Table Of ContentACTIVATORS AND INHIBITORS OF COMPLEMENT
ACTIVATORS AND
INHIBITORS OF
COMPLEMENT
edited by
R. B. SIM
M edical Research Council Scientific Staff and
University Research Lecturer,
University of Oxford, Oxford, U.K.
SPRINGER SCIENCE+BUSINESS MEDIA, B. V.
Library of Congress Cataloging-in-Publication Data
Activators and inhibitors of complement/edited by R.B. Sim.
p. cm.
Includes bibliographical references and index.
ISBN 978-94-010-5224-5 ISBN 978-94-011-2757-8 (eBook)
DOI 10.l007/978-94-011-2757-8
1. Complement activation. 2. Complement inhibition. I. Sim, R. B.
QRI85.8.C6.A28 1993
616.07'9--dc20 92-14814
ISBN 978-94-010-5224-5
printed on acid free paper
All Rights Reserved
© 1993 by Springer Science+Business Media Dordrecht
Originally published by K1uwer Academic Publishers in 1993
Softcover reprint of the hardcover 1s t edition 1993
No part of the material protected by this copyright notice may be reproduced or utilized in any
form or by any means, electronic or mechanical including photocopying, recording or by any
information storage and retrieval system, without written permission from copyright owner.
To
Margaret Mathieson Braidwood 1914-1986
and
Charles McIntosh Sim 1907-1988
Contents
List of Contributors IX
1. The Complement System 1
M.A. McAleer and R.B. Sim
2. The Structure of Immunoglobulins and Their Interaction with
Complement 17
D.R. Burton
3. Non-Immunoglobulin Activators of the Complement System 37
P.w. Taylor
4. Solid Phase Activators of the Alternative Pathway of Complement
and Their Use in vivo 69
P.D. Cooper
5. Nucleophilic Compounds Acting on C3 and C4 107
E. Sim, K.E. Parker and A. Jones
6. Effects of Drugs, Venoms and Charged Polymers on the Comple
ment System
I. von Zabern
6a. Effects of Venoms of Different Animal Species on the Comple-
ment System 127
6b. Drugs and Low Molecular Weight Compounds Affecting the
Complement System 137
6c. Action of Polyionic Substances on the Complement System 149
7. Monoclonal Antibodies Against the Terminal Complement Com-
ponents 167
R. Wiirzner
8. Autoantibodies Against Complement Components and Their Ef-
fects on Complement Activity 181
M. Loos, J. Alsenz, U. Antes and H.-P. Heinz
9. Use of Synthetic Pep tides in Exploring and Modifying Comple-
ment Reactivities 201
J.D. Lambris, J.D. Becherer, C. Servis and J. Alsenz
Index 233
vii
List of Contributors
JOCHEM ALSENZ
Institut fUr Medizinische Mikrobiologie, Johannes-Gutenberg Universitiit,
Augustplatz/Hochhaus, 6500 Mainz, Germany. Present Address: Basel Insti
tute for Immunology, Grenzacherstrasse 487, CH-4005 Basel, Switzerland
URSULA ANTES
Institut fUr Medizinische Mikrobiologie, Johannes-Gutenberg Universitiit,
Augustplatz/Hochhaus, 6500 Mainz, Germany
1. DAVID BECHERER
Basel Institute for Immunology, Grenzacherstrasse 487, CH-4005 Basel,
Switzerland
DENNIS R. BURTON
Department of Biochemistry, University of Sheffield, Sheffield S10 2TN,
U.K. Present Address: Research Institute for Scripps Clinic, Department of
Immunology, Scripps Clinic and Research Foundation, 10666 North Torrey
Pines Road, La Jolla, California 92037, USA
PETER D. COOPER
Division of Cell Biology, John Curtin School of Medical Research, Austra
lian National University, Canberra, ACT 2601, Australia
HANS-PETER HEINZ
Institut fUr Medizinische Mikrobiologie, Johannes-Gutenberg Universitiit,
Augustplatz/Hochhaus, 6500 Mainz, Germany
ALISON JONES
Department of Pharmacology, University of Oxford, Mansfield Road, Ox
ford OXl 3QT, UK
JOHN D. LAMBRIS
Basel Institute for Immunology, Grenzacherstrasse 487, CH-4005 Basel,
Switzerland. Present Address: Dept. of Pathology, Laboratory of Medicine,
University of Pennsylvania, Johnson Pavilion 410, Philadelphia Pa 19104,
USA
ix
x List of Contributors
MICHAEL LOOS
Institut fiir Medizinische Mikrobiologie, Johannes-Gutenberg Universitat,
AugustplatzjHochhaus, 6500 Mainz, Germany
MARCIA A. McALEER
MRC Immunochemistry Unit, Department of Biochemistry, University of
Oxford, South Parks Road, Oxford OXl 3QU, u.K. Present Address:
Nuffield Department of Surgery, John Radcliffe Hospital, Headington, Oxford
OX3 9DU, UK
KA Y E. PARKER
Department of Pharmacology, University of Oxford, Mansfield Road, Ox
ford OXl 3QT, U.K. Present Address: INSERM U-211, Plateau Technique
du CHR, Quai Moncousu, 44035 Nantes Cedex 01, France
CA THERINE SERVIS
Basel Institute for Immunology, Grenzacherstrasse 487, CH-4005 Basel,
Switzerland
EDITH SIM
Department of Pharmacology, Universty of Oxford, Mansfield Road, Ox
ford OXl 3QT, UK
ROBERT B. SIM
MRC Immunochemistry Unit, Department of Biochemistry, University of
Oxford, South Parks Road, Oxford OXl 3QU, UK
PETER W. TAYLOR
CIBA-Geigy Pharmaceuticals, Wimblehurst Road, Horsham, West Sussex
RHl2 4AB, UK
REINHARD WURZNER
MRC Immunochemistry Unit, Department of Biochemistry, University of
Oxford, South Parks Road, Oxford OXl 3QU, u.K. Present address: MRC
Molecular Immunopathology Unit, MRC Centre, Hills Road, Cambridge CE2
2QH, UK
INGE VON ZABERN
Max-Planck-Institut fUr Experimentelle Medizin, Abteilung Biochemische
Pharmakologie, Hermann-Rein-Strasse 3, 3400 Gottingen, Germany. Pres
ent Address: Klinikfur Aniisthesiologie der Universitiit Heidelberg, 1m Neuen
heimer Feld 110, 6900 Heidelberg, Germany
1. The complement
system
M. A. McALEER and R. B. SIM
The complement system is concerned with host defence against infection. The
system regulates the clearance or lysis of foreign cells, particles or macro
molecules and tissue breakdown products. It is composed of a series of proteins,
both membrane-bound and soluble, that interact with each other when the
system is activated by a number of different stimuli. Activation of complement
results in the assembly of bimolecular enzyme complexes (the C3 convertases),
one component of which is covalently bound to the surface of the complement
activator and the other is a catalytically active serine protease. This is able to
cleave and activate C3, the most abundant complement component. The major
fragment of activated C3, C3b, binds covalently to complement-activating
surfaces (e.g. cells, viruses). Once large amounts of C3b or proteolytic fragments
derived from C3b are deposited on activating surfaces phagocytosis of the coated
substance can occur. This occurs through the interaction of the surface-bound
C3 fragments with C3 receptors located on membranes of phagocytic cells. If the
complement activating substance is a cell, lysis and cell death can also occur
through a stepwise interaction involving the components C5, C6, C7, C8 and C9
which leads to assembly of the membrane attack complex (MAC). There are two
pathways of activation, the classical pathway and the alternative pathway
(Figure 1) [1]. Biochemical studies of complement proteins are far-advanced,
and complete amino acid sequences are available for most components. There is
now considerable interest in generating tertiary structures, so that the molecular
details of the protein-protein interactions of the system can be understood. Since
the system is involved in removal and killing of materials from the circulation
and tissues, it has considerable capacity to damage host tissue. In addition to the
beneficial effects of complement, undesirable complement-mediated tissue dam
age occurs in a wide range of situations, including mechanical injury, viral
infection, tissue damage initiated by autoantibodies, myocardial infarction and
rheumatoid arthritis. Diminished activity of the complement system is asso
ciated with susceptibility to infection and to inadequate removal of materials, e.g.
immune complexes, from the circulation, leading to lupus-like conditions and
possible damage to the small blood vessels particularly of the skin and kidneys.
There is therefore considerable interest in being able to manipulate the
R.B. Sim (ed.), Activators and Inhibitors of Complement, 1-15.
© 1993 Kluwer Academic Publishers.
2 M.A. McAleer and R.B. Sim
C3b deposition
and
C.:1b2a3b
""" ""'""c.~{ ~
(6
tj (7
C4b2a ____- .j
C3-C3b MAC
..
Ct3b
Activator
surface
C3(H20lBb and
C3b deposition
Figure 1. Activation of the complement system.
Activation of the classical pathway occurs via Cl, an assembly of three proteins, Clq, Clr
and CIs. Activated CIs cleaves C4 and C2, which form a complex, C4b2a (the C3 convertase
enzyme), which cleaves C3, forming C3b. C3b molecules bind covalently to the surface of
the complement activator, or react with water, and diffuse away. A C3b molecule binds covalently
to C4b2a, forming C4b2a3b (the C5 convertase enzyme), which cleaves C5, forming C5b. C6,7,8
and 9 then bind to C5b, forming the membrane attack complex (MAC) or terminal
complement complex (TCC).
In the alternative pathway, C3b formed by the classical pathway, or by the enzyme
C3(H 0)Bb, binds covalently to surfaces, via reaction with surface OH or NH2 groups. The
2
bound C3b may then be destroyed by control proteins (factor I and a cofactor such as
CRl, MCP or factor H), or it may form a C3bB complex, which is activated by factor D, to
form C3bBb, the alternative pathway C3 convertase enzyme, which converts more C3 to
C3b. Covalent deposition of a C3b molecule onto the C3bBb enzyme converts it to C3b Bb
2
(also written as C3bBbC3b) which activates C5, with subsequent assembly of the MAC.
Sites of action of the control proteins (boxed) are shown. Important biologically active
fragments are released during proteolytic activation of the complement proteins: these include
Ba and the anaphylotoxin and chemotactic factors C4a, C3a and C5a, released on activation
of factor B, C4, C3, and C5 respectively.
complement system for therapeutic purposes. The following chapters in this
book indicate the range of materials, natural or synthetic, which affect the
complement system, and illustrate some of the approaches used to alter the
activity of the system, in vitro or in vivo.
The classical pathway: activation and components
The classical pathway of complement consists of a group of 11 plasma
glycoproteins: C1q; C1r; C1s; C4; C2; C3; C5; C6; C7; C8 and C9. The irregularity
in numbering of components reflects the order in which components were first
The Complement System 3
identified. There are also several plasma glycoproteins that are involved in the
regulation of activation of this pathway as well as a number of membrane
associated molecules which act as reglators and/or receptors for fragments of
activated complement [2]. The proteins C5-C9 (the late components of
complement) are common to the alternative pathway and the glycoprotein C3
has a central role in both pathways (Figure 1). Properties of the soluble proteins
of the system are summarised in Table 1.
Table 1. Properties of the soluble complement proteins
Protein mo!.wt serum conc. no of poly peptide homology group or
(kD) (mgjlitre) chains homologues
Clq 465 80-100 18 MBP, SPA
Clr 85 35-50 1, cleaved to serine protease
2 on activation
Cis 85 35-50 1, cleaved to serine protease
2 on activation
C4 195 300-450 3 C3, C5, a2m
C2 110 15-25 1, cleaved to abnormal serine protease
2 on activation homo!. to factor B
C3 185 1000-1350 2 C4, C5, a2m
C5 185 60-90 2 C3, C4, a2m
C6 120 60-90 homologous to C7, C9
C8 a and fJ chains
C7 115 50-80 homologous to C6, C9,
C8 a and fJ chains
C8 160 60-100 3 a and fJ chains homologous
to C6, C7, C9
C9 75 50-80 homologous to C6, C7, C8
a and fJ chains
Factor B 90 180-250 1, cleaved to abnormal serine protease
2 on activation homo!. to C2
Factor D 25 2 1 serine protease
Properdin 220 20-30 oligomeric, usually thrombospondin
tetramer of 56kD
subunit
Factor H 155 200-700 1 member of RCA family,
with CRl, CR2, MCP, DAF
Factor I 88 30-40 2 serine protease
C4bp 540 200-400 7 x 70kD plus member of RCA family,
1 x 50kD with CRl, CR2, MCP, DAF
CI-Inh 110 150-300 1 serpin
Clq is the molecule that interacts with the activator, and so provides the
specificity in activation of this pathway. Classical pathway activation is most
commonly studied using immune complexes, containing IgG or IgM antibodies
as the activator. Many other substances however, in the absence of antibody,
such as viral membranes and Gram negative bacteria are also able to activate the
classical pathway. Immunoglobulin and non-immunoglobulin activators are
discussed in detail in chapters 2 and 3.
