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The Changes of Complement System The Changes of Complement System
in Thermal Injuryin Thermal Injury
한림의대 임상병리과
강 희 정
Overview of Presentation:Overview of Presentation:
• Review complement activation pathways, mechanisms of Review complement activation pathways, mechanisms of
normal inhibition and clinical correlatesnormal inhibition and clinical correlates
• Review the methods for evaluation of complement systemReview the methods for evaluation of complement system
• Review the changes of complement system in thermalReview the changes of complement system in thermal
injury and discuss the therapeutic relevance of IVIG injury and discuss the therapeutic relevance of IVIG
• Discuss new therapeutic trial of complement inhibitorsDiscuss new therapeutic trial of complement inhibitors
Complement System
Composition
Enzymes cascade including about 20 proteins
Activating protein, regulators, complement receptors
Function Identification and removal of foreign substances and ICs
Initiation and regulation of Immune response Defense mechanism
Excessive inflammation Tissue damage
Classical Pathway
Alternative Pathway
C1q C1qr2s2
C4b + C2C4a
C4b2a
C4C2b
C3fD, P
Ba
C3bBb
C3b + fB
Ab-AgComplex
C3a
C3 C3b-
MicrobesPolysaccharides
C3bBbC3b
C3a
C5
C5b
C6C7C8C9
Complement activation
MAC
MBL-MASP1- MASP2
Lectin Pathway
C4b2a3bC5b
Complement Pathway ActivatorsComplement Pathway Activators
ClassicalClassical AlternativeAlternative LectinLectinImmune complexes Immune complexes “Tickover” “Tickover” Repeating simple Repeating simple (natural IgM, IgG) (natural IgM, IgG) sugars sugarsC-reactive protein (CRP)C-reactive protein (CRP) Polysaccharides Polysaccharides (chromatin complexes)(chromatin complexes)Endothelial neoepitopesEndothelial neoepitopes Endotoxin Endotoxin in ischemic tissuein ischemic tissueMitochondrial membranesMitochondrial membranes IgA immune complexes IgA immune complexes
Serum amyloid PSerum amyloid P Amplification pathway Amplification pathway
C4 nephritic factorC4 nephritic factor C3 nephritic factor C3 nephritic factor
Antigen-antibody complex
C1qr2s2
C1qr2s2
C4
C4a
C4b2 C4b2a
C3
C3b C3a
C2
C4b2a3b
C2b
C3 convertase
C5 convertase
Classical Pathway Activation
C4b
Antigen-antibody complex
C3
C3bB C3bBb
C3
C3b C3a
Factor D
C3bBb3b
Ba
C3 convertase
C5 convertase
Alternative Pathway Activation
C3b
Factor B
Classical pathway activation
Microbial surfacePolysaccharides
C3 tickover
C3(H2O) C3(H2O)B C3(H2O)Bb C3(H2O)Bb
Classical Pathway
Cell or Ab bound
C3bC3bB
Ba
Ba
C3bBb C3bBb Solid phase
C3 convertase
Fluid phase C3 convertase
C3
C3b
C3a
C3bBb3b
AP C5 convertase
Factor B
Soluble C3
Proteolysis by Factor D
Stabilized byProperdin
AMPLIFICATION
C3 TICKOVER
S-S
S-CllO
S-S
S - CllO
R-N O
S-S
SH Cll
R-O O
S-S
SH Cll
OH O
S-S
SH Cll
C3a- +
Solid Phase C3bFluid Phase C3b
(Inactive)
C3Metastable C3*
Unstable thioester group
PolyC9
C5bC6
C5Conver
tase
C6
C7
C6
C8
C6
C8
C8C9
MAC
C5a
C5
S ProteinCD59
C7 C7 C7
C3bBbC3bC4b2a3b
Cell lysis via MAC
Binding of opsonized bacteriato complement receptors on
macrophage
Phagocytosis
C3b, C3d, iC3b
Functions of Complement System
Mast cell activationIncreased vascular permeability
Neutrophil recruitmentActivation of nuetrophils
Contraction of smooth muscle
Release of C5a, C3a
Acute phase response of liver
IC formation
RESCR1
Macrophage RBC
C3b
Factor I
CR3
iC3b
Deposition of C3b
Solubilization of IC
Clearance of IC
Complement Biologic Effects OccurComplement Biologic Effects OccurThrough Receptors and MAC-induced SignalsThrough Receptors and MAC-induced Signals
C3C3LectinLectin
AlternativeAlternative
C5C5 C5b-9 (MAC)C5b-9 (MAC)
C3aRC3aR C5aRC5aRG proteinG proteinlinkedlinked
C3b/C3d - CR1/CR2C3b/C3d - CR1/CR2iC3b - CR3iC3b - CR3
ClassicalClassical
Complement ReceptorsComplement Receptors
ReceptorReceptor LigandLigand Major FunctionsMajor FunctionsCR1CR1 C4b/C3b Immune complex transport (E)C4b/C3b Immune complex transport (E)
Phagocytosis (Macrophage, PMN)Phagocytosis (Macrophage, PMN) Humoral Immunity (B cells, FDC)Humoral Immunity (B cells, FDC)
CR2CR2 C3d (EBV) Humoral Immunity (B cells, FDC)C3d (EBV) Humoral Immunity (B cells, FDC)
CR3/CR4CR3/CR4 C3bi Phagocytosis (Macrophage, PMN)C3bi Phagocytosis (Macrophage, PMN)
C3aRC3aR C3a Activation (Mast cell, Macrophage)C3a Activation (Mast cell, Macrophage) Activation/Chemotaxis (PMN, Eosinophils)Activation/Chemotaxis (PMN, Eosinophils)
C5aRC5aR C5a Activation/Chemotaxis (PMN)C5a Activation/Chemotaxis (PMN) Acute Phase Response (Hepatocytes)Acute Phase Response (Hepatocytes) Platelet and Endothelial Cell ActivationPlatelet and Endothelial Cell Activation
In Vivo Roles of Complement RevealedIn Vivo Roles of Complement Revealedby Natural and Induced Deficiency Statesby Natural and Induced Deficiency States
Activation Pathway ProteinsActivation Pathway Proteins Regulatory ProteinsRegulatory Proteins- Protection from infection- Protection from infection - Protection of self cells- Protection of self cells
from complement injury from complement injury - Protection from immune - Protection from immune complex injurycomplex injury
C1 Activated C1
C4b + C2C4
C3D, P
C3b + B
C4b2a
C3bBb
C4b2a3b
C3bBbC3b
C1-INH
C4bBP iC4b
H iC3b
DAFMCP (I)
DAFMCP (I)
CD59
Decay DissociationI mediated cleavage
Decay DissociationI mediated cleavage
Complement System Activation and Regulation
MicrobesParasites
Ag-AbComplexes
C3b-Target
C3a
C3a
C5 C5b
C5a
C5a
C6-9MAC
Soluble and Membrane Proteins that Regulate Complement Activation
Soluble Serum ProteinC1 inhibitor
C4bpfactor HFactor I
Anaphylatoxin ActivatorS proteinSP-40,40
Integral Membrane Protein
CR1
Membrane Cofactor Protein
Decay Acceleration Factor
Homologous Restriction Factor
CD59
Normal Mechanisms of Complement InhibitionNormal Mechanisms of Complement Inhibition
MechanismMechanism ExampleExample TargetTarget1. Protease inhibitors1. Protease inhibitors C1-INHC1-INH C1r/C1sC1r/C1s
2. Proteases2. Proteases CarboxypeptidaseCarboxypeptidase C3a/C5aC3a/C5a
3. Decay-acceleration3. Decay-acceleration DAF (CD55)DAF (CD55) C3bBbC3bBb
4. Cofactor activity4. Cofactor activity MCP (CD46)MCP (CD46) C3bC3b
5. Inhibition of 5. Inhibition of CD59CD59 C5b-9 MACC5b-9 MAC assembly assembly
C3bC3bBb Bb
DAF DAF
C3b MCP C3b MCP iC3bMCP
Factor I
i
C3f
Membrane Protein Regulators of Complement Activation
Dissociation of C3 convertase
Inactivation of C3b
Homozygous Complement Deficiency -Disease Association
Immunologic Ds Infection Normal
C1, C2, C4 (n=112)
C3 (n=14)
C5-C8 (n=104)
Ross; Medicine 63: 243, 1984
Laboratory Tests in Deficiency of Complement Components
• CH50 - the reciprocal volume of patient serum necessary to lyse 50% of the sheep erythrocytes sensitized with anti-sheep erythrocytes antibody
• AH50 - the reciprocal volume of patient serum necessary to lyse 50% of the rabbit erythrocytes
감작면양혈구
보체활성화
용혈
혈청 계단희석
37C 항온
상층액 흡광도 측정
CH50
0102030405060708090
0 100 200 300
Dilutions of serum
% H
em
oly
sis
CH50 = 98
+
50% 용혈을 보인 혈청희석배수
Rabbit RBCDeposition of C3b Hemolysis
Serial dilutionsof pt’s serum
Incubation @ 37C Measurement of OD412
AH50
Algorithm for Complement AnalysisPatient with suspected complement deficiency
Serum
CH50 AH50
CH50 L or 0 AH50 Normal
CH50 L or 0AH50 L or 0
AH50 L or 0 CH50 Normal
NormalNo further testsnecessary
C1q, C1r, C1s levels or C1 function
C2 levels or function
C4 levels or function
C3, C5, C6, C7, C8, C9 levels or functions
Factor H, Factor I levels
Factor B level or function
Factor D function
Properdin level
• C3a (CP and AP)• C4a (CP)• C5a (CP and AP) • iC3b (CP and AP)• Bb (AP) • C4d (CP) • SC5b-9 (CP and AP)
EIARIA
Complement Split Products
Complement Activation ProfilesComplement Activation Profiles
PathwayPathway ProfileProfile ExamplesExamplesTHCTHC C4 C3 fBC4 C3 fB
ClassicalClassical L L L L L L Nl Nl SLE, RA with vasculitis,SLE, RA with vasculitis, mixed cryoglobulinemiamixed cryoglobulinemia
AlternativeAlternative L L NlNl L L L L Gn(-) septicemia, post-Gn(-) septicemia, post- streptoccal GN, C3Nefstreptoccal GN, C3Nef
BothBoth L L L L L L L L SLE, Type I Membrano-SLE, Type I Membrano- proliferative GNproliferative GN
Acute PhaseAcute Phase H H H H HH H H Infection, InflammatoryInfection, InflammatoryResponseResponse disorder, Pregnancy disorder, Pregnancy
TraumaActivate complement (~45min.) C3, C4 level decrease, C3a, C5a increase Depletion of complement components CH50 decrease, AH50 decrease Degree of C’ reduction is proportional to the severity of injury
Increased synthesis of complement protein Normalized levels of C’ proteins
Generation of large quantities of anaphylatoxin, C3a, C5a Desensitization of chemotactic effect of anaphylatoxin Decreased response of neutrophils Thermal injury preferentially alternative pathway affecteted
Complement Change in Sepsis
Continuous and persistent activation of complement system -Consumption of complement component Decreased CH50, AH50, Decreased or normal levels of C3, C4 Increased levels of activation products, C3a, C5a, Bb, sC5b-9 - Increased susceptibility to systemic infection
Excessive activation of complement - Anaphylatoxin cause hypotension including vasodilation, increased vascular permeability and histamine release. - Be prone to multiorgan failure, esp, adult respiratory distress syndrome
Chronological Changes in the Complement System in Sepsis H. Nakae, et al. Jpn J Surg 1996 26: 225-229
Time course of serum complement levels and the severity of sepsis
Method Measure C3a, C4a, C5a, CH50, C3, C4, C5 in the sera of pt with sepsis
Result CH50, C3 and C4 : significantly lower in non-surviving group than the surviving group
C3a, C4a, and C5a: significantly higher in non-surviving group than the surviving group
Complement profile may be useful for predicting the outcome of patientswith sepsis
B cell and antibodies improvement of bactericidal activity d/t neutralizing, opsonizing IgFc receptors stimulation of phagocytosisInflammation attenuation of complement mediated damage decrease in immune complex mediated inflammation induction of activation of endothelial cells neutralization of microbial toxinT cellCell growth
Immunoregulatory Effects of Immune Globulin
Effect of Intravenous Immunoglobulin on Complement System
Binding of C1q to Ig diverting the C attack
Binding of C3b, C4b to Ig from the target
Enhanced inactivation of C3b bound to immune complex
mainly by factor I
Idiopathic thrombocytopenic purpuraGuillain-Barre syndromeChronic inflammatory demyelinating polyradiculoneuropathyMyasthenia gravisMultifocal motor neutropathyCorticosteroid-resistant dermatomyositisKawasaki’s diseasePrevention of graft-versus host diseaseAntineutrophil cytoplasmic autoantibody positive vasculitisAutoimmune uveitisMultiple sclerosis
Autoimmune and Inflammatory Disease in Which the Beneficial Effect of IG Has Been Established
in Controlled Clinical Trials.
Prevention of Infection in Multiple Trauma Patients by High-dose Intravenous Immunoglobulin
E. E. Douzinas, et al. Crit Care Med 2000; 28: 8-15
Trauma patients receiving high dose of IVIg exhibit a reduction of septic complications and an improvement of serum bactericidal activity.
Supplemental Immune Globulins in Sepsis Karl Warden. Clin Chem Lab Med 1999; 37:341-349
The incidence of some severe infection is reduced by IVIg prophylaxisIVIg is not magic bullet of sepsis treatment but it may reduce mobidity. and represent a useful piece of combination treatment.
Objective : the possible protective role of C1inh was investigated
Method : Pigs were scalded with hot water
C1 inhibitor Tx group(n=8) and control group(n=7)
AH50, CH50, sC5b-9, C3
Result :
Edema formation reduced,
Cardiac output increased, Better oxygenation index(PO2/FIO2)
Higher CH50, AH50, lower sC5b-9 in Tx group received C1 inhibitor
C1 inhibitor Prevents Capillary Leakage after Thermal TraumaA Radke, et al. Crit Care Med 2000 28; 3224-3232
In burned pateints, activation of the complement is suggestedto play an important role in the development of the capillary leaksyndrome, sepsis and inflammatory tissue destruction.
IVIgs attenuate complement dependent tissue damage.
Application of IVIg is partly beneficial to prevent infection inmultiple trauma patients.
Complement inhibitors including IVIg are suggested to be a part of therapeutic modalities in burned patients.
Conclusion
A Novel Anti-human Factor B Monoclonal Antibody Inhibits Factor D-mediated Association
and Cleavage of Factor B
H. J. Kang, L. M. Mitchell, D. E. Hourcade, V. M. Holers
Dept. of Clinical Pathology, Hallym University College of Medicine
Dept. of Medicine, Washington University School of Medicine
Dept. of Medicine and Immunology,
University of Colorado Health Science Center
Factor BSerine ProteaseEssential for the initiation and propagation of the AP and amplification of the CP activity
Complement activation Pathogenic in various disease model Exact role of the AP : not clear
Well defined, inhibitory mAb to factor B Necessary for investigation of the role of AP
Immunization Protocol
Factor B deficient mice
Immunization with 50 ug purified human factor B and alum i.p.
1wk check serum anti-fB titer by ELISA
4wk boosting immunization (4 times)
Fusion of spleen cells to NY fox cell
Screening of clones by ELISA and Western Blot
Limiting Dilution
Obtaining hybridoma (E1128)
Fusion
E1128 mAb conjugated to activated sepharose 4B
A. fB + E1128 mAb-sepharose
B. fB + C3 + fD
C. C3 +fD
D. Buffer
wash
Elution with loading buffer
PAGE & Silver stain
Immunoprecipitation
A B C D
98 -
52 -
31 -
-20
0
20
40
60
80
100
120
1 10 100 1000 10000
Conc. of fB or fBa (nM) of fluid phase
% in
hib
itio
n
fB-fluid phase
fBa-fluid phase
The Inhibition of Binding of E1128 mAb to Immobilized fB by Fluid Phase fB or Ba
C G G L Y C P R C G W SCSLEGVEIKGCSFRLLQE---GQALEYVCPSGFYPYPVQTRTCRSTGSWSTLKTQDOKTVRKAE P-QN.N.S T.T.SHG SL.T.S Q.L..S -AS.L K.S.Q RSLS..V P.VNAYNQKA
C P NG Y D I F C GY G C G WRAIHCPRPHDFENGEYWPRSPYYNVSDEISFHCYDGYTLRGSANRTCQVNGRWSGQTAICKPVR A.VS I.T..LGS G.TVT.S S.FLFY PV.Q.RP..M D.E..V
C P G Y D V Y C G G C G WDNGACYCSNPGIPIGTRKVCSQYRLECSVTYHCSRGLTLRGSQRRTCQEGGSWSGTEPSCQDSFMYD H.P SL.AVRT FRFGHG K.R.R SN.V.T SE.E GN.V I.RQPYS
SCR1
SCR2
SCR3
1 2 3 4 5 6
7L
8
9 10 11 12L 13 14 15 16
17 18 19 20 21 22 23 24
Various factor B mutant for epitope analysis
Mut 2Mut 3
Putative Binding Site of E1128 mAb on X-Ray Model of MCP SCRs 1-2
Mut 1Mut 6Mut 8Mut 9
Type A VWF Trypsin-like SPSCR2 SCR3SCR1
BbBa
Factor D
NH2 COOH
Factor B
30kD 60kD
0
20
40
60
80
100
120
0 100 200 300 400 500
Conc. of MoAb (ug/mL)
% I
nh
ibit
ion
of
He
mo
lys
is
The Inhibition of Alternative Pathway by anti-hufB Monoclonal Antibody
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