Immunology-9 (Kyle) Flashcards
What is the classical pathway for complement activation?
Antigen : Ab complexes (First to act)
What is the lectin pathway of complement activation?
Lectin binding to pathogen surfaces (Second to act)
What is the alternative pathway of complement activation?
Pathogen surfaces. (Third to Act)
What is the common theme of complement activation?
Clevage of C3 to C3a and C3b. C3b will be covalently bound to surface components of pathogen.
What does the clevage of C3 do to the pathogens?
Recrutes inflammatory cells,
What does the complement cascade do?
Marks pathogens for destruction by phagocytes ( Opsonization )
What are anaphylatoxins?
Inflammatory mediators rpoduced by the complement cascade.
What do anaphylatoxins actually do ?
These small molecules are chemotactic and induce vascular permeability which induces inflammatory responses.
Where are components of the complement cascade produced?
In the liver in their inactive form.
What do anaphylatoxins do?
Recruit fluid and immune cells to sites of antigen deposition.
What is the most important product of the complement cascade?
Deposition of the opsonin C3b
Why is C3b important?
Complement receptors on phagocytes bind to C3b (and fragments of C3b) which facilitates uptake and destruction of the pathogen
What enzyme is C3b a part of that activates the membrane attack complex?
Convertase enzyme
What does C3a do ?
Recrutes phagocytes
Is the alternative pathway of activation a purely innate mechanism?
Yes