Respiratory Block Immunology Flashcards
What do infected/damaged host cells release in an immune response?
Danger signals and regulatory cytokines.
E.g. IFN a/b (interferons) induce an anti-viral state in local tissues
How do Natural killer cells work in an immune response?
They recognise and kill host cells that are infected with intracellular pathogens via the action of:
- Perforin
- Granzymes
- Fas (transmembrane protein from TNF)
Describe the complement system
The presence of pathogens leads to the activation of the complement system. This leads to the activation and initiation of:
- pathogen opsonisation
- phagocytosis
- pathogen killing
- mast cell degradation
What is involved in local pathogen infection and replication?
Tissue resident innate immune cells e.g. macrphages, mast cells secrete pro-inflammatory cytokines and other inflammatory mediatiors
Names some pro-inflammatory mediators
TNFa, IL-1, IL-6, C3a and C5a -these are produced by activated macrophages, mast cells, neutrophils and complement - local and systemic effects.
Name the local effects of pro-inflammatory mediators
vascular actions - alters the blood flow, vascular permeability and increased expression of adhesion molecules on endothelial cells leading to neutrophils recruitment into infected and inflammed cells.
This presents as pain, heat (calor) and redness (rubor)
Name the systemic effects of pro-inflammatory mediators
Fever, increased neutrophil production and maturation in the Bone Marrow, induction of the acute phase response (in the liver) resulting in increased levels of CRP and some complement proteins.
Describe the action of macrophages in response to extracellular pathogens.
kill via phagolysomal enzymes
proteases
acidic pH
production of ROS/RNS can be induced in response to IFNg secretion by NKC and effector TH1 Cells
Neutrophils kill via several distinct mechanisms - describe them
phagolysomal enzymes, proteases, acidic pH
production of ROS/RNS
secretion of lysosomal enzymes and proteases
