1
|
Complement component C3: A structural perspective and potential therapeutic implications. Semin Immunol 2022; 59:101627. [PMID: 35760703 PMCID: PMC9842190 DOI: 10.1016/j.smim.2022.101627] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Revised: 06/03/2022] [Accepted: 06/09/2022] [Indexed: 01/18/2023]
Abstract
As the most abundant component of the complement system, C3 and its proteolytic derivatives serve essential roles in the function of all three complement pathways. Central to this is a network of protein-protein interactions made possible by the sequential proteolysis and far-reaching structural changes that accompany C3 activation. Beginning with the crystal structures of C3, C3b, and C3c nearly twenty years ago, the physical transformations underlying C3 function that had long been suspected were finally revealed. In the years that followed, a compendium of crystallographic information on C3 derivatives bound to various enzymes, regulators, receptors, and inhibitors generated new levels of insight into the structure and function of the C3 molecule. This Review provides a concise classification, summary, and interpretation of the more than 50 unique crystal structure determinations for human C3. It also highlights other salient features of C3 structure that were made possible through solution-based methods, including Hydrogen/Deuterium Exchange and Small Angle X-ray Scattering. At this pivotal time when the first C3-targeted therapeutics begin to see use in the clinic, some perspectives are also offered on how this continually growing body of structural information might be leveraged for future development of next-generation C3 inhibitors.
Collapse
|
2
|
Narkhede YB, Gautam AK, Hsu RV, Rodriguez W, Zewde NT, Harrison RES, Arantes PR, Gaieb Z, Gorham RD, Kieslich C, Morikis D, Sahu A, Palermo G. Role of Electrostatic Hotspots in the Selectivity of Complement Control Proteins Toward Human and Bovine Complement Inhibition. Front Mol Biosci 2021; 8:618068. [PMID: 33829039 PMCID: PMC8020814 DOI: 10.3389/fmolb.2021.618068] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Accepted: 01/08/2021] [Indexed: 11/13/2022] Open
Abstract
Poxviruses are dangerous pathogens, which can cause fatal infection in unvaccinated individuals. The causative agent of smallpox in humans, variola virus, is closely related to the bovine vaccinia virus, yet the molecular basis of their selectivity is currently incompletely understood. Here, we examine the role of the electrostatics in the selectivity of the smallpox protein SPICE and vaccinia protein VCP toward the human and bovine complement protein C3b, a key component of the complement immune response. Electrostatic calculations, in-silico alanine-scan and electrostatic hotspot analysis, as introduced by Kieslich and Morikis (PLoS Comput. Biol. 2012), are used to assess the electrostatic complementarity and to identify sites resistant to local perturbation where the electrostatic potential is likely to be evolutionary conserved. The calculations suggest that the bovine C3b is electrostatically prone to selectively bind its VCP ligand. On the other hand, the human isoform of C3b exhibits a lower electrostatic complementarity toward its SPICE ligand. Yet, the human C3b displays a highly preserved electrostatic core, which suggests that this isoform could be less selective in binding different ligands like SPICE and the human Factor H. This is supported by experimental cofactor activity assays revealing that the human C3b is prone to bind both SPICE and Factor H, which exhibit diverse electrostatic properties. Additional investigations considering mutants of SPICE and VCP that revert their selectivity reveal an “electrostatic switch” into the central modules of the ligands, supporting the critical role of the electrostatics in the selectivity. Taken together, these evidences provide insights into the selectivity mechanism of the complement regulator proteins encoded by the variola and vaccinia viruses to circumvent the complement immunity and exert their pathogenic action. These fundamental aspects are valuable for the development of novel vaccines and therapeutic strategies.
Collapse
Affiliation(s)
- Yogesh B Narkhede
- Department of Bioengineering, University of California, Riverside, CA
| | - Avneesh K Gautam
- National Centre for Cell Science, Pune University Campus, Ganeshkhind, India
| | - Rohaine V Hsu
- Department of Bioengineering, University of California, Riverside, CA
| | - Wilson Rodriguez
- Department of Bioengineering, University of California, Riverside, CA
| | - Nehemiah T Zewde
- Department of Bioengineering, University of California, Riverside, CA
| | - Reed E S Harrison
- Department of Bioengineering, University of California, Riverside, CA
| | - Pablo R Arantes
- Department of Bioengineering, University of California, Riverside, CA
| | - Zied Gaieb
- Department of Bioengineering, University of California, Riverside, CA
| | - Ronald D Gorham
- Department of Bioengineering, University of California, Riverside, CA
| | - Chris Kieslich
- Department of Bioengineering, University of California, Riverside, CA.,Department of Chemical Engineering, Auburn University, Auburn, AL
| | - Dimitrios Morikis
- Department of Bioengineering, University of California, Riverside, CA
| | - Arvind Sahu
- National Centre for Cell Science, Pune University Campus, Ganeshkhind, India
| | - Giulia Palermo
- Department of Bioengineering, University of California, Riverside, CA.,Department of Chemistry, University of California, Riverside, CA
| |
Collapse
|
3
|
Sinha A, Singh AK, Kadni TS, Mullick J, Sahu A. Virus-Encoded Complement Regulators: Current Status. Viruses 2021; 13:v13020208. [PMID: 33573085 PMCID: PMC7912105 DOI: 10.3390/v13020208] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2020] [Revised: 01/21/2021] [Accepted: 01/22/2021] [Indexed: 11/29/2022] Open
Abstract
Viruses require a host for replication and survival and hence are subjected to host immunological pressures. The complement system, a crucial first response of the host immune system, is effective in targeting viruses and virus-infected cells, and boosting the antiviral innate and acquired immune responses. Thus, the system imposes a strong selection pressure on viruses. Consequently, viruses have evolved multiple countermeasures against host complement. A major mechanism employed by viruses to subvert the complement system is encoding proteins that target complement. Since viruses have limited genome size, most of these proteins are multifunctional in nature. In this review, we provide up to date information on the structure and complement regulatory functions of various viral proteins.
Collapse
Affiliation(s)
- Anwesha Sinha
- Complement Biology Laboratory, National Centre for Cell Science, S. P. Pune University Campus, Ganeskhind, Pune 411007, India; (A.S.); (A.K.S.); (T.S.K.)
| | - Anup Kumar Singh
- Complement Biology Laboratory, National Centre for Cell Science, S. P. Pune University Campus, Ganeskhind, Pune 411007, India; (A.S.); (A.K.S.); (T.S.K.)
| | - Trupti Satish Kadni
- Complement Biology Laboratory, National Centre for Cell Science, S. P. Pune University Campus, Ganeskhind, Pune 411007, India; (A.S.); (A.K.S.); (T.S.K.)
| | - Jayati Mullick
- Polio Virology Group, Microbial Containment Complex, ICMR-National Institute of Virology, Pune 411021, India;
| | - Arvind Sahu
- Complement Biology Laboratory, National Centre for Cell Science, S. P. Pune University Campus, Ganeskhind, Pune 411007, India; (A.S.); (A.K.S.); (T.S.K.)
- Correspondence: ; Tel.: +91-20-2570-8083; Fax: +91-20-2569-2259
| |
Collapse
|
4
|
Agrawal P, Sharma S, Pal P, Ojha H, Mullick J, Sahu A. The imitation game: a viral strategy to subvert the complement system. FEBS Lett 2020; 594:2518-2542. [DOI: 10.1002/1873-3468.13856] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Revised: 03/10/2020] [Accepted: 05/23/2020] [Indexed: 11/09/2022]
Affiliation(s)
- Palak Agrawal
- Complement Biology Laboratory National Centre for Cell Science S. P. Pune University Campus Ganeshkhind Pune 411007 India
| | - Samriddhi Sharma
- Complement Biology Laboratory National Centre for Cell Science S. P. Pune University Campus Ganeshkhind Pune 411007 India
| | - Pradipta Pal
- Complement Biology Laboratory National Centre for Cell Science S. P. Pune University Campus Ganeshkhind Pune 411007 India
| | - Hina Ojha
- Complement Biology Laboratory National Centre for Cell Science S. P. Pune University Campus Ganeshkhind Pune 411007 India
| | - Jayati Mullick
- Microbial Containment Complex ICMR‐National Institute of Virology Pune 411021 India
| | - Arvind Sahu
- Complement Biology Laboratory National Centre for Cell Science S. P. Pune University Campus Ganeshkhind Pune 411007 India
| |
Collapse
|
5
|
Ojha H, Ghosh P, Singh Panwar H, Shende R, Gondane A, Mande SC, Sahu A. Spatially conserved motifs in complement control protein domains determine functionality in regulators of complement activation-family proteins. Commun Biol 2019; 2:290. [PMID: 31396570 PMCID: PMC6683126 DOI: 10.1038/s42003-019-0529-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Accepted: 07/03/2019] [Indexed: 12/14/2022] Open
Abstract
Regulation of complement activation in the host cells is mediated primarily by the regulators of complement activation (RCA) family proteins that are formed by tandemly repeating complement control protein (CCP) domains. Functional annotation of these proteins, however, is challenging as contiguous CCP domains are found in proteins with varied functions. Here, by employing an in silico approach, we identify five motifs which are conserved spatially in a specific order in the regulatory CCP domains of known RCA proteins. We report that the presence of these motifs in a specific pattern is sufficient to annotate regulatory domains in RCA proteins. We show that incorporation of the lost motif in the fourth long-homologous repeat (LHR-D) in complement receptor 1 regains its regulatory activity. Additionally, the motif pattern also helped annotate human polydom as a complement regulator. Thus, we propose that the motifs identified here are the determinants of functionality in RCA proteins.
Collapse
Affiliation(s)
- Hina Ojha
- Complement Biology Laboratory, National Centre for Cell Science, S. P. Pune University campus, Pune, 411007 India
| | - Payel Ghosh
- Bioinformatics Centre, S. P. Pune University, Pune, 411007 India
| | - Hemendra Singh Panwar
- Complement Biology Laboratory, National Centre for Cell Science, S. P. Pune University campus, Pune, 411007 India
| | - Rajashri Shende
- Complement Biology Laboratory, National Centre for Cell Science, S. P. Pune University campus, Pune, 411007 India
| | | | - Shekhar C. Mande
- Structural Biology Laboratory, National Centre for Cell Science, S. P. Pune University campus, Pune, 411007 India
- Present Address: Council of Scientific and Industrial Research (CSIR), Anusandhan Bhawan, 2 Rafi Marg, New Delhi, 110001 India
| | - Arvind Sahu
- Complement Biology Laboratory, National Centre for Cell Science, S. P. Pune University campus, Pune, 411007 India
| |
Collapse
|
6
|
Molecular engineering of an efficient four-domain DAF-MCP chimera reveals the presence of functional modularity in RCA proteins. Proc Natl Acad Sci U S A 2019; 116:9953-9958. [PMID: 31036650 DOI: 10.1073/pnas.1818573116] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
The complement system is highly efficient in targeting pathogens, but lack of its apposite regulation results in host-cell damage, which is linked to diseases. Thus, complement activation is tightly regulated by a series of proteins, which primarily belong to the regulators of complement activation (RCA) family. Structurally, these proteins are composed of repeating complement control protein (CCP) domains where two to four successive domains contribute to the regulatory functions termed decay-accelerating activity (DAA) and cofactor activity (CFA). However, the precise constitution of the functional units and whether these units can be joined to form a larger composition with dual function have not been demonstrated. Herein, we have parsed the functional units for DAA and CFA by constructing chimeras of the decay-accelerating factor (DAF) that exhibits DAA and membrane cofactor protein (MCP) that exhibits CFA. We show that in a four-CCP framework, a functional unit for each of the regulatory activities is formed by only two successive CCPs wherein each participates in the function, albeit CCP2 has a bipartite function. Additionally, optimal activity requires C-terminal domains that enhance the avidity of the molecule for C3b/C4b. Furthermore, by composing a four-CCP DAF-MCP chimera with robust CFA (for C3b and C4b) and DAA (for classical and alternative pathway C3 convertases), named decay cofactor protein, we show that CCP functional units can be linked to design a dual-activity regulator. These data indicate that the regulatory determinants for these two biological processes are distinct and modular in nature.
Collapse
|
7
|
Gurjar BS, Manikanta Sriharsha T, Bhasym A, Prabhu S, Puraswani M, Khandelwal P, Saini H, Saini S, Verma AK, Chatterjee P, Guchhait P, Bal V, George A, Rath S, Sahu A, Sharma A, Hari P, Sinha A, Bagga A. Characterization of genetic predisposition and autoantibody profile in atypical haemolytic-uraemic syndrome. Immunology 2018; 154:663-672. [PMID: 29485195 PMCID: PMC6050217 DOI: 10.1111/imm.12916] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Revised: 02/01/2018] [Accepted: 02/02/2018] [Indexed: 12/25/2022] Open
Abstract
We previously reported that Indian paediatric patients with atypical haemolytic-uraemic syndrome (aHUS) showed high frequencies of anti-complement factor H (FH) autoantibodies that are correlated with homozygous deletion of the genes for FH-related proteins 1 and 3 (FHR1 and FHR3) (FHR1/3-/- ). We now report that Indian paediatric aHUS patients without anti-FH autoantibodies also showed modestly higher frequencies of the FHR1/3-/- genotype. Further, when we characterized epitope specificities and binding avidities of anti-FH autoantibodies in aHUS patients, most anti-FH autoantibodies were directed towards the FH cell-surface anchoring polyanionic binding site-containing C-terminal short conservative regions (SCRs) 17-20 with higher binding avidities than for native FH. FH SCR17-20-binding anti-FH autoantibodies also bound the other cell-surface anchoring polyanionic binding site-containing region FH SCR5-8, at lower binding avidities. Anti-FH autoantibody avidities correlated with antibody titres. These anti-FH autoantibody characteristics did not differ between aHUS patients with or without the FHR1/3-/- genotype. Our data suggest a complex matrix of interactions between FHR1-FHR3 deletion, immunomodulation and anti-FH autoantibodies in the aetiopathogenesis of aHUS.
Collapse
Affiliation(s)
| | | | - Angika Bhasym
- Regional Centre for BiotechnologyFaridabadIndia
- Department of BiotechnologyManipal Academy of Higher EducationManipalIndia
| | - Savit Prabhu
- Paediatric Biology CentreTranslational Health Science and Technology InstituteFaridabadIndia
| | - Mamta Puraswani
- Department of PaediatricsAll India Institute of Medical SciencesNew DelhiIndia
| | - Priyanka Khandelwal
- Department of PaediatricsAll India Institute of Medical SciencesNew DelhiIndia
| | - Himanshi Saini
- Department of PaediatricsAll India Institute of Medical SciencesNew DelhiIndia
| | - Savita Saini
- Department of PaediatricsAll India Institute of Medical SciencesNew DelhiIndia
| | | | | | | | - Vineeta Bal
- National Institute of ImmunologyNew DelhiIndia
- Paediatric Biology CentreTranslational Health Science and Technology InstituteFaridabadIndia
| | - Anna George
- National Institute of ImmunologyNew DelhiIndia
| | - Satyajit Rath
- National Institute of ImmunologyNew DelhiIndia
- Paediatric Biology CentreTranslational Health Science and Technology InstituteFaridabadIndia
- Agharkar Research InstitutePuneIndia
| | - Arvind Sahu
- National Centre for Cell ScienceS. P. Pune University CampusPuneIndia
| | - Amita Sharma
- Department of PaediatricsAll India Institute of Medical SciencesNew DelhiIndia
| | - Pankaj Hari
- Department of PaediatricsAll India Institute of Medical SciencesNew DelhiIndia
| | - Aditi Sinha
- Department of PaediatricsAll India Institute of Medical SciencesNew DelhiIndia
| | - Arvind Bagga
- Department of PaediatricsAll India Institute of Medical SciencesNew DelhiIndia
| |
Collapse
|
8
|
Species Specificity of Vaccinia Virus Complement Control Protein for the Bovine Classical Pathway Is Governed Primarily by Direct Interaction of Its Acidic Residues with Factor I. J Virol 2017; 91:JVI.00668-17. [PMID: 28724763 DOI: 10.1128/jvi.00668-17] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Accepted: 07/13/2017] [Indexed: 01/23/2023] Open
Abstract
Poxviruses display species tropism-variola virus is a human-specific virus, while vaccinia virus causes repeated outbreaks in dairy cattle. Consistent with this, variola virus complement regulator SPICE (smallpox inhibitor of complement enzymes) exhibits selectivity in inhibiting the human alternative complement pathway and vaccinia virus complement regulator VCP (vaccinia virus complement control protein) displays selectivity in inhibiting the bovine alternative complement pathway. In the present study, we examined the species specificity of VCP and SPICE for the classical pathway (CP). We observed that VCP is ∼43-fold superior to SPICE in inhibiting bovine CP. Further, functional assays revealed that increased inhibitory activity of VCP for bovine CP is solely due to its enhanced cofactor activity, with no effect on decay of bovine CP C3-convertase. To probe the structural basis of this specificity, we utilized single- and multi-amino-acid substitution mutants wherein 1 or more of the 11 variant VCP residues were substituted in the SPICE template. Examination of these mutants for their ability to inhibit bovine CP revealed that E108, E120, and E144 are primarily responsible for imparting the specificity and contribute to the enhanced cofactor activity of VCP. Binding and functional assays suggested that these residues interact with bovine factor I but not with bovine C4(H2O) (a moiety conformationally similar to C4b). Mapping of these residues onto the modeled structure of bovine C4b-VCP-bovine factor I supported the mutagenesis data. Taken together, our data help explain why the vaccine strain of vaccinia virus was able to gain a foothold in domesticated animals.IMPORTANCE Vaccinia virus was used for smallpox vaccination. The vaccine-derived virus is now circulating and causing outbreaks in dairy cattle in India and Brazil. However, the reason for this tropism is unknown. It is well recognized that the virus is susceptible to neutralization by the complement classical pathway (CP). Because the virus encodes a soluble complement regulator, VCP, we examined whether this protein displays selectivity in targeting bovine CP. Our data show that it does exhibit selectivity in inhibiting the bovine CP and that this is primarily determined by its amino acids E108, E120, and E144, which interact with bovine serine protease factor I to inactivate bovine C4b-one of the two subunits of CP C3-convertase. Of note, the variola complement regulator SPICE contains positively charged residues at these positions. Thus, these variant residues in VCP help enhance its potency against the bovine CP and thereby the fitness of the virus in cattle.
Collapse
|
9
|
de Jorge EG, Yebenes H, Serna M, Tortajada A, Llorca O, de Córdoba SR. How novel structures inform understanding of complement function. Semin Immunopathol 2017; 40:3-14. [PMID: 28808775 DOI: 10.1007/s00281-017-0643-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Accepted: 08/03/2017] [Indexed: 11/30/2022]
Abstract
During the last decade, the complement field has experienced outstanding advancements in the mechanistic understanding of how complement activators are recognized, what C3 activation means, how protein complexes like the C3 convertases and the membrane attack complex are assembled, and how positive and negative complement regulators perform their function. All of this has been made possible mostly because of the contributions of structural biology to the study of the complement components. The wealth of novel structural data has frequently provided support to previously held knowledge, but often has added alternative and unexpected insights into complement function. Here, we will review some of these findings focusing in the alternative and terminal complement pathways.
Collapse
Affiliation(s)
- Elena Goicoechea de Jorge
- Department of Microbiology I (Immunology), Complutense University School of Medicine and 12 de Octubre Health Research Institute (imas12), Madrid, Spain
| | - Hugo Yebenes
- Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas, Ramiro de Maeztu 9, 28040, Madrid, Spain
| | - Marina Serna
- Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas, Ramiro de Maeztu 9, 28040, Madrid, Spain
| | - Agustín Tortajada
- Department of Microbiology I (Immunology), Complutense University School of Medicine and 12 de Octubre Health Research Institute (imas12), Madrid, Spain
| | - Oscar Llorca
- Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas, Ramiro de Maeztu 9, 28040, Madrid, Spain.,Structural Biology Programme, CNIO, C/ Melchor Fernández Almagro 3, 28029, Madrid, Spain
| | - Santiago Rodríguez de Córdoba
- Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas, Ramiro de Maeztu 9, 28040, Madrid, Spain. .,Ciber de Enfermedades Raras, Madrid, Spain.
| |
Collapse
|
10
|
Xue X, Wu J, Ricklin D, Forneris F, Di Crescenzio P, Schmidt CQ, Granneman J, Sharp TH, Lambris JD, Gros P. Regulator-dependent mechanisms of C3b processing by factor I allow differentiation of immune responses. Nat Struct Mol Biol 2017; 24:643-651. [PMID: 28671664 DOI: 10.1038/nsmb.3427] [Citation(s) in RCA: 81] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Accepted: 06/02/2017] [Indexed: 12/26/2022]
Abstract
The complement system labels microbes and host debris for clearance. Degradation of surface-bound C3b is pivotal to direct immune responses and protect host cells. How the serine protease factor I (FI), assisted by regulators, cleaves either two or three distant peptide bonds in the CUB domain of C3b remains unclear. We present a crystal structure of C3b in complex with FI and regulator factor H (FH; domains 1-4 with 19-20). FI binds C3b-FH between FH domains 2 and 3 and a reoriented C3b C-terminal domain and docks onto the first scissile bond, while stabilizing its catalytic domain for proteolytic activity. One cleavage in C3b does not affect its overall structure, whereas two cleavages unfold CUB and dislodge the thioester-containing domain (TED), affecting binding of regulators and thereby determining the number of cleavages. These data explain how FI generates late-stage opsonins iC3b or C3dg in a context-dependent manner, to react to foreign, danger or healthy self signals.
Collapse
Affiliation(s)
- Xiaoguang Xue
- Crystal and Structural Chemistry, Bijvoet Center for Biomolecular Research, Department of Chemistry, Faculty of Science, Utrecht University, Utrecht, the Netherlands
| | - Jin Wu
- Crystal and Structural Chemistry, Bijvoet Center for Biomolecular Research, Department of Chemistry, Faculty of Science, Utrecht University, Utrecht, the Netherlands
| | - Daniel Ricklin
- Department of Pathology &Laboratory Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Federico Forneris
- Crystal and Structural Chemistry, Bijvoet Center for Biomolecular Research, Department of Chemistry, Faculty of Science, Utrecht University, Utrecht, the Netherlands
| | - Patrizia Di Crescenzio
- Department of Pathology &Laboratory Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Christoph Q Schmidt
- Department of Pathology &Laboratory Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Institute of Pharmacology of Natural Products and Clinical Pharmacology, Ulm University, Ulm, Germany
| | - Joke Granneman
- Crystal and Structural Chemistry, Bijvoet Center for Biomolecular Research, Department of Chemistry, Faculty of Science, Utrecht University, Utrecht, the Netherlands
| | - Thomas H Sharp
- Section Electron Microscopy, Department of Molecular Cell Biology, Leiden University Medical Center, Leiden, the Netherlands
| | - John D Lambris
- Department of Pathology &Laboratory Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Piet Gros
- Crystal and Structural Chemistry, Bijvoet Center for Biomolecular Research, Department of Chemistry, Faculty of Science, Utrecht University, Utrecht, the Netherlands
| |
Collapse
|
11
|
Agrawal P, Nawadkar R, Ojha H, Kumar J, Sahu A. Complement Evasion Strategies of Viruses: An Overview. Front Microbiol 2017; 8:1117. [PMID: 28670306 PMCID: PMC5472698 DOI: 10.3389/fmicb.2017.01117] [Citation(s) in RCA: 104] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Accepted: 05/31/2017] [Indexed: 12/11/2022] Open
Abstract
Being a major first line of immune defense, the complement system keeps a constant vigil against viruses. Its ability to recognize large panoply of viruses and virus-infected cells, and trigger the effector pathways, results in neutralization of viruses and killing of the infected cells. This selection pressure exerted by complement on viruses has made them evolve a multitude of countermeasures. These include targeting the recognition molecules for the avoidance of detection, targeting key enzymes and complexes of the complement pathways like C3 convertases and C5b-9 formation - either by encoding complement regulators or by recruiting membrane-bound and soluble host complement regulators, cleaving complement proteins by encoding protease, and inhibiting the synthesis of complement proteins. Additionally, viruses also exploit the complement system for their own benefit. For example, they use complement receptors as well as membrane regulators for cellular entry as well as their spread. Here, we provide an overview on the complement subversion mechanisms adopted by the members of various viral families including Poxviridae, Herpesviridae, Adenoviridae, Flaviviridae, Retroviridae, Picornaviridae, Astroviridae, Togaviridae, Orthomyxoviridae and Paramyxoviridae.
Collapse
Affiliation(s)
- Palak Agrawal
- Complement Biology Laboratory, National Centre for Cell Science, Savitribai Phule Pune UniversityPune, India
| | - Renuka Nawadkar
- Complement Biology Laboratory, National Centre for Cell Science, Savitribai Phule Pune UniversityPune, India
| | - Hina Ojha
- Complement Biology Laboratory, National Centre for Cell Science, Savitribai Phule Pune UniversityPune, India
| | - Jitendra Kumar
- Complement Biology Laboratory, National Centre for Cell Science, Savitribai Phule Pune UniversityPune, India
| | - Arvind Sahu
- Complement Biology Laboratory, National Centre for Cell Science, Savitribai Phule Pune UniversityPune, India
| |
Collapse
|
12
|
Forneris F, Wu J, Xue X, Ricklin D, Lin Z, Sfyroera G, Tzekou A, Volokhina E, Granneman JC, Hauhart R, Bertram P, Liszewski MK, Atkinson JP, Lambris JD, Gros P. Regulators of complement activity mediate inhibitory mechanisms through a common C3b-binding mode. EMBO J 2016; 35:1133-49. [PMID: 27013439 PMCID: PMC4868954 DOI: 10.15252/embj.201593673] [Citation(s) in RCA: 72] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Accepted: 02/29/2016] [Indexed: 01/17/2023] Open
Abstract
Regulators of complement activation (RCA) inhibit complement‐induced immune responses on healthy host tissues. We present crystal structures of human RCA (MCP, DAF, and CR1) and a smallpox virus homolog (SPICE) bound to complement component C3b. Our structural data reveal that up to four consecutive homologous CCP domains (i–iv), responsible for inhibition, bind in the same orientation and extended arrangement at a shared binding platform on C3b. Large sequence variations in CCP domains explain the diverse C3b‐binding patterns, with limited or no contribution of some individual domains, while all regulators show extensive contacts with C3b for the domains at the third site. A variation of ~100° rotation around the longitudinal axis is observed for domains binding at the fourth site on C3b, without affecting the overall binding mode. The data suggest a common evolutionary origin for both inhibitory mechanisms, called decay acceleration and cofactor activity, with variable C3b binding through domains at sites ii, iii, and iv, and provide a framework for understanding RCA disease‐related mutations and immune evasion.
Collapse
Affiliation(s)
- Federico Forneris
- Crystal and Structural Chemistry, Bijvoet Center for Biomolecular Research, Department of Chemistry, Faculty of Science Utrecht University, Utrecht, The Netherlands
| | - Jin Wu
- Crystal and Structural Chemistry, Bijvoet Center for Biomolecular Research, Department of Chemistry, Faculty of Science Utrecht University, Utrecht, The Netherlands
| | - Xiaoguang Xue
- Crystal and Structural Chemistry, Bijvoet Center for Biomolecular Research, Department of Chemistry, Faculty of Science Utrecht University, Utrecht, The Netherlands
| | - Daniel Ricklin
- Department of Pathology & Laboratory Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Zhuoer Lin
- Department of Pathology & Laboratory Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Georgia Sfyroera
- Department of Pathology & Laboratory Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Apostolia Tzekou
- Department of Pathology & Laboratory Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Elena Volokhina
- Department of Pediatric Nephrology (830), Radboud University Medical Center, Nijmegen, The Netherlands
| | - Joke Cm Granneman
- Crystal and Structural Chemistry, Bijvoet Center for Biomolecular Research, Department of Chemistry, Faculty of Science Utrecht University, Utrecht, The Netherlands
| | - Richard Hauhart
- Department of Medicine, Division of Rheumatology, Washington University School of Medicine, St. Louis, MO, USA
| | - Paula Bertram
- Department of Medicine, Division of Rheumatology, Washington University School of Medicine, St. Louis, MO, USA
| | - M Kathryn Liszewski
- Department of Medicine, Division of Rheumatology, Washington University School of Medicine, St. Louis, MO, USA
| | - John P Atkinson
- Department of Medicine, Division of Rheumatology, Washington University School of Medicine, St. Louis, MO, USA
| | - John D Lambris
- Department of Pathology & Laboratory Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Piet Gros
- Crystal and Structural Chemistry, Bijvoet Center for Biomolecular Research, Department of Chemistry, Faculty of Science Utrecht University, Utrecht, The Netherlands
| |
Collapse
|