Cytokines Flashcards
What is the role of TNFa?
To promote apoptosis.
How does TNF cause a response?
It binds as a TNF trimer to three TNFRs, bringing them together. This enables activation and signalling via a Death domain, TRADD and FADD, stimulating apoptosis via caspase and JNK. It can also signs, via TRAF, which activates NFkB, leading to cell survival.
What are three local effects of TNFa?
Platelet influx, Microthrombus, and effluent of fluid from capillaries.
What is etanercept?
A decoy TNFa receptor for anti-TNF therapy.
What is the role of Th1?
Stimulated by virus/bacteria and produces IFNa/B or IL-12/18 and IFNy respectively. It activates macrophages and IgG antibodies.
What is Th17?
Stimulated by bacteria/fungi on epithelial surfaces and produces IL-17/23. It causes neutrophil recruitment and also implicated in autoimmune diseases.
What is Th2?
Stimulated by multicellular parasites, allergens, and pollutants (DEP) and produces IL-4/10/13. It causes induction of IgE and eosinophils.
How is the production of type I INFs stimulated?
Intracellular TLRs 3, 7, 8 and 9 on endosomes are activated by dsRNA. Viral RNA activates RIG-1, activating IPS-1, activating NFkB and IRF.
How if IFNy stimulated and what is its role?
It is stimulated by IL-12 in order to create a delayed response to a viral infection. In the Th1 response, it activates macrophages.
Outline INF signalling in the JAK/STAT pathway.
INFa/B binds heterodymeric Type I receptors. JAK1 and TYK2 kinases phosphorylate the receptors, allowing STAT binding and activation.
Name four inflammatory mediators?
Small molecules (ROI/RNI), coagulation factors, complement (C3a C5a), and purines.
