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Steer B, Adler B, Jonjic S, Stewart JP, Adler H. A gammaherpesvirus complement regulatory protein promotes initiation of infection by activation of protein kinase Akt/PKB. PLoS One 2010; 5:e11672. [PMID: 20657771 PMCID: PMC2908122 DOI: 10.1371/journal.pone.0011672] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2010] [Accepted: 06/27/2010] [Indexed: 12/22/2022] Open
Abstract
Background Viruses have evolved to evade the host's complement system. The open reading frames 4 (ORF4) of gammaherpesviruses encode homologs of regulators of complement activation (RCA) proteins, which inhibit complement activation at the level of C3 and C4 deposition. Besides complement regulation, these proteins are involved in heparan sulfate and glycosaminoglycan binding, and in case of MHV-68, also in viral DNA synthesis in macrophages. Methodology/Principal Findings Here, we made use of MHV-68 to study the role of ORF4 during infection of fibroblasts. While attachment and penetration of virions lacking the RCA protein were not affected, we observed a delayed delivery of the viral genome to the nucleus of infected cells. Analysis of the phosphorylation status of a variety of kinases revealed a significant reduction in phosphorylation of the protein kinase Akt in cells infected with ORF4 mutant virus, when compared to cells infected with wt virus. Consistent with a role of Akt activation in initial stages of infection, inhibition of Akt signaling in wt virus infected cells resulted in a phenotype resembling the phenotype of the ORF4 mutant virus, and activation of Akt by addition of insulin partially reversed the phenotype of the ORF4 mutant virus. Importantly, the homologous ORF4 of KSHV was able to rescue the phenotype of the MHV-68 ORF4 mutant, indicating that ORF4 is functionally conserved and that ORF4 of KSHV might have a similar function in infection initiation. Conclusions/Significance In summary, our studies demonstrate that ORF4 contributes to efficient infection by activation of the protein kinase Akt and thus reveal a novel function of a gammaherpesvirus RCA protein.
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Affiliation(s)
- Beatrix Steer
- The Institute of Molecular Immunology, Clinical Cooperation Group Hematopoietic Cell Transplantation, Helmholtz Zentrum München - German Research Center for Environmental Health, Munich, Germany
| | - Barbara Adler
- Max von Pettenkofer-Institute, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Stipan Jonjic
- Department of Histology and Embryology, Faculty of Medicine, University of Rijeka, Rijeka, Croatia
| | - James P. Stewart
- Centre for Comparative Infectious Diseases, Department of Medical Microbiology, University of Liverpool, Liverpool, United Kingdom
| | - Heiko Adler
- The Institute of Molecular Immunology, Clinical Cooperation Group Hematopoietic Cell Transplantation, Helmholtz Zentrum München - German Research Center for Environmental Health, Munich, Germany
- * E-mail:
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Potempa M, Potempa J, Kantyka T, Nguyen KA, Wawrzonek K, Manandhar SP, Popadiak K, Riesbeck K, Eick S, Blom AM. Interpain A, a cysteine proteinase from Prevotella intermedia, inhibits complement by degrading complement factor C3. PLoS Pathog 2009; 5:e1000316. [PMID: 19247445 PMCID: PMC2642729 DOI: 10.1371/journal.ppat.1000316] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2008] [Accepted: 01/28/2009] [Indexed: 12/19/2022] Open
Abstract
Periodontitis is an inflammatory disease of the supporting structures of the teeth caused by, among other pathogens, Prevotella intermedia. Many strains of P. intermedia are resistant to killing by the human complement system, which is present at up to 70% of serum concentration in gingival crevicular fluid. Incubation of human serum with recombinant cysteine protease of P. intermedia (interpain A) resulted in a drastic decrease in bactericidal activity of the serum. Furthermore, a clinical strain 59 expressing interpain A was more serum-resistant than another clinical strain 57, which did not express interpain A, as determined by Western blotting. Moreover, in the presence of the cysteine protease inhibitor E64, the killing of strain 59 by human serum was enhanced. Importantly, we found that the majority of P. intermedia strains isolated from chronic and aggressive periodontitis carry and express the interpain A gene. The protective effect of interpain A against serum bactericidal activity was found to be attributable to its ability to inhibit all three complement pathways through the efficient degradation of the alpha-chain of C3 -- the major complement factor common to all three pathways. P. intermedia has been known to co-aggregate with P. gingivalis, which produce gingipains to efficiently degrade complement factors. Here, interpain A was found to have a synergistic effect with gingipains on complement degradation. In addition, interpain A was able to activate the C1 complex in serum, causing deposition of C1q on inert and bacterial surfaces, which may be important at initial stages of infection when local inflammatory reaction may be beneficial for a pathogen. Taken together, the newly characterized interpain A proteinase appears to be an important virulence factor of P. intermedia.
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Affiliation(s)
- Michal Potempa
- Lund University, Department of Laboratory Medicine, Section of Medical Protein Chemistry, University Hospital Malmö, Malmö, Sweden
- Jagiellonian University, Department of Microbiology, Krakow, Poland
| | - Jan Potempa
- Jagiellonian University, Department of Microbiology, Krakow, Poland
- University of Georgia, Department of Biochemistry and Molecular Biology, Athens, Georgia, United States of America
| | - Tomasz Kantyka
- Jagiellonian University, Department of Microbiology, Krakow, Poland
| | - Ky-Anh Nguyen
- Westmead Millennium Institute, Institute of Dental Research, Sydney, Australia
| | | | - Surya P. Manandhar
- Westmead Millennium Institute, Institute of Dental Research, Sydney, Australia
| | - Katarzyna Popadiak
- Lund University, Department of Laboratory Medicine, Section of Medical Protein Chemistry, University Hospital Malmö, Malmö, Sweden
- Jagiellonian University, Department of Microbiology, Krakow, Poland
| | - Kristian Riesbeck
- Lund University, Department of Laboratory Medicine, Section of Medical Microbiology, University Hospital Malmö, Malmö, Sweden
| | - Sigrun Eick
- Department of Medical Microbiology, University Hospital of Jena, Jena, Germany
| | - Anna M. Blom
- Lund University, Department of Laboratory Medicine, Section of Medical Protein Chemistry, University Hospital Malmö, Malmö, Sweden
- * E-mail:
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10
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Okroj M, Mark L, Stokowska A, Wong SW, Rose N, Blackbourn DJ, Villoutreix BO, Spiller OB, Blom AM. Characterization of the complement inhibitory function of rhesus rhadinovirus complement control protein (RCP). J Biol Chem 2008; 284:505-514. [PMID: 18990693 DOI: 10.1074/jbc.m806669200] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Rhesus rhadinovirus (RRV) is currently the closest known, fully sequenced homolog of human Kaposi sarcoma-associated herpesvirus. Both these viruses encode complement inhibitors as follows: Kaposi sarcoma-associated herpesvirus-complement control protein (KCP) and RRV-complement control protein (RCP). Previously we characterized in detail the functional properties of KCP as a complement inhibitor. Here, we performed comparative analyses for two variants of RCP protein, encoded by RRV strains H26-95 and 17577. Both RCP variants and KCP inhibited human and rhesus complement when tested in hemolytic assays measuring all steps of activation via the classical and the alternative pathway. RCP variants from both RRV strains supported C3b and C4b degradation by factor I and decay acceleration of the classical C3 convertase, similar to KCP. Additionally, the 17577 RCP variant accelerated decay of the alternative C3 convertase, which was not seen for KCP. In contrast to KCP, RCP showed no affinity to heparin and is the first described complement inhibitor in which the binding site for C3b/C4b does not interact with heparin. Molecular modeling shows a structural disruption in the region of RCP that corresponds to the KCP-heparin-binding site. This makes RRV a superior model for future in vivo investigations of complement evasion, as RCP does not play a supportive role in viral attachment as KCP does.
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Affiliation(s)
- Marcin Okroj
- Department of Laboratory Medicine, Lund University, University Hospital Malmo¨, Malmo¨ S-20502, Sweden, the Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon 97006, the National Institute for Biological Standards and Control, Herts EN6 3QG, United Kingdom, the Cancer Research UK Institute for Cancer Studies, University of Birmingham, Birmingham B15 2TT, United Kingdom, INSERM MTi, University Paris Diderot, Paris 75013, France, and the Department of Child Health, Cardiff University, Wales School of Medicine, Cardiff CF14 4XN, United Kingdom
| | - Linda Mark
- Department of Laboratory Medicine, Lund University, University Hospital Malmo¨, Malmo¨ S-20502, Sweden, the Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon 97006, the National Institute for Biological Standards and Control, Herts EN6 3QG, United Kingdom, the Cancer Research UK Institute for Cancer Studies, University of Birmingham, Birmingham B15 2TT, United Kingdom, INSERM MTi, University Paris Diderot, Paris 75013, France, and the Department of Child Health, Cardiff University, Wales School of Medicine, Cardiff CF14 4XN, United Kingdom
| | - Anna Stokowska
- Department of Laboratory Medicine, Lund University, University Hospital Malmo¨, Malmo¨ S-20502, Sweden, the Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon 97006, the National Institute for Biological Standards and Control, Herts EN6 3QG, United Kingdom, the Cancer Research UK Institute for Cancer Studies, University of Birmingham, Birmingham B15 2TT, United Kingdom, INSERM MTi, University Paris Diderot, Paris 75013, France, and the Department of Child Health, Cardiff University, Wales School of Medicine, Cardiff CF14 4XN, United Kingdom
| | - Scott W Wong
- Department of Laboratory Medicine, Lund University, University Hospital Malmo¨, Malmo¨ S-20502, Sweden, the Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon 97006, the National Institute for Biological Standards and Control, Herts EN6 3QG, United Kingdom, the Cancer Research UK Institute for Cancer Studies, University of Birmingham, Birmingham B15 2TT, United Kingdom, INSERM MTi, University Paris Diderot, Paris 75013, France, and the Department of Child Health, Cardiff University, Wales School of Medicine, Cardiff CF14 4XN, United Kingdom
| | - Nicola Rose
- Department of Laboratory Medicine, Lund University, University Hospital Malmo¨, Malmo¨ S-20502, Sweden, the Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon 97006, the National Institute for Biological Standards and Control, Herts EN6 3QG, United Kingdom, the Cancer Research UK Institute for Cancer Studies, University of Birmingham, Birmingham B15 2TT, United Kingdom, INSERM MTi, University Paris Diderot, Paris 75013, France, and the Department of Child Health, Cardiff University, Wales School of Medicine, Cardiff CF14 4XN, United Kingdom
| | - David J Blackbourn
- Department of Laboratory Medicine, Lund University, University Hospital Malmo¨, Malmo¨ S-20502, Sweden, the Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon 97006, the National Institute for Biological Standards and Control, Herts EN6 3QG, United Kingdom, the Cancer Research UK Institute for Cancer Studies, University of Birmingham, Birmingham B15 2TT, United Kingdom, INSERM MTi, University Paris Diderot, Paris 75013, France, and the Department of Child Health, Cardiff University, Wales School of Medicine, Cardiff CF14 4XN, United Kingdom
| | - Bruno O Villoutreix
- Department of Laboratory Medicine, Lund University, University Hospital Malmo¨, Malmo¨ S-20502, Sweden, the Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon 97006, the National Institute for Biological Standards and Control, Herts EN6 3QG, United Kingdom, the Cancer Research UK Institute for Cancer Studies, University of Birmingham, Birmingham B15 2TT, United Kingdom, INSERM MTi, University Paris Diderot, Paris 75013, France, and the Department of Child Health, Cardiff University, Wales School of Medicine, Cardiff CF14 4XN, United Kingdom
| | - O Brad Spiller
- Department of Laboratory Medicine, Lund University, University Hospital Malmo¨, Malmo¨ S-20502, Sweden, the Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon 97006, the National Institute for Biological Standards and Control, Herts EN6 3QG, United Kingdom, the Cancer Research UK Institute for Cancer Studies, University of Birmingham, Birmingham B15 2TT, United Kingdom, INSERM MTi, University Paris Diderot, Paris 75013, France, and the Department of Child Health, Cardiff University, Wales School of Medicine, Cardiff CF14 4XN, United Kingdom
| | - Anna M Blom
- Department of Laboratory Medicine, Lund University, University Hospital Malmo¨, Malmo¨ S-20502, Sweden, the Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon 97006, the National Institute for Biological Standards and Control, Herts EN6 3QG, United Kingdom, the Cancer Research UK Institute for Cancer Studies, University of Birmingham, Birmingham B15 2TT, United Kingdom, INSERM MTi, University Paris Diderot, Paris 75013, France, and the Department of Child Health, Cardiff University, Wales School of Medicine, Cardiff CF14 4XN, United Kingdom.
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Sequence diversity of the Trypanosoma cruzi complement regulatory protein family. Infect Immun 2007; 76:750-8. [PMID: 18070905 DOI: 10.1128/iai.01104-07] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
As a central component of innate immunity, complement activation is a critical mechanism of containment and clearance of microbial pathogens in advance of the development of acquired immunity. Several pathogens restrict complement activation through the acquisition of host proteins that regulate complement activation or through the production of their own complement regulatory molecules (M. K. Liszewski, M. K. Leung, R. Hauhart, R. M. Buller, P. Bertram, X. Wang, A. M. Rosengard, G. J. Kotwal, and J. P. Atkinson, J. Immunol. 176:3725-3734, 2006; J. Lubinski, L. Wang, D. Mastellos, A. Sahu, J. D. Lambris, and H. M. Friedman, J. Exp. Med. 190:1637-1646, 1999). The infectious stage of the protozoan parasite Trypanosoma cruzi produces a surface-anchored complement regulatory protein (CRP) that functions to inhibit alternative and classical pathway complement activation (K. A. Norris, B. Bradt, N. R. Cooper, and M. So, J. Immunol. 147:2240-2247, 1991). This study addresses the genomic complexity of the T. cruzi CRP and its relationship to the T. cruzi supergene family comprising active trans-sialidase (TS) and TS-like proteins. The TS superfamily consists of several functionally distinct subfamilies that share a characteristic sialidase domain at their amino termini. These TS families include active TS, adhesions, CRPs, and proteins of unknown functions (G. A. Cross and G. B. Takle, Annu. Rev. Microbiol. 47:385-411, 1993). A sequence comparison search of GenBank using BLASTP revealed several full-length paralogs of CRP. These proteins share significant homology at their amino termini and a strong spatial conservation of cysteine residues. Alternative pathway complement regulation was confirmed for CRP paralogs with 58% (low) and 83% (high) identity to AAB49414. CRPs are functionally similar to the microbial and mammalian proteins that regulate complement activation. Sequence alignment of mammalian complement control proteins to CRP showed that these sequences are distinct, supporting a convergent evolutionary pathway. Finally, we show that a clonal line of T. cruzi expresses multiple unique copies of CRP that are differentially recognized by patient sera.
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