The complement system Flashcards
The (blank) is composed of more than 30 constitutively expressed proteins and their cleavage products that play and important role in the early stages of innate immunity.
complement system
What are the three pathways of complement activation that converge to make C3 convertases?
classical, lectin and alternative
What does C3 convertases generate?
opsonic C3b molecules on pathogen surfaces
Phagocytic cells recognize and destroy pathogens opsonized by (blank)
C3b
(blank) and (blank) bind to potentially harmful immune complexes and promote their blood clearance
C4b and C3b
(blank) and (blank) are anaphylatoxins that recruit and activate inflammatory cells
C5a and C3a
Formation of the (blank) promotoes assembly of the membrane attack complex (C6-C9) that kills certain bacteria
C5 convertase
complement is very potent so its activation is (blank)
tightly regulated
Deficiencies in complement results in what?
suscpetibility to microorganisms and immune complex diseases
a 67 year old women is hospitalized with a fever of unknown orgin. An elevate C reactive protein and erythrocyte sedimentation rate suggests an ongoing systemic inflammatory response. Which cytokine is especially important in these elevations?
IL 6 (remember that is the interluekin on the liver where c reactive protein will be found)
A 4 year old male presents with serious recurrent bacterial infections and has a big liver and spleen. an immunodeficiency disease is suspected, Everything is normal except a dihyrdorodamine test reveals that the patients neutrophils didnt reduce the dye. Why?
deficiency in NADPH oxidation
A 3 week old female with omphalitis has a diaper rash and bacterial pneumonia. Radiology is clear. Staph skin ulcer was looked at and there was very few neutrophils. What happened?
Deficiency in CD18
A 4 month old child has a staph skin infection without puss formation. has delayed umbilical cord separation and has some umbilicus. Has luekocytosis (too many whiteblood cells) but no b2 integrins. What immunological problem will this lead to?
Reduced diapedesis of neutrophils.
What is an important component of the immediate innate immune response to pathogens?
complement
How does the complement system work with the adaptive immunity?
works with antibodies in response to pathogens
The complement system is critical for innate and adaptive immunity. AND it plays an important role in eliminating (blank)
immune complexes
What does the complement system share with the coagulation and kinin systems?
cascades of proteolytic steps
zymogens (need to be cleaved to become activated)
amplification
What all can complements do besides kill?
they can cause inflammation, promote chemotaxis and activate immune cells
Some complement components can form (blank) in pathogen membranes that case lysis and death
pores (super rare)
What is the most important component of the complement?
its ability to opsonize
What do all three pathways of the complement system create?
C3 convertase
C3 convertase creates what 3 things?
C3b and C3a, C5a
What is the most important component of the complement system and why?
C3b because it is a potent opsonate
What does C3a and C5a promote?
inflammation and recruitment of phagoytic cells