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Pumpens P, Renhofa R, Dishlers A, Kozlovska T, Ose V, Pushko P, Tars K, Grens E, Bachmann MF. The True Story and Advantages of RNA Phage Capsids as Nanotools. Intervirology 2016; 59:74-110. [DOI: 10.1159/000449503] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2016] [Accepted: 08/30/2016] [Indexed: 11/19/2022] Open
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A Modular Vaccine Development Platform Based on Sortase-Mediated Site-Specific Tagging of Antigens onto Virus-Like Particles. Sci Rep 2016; 6:25741. [PMID: 27170066 PMCID: PMC4864371 DOI: 10.1038/srep25741] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2015] [Accepted: 04/21/2016] [Indexed: 12/16/2022] Open
Abstract
Virus-like particles (VLPs) can be used as powerful nanoscale weapons to fight against virus infection. In addition to direct use as vaccines, VLPs have been extensively exploited as platforms on which to display foreign antigens for prophylactic vaccination and immunotherapeutic treatment. Unfortunately, fabrication of new chimeric VLP vaccines in a versatile, site-specific and highly efficient manner is beyond the capability of traditional VLP vaccine design approaches, genetic insertion and chemical conjugation. In this study, we described a greatly improved VLP display strategy by chemoenzymatic site-specific tailoring antigens on VLPs surface with high efficiency. Through the transpeptidation mediated by sortase A, one protein and two epitopes containing N-terminal oligoglycine were conjugated to the LPET motif on the surface of hepatitis B virus core protein (HBc) VLPs with high density. All of the new chimeric VLPs induced strong specific IgG responses. Furthermore, the chimeric VLPs with sortase A tagged enterovirus 71 (EV71) SP70 epitope could elicit effective antibodies against EV71 lethal challenging as well as the genetic insertion chimeric VLPs. The sortase A mediated chemoenzymatic site-specific tailoring of the HBc VLP approach shows great potential in new VLP vaccine design for its simplicity, site specificity, high efficiency, and versatility.
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Liao Y, Zhang SM, Neo TL, Tam JP. Tryptophan-dependent membrane interaction and heteromerization with the internal fusion peptide by the membrane proximal external region of SARS-CoV spike protein. Biochemistry 2015; 54:1819-30. [PMID: 25668103 DOI: 10.1021/bi501352u] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The spike (S) protein of severe acute respiratory syndrome-associated CoV (SARS-CoV) mediates membrane fusion and viral entry. These events involve structural rearrangements, including heteromerization between two heptad repeats (HR1 and HR2) to form a trimer of dimers as a six-helix bundle (6-HB), a quaternary protein structure that brings two distant clusters of hydrophobic sequences into the proximity of each other, the internal fusion peptide (IFP) preceding HR1, and the highly conserved tryptophan (Trp)-rich membrane proximal external region (MPER) following HR2. Here, we show that MPER can undergo self-oligomerization and heteromerization with IFP, events that are Trp-dependent. To delineate the roles of Trp residues of MPER in forming these quaternary structures and interacting with membranes, we employed a panel of synthetic peptides: MPER peptide (M-wt) and its alanine (Ala) and phenylalanine (Phe) analogues. Ala substitutions of Trp inhibited its association with cellular membranes. Chemical cross-linking experiments showed that M-wt can self-interact to form oligomers and cross-interact with IFP23, a synthetic IFP peptide, to form a heterohexamer. In comparison, little high-order oligomer was formed between M-wt and fusion peptide. The specific interaction between M-wt and IFP23 was confirmed by immunofluorescence staining experiments. In aqueous solutions, both M-wt and IFP23 displayed random secondary structures that became helical in hydrophobic solvents. Triple-Ala substitutions of Trp in M-wt, but not the corresponding triple-Phe analogue, disrupted oligomerization of M-wt and hetero-oligomerization of M-wt with IFP23. Overall, our results show that Trp residues of MPER play a key role in maintaining the structure and functions of MPER, allowing it to interact with IFP to form a MPER-IFP heteromer, a putative quaternary structure extending from the 6-HB, and function in membrane fusion. Finally, we showed that a MPER peptide could serve as an inhibitor in the entry process.
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Affiliation(s)
- Ying Liao
- School of Biological Sciences, Nanyang Technological University , 60 Nanyang Drive, Singapore 637551
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Hosie MJ, Pajek D, Samman A, Willett BJ. Feline immunodeficiency virus (FIV) neutralization: a review. Viruses 2011; 3:1870-90. [PMID: 22069520 PMCID: PMC3205386 DOI: 10.3390/v3101870] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2011] [Revised: 09/28/2011] [Accepted: 09/29/2011] [Indexed: 11/16/2022] Open
Abstract
One of the major obstacles that must be overcome in the design of effective lentiviral vaccines is the ability of lentiviruses to evolve in order to escape from neutralizing antibodies. The primary target for neutralizing antibodies is the highly variable viral envelope glycoprotein (Env), a glycoprotein that is essential for viral entry and comprises both variable and conserved regions. As a result of the complex trimeric nature of Env, there is steric hindrance of conserved epitopes required for receptor binding so that these are not accessible to antibodies. Instead, the humoral response is targeted towards decoy immunodominant epitopes on variable domains such as the third hypervariable loop (V3) of Env. For feline immunodeficiency virus (FIV), as well as the related human immunodeficiency virus-1 (HIV-1), little is known about the factors that lead to the development of broadly neutralizing antibodies. In cats infected with FIV and patients infected with HIV-1, only rarely are plasma samples found that contain antibodies capable of neutralizing isolates from other clades. In this review we examine the neutralizing response to FIV, comparing and contrasting with the response to HIV. We ask whether broadly neutralizing antibodies are induced by FIV infection and discuss the comparative value of studies of neutralizing antibodies in FIV infection for the development of more effective vaccine strategies against lentiviral infections in general, including HIV-1.
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MESH Headings
- Amino Acid Sequence
- Animals
- Antibodies, Neutralizing/blood
- Antibodies, Neutralizing/immunology
- Antibodies, Viral/blood
- Antibodies, Viral/immunology
- Cat Diseases/immunology
- Cat Diseases/prevention & control
- Cat Diseases/virology
- Cats
- Gene Products, env/genetics
- Gene Products, env/immunology
- Gene Products, env/metabolism
- Humans
- Immune Evasion
- Immunity, Humoral
- Immunodeficiency Virus, Feline/genetics
- Immunodeficiency Virus, Feline/immunology
- Immunodominant Epitopes/immunology
- Lentivirus Infections/immunology
- Lentivirus Infections/prevention & control
- Lentivirus Infections/veterinary
- Lentivirus Infections/virology
- Molecular Sequence Data
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Affiliation(s)
- Margaret J Hosie
- Medical Research Council, University of Glasgow Centre for Virus Research, Henry Wellcome Building for Comparative Medical Sciences, 464 Bearsden Road, Glasgow G61 1QH, UK.
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Aromatic amino acids in the juxtamembrane domain of severe acute respiratory syndrome coronavirus spike glycoprotein are important for receptor-dependent virus entry and cell-cell fusion. J Virol 2008; 82:2883-94. [PMID: 18199653 DOI: 10.1128/jvi.01805-07] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The severe acute respiratory syndrome coronavirus (SARS-CoV) spike glycoprotein (S) is a class I viral fusion protein that binds to its receptor glycoprotein, human angiotensin converting enzyme 2 (hACE2), and mediates virus entry and cell-cell fusion. The juxtamembrane domain (JMD) of S is an aromatic amino acid-rich region proximal to the transmembrane domain that is highly conserved in all coronaviruses. Alanine substitutions for one or two of the six aromatic residues in the JMD did not alter the surface expression of the SARS-CoV S proteins with a deletion of the C-terminal 19 amino acids (S Delta19) or reduce binding to soluble human ACE2 (hACE2). However, hACE2-dependent entry of trypsin-treated retrovirus pseudotyped viruses expressing JMD mutant S Delta19 proteins was greatly reduced. Single alanine substitutions for aromatic residues reduced entry to 10 to 60% of the wild-type level. The greatest reduction was caused by residues nearest the transmembrane domain. Four double alanine substitutions reduced entry to 5 to 10% of the wild-type level. Rapid hACE2-dependent S-mediated cell-cell fusion was reduced to 60 to 70% of the wild-type level for all single alanine substitutions and the Y1188A/Y1191A protein. S Delta19 proteins with other double alanine substitutions reduced cell-cell fusion further, from 40% to less than 20% of wild-type levels. The aromatic amino acids in the JMD of the SARS-CoV S glycoprotein play critical roles in receptor-dependent virus-cell and cell-cell fusion. Because the JMD is so highly conserved in all coronavirus S proteins, it is a potential target for development of drugs that may inhibit virus entry and/or cell-cell fusion mediated by S proteins of all coronaviruses.
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Giannecchini S, D'Ursi AM, Esposito C, Scrima M, Zabogli E, Freer G, Rovero P, Bendinelli M. Antibodies generated in cats by a lipopeptide reproducing the membrane-proximal external region of the feline immunodeficiency virus transmembrane enhance virus infectivity. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2007; 14:944-51. [PMID: 17596431 PMCID: PMC2044484 DOI: 10.1128/cvi.00140-07] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The immunogenicity of a lipoylated peptide (lipo-P59) reproducing the membrane-proximal external region (MPER) of the transmembrane glycoprotein of feline immunodeficiency virus (FIV) was investigated with cats. In the attempt to mimic the context in which MPER is located within intact virions, lipo-P59 was administered in association with membrane-like micelles. Analyses showed that in this milieu, lipo-P59 had a remarkable propensity to be positioned at the membrane interface, displayed a large number of ordered structures folded in turn helices, and was as active as lipo-P59 alone at inhibiting FIV infectivity in vitro. The antibodies developed differed from the ones previously obtained by immunizing cats with the nonlipoylated version of the peptide (G. Freer, S. Giannecchini, A. Tissot, M. F. Bachmann, P. Rovero, P. F. Serres, and M. Bendinelli, Virology 322:360-369, 2004) in epitope specificity and in the fact that they bound FIV virions. However, they too lacked virus-neutralizing activity and actually enhanced FIV infectivity for lymphoid cell cultures. It is concluded that the use of MPER-reproducing oligopeptides is not a viable approach for vaccinating against FIV.
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Affiliation(s)
- Simone Giannecchini
- Retrovirus Center and Virology Section, Department of Experimental Pathology, University of Pisa, I-56127 Pisa, Italy
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FIV as a Model for HIV: An Overview. IN VIVO MODELS OF HIV DISEASE AND CONTROL 2007. [PMCID: PMC7121254 DOI: 10.1007/0-387-25741-1_7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Animal models for human immunodeficiency virus (HIV) infection play a key role in understanding the pathogenesis of AIDS and the development of therapeutic agents and vaccines. As the only lentivirus that causes an immunodeficiency resembling that of HIV infection, in its natural host, feline immunodeficiency virus (FIV) has been a unique and powerful model for AIDS research. FIV was first described in 1987 by Niels Pedersen and co-workers as the causative agent for a fatal immunodeficiency syndrome observed in cats housed in a cattery in Petaluma, California. Since this landmark observation, multiple studies have shown that natural and experimental infection of cats with biological isolates of FIV produces an AIDS syndrome very similar in pathogenesis to that observed for human AIDS. FIV infection induces an acute viremia associated with Tcell alterations including depressed CD4 :CD8 T-cell ratios and CD4 T-cell depletion, peripheral lymphadenopathy, and neutropenia. In later stages of FIV infection, the host suffers from chronic persistent infections that are typically self-limiting in an immunocompetent host, as well as opportunistic infections, chronic diarrhea and wasting, blood dyscracias, significant CD4 T-cell depletion, neurologic disorders, and B-cell lymphomas. Importantly, chronic FIV infection induces a progressive lymphoid and CD4 T-cell depletion in the infected cat. The primary mode of natural FIV transmission appears to be blood-borne facilitated by fighting and biting. However, experimental infection through transmucosal routes (rectal and vaginal mucosa and perinatal) have been well documented for specific FIV isolates. Accordingly, FIV disease pathogenesis exhibits striking similarities to that described for HIV-1 infection.
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Ambühl PM, Tissot AC, Fulurija A, Maurer P, Nussberger J, Sabat R, Nief V, Schellekens C, Sladko K, Roubicek K, Pfister T, Rettenbacher M, Volk HD, Wagner F, Müller P, Jennings GT, Bachmann MF. A vaccine for hypertension based on virus-like particles: preclinical efficacy and phase I safety and immunogenicity. J Hypertens 2007; 25:63-72. [PMID: 17143175 DOI: 10.1097/hjh.0b013e32800ff5d6] [Citation(s) in RCA: 155] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND Despite the availability of efficacious drugs, the success of treating hypertension is limited by patients' inconsistent drug intake. Immunization against angiotensin II may offer a valuable alternative to conventional drugs for the treatment of hypertension, because vaccines induce relatively long-lasting effects and do not require daily dosing. Here we describe the preclinical development and the phase I clinical trial testing of a virus-like particle (VLP)-based antihypertensive vaccine. METHODS AND RESULTS An angiotensin II-derived peptide was conjugated to the VLP Qbeta (AngQb). AngQb was highly immunogenic in mice and rats. To test for efficacy, spontaneously hypertensive rats (SHR) were immunized with 400 microg AngQb or VLP alone. Group mean systolic blood pressure (SBP) was reduced by up to 21 mmHg (159 +/- 2 versus 180 +/- 5 mmHg, P < 0.001), and total angiotensin II levels (antibody-bound and free) were increased ninefold (85 +/- 20 versus 9 +/- 1 pmol/l, P = 0.002) compared with VLP controls. SHR treated with the angiotensin-converting enzyme (ACE) inhibitor ramipril (1 mg/kg per day by mouth) reached an SBP of 155 +/- 2 mmHg. Twelve healthy volunteers of a placebo-controlled randomized phase I trial were injected once with 100 microg AngQb. Angiotensin II-specific antibodies were raised in all subjects (100% responder rate) and AngQb was well tolerated. CONCLUSIONS AngQb reduces blood pressure in SHR to levels obtained with an ACE inhibitor, and is immunogenic and well tolerated in humans. Therefore, vaccination against angiotensin II has the potential to become a useful antihypertensive treatment providing long-lasting effects and improving patient compliance.
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Giannecchini S, Alcaro MC, Isola P, Sichi O, Pistello M, Papini AM, Rovero P, Bendinelli M. Feline Immunodeficiency Virus Plasma Load Reduction by a Retroinverso Octapeptide Reproducing the Trp-Rich Motif of the Transmembrane Glycoprotein. Antivir Ther 2005. [DOI: 10.1177/135965350501000505] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The Trp-rich motif (TrpM) of the transmembrane glycoprotein (TM) of lentiviruses is an attractive domain on which to design new potential cell entry peptide inhibitors. We recently demonstrated that an octapeptide reproducing the TrpM of feline immunodeficiency virus (FIV), designated C8, broadly inhibited this virus in vitro and that the retroinverso analogue of this peptide (riC8) was almost as inhibitory and exhibited features suggestive of a much increased stability. Here, we demonstrated that riC8 is indeed highly stable, maintaining its concentration unchanged for at least 24 h in cat serum in vitro. Furthermore, once inoculated into cats, riC8 produced no major acute toxic effects and exhibited satisfactory pharmacokinetic properties. Finally, we report the results of a short-term monotherapy experiment in chronically FIV-infected cats showing that riC8 is well tolerated and also has substantial antiviral activity in vivo. In particular, the mean viral load of riC8-treated animals declined progressively with increasing time of treatment, whereas that of control animals given C8 or solvent alone did not. These results provide the first evidence that clinically useful inhibition of virus replication with a small peptide derived from a functional domain of the TM of a lentivirus can be achieved in vivo.
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Affiliation(s)
- Simone Giannecchini
- Retrovirus Centre and Virology Section, Department of Experimental Pathology, University of Pisa, Pisa, Italy
- Present address: Department of Public Health, University of Florence, Florence, Italy
| | - Maria Claudia Alcaro
- Laboratory of Peptide and Protein Chemistry and Biology, University of Florence, Florence, Italy
| | - Patrizia Isola
- Retrovirus Centre and Virology Section, Department of Experimental Pathology, University of Pisa, Pisa, Italy
| | - Olimpia Sichi
- Retrovirus Centre and Virology Section, Department of Experimental Pathology, University of Pisa, Pisa, Italy
| | - Mauro Pistello
- Retrovirus Centre and Virology Section, Department of Experimental Pathology, University of Pisa, Pisa, Italy
| | - Anna Maria Papini
- Laboratory of Peptide and Protein Chemistry and Biology, University of Florence, Florence, Italy
| | - Paolo Rovero
- Laboratory of Peptide and Protein Chemistry and Biology, University of Florence, Florence, Italy
| | - Mauro Bendinelli
- Retrovirus Centre and Virology Section, Department of Experimental Pathology, University of Pisa, Pisa, Italy
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