Review 1.2 Flashcards
CR1
complement receptor 1
binds C3b and C4b
major activator receptor for macros and PMNs
CR3
binds C3bi- bound complexes
CR2
mainly found on Bcells, involved in their activation
CR4
similar to CR3, but also adhesion molecule.
development of B lymphocytes
steps.
RAG
encode enzymes that play an important role in the rearrangement and recombination of the genes of immunoglobulin and T cell receptor molecules during the process of VDJ recombination.
what tests B lymphs when they are graduating?
stroma cells, they secrete cytokines at them.
how are histones modified?
acetylation- activates, methylation- inactivates.
SCID
severe combined immunodeficiency disease
gamma chain deficiency- cytokine receptor. shared by IL-2 family of receptors.
type 1 interferons
antiviral response that results in cells having a higher level of resistance to infection than unactivated cells.response driven by JAC STAT pathway.Main effect: resistance of viral replication, and infection.recognized by NK cells.
immunomodulatory.
type 2 interferons
produced by Nk cells. AKA gamma interferon. Activates Macrophages.
what induces liver to produce acute phase proteins?
IL-6
c-reactive protein
opsonin, induces phagocytocis
C’ functions
opsonization and phagocytocis- binds C3b, recognized by phagocyte, then its eaten.stimulation of inflammatory reactions- recruits and activates leukocytes by C5a and C3acomplement mediated cytolysis- recruits components, forms pore, osmotic lysis of microbe.
C3 convertase
cleaves C3 so that it can tag bacteria for destruction.C3a, part of C3 will then recruit phagsAKA C3bBb
3 ways that complement is activated
Classical - least important.
Lectin - activated by acute phase proteins. has to go to liver first.
Alternative - doesn’t need antibody, most important. first to act.
they all lead to cleavage of C3 to C3a and b. C3b can also cleave C3 to make more C3a
amplification
C3 cleavage
Alternative pathway
main way to activate complement. C3 cleavage driven by:
Factor B- forms C3bBb complex aka C3 convertase
Factor D- cleaves B when bound to C3b to Ba and Bb
Properdin- stabilizes complexes formed by other factors. positive regulator. accelerator.
regulation of C3 activation
Factor H+ Factor I- inhibitor, slows down consumption of C3^^^ if missing this then you are more susceptible to encapsulated bacteria.
C5
initiates assembly of membrane attack complex in solutionactivated by C5 convertase, activates terminal part of complement
MAC
membrane attack complex. formed by complement, poly 9 forms the pores.
C8 deficiency
recurrent Neisseria infections to to lack of MAC
C3 mutations
no complement response!!!!!severe, recurrent infections
C5 mutations
increased complement activation, deplete C3, recurrent infections.