Term
What proteins in the horseshoe crab are homologous to vertebrate complement proteins? |
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Definition
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Term
What types of molecules can activate the vertebrate complement system? |
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Definition
PAMPs antibodies + microbial antigens coagulation/fibrinolytic components |
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Term
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Definition
punches holes in the microbial cell membranes, resulting in osmotic lysis |
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Term
What are the 3 complement pathways? |
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Definition
Alternative Pathway Lectin-Binding Pathway Classical Pathway |
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Term
Which are the oldest complement genes? |
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Definition
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Term
Duplications of C3 led to... |
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Definition
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Term
Duplication of Bf led to.... |
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Definition
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Term
The classical pathway developed as a result of... |
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Definition
duplication events leading to C6,C7,C8 & C9 |
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Term
Chickens lack the complement genes for... |
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Definition
C2, C9, MASP1, Factor P (properdin) |
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Term
Zebrafish lack the complement genes for... |
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Definition
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Term
Which complement proteins are produced by the liver? |
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Definition
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Term
Which complement proteins are produced by macrophages? |
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Definition
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Term
Neutrophils are capable of producing & storing... |
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Definition
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Term
Host cells are rich in sialic acid, allowing _____ to bind to C3b |
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Definition
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Term
What happens to C3a produced by the spontaneous degradation of C3 in the alternative pathway? |
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Definition
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Term
Which complement receptors is iC3b able to bind to? |
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Definition
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Term
Describe the construction of an anchor molecule |
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Definition
1. C5 binds to C3b on microbial cell surfaces 2. C3bBb or C4bC2b cleaves C5 3. C5a is released into humoral fluid 4. C6 & C7 bind to C5b forming C5b67 5. Complex formed is inserted into membrane |
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Term
Describe the assembly of the MAC |
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Definition
C8 & C9 bind to C5b67 complex MAC is created, acting as a pore which inhibits osmotic regulation of the microbial cell |
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Term
What activates the lectin-binding pathway? |
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Definition
MBL or ficolins bind to microbial cell wall, activating a MASP2 complex |
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Term
MASP2 is critical for the lectin-binding pathway and also... |
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Definition
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Term
What activates the classical pathway? |
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Definition
IgM or IgG produced during the acquired immune response attach to the microbial surface, resulting in a conformational change which exposes the Fc region of the antibody (the Fc region contains complement-binding sites) |
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Term
What is the most important regulator of the classical pathway? What does it do? |
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Definition
C1-INH -blocks C1r & C1s, preventing C4bC2b assembly |
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Term
What proteins are able to accelerate the decay of C3 & C5 convertases? |
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Definition
CD55 Hf If C4-binding protein CR1 (CD35) |
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Term
Which proteins block the insertion of of C5b678 into the microbial cell mmb? |
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Definition
vitronectin clusterin CD59 (protectin) |
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Term
What ligands does CR1 bind? What effect does their binding have on the immune response? |
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Definition
C3b C4b iC3b
-allows the complexes to be removed by the spleen & liver |
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Term
Where are CR1 receptors found in primates? |
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Definition
90% are on RBCs 10% are on phagocytic cells |
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Term
What ligands does CR2 bind? What effect does this have? |
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Definition
C3d
-CD19/CR2 complex is formed, releasing a signal to increase activation of B cells in response to microbial presence |
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Term
What ligands does CR3 bind? What effect does this have? |
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Definition
iC3b
-mediates phagocytosis & cytotoxicity |
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Term
What ligands does CR4 bind? What effect does this have? |
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Definition
breakdown products of C3
-mediates phagocytosis, cytotoxicity, clotting |
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Term
Where are C3aR & C5aR found? What happens when they bind to C3a and C5a? |
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Definition
mast cells eosinophils basophils
degranulation, release of vasoactive compounds |
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Term
What ligand does C1qR bind? What effect does this have? |
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Definition
C1q
-mediates phagocytosis of apoptotic bodies -mediates macrophage differentiation -mediates DC migration |
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Term
What ligands does CRIg bind? What effect does this have? |
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Definition
C3b & iC3b
phagocytosis of pathogens in the blood |
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Term
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Definition
tissue macrophages e.g. Kupffer cells |
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Term
C1q can act as an opsonin for... |
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Definition
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Term
C3b & C4b can act as opsonins for..... |
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Definition
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Term
Which complement proteins have vasoactive properties? |
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Definition
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Term
What are the anaphylactic effects of C3a & C5a? (5) |
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Definition
-mast cell/eosinophil degranulation -platelet release of vasoactive compounds -increased vascular permeability -neutrophil release of lysosomal enzymes -macrophage release of thromboxane |
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Term
Which C3 breakdown product is bacteriolytic? |
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Definition
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Term
What causes BLAD in cattle? |
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Definition
SNP in CD18 reduces B2 expression, preventing leukocyte adhesion |
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Term
What causes glomerulonephritis? |
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Definition
SNP in Hf leading to excess C3b being deposited in the kidneys |
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Term
SNPs in which complement genes increases the risk of asthma? |
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Definition
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Term
Which component of the coagulation-fibrinolysis process acts strictly as a C3 convertase? |
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Definition
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Term
Which components of the coagulation-fibrinolysis process act as C3 & C5 convertases? |
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Definition
Factors X, XI, IX thrombin plasmin |
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Term
How does Streptococci M affect complement activation? |
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Definition
masks C3b binding sites, preventing opsonization |
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Term
How does Staph aureus affect complement activation? |
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Definition
produces fibrinogen-binding protein which changes the shape of C3b, preventing interaction with Bf |
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Term
How does Salmonella enterica affect complement activation? |
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Definition
Rck gene prevents MAC from being inserted into bacterial mmb |
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Term
How does E coli affect complement activation? |
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Definition
produces Stx which activates the complement system -binds to Hf, downregulates CD59 in kidney cells, increases C3b production -MACs on renal cells lead to hemolytic uremic syndrome |
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