COD Inflammation Flashcards
What is inflammation?
The body’s attempt at self-protection
To remove harmful stimuli and begin the healing process
Generally non-specific
No long lasting immunity to the host in the acute stage
Evolutionary older defense strategy
What is chronic inflammation?
Persist longer than necessary
Cause more harm than good
Severe and progressive
What are the symptoms of inflammation? How is it classically defined?
Redness Warmth Pain Swelling Loss of function
How are cytokines involved in inflammation?
They orchestrate the immune and inflammatory responses
Include chemokines, interleukins, tumour necrosis factors
Produced by a range of cells including macrophages, B and T lymphocytes, mast cells, fibroblasts
They act by binding to the cell surface receptors that then trigger intracellular signal transduction cascades
Decoy receptors negate cytokine actions. Can also inhibit by use of neutralising monoclonal antibodies
What are the 2 major systems in the complement system?
Classical: starts when antibody binds to pathogen/bacteria
Alternative: Starts spontaneously
Describe the complement system
Consists of several small proteins generally synthesised in the liver and normally circulate as inactive precursors (pro-protein)
Series of proteolytic reactions with the end result of:
Stimulation of phagocytosis to clear foreign and damaged material
Proxy inflammation to attract additional phagocytes
Activation of cell-killing membrane attack complex
Describe the adaptive immune system
2nd line of defense
Highly specialised
Highly specific
Long lasting
Immunological memory
Recognition of “non-self” antigens from “self”
Humoral immunity and cell-mediated immunity
B lymphocytes: produce antibodies (immunoglobulins)
T lymphocytes: cell-mediated immune response (Th1, Th2, Th17, Tregs) in response to antigen presenting cell (e.g. dendritic cells). Antigen presentation is in conjunction with major histocompatibility complex
Describe acute phase proteins
Class of secreted plasma proteins
Concentration increases or decreases in response to inflammation
Response is called acute phase reaction
Changes in mainly transcription of genes in liver due to increase plasma concentrations of cytokines such as IL-1, IL-6 and TNF-α due to inflammation
Protective function:
C-reactive protein, complement factors, serum amyloid A, haptoglobin: inhibit growth of microbes
Fibrinogen, prothrombin, Factor VIII: Coagulation factors that trap invading microbes in blood clots
Haptoglobin: binds haemoglobin, inhibits microbe iron uptake
What are the basis of the 5 cardinal signs?
Increased blood flow due to vascular dilatation gives redness and heat
Increased vascular permeability gives oedema causing tissue swelling
Certain chemical mediators stimulate sensory nerve endings giving pain. Nerves also stimulated by stretching from oedema
Pain and swelling result in loss of function
What are inducers?
Pathogen-associated molecular patterns (PAMPs): Defined set of conserved molecular patterns/structures carried by pathogens that are essential for their survival. Host has evolved a corresponding set of receptors (Pattern-recognition receptors) that detect their presence
Virulence Factors: Restricted to pathogens. They are generally not sensed directly by dedicated receptors but the effects of their activity, particularly adverse, are responsible for triggering inflammatory response
Damage-associated molecular patterns (DAMPs) are endogenous molecules/molecular patterns that signal damage (endogenous stress signals)