beta?
Th3
Does TNF - alpha ( Tumor necrosis factor - alpha ) increase or decrease blood pressure?
Decrease blood pressure
Is TNF - beta similar or opposite of TNF - alpha?
Similar
-> Even shares the same receptor
What does TNF - alpha cause other than reduced blood pressure?
Inflammation
Toxic effects
-> Cachexia
- -> Muscle atrophy
- -> Significant loss of body weight
What are the 5 receptor family?
Ig superfamily receptor
Class 1 cytokine receptor
Class 2 cytokine ( IFN ) receptor
TNF receptor
Chemokine receptors
What is the 5 steps of signal transduction of cytokines?
Cytokines => receptors
-> Activation of JAK ( Janus kinase )
- -> Phosphorylation of STAT
- - -> Dimerization of STAT
- - - -> Activation of DNA by STAT
What are 3 cytokine regulations?
Changes in receptor expression
Specific binding proteins
-> IL - 1RA ( IL - 1 receptor antagonist )
-> Soluble TNF - alpha R
- -> Floating receptor lol
Cytokines exerting opposite effects
-> Th1 up = Th2 down
What is the costimulation for Th1 & Th2 factor?
Th1
-> CD80
Th2
-> CD86
Which ILs are mainly responsible for differentiation for Th1 & Th2?
Th1
-> IL - 12
Th2
-> IL - 1
-> IL - 4
-> IL - 6
Does Th1 / Th2 promote cellular - mediated immunity / humoral immunity?
Does Th1 / Th2 generate immunity to intracellular / extracellular organisms?
Th1
-> Intracellular
Th2
-> Extracellular