Complement System Flashcards
What does C1-INH do?
Inactivates C1 from forming the C14b2b complex, stops classical pathway after the pathogen has been cleared.
What is the overall order of the initial steps of classical pathway (up to 5b)?
C1q –> r –> s –> 4 –> 2 –> 3 –> 5b (then 6, 7 etc.)
Which complement protein is involved in opsonization?
C3b
Which complement proteins are involved in chemotaxis?
C3a, C5a
Which complement proteins are anaphylotoxins?
C3a, C5a
What is the result of the membrane attack complex?
Membrane pore formation and lysis of the organism.
Name the inhibitors of the alternative complement pathway.
Factor H, Factor I
Which pathway is C3bBbP involved in?
Alternative pathway.
What foreign molecule activates the alternative complement pathway? Why does it not need Ab?
C3b is a product of natural C3 serum degradation, and binds to the LPS of gram negative bacteria, then the rest of the proteins come in!
What foreign thing activates the lectin pathway?
Organisms with mannose on their surface.
Which pathway is C4b2b involved in?
Lectin pathway
Which complement proteins are missing in a person that gets overwhelming Neisserial infections?
C6, 7, 8
What results from having no C1-INH?
Hereditary angioedema.
What infections are common if someone has no alternative pathway?
Bacterial infections
Which complement protein(s) are often absent when a person is susceptible to systemic lupus erythematosus (SLE)?
C1q, C2, or C4
