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The role of higher-order protein structure in supporting binding by heteroclitic monoclonal antibodies: The monoclonal antibody KIM185 to CD18 also binds C4-binding protein

Gjelstrup, Louise Carstensen; Andersen, Stig Henrik; Petersen, Steen Yang; Enghild, Jan J.; Blom, Anna LU ; Vorup-Jensen, Thomas and Thiel, Steffen (2011) In Molecular Immunology 49(1-2). p.38-47
Abstract
Heteroclitic monoclonal antibodies are characterized by the ability to bind multiple epitopes with little or no similarity. Such antibodies have been reported earlier, but insight into to the molecular basis of this propensity is limited. Here we report that the KIM185 antibody to human CD18 reacts with the plasma protein C4b-binding protein (C4BP). This was revealed during affinity purification procedures where human serum was incubated with surfaces coated with monoclonal antibodies to CD18. Other monoclonal antibodies to CD18 (KIM127 and TS1/18) showed no such interaction with C4BP. We constructed a sandwich-type time-resolved immunofluorometric assay using KIM185 both as capture and developing antibody. By use of proteolytic fragments... (More)
Heteroclitic monoclonal antibodies are characterized by the ability to bind multiple epitopes with little or no similarity. Such antibodies have been reported earlier, but insight into to the molecular basis of this propensity is limited. Here we report that the KIM185 antibody to human CD18 reacts with the plasma protein C4b-binding protein (C4BP). This was revealed during affinity purification procedures where human serum was incubated with surfaces coated with monoclonal antibodies to CD18. Other monoclonal antibodies to CD18 (KIM127 and TS1/18) showed no such interaction with C4BP. We constructed a sandwich-type time-resolved immunofluorometric assay using KIM185 both as capture and developing antibody. By use of proteolytic fragments of KIM185 and recombinant deletion mutants of C4BP the interaction sites were mapped to the variable region of KIM185 and the oligomerization domain of C4BP, respectively. C4BP is a large oligomeric plasma protein that binds activated complement factor C4b and other endogenous ligands as well as microorganisms. By use of the recent crystallographic data on the structure of CD11c/CD18 and prediction of the secondary structure of the C4BP oligomerization domain, we show that epitopes bound by KIM185 in these proteins are unlikely to share any major structural similarity. However, both antigens may form oligomers that would enable avid binding by the antibody. Our report points to the astonishing ability of heteroclitic antibodies to accommodate the binding of multiple proteins with no or little structural similarity within the confined space of the variable regions. (C) 2011 Elsevier Ltd. All rights reserved. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
beta(2) integrin, C4 binding protein, Antibody cross reactivity, Heteroclitic antibodies
in
Molecular Immunology
volume
49
issue
1-2
pages
38 - 47
publisher
Pergamon
external identifiers
  • wos:000298117800006
  • scopus:82455199178
ISSN
1872-9142
DOI
10.1016/j.molimm.2011.07.018
language
English
LU publication?
yes
id
9b31f5b7-908c-4764-9ce1-db7ea6dfcca7 (old id 2333539)
date added to LUP
2012-02-01 07:39:12
date last changed
2017-01-01 05:51:06
@article{9b31f5b7-908c-4764-9ce1-db7ea6dfcca7,
  abstract     = {Heteroclitic monoclonal antibodies are characterized by the ability to bind multiple epitopes with little or no similarity. Such antibodies have been reported earlier, but insight into to the molecular basis of this propensity is limited. Here we report that the KIM185 antibody to human CD18 reacts with the plasma protein C4b-binding protein (C4BP). This was revealed during affinity purification procedures where human serum was incubated with surfaces coated with monoclonal antibodies to CD18. Other monoclonal antibodies to CD18 (KIM127 and TS1/18) showed no such interaction with C4BP. We constructed a sandwich-type time-resolved immunofluorometric assay using KIM185 both as capture and developing antibody. By use of proteolytic fragments of KIM185 and recombinant deletion mutants of C4BP the interaction sites were mapped to the variable region of KIM185 and the oligomerization domain of C4BP, respectively. C4BP is a large oligomeric plasma protein that binds activated complement factor C4b and other endogenous ligands as well as microorganisms. By use of the recent crystallographic data on the structure of CD11c/CD18 and prediction of the secondary structure of the C4BP oligomerization domain, we show that epitopes bound by KIM185 in these proteins are unlikely to share any major structural similarity. However, both antigens may form oligomers that would enable avid binding by the antibody. Our report points to the astonishing ability of heteroclitic antibodies to accommodate the binding of multiple proteins with no or little structural similarity within the confined space of the variable regions. (C) 2011 Elsevier Ltd. All rights reserved.},
  author       = {Gjelstrup, Louise Carstensen and Andersen, Stig Henrik and Petersen, Steen Yang and Enghild, Jan J. and Blom, Anna and Vorup-Jensen, Thomas and Thiel, Steffen},
  issn         = {1872-9142},
  keyword      = {beta(2) integrin,C4 binding protein,Antibody cross reactivity,Heteroclitic antibodies},
  language     = {eng},
  number       = {1-2},
  pages        = {38--47},
  publisher    = {Pergamon},
  series       = {Molecular Immunology},
  title        = {The role of higher-order protein structure in supporting binding by heteroclitic monoclonal antibodies: The monoclonal antibody KIM185 to CD18 also binds C4-binding protein},
  url          = {http://dx.doi.org/10.1016/j.molimm.2011.07.018},
  volume       = {49},
  year         = {2011},
}