Lecture 18 Flashcards
Are cytokines
soluble/insoluble
intraceullular/intercellular signalling molecules
Act enzymatically/non-enzymatically
act through non specific/specific receptors
found in u and mmol concentrations/pico and nanomol concentrations
pleotropic/highly specific
soluble
interceullular signalling molecules
act non-enzymatically
through specific receptors
are found in pico/nanomol concentrations
pleotropic
What are three pro-inflammatory cytokines?
TNFalpha
IL-6
IL-1beta
What are two antiinflammatory cytokines?
IL-10
TGFbeta
How is a fever induced when theres an infection?
Cytokines are exogenous pyrogen and increase the thermoregulatory set-point in the hypothalamus.
What is the effect of pro-inflam cytokines on other pro-inflam cytokines?
They up-regulate the synthesis of other pro-inflam cytokines in a positive feedback loop. If there was no regulation it would always be increasing.
Do cytokines stimulate or inhibit the production of acute phase proteins? Why?
Stimulate. Acute phase proteins are produced in the liver and change the blood vessel vascularity which makes it easier for immune cells to move in and out of blood
What impact to cytokines have on inflammatory cells?
Cytokines attract inflammatory cells in a positive feedback loop.
What are cytokine storms? What are two reasons for them?
Cytokine storms are unregulated pro-inflammatory cytokine production.
caused by 1. a massive stimulation signal
- the inability to turn off the immune response
What do cytokine storms do to the body?
Causes local edema due to vasodilation, a massive efflux of fluids out of the blood and into the tissues. This causes severe swelling and a large decrease in blood pressure. Causes septic shock (extrememly low blood pressure) which kills 30% of patients.
When do anti-inflammatory cytokines act?
After the pathogen has cleared
What is the function of IL-10?
IL-12 inhibits cytokine release by macrophages and stops the production of TNF.
What is the immediate effect of cytokines on the liver and what is the outcome?
Immediate- production of acute phase proteins
Outcome- complement activation
What is the immediate effect of cytokines on the bone marrow and what is the outcome?
immediate- mobilisation of neutrophils
outcomes- phagocytosis
What is the immediate effect of cytokines on the brain and what is the outcome?
Immediate- increase in body temperature
Outcome- Decreased viral and bacterial replication
- increased antigen processing
- increased specific immune response
What is the immediate effect of cytokines on the muscles and what is the outcome?
Immediate- protein and energy mobilisation
- increased body temperature
Outcome-
- Decreased viral and bacterial replication
- increased antigen processing
- increased specific immune response
When immune cells migrate to the lymph node, what does the lymph node do to help fight infection?
Starts an adaptive immune response
What is the effect of chemokines at the site of infection?
Attract cells to the wound site and stimulate and sustain the inflammatory response
Why are chemokines produced by cells?
They’re produced in response to infection or damage
What is one similarity between chemokines and cytokines and what are three differences?
Similarity- bind to specific surface receptors
Differences- 1. chemokines are less pleotropic (more specific)
- usually dont induce other chemokines
- more specialised functions in inflammation and repair
Chemokine CXCL8
produced by what cells
receptors
cells attracted
major effects
produced by macrophages, monocytes, fibroblasts, keratinocytes, endothelial cells
receptors are CXR1 and CXR2
Cells attracted are neutrophils and naive T cells
Major effects: mobilises, activates, and degranulates neutrophils. Angiogenesis (formation of new blood vessels)
What is the overall function of CXCL8?
Inflammation response initiation and repair
What is the overall funciton of CCL2?
Sustain the inflammation response
Chemokine CCL2
produced by what cells
receptors
cells attracted
major effects
produced by macrophages, keratinocytes, fibroblasts, monocytes
receptor is CCR2
cells attracted are monocytes, natural killer cells, T cells, basophils and dendritic cells
Major effects- activates macrophages and causes histamine release
