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Gentile CM, Borovjagin AV, Richter JR, Jani AH, Wu H, Zinn KR, Warram JM. Genetic strategy to decrease complement activation with adenoviral therapies. PLoS One 2019; 14:e0215226. [PMID: 31026285 PMCID: PMC6485611 DOI: 10.1371/journal.pone.0215226] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Accepted: 03/28/2019] [Indexed: 11/22/2022] Open
Abstract
Background A major obstacle to using recombinant adenoviral vectors in gene therapy is the natural ability of human adenovirus to activate the classical and alternate complement pathways. These innate immune responses contribute to hepatic adenoviral uptake following systemic delivery and enhance the humoral immune responses associated with adenoviral infection. Methods A recombinant Ad5 vector was genetically modified to display a peptide sequence (“rH17d’”), a known inhibitor of the classical complement pathway. The replication-defective vectors Ad5.HVR2-rH17d’ and Ad5.HVR5-rH17d’ were constructed by engineering the rH17d’ peptide into the hypervariable region (HVR)-2 or HVR5 of their major capsid protein hexon. Control Ad5 vectors were created by incorporation of a 6-histidine (His6)-insert in either HVR2 or HVR5 (Ad5.HVR2-His6 and Ad5.HVR5-His6, respectively). All vectors encoded CMV promoter-controlled firefly luciferase (Luc). The four vectors were evaluated in TIB76 mouse liver cells and immunocompetent mice to compare infectivity and liver sequestration, respectively. Results In vitro studies demonstrated that preincubation of all the Ad5 vectors with fresh serum significantly increased their gene transfer relative to preincubation with PBS except Ad5.HVR5-rH17d’, whose infectivity of liver cells showed no serum-mediated enhancement. In line with that, mice injected with Ad5.HVR2-rH17d’ or Ad5.HVR5-rH17d’ showed significantly lower luciferase expression levels in the liver as compared to the respective control vectors, whereas efficiency of tumor transduction by rH17d’ and His6 vectors following their intratumoral injection was similar. Conclusions Displaying a complement-inhibiting peptide on the Ad5 capsid surface by genetic modification of the hexon protein could be a suitable strategy for reducing Ad5 liver tropism (Ad5 sequestration by liver), which may be applicable to other gene therapy vectors with natural liver tropism.
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Affiliation(s)
- Christopher M. Gentile
- Department of Otolaryngology, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Anton V. Borovjagin
- Department of Biomedical Engineering, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Jillian R. Richter
- Department of Surgery, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Aditi H. Jani
- University School of Medicine at University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Hongju Wu
- Department of Medicine, Tulane University, Tulane, Louisiana, United States of America
| | - Kurt R. Zinn
- Department of Radiology, Michigan State University, East Lansing, Michigan, United States of America
| | - Jason M. Warram
- Department of Otolaryngology, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
- * E-mail:
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Abstract
Complement is a key component of immunity with crucial inflammatory and opsonic properties; inappropriate activation of complement triggers or exacerbates inflammatory disease. Complement dysregulation is a core feature of some diseases and contributes to pathology in many others. Approved agents have been developed for and are highly effective in some orphan applications, but their progress to use in more common diseases has been slow. Numerous challenges, such as target concentration or high turnover, limit the efficacy of these agents in humans. Numerous novel agents targeting different parts of the complement system in different ways are now emerging from pre-clinical studies and are entering Phase I/II trials; these agents bring the potential for more-effective and more-specific anti-complement therapies in disease. Other agents, both biologic and small molecule, are in Phase II or III trials for both rare and common diseases — administration routes include localized (for example, intravitreal) and systemic routes. There is an urgent need to develop biomarkers and imaging methods that enable monitoring of the effects and efficacy of anti-complement agents.
The complement cascade, a key regulator of innate immunity, is a rich source of potential therapeutic targets for diseases including autoimmune, inflammatory and degenerative disorders. Morgan and Harris discuss the progress made in modulating the complement system and the existing challenges, including dosing, localization of the drug to the target and how to interfere with protein–protein interactions. The complement system is a key innate immune defence against infection and an important driver of inflammation; however, these very properties can also cause harm. Inappropriate or uncontrolled activation of complement can cause local and/or systemic inflammation, tissue damage and disease. Complement provides numerous options for drug development as it is a proteolytic cascade that involves nine specific proteases, unique multimolecular activation and lytic complexes, an arsenal of natural inhibitors, and numerous receptors that bind to activation fragments. Drug design is facilitated by the increasingly detailed structural understanding of the molecules involved in the complement system. Only two anti-complement drugs are currently on the market, but many more are being developed for diseases that include infectious, inflammatory, degenerative, traumatic and neoplastic disorders. In this Review, we describe the history, current landscape and future directions for anti-complement therapies.
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Abdullah M, Schultz H, Kähler D, Branscheid D, Dalhoff K, Zabel P, Vollmer E, Goldmann T. Expression of the acute phase protein haptoglobin in human lung cancer and tumor-free lung tissues. Pathol Res Pract 2009; 205:639-47. [DOI: 10.1016/j.prp.2009.04.007] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/18/2008] [Revised: 03/26/2009] [Accepted: 04/09/2009] [Indexed: 10/20/2022]
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Krishnan V, Ponnuraj K, Xu Y, Macon K, Volanakis JE, Narayana SVL. The crystal structure of cobra venom factor, a cofactor for C3- and C5-convertase CVFBb. Structure 2009; 17:611-9. [PMID: 19368894 DOI: 10.1016/j.str.2009.01.015] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2008] [Revised: 01/27/2009] [Accepted: 01/27/2009] [Indexed: 10/20/2022]
Abstract
Cobra venom factor (CVF) is a functional analog of human complement component C3b, the active fragment of C3. Similar to C3b, in human and mammalian serum, CVF binds factor B, which is then cleaved by factor D, giving rise to the CVFBb complex that targets the same scissile bond in C3 as the authentic complement convertases C4bC2a and C3bBb. Unlike the latter, CVFBb is a stable complex and an efficient C5 convertase. We solved the crystal structure of CVF, isolated from Naja naja kouthia venom, at 2.6 A resolution. The CVF crystal structure, an intermediate between C3b and C3c, lacks the TED domain and has the CUB domain in an identical position to that seen in C3b. The similarly positioned CUB and slightly displaced C345c domains of CVF could play a vital role in the formation of C3 convertases by providing important primary binding sites for factor B.
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Janssen BJC, Gros P. Conformational complexity of complement component C3. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2007; 586:291-312. [PMID: 16893080 DOI: 10.1007/0-387-34134-x_20] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- Bert J C Janssen
- Crystal and Structural Chemistry, Bijvoet Center for Biomolecular Research, Dept. of Chemistry, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
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Hui KM, Magnadóttir B, Schifferli JA, Inal JM. CRIT peptide interacts with factor B and interferes with alternative pathway activation. Biochem Biophys Res Commun 2006; 344:308-14. [PMID: 16600177 DOI: 10.1016/j.bbrc.2006.03.101] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2006] [Accepted: 03/17/2006] [Indexed: 01/11/2023]
Abstract
Complement C2 receptor inhibitor trispanning (CRIT) inhibits the classical pathway (CP) C3 convertase formation by competing with C4b for the binding of C2. The C-terminal 11-amino-acid of the first CRIT-extracellular domain (CRIT-H17) has a strong homology with a sequence in the C4beta chain, which is responsible for the binding of C2. Since the CP and alternative pathway (AP) C3 convertases have many functional and structural similarities, we further investigated the effects of CRIT-H17 on the AP. The factor D-mediated cleavage of factor B (FB) was blocked by CRIT-H17. By ELISA and immunoblot, CRIT-H17 was shown to bind FB. CRIT-H17 had no decay activity on the C3bBb complex as compared to decay-accelerating factor. Binding of CRIT-H17 to FB did not interfere with the assembly of C3bB complex. In a haemolytic assay using C2-deficient serum, CRIT-H17 interfered with AP complement activation.
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Affiliation(s)
- Kwok-Min Hui
- University Hospital Basel, Immunonephrology, Department of Research, Hebelstrasse 20, CH-4031 Basel, Switzerland.
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Inal JM. Complement C2 receptor inhibitor trispanning: from man to schistosome. ACTA ACUST UNITED AC 2005; 27:320-31. [PMID: 16235057 DOI: 10.1007/s00281-005-0009-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2005] [Accepted: 05/20/2005] [Indexed: 01/03/2023]
Abstract
Horizontal gene transfer (HGT), in relation to genetic transfer between hosts and parasites, is a little described mechanism. Since the complement inhibitor CRIT was first discovered in the human Schistosoma parasite (the causative agent of Bilharzia) and in Trypanosoma cruzi (a parasite causing Chagas' disease), it has been found to be distributed amongst various species, ranging from the early teleost cod to rats and humans. In terms of evolutionary distance, as measured in a phylogenetic analysis of these CRIT genes at nucleotide level, the parasitic species are as removed from their human host as is the rat sequence, suggesting HGT. The hypotheses that CRIT in humans and schistosomes is orthologous and that the presence of CRIT in schistosomes occurs as a result of host-to-parasite HGT are presented in the light of empirical data and the growing body of data on mobile genetic elements in human and schistosome genomes. In summary, these data indicate phylogenetic proximity between Schistosoma and human CRIT, identity of function, high nucleotide/amino acid identity and secondary protein structure, as well as identical genomic organization.
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Affiliation(s)
- Jameel M Inal
- Immunonephrology, Department of Research, University Hospital Basel, Basel, Switzerland.
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Inal J, Miot S, Schifferli JA. The complement inhibitor, CRIT, undergoes clathrin-dependent endocytosis. Exp Cell Res 2005; 310:54-65. [PMID: 16112669 DOI: 10.1016/j.yexcr.2005.07.003] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2005] [Revised: 07/07/2005] [Accepted: 07/07/2005] [Indexed: 01/22/2023]
Abstract
Complement C2 receptor inhibitor trispanning (CRIT) is a receptor for the second component of complement and is found in various tissues and hemopoietic cells. On binding to CRIT, C2 cannot be activated to potentially form a variant-C3 convertase as it is rendered non-cleavable by C1s. CRIT thus limits the amount of C3 convertase formed on the cell surface. In this study we have shown, using flow cytometry and immunofluorescence microscopy, that human CRIT undergoes endocytosis from the plasma membrane. The endocytosis, possibly ligand mediated, occurs via clathrin-coated pits as it can be inhibited by prior incubation of cells in hypertonic medium or with chlorpromazine, at 37 degrees C. However, inhibition of endocytosis was not possible after treatment with nystatin, or filipin, inhibitors of caveolae/raft-dependent endocytosis. In the presence of C2 alone, CRIT associates with the adapter protein, beta-arrestin-2, and whether in association with C2 or not, then appears in the perinuclear region, but does not appear to be translocated into the nucleus. Apart from the C3aR and C5aR that internalize the anaphylatoxic peptides, this is the first report of the internalization via the clathrin pathway of a receptor for a complement serum protein.
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Affiliation(s)
- Jameel Inal
- University Hospital Basel, Immunonephrology, Department of Research, 4031 Basel, Switzerland.
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Inal JM, Hui KM, Miot S, Lange S, Ramirez MI, Schneider B, Krueger G, Schifferli JA. Complement C2 receptor inhibitor trispanning: a novel human complement inhibitory receptor. THE JOURNAL OF IMMUNOLOGY 2005; 174:356-66. [PMID: 15611259 DOI: 10.4049/jimmunol.174.1.356] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
The complement system presents a powerful defense against infection and is tightly regulated to prevent damage to self by functionally equivalent soluble and membrane regulators. We describe complement C2 receptor inhibitor trispanning (CRIT), a novel human complement regulatory receptor, expressed on hemopoietic cells and a wide range of tissues throughout the body. CRIT is present in human parasites through horizontal transmission. Serum complement component C2 binds to the N-terminal extracellular domain 1 of CRIT, which, in peptide form, blocks C3 convertase formation and complement-mediated inflammation. Unlike C1 inhibitor, which inhibits the cleavage of C4 and C2, CRIT only blocks C2 cleavage but, in so doing, shares with C1 inhibitor the same functional effect, of preventing classical pathway C3 convertase formation. Ab blockage of cellular CRIT reduces inhibition of cytolysis, indicating that CRIT is a novel complement regulator protecting autologous cells.
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Affiliation(s)
- Jameel M Inal
- Immunonephrology Lab 414, Department of Research, University Hospital Basel, Hebelstrasse 20, 4031 Basel, Switzerland.
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Abstract
Many orthologous proteins of known mammalian receptors have been discovered in parasites. Besides disguising the parasite as self in terms of the host immune system, evidence is accumulating that these receptors link to signalling pathways in parasites that appear to be involved in their growth or development. Recently, several proteins of the host complement system, which forms part of the innate defence against invading microorganisms, have been shown to possess alternative functions. These complement proteins interact with signalling pathways involved in early development and differentiation, as well as organ and tissue regeneration. By altering cellular interactions and responses, complement is being shown to have novel roles besides the originally described inflammatory role. The possibility exists that, as for other host factors interacting with parasites and affecting their growth or development, host complement proteins could also have such an influence.
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Affiliation(s)
- Jameel M Inal
- University Hospital Basel, Department of Research 414, Hebelstrasse 20, Basel CH-4031, Switzerland.
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