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Separation of decay-accelerating and cofactor functional activities of Kaposi's sarcoma-associated herpesvirus complement control protein using monoclonal antibodies

Mark, Linda; Proctor, David G; Blackbourn, David J; Blom, Anna LU and Spiller, O. Brad (2008) In Immunology 123(2). p.228-238
Abstract
Complement is an essential part of the innate immune system, which clears pathogens without requirement for previous exposure, although it also greatly enhances the efficacy and response of the cellular and humoral immune systems. Kaposi's sarcoma-associated herpesvirus (KSHV) is the most recently identified human herpesvirus and the likely aetiological agent of Kaposi's sarcoma, primary effusion lymphoma and multicentric Castleman's disease. We previously reported that the KSHV complement control protein (KCP) was expressed on infected cells and virions, and could inhibit complement through decay-accelerating activity (DAA) of the classical C3 convertase and cofactor activity (CFA) for factor I (FI)-mediated degradation of C4b and C3b, as... (More)
Complement is an essential part of the innate immune system, which clears pathogens without requirement for previous exposure, although it also greatly enhances the efficacy and response of the cellular and humoral immune systems. Kaposi's sarcoma-associated herpesvirus (KSHV) is the most recently identified human herpesvirus and the likely aetiological agent of Kaposi's sarcoma, primary effusion lymphoma and multicentric Castleman's disease. We previously reported that the KSHV complement control protein (KCP) was expressed on infected cells and virions, and could inhibit complement through decay-accelerating activity (DAA) of the classical C3 convertase and cofactor activity (CFA) for factor I (FI)-mediated degradation of C4b and C3b, as well as acting as an attachment factor for binding to heparan sulphate on permissive cells. Here, we determined the ability of a panel of monoclonal anti-KCP antibodies to block KCP functions relative to their recognized epitopes, as determined through binding to recombinant KCP containing large (entire domain) or small (2-3 amino acid residue) alterations. One antibody recognizing complement control protein (CCP) domain 1 blocked heparin binding, DAA and C4b CFA, but was poor at blocking C3b CFA, while a second antibody recognizing CCP4 blocked C3b CFA and 80% DAA, but not C4b CFA or heparan sulphate binding. Two antibodies recognizing CCP2 and CCP3 were capable of blocking C3b and C4b CFA and heparan sulphate binding, but only one could inhibit DAA. These results show that, while KCP is a multifunctional protein, these activities do not completely overlap and can be isolated through incubation with monoclonal antibodies. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Kaposi’s sarcoma-associated herpesvirus, human herpesvirus (HHV)-8, complement, complement inhibition, complement control protein domains, virus, antibodies
in
Immunology
volume
123
issue
2
pages
228 - 238
publisher
Wiley-Blackwell
external identifiers
  • pmid:17764451
  • wos:000252208800009
  • scopus:37849014064
ISSN
0019-2805
DOI
10.1111/j.1365-2567.2007.02692.x
language
English
LU publication?
yes
id
fa37c069-8a34-4cb7-9d52-ef723cda36cb (old id 1138708)
date added to LUP
2008-04-29 09:29:45
date last changed
2017-02-26 03:42:00
@article{fa37c069-8a34-4cb7-9d52-ef723cda36cb,
  abstract     = {Complement is an essential part of the innate immune system, which clears pathogens without requirement for previous exposure, although it also greatly enhances the efficacy and response of the cellular and humoral immune systems. Kaposi's sarcoma-associated herpesvirus (KSHV) is the most recently identified human herpesvirus and the likely aetiological agent of Kaposi's sarcoma, primary effusion lymphoma and multicentric Castleman's disease. We previously reported that the KSHV complement control protein (KCP) was expressed on infected cells and virions, and could inhibit complement through decay-accelerating activity (DAA) of the classical C3 convertase and cofactor activity (CFA) for factor I (FI)-mediated degradation of C4b and C3b, as well as acting as an attachment factor for binding to heparan sulphate on permissive cells. Here, we determined the ability of a panel of monoclonal anti-KCP antibodies to block KCP functions relative to their recognized epitopes, as determined through binding to recombinant KCP containing large (entire domain) or small (2-3 amino acid residue) alterations. One antibody recognizing complement control protein (CCP) domain 1 blocked heparin binding, DAA and C4b CFA, but was poor at blocking C3b CFA, while a second antibody recognizing CCP4 blocked C3b CFA and 80% DAA, but not C4b CFA or heparan sulphate binding. Two antibodies recognizing CCP2 and CCP3 were capable of blocking C3b and C4b CFA and heparan sulphate binding, but only one could inhibit DAA. These results show that, while KCP is a multifunctional protein, these activities do not completely overlap and can be isolated through incubation with monoclonal antibodies.},
  author       = {Mark, Linda and Proctor, David G and Blackbourn, David J and Blom, Anna and Spiller, O. Brad},
  issn         = {0019-2805},
  keyword      = {Kaposi’s sarcoma-associated herpesvirus,human herpesvirus
(HHV)-8,complement,complement inhibition,complement control protein
domains,virus,antibodies},
  language     = {eng},
  number       = {2},
  pages        = {228--238},
  publisher    = {Wiley-Blackwell},
  series       = {Immunology},
  title        = {Separation of decay-accelerating and cofactor functional activities of Kaposi's sarcoma-associated herpesvirus complement control protein using monoclonal antibodies},
  url          = {http://dx.doi.org/10.1111/j.1365-2567.2007.02692.x},
  volume       = {123},
  year         = {2008},
}