innate immunity Flashcards
What is the fundamental feature of innate immunity?
recognition of antigen by non-specific pattern recognition receptors
What are the functions of innate immunity?
- prevents infection
- responds rapidly
- promotes acute inflammation
What are PAMPS?
- Pathogen-Associated Molecular Patterns
What are PRRs?
Pattern Recognition Receptors
What are the functions of phagocytosis?
- killing
- activation of inflammation
- antigen presentation
What is the process by which natural killer cells kill pathogens?
- antibody-dependent cellular cytotoxicity (ADCC)
- NK cell recognises anitbody-coated bacteria by Fc receptor, target killed by non phagocytic means
What are eosinophils for?
- defence against parasites
- granules contain toxic enzymes
- can perform ADCC
- found in sites of allergic inflammation
What are the two types of soluble mediatprs that phagocytosis releases?
- cytokines
- chemokines
What are the 3 types of cytokines?
- tumour necrosis factor alpha (TNF-alpha)
- interleukin-1 (IL-1)
- interleukin-6 (IL-6)
What type of chemokine is released?
CXCL8
How do cytokines and chemokines promote local inflammation?
- attract other cells (mostly neutrophils)
- act on blood vessels
What effects do cytokines/chemokines have on blood vessels to promote local inflammation?
- vasodilation
- increased permeability
- increased adhesion molecules on blood vessel endothelium
What are soluble mediators?
secreted substance that circulate and mediate an effect
What is complement?
series of enzymes that are produced in the liver and circulate in the bloodstream in an inactive form
What are the 3 pathways to trigger a complement?
- classical (antibody)
- mannan-binding (pattern recognition receptor)
- alternative (bacteria)
