The%20Complement%20System%20and%20Kinin%20System

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The Complement Systemand Kinin System

• Manfred Maitz
• www.manfred.maitz-online.de

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Outline

• Complement System
• Background
• Reactions of the complement cascade
• Regulation and activation of the complement
  cascade
• Effects of Complement activation
• Evaluation methods
• Consequences for biomaterials
• Kinin System
• Reactions and interactions with other systems
• Summary and Conclusions

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Background

• Evolutionary old system
• Non specific defence system
• Constitutive
• Very fast
• Selectivity and self-tolerance
• Activation by antibodies possible
• Interaction with the specific immune system
• Functions
• Lysis of cells/ bacteria and viruses
• Opsonization for phagocytes
• Immune Clearance
• Similarities and crosstalks with the clotting
  cascade
• Cascade of serine proteases, which activate each
  other
• Two (three) pathways of activation
• Factor XIIa (Hageman-Factor) activates both the
  clotting cascade and the complement cascade

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Outline

• Complement System
• Background
• Reactions of the complement cascade
• Regulation and activation of the complement
  cascade
• Effects of Complement activation
• Evaluation methods
• Consequences for biomaterials
• Kinin System
• Reactions and interactions with other systems
• Summary and Conclusions

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The Membrane Attack Complex
C5
C9
C9
C9
C9
C9
C9
C9
C9
C9
C9
C9
C7
C8
C6
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The Complement Cascade
C5a
C5
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Outline

• Complement System
• Background
• Reactions of the complement cascade
• Regulation and activation of the complement
  cascade
• Effects of Complement activation
• Evaluation methods
• Consequences for biomaterials
• Kinin System
• Reactions and interactions with other systems
• Summary and Conclusions

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Regulation of the Complement Cascade

• Short half-time of
• C3b
• C3bBb
• C5b
• C1 inhibitor
• Inhibits the C1s activity
• Protein S in Serum
• Binds to C5b67
• Inhibits Formation of the Membrane Attack Complex
• HRF or CD59
• Bind to C8
• Inhibits C9 binding
• Factor H
• Binds to C3b
• Facilitates binding of Factor I
• cleaves C3b to inactive iC3b
• cleaves C4b to inactive fragments
• Decay Accelerating Factor
• Increased dissociation of C3 convertase (both
  pathways)

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Complement Activation

• General
• Hydrophobic surfaces
• Oxides
• Strong binding of C3(b) to nucleophilic groups
  (-NH2, -OH)
• Higher absorption of C3 to crystalline TiO2 than
  to amorphous
• Kallikrein directly activates C5
• Plasmin directly activates C5
• Classical Pathway
• Antibodies IgM, IgG1, IgG2, IgG3
• Lectin via the mannan binding protein (MBP)
  Lectin Pathway
• Hageman Factor (F XIIa)
• Rough surfaces
• C-reactive protein (CRP)
• (Zirkonium, transiently)
• Alternative Pathway
• PE debries
• Acetylated chitosan

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Outline

• Complement System
• Background
• Reactions of the complement cascade
• Regulation and activation of the complement
  cascade
• Effects of Complement activation
• Evaluation methods
• Consequences for biomaterials
• Kinin System
• Reactions and interactions with other systems
• Summary and Conclusions

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Complement Receptors
Receptor Ligand Cellular distribution
CR1 (CD35) C3bgtiC3bC4b B-CellsPhagocytesRBCfollicular dendritic cells
CR2 (CD21) iC3bC3dg B cellsepithelial cells
CR3 (CD18/11b) iC3bZymosanICAM-1 PhagocytesNK Cellsfollicular dendritic cells
CR4 (CD18/11c) iC3b Phagocytes
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Anaphylatoxins

• Fragments C5a, C3a, C4a
• Degranulation of Phagocytes
• Reactive oxygen species
• Prostaglandins
• Monocytes ? IL-1, IL-6
• Mast cells? Histamine
• Chemotaxis
• Only C5a

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Consequences in vitro

• Lysis of innocent neighbour cells
• Red blood cells
• Activation of phagocytic cells
• Release of reactive oxygen species
• Release of mediators

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Consequences in vivo

• Factors of complement activation at revised hip
  implants
• One single study (Tang L. et al. J Biomed Mater
  Res 41 333-340 (1998))
• Au-Mercaptoglycerol induces strong inflammatory
  response in control animals.
• No reaction in Complement-depleted animals.

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Outline

• Complement System
• Background
• Reactions of the complement cascade
• Regulation and activation of the complement
  cascade
• Effects of Complement activation
• Evaluation methods
• Consequences for biomaterials
• Kinin System
• Reactions and interactions with other systems
• Summary and Conclusions

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The Complement Cascade
C5a
C5
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Methods for Investigation

• General/Common pathway
• Lysis of sheep red blood cells
• Solid phase methods (ELISA, RIA)
• Products C3a, C5a, sC5b-9
• Consumption of C3
• Ellipsometry
• Classical Pathway
• Measurement of C1qrs
• Measurement of C2b or C4b2a
• Alternative Pathway
• Measurement of Ba or C3bBb
• Measurement of Properidin

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Outline

• Complement System
• Background
• Reactions of the complement cascade
• Regulation and activation of the complement
  cascade
• Effects of Complement activation
• Evaluation methods
• Consequences for biomaterials
• Kinin System
• Reactions and interactions with other systems
• Summary and Conclusions

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Biomaterials Consequences

• Testing for complement activation included in
  standard test programs
• Covalent binding of Factor H to the surface of a
  blood contacting implant
• Reduced C3a, sC5b-9
• Inhibition of FXII activation by Heparin-ATIII

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Outline

• Complement System
• Background
• Reactions of the complement cascade
• Regulation and activation of the complement
  cascade
• Effects of Complement activation
• Evaluation methods
• Consequences for biomaterials
• Kinin System
• Reactions and interactions with other systems
• Summary and Conclusions

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The Clotting Cascade
Intrinsic Pathway
Extrinsic Pathway
Surface Contact Collagen FXII activator
Tissue/Cell Defect
F XIIa
F XII
F VII
F VIIa
Ca2
F XIa
F XI
Ca2
F IXa
F IX
F III (Tissue Thromboplastin)
Ca2
F VIIIa
F VIII
Platelet Factor 3
Factor F Xa
Factor F X
Factor F X
Ca2
Ca2
Prothrombin I
Thrombin
Ca2
F XIIIa
F XIII
Fibrinmonomers
Fibrinpolymers
Fibrinogen
CrosslinkedFibrin Meshwork
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The Kinin System

• Effects
• vascular smooth muscle relaxation
• Increased permeability of blood vessels ? Oedema
• Pain
• Interaction with clotting cascade
• Interaction with fibrinolytic cascade
• Interaction with complement cascade

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Outline

• Complement System
• Background
• Reactions of the complement cascade
• Regulation and activation of the complement
  cascade
• Effects of Complement activation
• Evaluation methods
• Consequences for biomaterials
• Kinin System
• Reactions and interactions with other systems
• Summary and Conclusions

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Conclusions

• The blood plasma has four cascade systems
• Clotting cascade
• Fibrinolytic cascade
• Complement system
• Kinin system
• All four systems are proteolytic cascades
• Besides the main streams there are many cross
  connections with minor importance
• Common activators and cross activation
• Common inhibitors/ regulators
• C1 Esterase Inhibitor
• Hageman Factor (F XII)
• Effective in all systems
• Directly activated by surfaces (esp. negatively
  charged)
• 1-3 people have deficiencies without clinical
  syndromes
• Plasmin
• Directly effective in three systems
• Indirectly also effective on the clotting cascade

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General Conclusions

• Biomaterials research is an interdisciplinary
  field
• Physics/Materials science
• Modification and check of physical surface
  properties
• Roughness
• Surface free energy
• Hardness, tribological properties
• Surface charges, electrical and electronic
  properties
• Bulk properties
• Chemistry
• Corrosion
• Polymers
• Chemical surface modification
• Chemical reactions of the biomolecules with the
  biomaterial
• Life science
• Knowledge about the normal biochemical situation
• Knowledge about changes at certain diseases
• Check of influences due to the biomaterial
• Support of the physiological situation