Effector Mechanisims Of Humoral Immunity (Ch. 8) Flashcards
How do vaccines work
By stimulating ab
What does TNF do
Stimulates inflammation, coag., and apoptosis
What is the function of IgG
Opsonization of Ag for phagocytosis
Act. Of compliment pathway
ADCC by NK cells
Feedback inhibition of B Cell activation
What is the function of IgM
Activation of classical pathway complement
What is the function of IgA
Mucosal immunity
What is the function of IgE
Eos and mast cell mediated defense against parasites
What is the role of FCRN and how does it work
Keeps IgG alive for a long time
Binds to endosomes with IgG/Ag complex
Separates IgG from Ag and transports IgG back to surface of the cell.
What IgG in humans binds to macro. And neutrophils to ingest microbes and what do they bind to?
IgG1 and IgG3 which bind to FcyR1
Where does Ab mediated phagocytosis (using IgG1 and IgG3) usually occur
In the spleen
What is the function of FcyR1
Ab mediated phagocytosis
What is the function of FcyRIIB
Feed back inhibition of B cells, attenuation of inflammation
What is the function of FcyRIIIA
ADCC in NK cells
What is the function of FceR1
Activation of mast cells and eosinophils
Pooled IgG from healthy pt. Will do what
Treat inflammation
What cells express FcyRIIIA and what do they do
NK cells express this, allows NK cells to bind to IgG on microbes and activate a release of granules to kill microbe
Called Ab-dependent cellular cytoxicity (ADCC)
How does Ige kill worms
Binds to them and attracts Eos to them to bind through FceRI
Th-2 Cells must also secrete IL-5 to activate Eos.
What is the function of C3b
Opsonin of microbes which allows them to be destroyed by phagocytes after being recognized by CR1
What is the function of C3a
Inflammation
What is the function of C1 (and its parts)
Overall initiates the classical pathway
C1q binds to the Fc portion of IgG, C1r and C1s lead to C4 and C2 activation
What is the function of C4a
Stimulates inflammation
What does Factor D do?
In alternative pathway, breaks down Factor B into Bb which then attaches to C3b to become C3Bb
What is C3 convertase
C3bBb
What does C3bBb do next in alt. Pathway?
Binds to one more C3b and makes C3bBb3b which is now the C5 convertase and continues the pathway
What does C5a do
Inflammation
Which C actually opens up the cell for lysis
C9
B-cells recognize what opsonin with what receptor
Recognize C3d with CR2 (CD 21)
Phagocytes recognize what opsonin with what receptor
C3b with CR 1 (CD35)
Compliment proteins are also recognized by what in germinal centers
FDCs which allow for increased affinity B cells
What does C1 INH do
Blocks C1r2s2 in classical comp. pathway
What does DAF do
DAF along with CR1 remove either Bb (in alt. Pathway) or C4b (in classical pathway)
This stops the formation of C3 convertase
What does MCP (CD49) do
Along with CR1 act as cofactors of Factor 1 which destroys C3b
What does C4BP do
Acts as a cofactors for Factor I
Causes dissociation of classical pathway C3 convertase subunits
What does CD 59 do
Blocks C9 binding and prevents formation of the MAC
What is caused by a deficiency of C1 INH
Hereditary angioedema due to increased C1 and increased inflammation from it
What is paroxysmal nocturnal hemoglobinuria
An acquired deficiency of HSC of a membrane anchor of DAF and CD 59 which leads to unregulated comp. act. And RBC lysis
What causes a heavy-chain switch to IgA
TGF-B
What transports IgA into the lumen
Poly-Ig Receptor, also prevents it from being destroyed
