immunology complement

What is the complement system?
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What are the characteristics of C1r and C1s?-enzymatic -It needs to be stimulated in order to become enzymaticTo what and why does C1 bind to?1 IgM molecule because it has 2 binding sites___ needs to be close enough so ___ heads can attach to it.IgG C1How many IgG antibodies are in an Ag-Ab complex?2What are the Activation Units?C4 C2 C3________change of C1q activates ___ first which then activates ___Conformational C1r C1sWhat does C1s become when it is enzymatically activated?C1 esteraseWhat does C1 esterase activate?C4 and C2After C4 is activated, it splits into _____ and _____C4a and C4bAFter C2 is activated, it splits into _____ and ____.C2a and C2bWhat happens to C4a and C2a?They are small fragments that diffuse into serumWhat does C4bC2b do?binds to cell membraneFragments have/are...short life spans and are biologically activeWhat happens in the formation of C3 Convertase?C4bC2b becomes enzymatically active (C42) which then will activate C3What is C42 called?C3 convertaseWhat does C3 convertase do?It cleaves C3 protein into C3a and C3bWhat is C3a?It is a small fragment that diffuses into serumWhat does C3b do in the classic path?lands on antigen to facilitate phagocytosisWhat is C4bC2bC3b called?C5 convertaseWhat happens in the Membrane Attack Complex?C5 convertase splits C5 into C5a and C5bWhat does C5b do?It attaches to membrane and functions as a stabilizerWhat do C6 and C7 do?They penetrate the membranewhat does C8 do?initiates leakageWhat does C9 do?accelerates membrane destruction causing materials inside cell to leak out and causes whatever materials outside the cell to go in (K/NA) and causes cell to swell and lyse/ruptureWhat substances is the Alernative Pathway activated by?- Aggregated IgG4 -IgA -IgD -IgE -Yeast cell walls -Bacterial endotoxins -Cobra venom proteinWhat are the differences between the Alternative and Classic Pathways?-Initiation occurs by WATER HYDROLYSIS of C3 -Involves proteins called Factor B and D -Stability is controlled by properdin -It is faster -Does not require antibody (innateWhat does properdin do?holds units togetherWhat happens in inactivation of the Alternative Pathway?C3 is cleaved by hydrolysis or coagulation or fibrinolytic enzymes into C3a and C3bWhat does C3b do in the inactivation of the alertnative pathway?It attaches to cell surfaceWhat attaches to C3b when its on the cell surface?Factor HWhat does factor H activate?Factor 1What does Factor 1 do?it cleaves C3b into C3c and C3d so the cells that we dont want to destroy are protectedWhat happens in the activation of the Alternative Pathyway?C3 is cleaved by hydrolyis or coagulation or fibrinolytic enzymes into C3a and C3b?What does C3b do in the activation of the alternative path?C3b attaches to bacterial cell surfaceWhat attaches to C3b?factor BWhat does factor D do?it hydrolyzes Factor B into Ba and BbWhat does Factor Bb do?it attaches to C3b which is unstable, so properdin comes to stabilizeWhat does C3bnPBb do?It acts as C5 convertaseWhat steps are identical to the Classical pathway?C6, C7, C8 & C9 to form the MAC unitWhat are the regulators of the Complement Pathways?-C1 esterase - C4b-binding protein -Factor I -Factor H -S protein (virtronectin) -C3b inactivator (iC3b) -Anaphylatoxin inactivatorWhat does C1 esterase do?Inactivates C1r and C1s,C3bBb, coagulation and fibrinolysis enzymesWhat does C4b-binding protein do?inactivates c4bWhat does Factor I do?Cleaves C3b in the alernative pathway and cleaves C4d in the classical pathwayWhat does Factor H do?Attaches to C3b and facilitates inactivation by Factor IWhat does S protein (Virtronectin) do?Prevents C5b67 (MAC unit) from binding to the membrane (no penetration into cell)What does C3b inactivator (iC3b) do?splits C3b into C3c and C3dWhat does anaphylatoxin inactivator do?Destroys activity of C3a and C5aWhat is Hereditary Angiodema (HANE)?involves C1 esterase inhibitor deficiencyWhat is the immunological profile of HANE?Low C4 concentration because we are not regulation C1 which is what makes C4. -15% will have normal levels of nonfunctional C1 esterase inhibitorWhat is the treatment for HANE?-Androgens (methyltestoseterone/fluoxymesterone) to increase liver synthesis of C1INH -Fresh frozen plasma (contains enzyme) -Danazol- use prophylactically (before symptoms appear!) -amicar (inhibitor of fibrinolysis which activates C1)What do C5a, c3a, and C4a do as complement cleavage products?play an important reponse in enhancing the immune response before going into the serumWhich is Most potent, potent, and weak?C5a, C3a, C4awhat aresome ofthe biological actions of the complement cleavage products?-Act on Smooth muscle -changes permeability of blood vessels -Mast cells secrete histamine -Neutrophil chemotaxisWhat does C2b do as a cleavage product?Activates Kinin- causes edemaWhat does C1 and C4a2a do as a cleavage product?amplifies complementWhat does C3b and C4b do as a cleavage product?induces opsonization (enhances phagocytosis by bringing in macrophagesWhat does C1 and C4 do as a cleavage product?neutrolizes virusesWhat are Complement deficiencies?Autosomal recessive disorders (inherited)What are complement deficiencies characterized by?Low complement titers (CH50 titer)When people have deficiencies of the alternative pathway they are more susceptible to...-Neisseria -S. Pneumo -h. influenza -s. aureusWhat are you susceptible to when you have a deficiency of classic Components 1,4 and 2?autoimmune diseases like SLE and glomerulonephritisWhat kind of symptoms do you have with a defiency of classic components 1, 4 and 2?mild because you still have an alternative pathwayWhat do deficiencies in C3 and the terminal components result in?overwhelming pyogenic infectionsWhat is the total Hemolytic Complement Assay (CH50)?A screen test for most complement disordersHow do you perform the Total hemolytic Complement Assay (CH50)?-You use serial dilutions of patients serum or fluid -add indicator sensitized sheep RBC's with rabbit antibodies attached to it -add guinea pig complement to see if it lysed sheep RBC's -Measure lysis spectrophotometrically and compare to standard curveWhat are precautions when using complement assays?Complement is easily inactivatedHow is complement easily inactivated?-Heating it to 56 degrees C for 30 min -aging at room temp-complement protein disappear -Violent agitationHow do you measure individual Complemtn components?-Functional Assays -Immunoassays -Radial immunodiffusion -rate NephelometryHow do you measure individual components by functional assays?Add components sequentially and observe for lysisWhat are immunoassays used mainly to test for?C3 and C4What can Consumption of Complement proteins due to presence of immune responses mean?-systemic lupus erythematosis -Acute glomerulonephritis -Acute serum sickness -Advanced cirrhosisWhat can Decreased synthesis of Complement mean?-Malnutrition -Hereditary deficienciesWhat can increased catabolism or loss of complemnt mean?-extensive burnsWhat can inhibtor activity of complemnt mean?--Hereditaroy disordersWhat can elevated complement levels mean?-Overproduction of complemnt -associated with stimulation of reticuloendothelial cells that produce complement - Inflammatory reactions may produce byproducts that stimulate complementWhat diseases can cause overproduction of complement?-Obstructive Jaundice -Thyroiditis -Acute Rheumatic Fever -Rheumatoid Arthritis -Malignant DiseaseWhat are the components of the Complement fixation Test?-sheep RBCs -Guinea pig complement -Rebbit antibody to sheep RBC's -Inactivated serum of patientWhat are you looking for in the complement fixation test?antibodiesIf lysis occurs, what is the result of the complement fixation test?negative for antibodies