Table Of ContentCharacterization of antibody specificity
using peptide array technologies
Björn Forsström
Kungliga Tekniska Högskolan, KTH
Royal Institute of Technology
School of Biotechnology
Stockholm 2014
(cid:13)c Björn Forsström 2014
KTH, Royal Institute of Technology
School of Biotechnology
Division of Proteomics and Nanobiotechnology
Science for Life Laboratory
Tomtebodavägen 23A
171 65 Solna, Sweden
ISBN 978-91-7595-316-8
TRITA-BIO Report 2014:16
ISSN 1654-2312
Printed by US-AB 2014
Abstract
Antibodiesplayanimportantroleinthenaturalimmuneresponsetoinvading
pathogens. The strong and specific binding to their antigens also make them
indispensable tools for research, diagnostics and therapy.
This thesis describes the development of methods for characterization of an-
tibody specificity and the use of these methods to investigate the polyclonal
antibody response after immunization. Paper I describes the development
of an epitope-specific serum fractionation technique based on epitope map-
ping using overlapping peptides followed by chromatographic separation of
polyclonal serum. This technique together with another epitope mapping
technique based on bacterial display of protein fragments were then used to
generate antibody sandwich pairs (Paper I), investigate epitope variations of
repeated immunizations (Paper II) and to determine the ratio of antibodies
targeting linear and conformational epitopes of polyclonal antibodies (Paper
III). Paper IV describes the optimization of in situ-synthesized high-density
peptide arrays for epitope mapping and how different peptide lengths influ-
ence epitope detection and resolution. In Paper V we show the development
of planar peptide arrays covering the entire human proteome and how these
arrays can be used for epitope mapping and off-target binding analysis. In
Paper VI we show how polyclonal antibodies targeting linear epitopes can
be used for peptide enrichment in a rapid, absolute protein quantification
protocol based on mass spectrometry.
Altogether these investigations demonstrate the usefulness of peptide arrays
for fast and straightforward characterization of antibody specificity. The
work also contributes to a deeper understanding of the polyclonal anti-
body response obtained after immunization with recombinant protein frag-
ments.
Keywords: Antibody, Epitope mapping, Peptide array, Suspension bead
array, Antigen, Specificity, Cross-reactivity, Immunization, Immunogenic-
ity
iii
Populärvetenskaplig sammanfattning
Antikroppar är molekyler i kroppens immunförsvar som skyddar oss genom att
neutralisera till exempel virus, bakterier och gifter. Vid en infektion eller immu-
nisering (vaccinering) bildas det antikroppar som specifikt binder till de antigen,
d.v.s. främmande molekyler och celler, som orsakat antikroppssvaret. Den mycket
specifika interaktionen mellan en antikropp och dess antigen är en egenskap som
gör antikroppar till utmärkta forskningsredskap för att detektera kroppens olika
proteiner, men också för att diagnostisera och behandla sjukdomar.
För att ta fram en antikropp som är specifik mot ett visst protein så kan man
immunisera ett djur med proteinet. Djuret producerar då antikroppar mot pro-
teinet och dessa kan sedan renas fram ur djurets serum. För att kunna lita på
resultat från antikroppsbaserade tester så måste man först validera antikroppens
specificitet mot antigenet så att man vet att den faktiskt binder det den ska och
att den inte binder andra proteiner. En viktig del av valideringen är att ta reda
på vilka delar av proteinet som antikroppen binder till. Dessa delar kallas epitoper
och det finns många olika tekniker för att kartlägga var dessa är lokaliserade på
proteinet, s.k epitopmappning.
Den här avhandlingen är baserad på fem publicerade artiklar och ett manuskript
somharepitopmappningsomrödtråd. IPaperI,IIochIIIanvändsepitopmapp-
ningtillsammansmedenepitopspecifikfraktioneringförattfåenökadförståelseför
det antikroppssvar som uppstår efter immunisering med proteinfragment. Vi visar
att bara ett fåtal av alla antikroppar med olika epitopspecificiteter bidrar till den
önskade bindningen i flera vanliga antikroppsbaserade analyser och att antikrop-
parnatillstörstadelbindertilllinjära epitoper. Vivisarocksåattantikropparsom
kommer från upprepade immuniseringar med samma antigen har stora likheter i
epitopspecificitet, men att de är långt ifrån identiska. Paper IV och V beskriver
utvecklingen av peptidarrayer med hög densitet, d.v.s. ordnade ytor av miljontals
proteindelar och hur dessa kan användas för epitopmappning samt analys av an-
tikroppars bindning till delar av alla människans proteiner. I Paper VI beskriver
vi utvecklingen av en metod för att med hjälp av antikroppar anrika peptider från
biologiska prover och hur det tillsammans med masspektrometri möjliggör snabb
analys av flera proteiner på samma gång.
iv
Thesis defense
This thesis will be defended November 28th 2014 at 10.15, in Gar-
daulan, Folkhälsomyndigheten, Nobels väg 18, Solna, for the degree
of Doctor of Technology in Biotechnology.
Respondent:
Björn Forsström graduated as master of science in engineering from KTH
Biotechnology in 2008 and worked as research engineer within the Human
Protein Atlas-project before starting his PhD studies at the Division of Pro-
teomics and Nanobiotechnology, KTH.
Faculty opponent:
Markus Templin, Head of the Department of Assay Development at the
Natura and Medical Sciences Institute (NMI), University of Tübingen, Ger-
many
Evaluation committee:
Marita Troye-Blomberg, Professor at Stockholm University, The Wenner-
Gren Institute, Immunology
Mats A. A. Persson, Associate Professor at Karolinska Institutet, Depart-
ment of Clinical Neuroscience, Center for Molecular Medicine
Ola Söderberg, Senior lecturer at Uppsala University, Department of Im-
munology, Genetics and Pathology
Chairman:
Stefan Ståhl, professor at KTH, School of Biotechnology, Division of Protein
Technology
Main supervisor:
Mathias Uhlén, professor at KTH, School of Biotechnology, Division of Pro-
teomics and Nanobiotechnology
Co-supervisor:
Henrik Johannesson, Group Leader, Research and Development, Atlas Anti-
bodies AB.
v
List of publications
The presented thesis is based on the following six articles, referred to by their
Roman numerals (I-VI). All articles are included in the Appendix.
Paper I - Barbara Hjelm, Björn Forsström, Ulrika Igel, Henrik Johan-
nesson, Charlotte Stadler, Emma Lundberg, Fredrik Pontén, Anna Sjöberg,
Johan Rockberg, Jochen M. Schwenk, Peter Nilsson, Christine Johansson,
Mathias Uhlén (2011). Generation of monospecific antibodies based on affin-
ity capture of polyclonal antibodies. Protein Science 20(11): 1824-35 doi:
10.1002/pro.716
Paper II - Barbara Hjelm, Björn Forsström, John Löfblom, Johan Rock-
berg, Mathias Uhlén (2012). Parallel immunizations of rabbits using the
same antigen yield antibodies with similar, but not identical, epitopes. PLoS
One 7(12): e45817 doi: 10.1371/journal.pone.0045817
Paper III - Björn Forsström, Barbara Bisławska Axnäs, Johan Rockberg,
Hanna Danielsson, Anna Bohlin, Mathias Uhlén. Dissecting antibodies with
regardstolinearandconformationalepitopes. Manuscript submitted to PLoS
One
Paper IV - Søren Buus, Johan Rockberg, Björn Forsström, Peter Nilsson,
Mathias Uhlén, Claus Schafer-Nielsen (2012) High-resolution mapping of lin-
earantibodyepitopesusingultrahigh-densitypeptidemicroarrays. Molecular
& CellularProteomics 11(12): 1790-800doi: 10.1074/mcp.M112.020800
Paper V - Björn Forsström, Barbara Bisławska Axnäs, Klaus-Peter Sten-
gele, Jochen Bühler, Thomas J. Albert, Todd A. Richmond, Francis Jingxin
Hu, Peter Nilsson, Elton P. Hudson, Johan Rockberg, Mathias Uhlén (2014).
Proteome-wide epitope mapping of antibodies using ultra-dense peptide ar-
rays. Molecular & Cellular Proteomics 13(6): 1585-97 doi: 10.1074/mcp.
M113.033308
vi
Paper VI - Fredrik Edfors*, Tove Boström*, Björn Forsström, Marlis
Zeiler, Henrik Johansson, Emma Lundberg, Sophia Hober, Janne Lehtiö,
Matthias Mann, Mathias Uhlén (2014). Immunoproteomics using polyclonal
antibodies and stable isotope-labeled affinity-purified recombinant proteins.
Molecular & Cellular Proteomics 13(6): 1611-24 doi: 10.1074/mcp.
M113.034140
*Both authors contributed equally to the work.
vii
Abbreviations
3D Three-dimensional
ANLN Actin-binding protein anilin
BCR B cell receptor
C-terminus Carboxy-terminus
CDR Complementarity determining region
CNDP1 Carnosine dipeptidase 1
CTL Cytotoxic T lymphocyte
DNA Deoxyribonucleic acid
Fab Fragment antigen binding
Fc Fragment crystallizable
Ig Immunoglobulin
K Equilibrium dissociation constant
D
k Association rate constant
off
k Dissociation rate constant
on
LC-MS/MS Liquid chromatography-tandem mass spectrometry
MHC Major histocompatibility complex
N-terminus Amino-terminus
PCR Polymerase chain reaction
PODXL Podocalyxin-like protein
PrEST Protein epitope signature tag
RBM3 RNA-binding protein 3
SATB2 Special AT-rich binding protein 2
scFv Single-chain variable fragment
siRNA Short interfering ribonucleic acid
TCR T cell receptor
T cell Helper T cell
H
TYMP Thymidine phosphorylase
ix
Contents
Abstract . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iii
Populärvetenskaplig sammanfattning . . . . . . . . . . . . . . . . . iv
Thesis defense . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . v
List of publications . . . . . . . . . . . . . . . . . . . . . . . . . . . vi
Abbreviations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ix
1 Introduction 1
Antibodies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Antibody structure . . . . . . . . . . . . . . . . . . . . . . . . 1
The immune system . . . . . . . . . . . . . . . . . . . . . . . 3
Antibody diversity . . . . . . . . . . . . . . . . . . . . . . . . 3
B cell activation, clonal expansion, affinity maturation and
class switching . . . . . . . . . . . . . . . . . . . . . . 6
Antibodies for research, diagnosis and therapy . . . . . . . . . . . . 9
Epitopes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Immunization and generation of polyclonal antibodies . . . . . 9
Immunogens . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Monoclonal antibodies . . . . . . . . . . . . . . . . . . . . . . 12
Array technologies . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Protein microarrays . . . . . . . . . . . . . . . . . . . . . . . . 14
Peptide microarrays . . . . . . . . . . . . . . . . . . . . . . . . 15
Suspension bead arrays . . . . . . . . . . . . . . . . . . . . . . 17
Reverse phase protein arrays . . . . . . . . . . . . . . . . . . . 17
Antibody arrays . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Characterization of antibody binding . . . . . . . . . . . . . . . . . 18
x
Description:The antigen binding sites, or complementarity determining regions (CDRs) bacterial cell walls, and in response produce unspecific antimicrobial sub- . random antibody specificities and selecting only those that bind, the . Antibodies intended for research are made to bind target proteins and the.