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Structural and functional studies of novel viral complement inhibitors

Mark, Linda LU (2006) In 2006:140
Abstract
Viruses have developed several strategies to evade the complement system, a part of the immune system. The fourth open reading frame of the human virus Kaposi's sarcoma-associated herpesvirus (KSHV) encodes a type 1 transmembrane protein. This contains four complement control protein domains (CCP domains), and is thus structurally similar to human complement inhibitors. We named it KSHV complement control protein (KCP). Using recombinant KCP, we showed that it can inhibit the complement system by disrupting a key enzymatic complex, the C3 convertase. We predicted the 3D structure of KCP by homology modeling. Functionally important sites in KCP were mapped using mutants where either one to three amino acids, or entire CCP domains, were... (More)
Viruses have developed several strategies to evade the complement system, a part of the immune system. The fourth open reading frame of the human virus Kaposi's sarcoma-associated herpesvirus (KSHV) encodes a type 1 transmembrane protein. This contains four complement control protein domains (CCP domains), and is thus structurally similar to human complement inhibitors. We named it KSHV complement control protein (KCP). Using recombinant KCP, we showed that it can inhibit the complement system by disrupting a key enzymatic complex, the C3 convertase. We predicted the 3D structure of KCP by homology modeling. Functionally important sites in KCP were mapped using mutants where either one to three amino acids, or entire CCP domains, were altered.



We also found that a patch of positively charged amino acids in CCP 1-2 of KCP can bind to heparin and weakly to heparin like proteoglycans at the surface of cells, which seems to aid the virus in the attachment step prior to cell entry.



In order to study the biological role of complement inhibition for this type of virus, we want to use the KSHV homologue rhesus rhadinovirus (RRV), since this virus is both technically easier to work with than KCP and also permits in vivo studies, by naturally infecting Rhesus Macaques. RRV complement control protein (RCP) is the KCP homologue in RRV. We have characterized its gene, confirmed that RCP is expressed and present on the surface of virus and performed experiments indicating that it is a functional complement inhibitor. (Less)
Abstract (Swedish)
Popular Abstract in Swedish

Komplementsystemet är en del av immunförsvaret. Virus har utarbetat sätt för att skydda sig från komplementsystemet. Det humana herpesviruset KSHV (Kaposi's sarcoma-associated herpesvirus) har i sitt genom en gen som kodar för ett protein som vi har döpt till KCP (KSHV complement control protein). KCP har en transmembran del och en extracellulär del med fyra proteindomäner kallade CCP (complement control protein). Detta gör KCP strukturellt lik en grupp av mänskliga komplementhämmare. Vi har producerat rekombinant KCP och visat att det hämmar komplementsystemet genom att verka på ett nyckelkomplex, C3-konvertaset. Vi har gjort en teoretisk modell över KCPs tredimensionella struktur och sedan... (More)
Popular Abstract in Swedish

Komplementsystemet är en del av immunförsvaret. Virus har utarbetat sätt för att skydda sig från komplementsystemet. Det humana herpesviruset KSHV (Kaposi's sarcoma-associated herpesvirus) har i sitt genom en gen som kodar för ett protein som vi har döpt till KCP (KSHV complement control protein). KCP har en transmembran del och en extracellulär del med fyra proteindomäner kallade CCP (complement control protein). Detta gör KCP strukturellt lik en grupp av mänskliga komplementhämmare. Vi har producerat rekombinant KCP och visat att det hämmar komplementsystemet genom att verka på ett nyckelkomplex, C3-konvertaset. Vi har gjort en teoretisk modell över KCPs tredimensionella struktur och sedan hittat ställen som var viktiga för KCPs funktion, genom punktmutationer och domändeletioner. Vi har också funnit att en positivt laddad region i den första och andra CCP domänen binder till heparin och heparinliknande molekyler på ytan av celler. Det verkar som att KCP på ytan av virus därmed bidrar till att virusen ankrar på nya värdceller som ett första steg mot infektion av dessa celler. För att kunna studera hur viktig KCPs komplementinhibering och cellankring är för den här typen av virus så vill vi använda oss av en homolog till KSHV som heter RRV (rhesus rhadinovirus). RRV är tekniskt lättare att arbeta med än KSHV och djurförsök skulle kunna vara möjliga. RRV kodar för en homolog till KCP, vilken vi döpt till RCP (RRV complement control protein). Vi har karaktäriserat dess gen och genprodukt och konfirmerat att RCP finns uttryckt på ytan av virus. Vi har också gjort experiment som indikerar att det är en funktionell komplementhämmare. (Less)
Please use this url to cite or link to this publication:
author
supervisor
opponent
  • Dr Rodriguez de Cordoba, Santiago, Departamento de Inmunologia,
organization
publishing date
type
Thesis
publication status
published
subject
keywords
transplantation, serologi, serology, Kaposi's sarcoma-associated herpesvirus, Immunologi, Immunology, homology modeling, complement inhibitor
in
2006:140
pages
125 pages
publisher
Department of Laboratory Medicine, Lund University
defense location
Lilla aulan, ing 59 ,UMAS, Malmö
defense date
2006-12-08 09:15:00
ISSN
1652-8220
ISBN
91-85559-62-8
language
English
LU publication?
yes
additional info
id
549b4603-9409-4662-a273-95a9018af58a (old id 547606)
date added to LUP
2016-04-01 16:55:37
date last changed
2019-05-21 08:45:40
@phdthesis{549b4603-9409-4662-a273-95a9018af58a,
  abstract     = {Viruses have developed several strategies to evade the complement system, a part of the immune system. The fourth open reading frame of the human virus Kaposi's sarcoma-associated herpesvirus (KSHV) encodes a type 1 transmembrane protein. This contains four complement control protein domains (CCP domains), and is thus structurally similar to human complement inhibitors. We named it KSHV complement control protein (KCP). Using recombinant KCP, we showed that it can inhibit the complement system by disrupting a key enzymatic complex, the C3 convertase. We predicted the 3D structure of KCP by homology modeling. Functionally important sites in KCP were mapped using mutants where either one to three amino acids, or entire CCP domains, were altered.<br/><br>
<br/><br>
We also found that a patch of positively charged amino acids in CCP 1-2 of KCP can bind to heparin and weakly to heparin like proteoglycans at the surface of cells, which seems to aid the virus in the attachment step prior to cell entry.<br/><br>
<br/><br>
In order to study the biological role of complement inhibition for this type of virus, we want to use the KSHV homologue rhesus rhadinovirus (RRV), since this virus is both technically easier to work with than KCP and also permits in vivo studies, by naturally infecting Rhesus Macaques. RRV complement control protein (RCP) is the KCP homologue in RRV. We have characterized its gene, confirmed that RCP is expressed and present on the surface of virus and performed experiments indicating that it is a functional complement inhibitor.},
  author       = {Mark, Linda},
  isbn         = {91-85559-62-8},
  issn         = {1652-8220},
  language     = {eng},
  publisher    = {Department of Laboratory Medicine, Lund University},
  school       = {Lund University},
  series       = {2006:140},
  title        = {Structural and functional studies of novel viral complement inhibitors},
  year         = {2006},
}