The Experts below are selected from a list of 5952 Experts worldwide ranked by ideXlab platform
Kathrin U. Jansen - One of the best experts on this subject based on the ideXlab platform.
-
Human papillomavirus type 6 virus-like particles present overlapping yet distinct conformational epitopes.
The Journal of general virology, 2003Co-Authors: Xin-min Wang, James C. Cook, Kathrin U. Jansen, Neil D. Christensen, Steven W. Ludmerer, Jessica C Lee, William L McclementsAbstract:The epitope for a human papillomavirus (HPV) type 6 conformation-dependent, neutralizing monoclonal antibody (mAb) was partially mapped using HPV L1 recombinant virus-like particles (VLPs). The mAb H6.J54 is cross-reactive with the closely related HPV types 6 and 11. By making HPV-6-like amino acid substitutions in the cottontail rabbit papillomavirus (CRPV) major Capsid Protein L1, we were able to transfer H6.J54 binding activity into a CRPV/HPV-6 hybrid L1 Protein. Full binding activity was achieved with only nine amino acid changes and identified a region centred on the HPV-6 residues 49-54. This region has previously been shown to be a critical part of HPV-6 type-specific epitopes. Fine mapping of the region by scanning a series of alanine substitution mutations showed that in HPV-6 VLPs this type-common epitope overlaps HPV-6 type-specific epitopes.
-
A novel human papillomavirus type 6 neutralizing domain comprising two discrete regions of the major Capsid Protein L1.
Virology, 2001Co-Authors: Mcclements William L, Kathrin U. Jansen, Xin-min Wang, Jessica C. Ling, Dee Marie Skulsky, Neil D. Christensen, Steven W. LudmererAbstract:We have mapped the binding sites on human papillomavirus (HPV) type 6 for three HPV 6-specific neutralizing monoclonal antibodies (mAbs). The critical binding residues were first identified by making HPV 11-like amino acid substitutions in the HPV 6 major Capsid Protein L1 and assaying the resulting virus-like particles (VLPs) for reactivity with the mAbs. To confirm the relevance of these residues for mAb binding, we demonstrated that HPV 6 type-specificity could be transferred to HPV 11 VLPs by making the appropriate HPV 6-like amino acid substitutions in the HPV 11 L1. Two binding regions were found. For one mAb, all critical residues are centered at residue 53, while for the other two mAbs, type-specific binding also requires a second site located more than 100 residues distal to the first. Both binding sites coincide with regions of L1 where the sequences of the closely related HPV 6 and 11 diverge. These regions are where the L1 sequences are the least well conserved among all HPV types and they have been implicated in type-specific binding for other HPV types. This suggests that clusters of diverged residues, surrounded by conserved L1 sequences, are presented on the surface of assembled particles and are responsible for eliciting critical humoral immune responses to the virus.
-
Purification of virus-like particles of recombinant human papillomavirus type 11 major Capsid Protein L1 from Saccharomyces cerevisiae.
Protein expression and purification, 1999Co-Authors: James C. Cook, Joseph G. Joyce, Hugh A. George, Loren D. Schultz, William M. Hurni, Kathrin U. Jansen, Robert W. Hepler, Robert S. Lowe, Paul M. KellerAbstract:Abstract Recombinant major Capsid Protein, L1 ( M r = 55,000), of human papillomavirus type 11 was expressed intracellularly at high levels in a galactose-inducible Saccharomyces cerevisiae expression system by an HPV6/11 hybrid gene. The Capsid Protein self-assembled into virus-like particles (VLPs) and accounted for 15% of the total soluble Protein. A purification process was developed that consisted of two main steps: microfiltration and cation-exchange chromatography. The purified VLPs were 98% homogeneous, and the overall purification yield was 10%. The final product was characterized by several analytical methods and was highly immunogenic in mice.
-
Protection against Papillomavirus with a Polynucleotide Vaccine
The Journal of infectious diseases, 1996Co-Authors: John J. Donnelly, Kathrin U. Jansen, Douglas Martinez, Ronald W. Ellis, Donna L. Montgomery, Margaret A. LiuAbstract:Genital infections with human papillomavirus (HPV) are increasingly recognized as a significant source of human disease; HPV is now implicated in up to 90% of cervical carcinomas. Neutralizing antibodies against papillomaviruses recognize conformational epitopes formed when viral Capsid Proteins assemble into virions or virus-like particles. Immunization with plasmid DNA encoding the major viral Capsid Protein L1 was studied as a means of inducing neutralizing antibodies and protection against virus challenge. In a cottontail rabbit papillomavirus (CRPV) model, immunization with plasmid DNA encoding L1 elicited conformationally specific neutralizing antibodies and provided immunity against papilloma formation upon challenge with CRPV. Immunization with DNA encoding the Capsid Protein may provide a means of protecting humans against HPV and would simplify the production of multivalent vaccines by combining plasmids that encode the viral Capsid Proteins of different strains. This may be of importance given the multiplicity of HPV types capable of causing disease.
-
Sequence conservation within the major Capsid Protein of human papillomavirus (HPV) type 18 and formation of HPV-18 virus-like particles in Saccharomyces cerevisiae.
The Journal of general virology, 1996Co-Authors: K J Hofmann, M P Neeper, H Z Markus, D R Brown, M Müller, Kathrin U. JansenAbstract:The major Capsid Protein L1 of human papillomaviruses (HPVs) has been identified as a promising candidate antigen for a prophylactic HPV vaccine. Since amino acid sequence heterogeneity has been demonstrated for the L1 genes within individual HPV types, nucleotide sequences of L1 were determined from six HPV-18 clinical isolates and the cervical carcinoma cell line SW756 and compared to the published HPV-18 prototype sequence. The sequences were almost identical between the clinical isolates and SW756 but differed markedly from the published prototype sequence. Resequencing the prototype HPV-18 revealed that these differences were due to sequencing artifacts of the prototype HPV-18 sequence archived in GenBank. Thus, the HPV-18 L1 genes seem to display a very high level of sequence conservation. The HPV-18 L1 gene derived from SW756 was expressed in Saccharomyces cerevisiae and self-assembly of the L1 Protein into virus-like particles was demonstrated.
Martin Sapp - One of the best experts on this subject based on the ideXlab platform.
-
human papillomavirus major Capsid Protein L1 remains associated with the incoming viral genome throughout the entry process
Journal of Virology, 2017Co-Authors: Stephen Digiuseppe, Malgorzata Bienkowskahaba, Lucile G M Guion, Timothy R Keiffer, Martin SappAbstract:ABSTRACT During infectious entry, acidification within the endosome triggers uncoating of the human papillomavirus (HPV) Capsid, whereupon host cyclophilins facilitate the release of most of the major Capsid Protein, L1, from the minor Capsid Protein L2 and the viral genome. The L2/DNA complex traffics to the trans -Golgi network (TGN). After the onset of mitosis, HPV-harboring transport vesicles bud from the TGN, followed by association with mitotic chromosomes. During this time, the HPV genome remains in a vesicular compartment until the nucleus has completely reformed. Recent data suggest that while most of L1 Protein dissociates and is degraded in the endosome, some L1 Protein remains associated with the viral genome. The L1 Protein has DNA binding activity, and the L2 Protein has multiple domains capable of interacting with L1 capsomeres. In this study, we report that some L1 Protein traffics with L2 and viral genome to the nucleus. The accompanying L1 Protein is mostly full length and retains conformation-dependent epitopes, which are recognized by neutralizing antibodies. Since more than one L1 molecule contributes to these epitopes and requires assembly into capsomeres, we propose that L1 Protein is present in the form of pentamers. Furthermore, we provide evidence that the L1 Protein interacts directly with viral DNA within the Capsid. Based on our findings, we propose that the L1 Protein, likely arranged as capsomeres, stabilizes the viral genome within the subviral complex during intracellular trafficking. IMPORTANCE After internalization, the nonenveloped human papillomavirus virion uncoats in the endosome, whereupon conformational changes result in a dissociation of a subset of the major Capsid Protein L1 from the minor Capsid Protein L2, which remains in complex with the viral DNA. Recent data suggest that some L1 Protein may accompany the viral genome beyond the endosomal compartment. We demonstrate that conformationally intact L1 Protein, likely still arranged as capsomeres, remains associated with the incoming viral genome throughout mitosis and transiently resides in the nucleus until after the viral DNA is released from the transport vesicle.
-
cyclophilins facilitate dissociation of the human papillomavirus type 16 Capsid Protein L1 from the l2 dna complex following virus entry
Journal of Virology, 2012Co-Authors: Malgorzata Bienkowskahaba, Carlyn Williams, Seong-man Kim, Robert L. Garcea, Martin SappAbstract:Human papillomaviruses (HPV) are composed of the major and minor Capsid Proteins, L1 and L2, that enCapsidate a chromatinized, circular double-stranded DNA genome. At the outset of infection, the interaction of HPV type 16 (HPV16) (pseudo)virions with heparan sulfate proteoglycans triggers a conformational change in L2 that is facilitated by the host cell chaperone cyclophilin B (CyPB). This conformational change results in exposure of the L2 N terminus, which is required for infectious internalization. Following internalization, L2 facilitates egress of the viral genome from acidified endosomes, and the L2/DNA complex accumulates at PML nuclear bodies. We recently described a mutant virus that bypasses the requirement for cell surface CyPB but remains sensitive to cyclosporine for infection, indicating an additional role for CyP following endocytic uptake of virions. We now report that the L1 Protein dissociates from the L2/DNA complex following infectious internalization. Inhibition and small interfering RNA (siRNA)-mediated knockdown of CyPs blocked dissociation of L1 from the L2/DNA complex. In vitro, purified CyPs facilitated the dissociation of L1 pentamers from recombinant HPV11 L1/L2 complexes in a pH-dependent manner. Furthermore, CyPs released L1 capsomeres from partially disassembled HPV16 pseudovirions at slightly acidic pH. Taken together, these data suggest that CyPs mediate the dissociation of HPV L1 and L2 Capsid Proteins following acidification of endocytic vesicles.
-
Cyclophilins Facilitate Dissociation of the Human Papillomavirus Type 16 Capsid Protein L1 from the L2/DNA Complex following Virus Entry
Journal of virology, 2012Co-Authors: Malgorzata Bienkowska-haba, Carlyn Williams, Seong-man Kim, Robert L. Garcea, Martin SappAbstract:Human papillomaviruses (HPV) are composed of the major and minor Capsid Proteins, L1 and L2, that enCapsidate a chromatinized, circular double-stranded DNA genome. At the outset of infection, the interaction of HPV type 16 (HPV16) (pseudo)virions with heparan sulfate proteoglycans triggers a conformational change in L2 that is facilitated by the host cell chaperone cyclophilin B (CyPB). This conformational change results in exposure of the L2 N terminus, which is required for infectious internalization. Following internalization, L2 facilitates egress of the viral genome from acidified endosomes, and the L2/DNA complex accumulates at PML nuclear bodies. We recently described a mutant virus that bypasses the requirement for cell surface CyPB but remains sensitive to cyclosporine for infection, indicating an additional role for CyP following endocytic uptake of virions. We now report that the L1 Protein dissociates from the L2/DNA complex following infectious internalization. Inhibition and small interfering RNA (siRNA)-mediated knockdown of CyPs blocked dissociation of L1 from the L2/DNA complex. In vitro, purified CyPs facilitated the dissociation of L1 pentamers from recombinant HPV11 L1/L2 complexes in a pH-dependent manner. Furthermore, CyPs released L1 capsomeres from partially disassembled HPV16 pseudovirions at slightly acidic pH. Taken together, these data suggest that CyPs mediate the dissociation of HPV L1 and L2 Capsid Proteins following acidification of endocytic vesicles.
-
Characterization of neutralizing epitopes within the major Capsid Protein of human papillomavirus type 33
Virology journal, 2006Co-Authors: Stefanie D Roth, Martin Sapp, Rolf E. Streeck, Hans-christoph SelinkaAbstract:Infections with papillomaviruses induce type-specific immune responses, mainly directed against the major Capsid Protein, L1. Based on the propensity of the L1 Protein to self-assemble into virus-like particles (VLPs), type-specific vaccines have already been developed. In order to generate vaccines that target a broader spectrum of HPV types, extended knowledge of neutralizing epitopes is required. Despite the association of human papillomavirus type 33 (HPV33) with cervical carcinomas, fine mapping of neutralizing conformational epitopes on HPV33 has not been reported yet. By loop swapping between HPV33 and HPV16 Capsid Proteins, we have identified amino acid sequences critical for the binding of conformation-dependent type-specific neutralizing antibodies to surface-exposed hyper variable loops of HPV33 Capsid Protein L1. Reactivities of monoclonal antibodies (mAbs) H33.B6, H33.E12, H33.J3 and H16.56E with HPV16:33 and HPV33:16 hybrid L1 VLPs revealed the complex structures of their conformational epitopes as well as the major residues contributing to their binding sites. Whereas the epitope of mAb H33.J3 was determined by amino acids (aa) 51-58 in the BC loop of HPV33 L1, sequences of at least two hyper variable loops, DE (aa 132-140) and FGb (aa 282-291), were found to be essential for binding of H33.B6. The epitope of H33.E12 was even more complex, requiring sequences of the FGa loop (aa 260-270), in addition to loops DE and FGb. These data demonstrate that neutralizing epitopes in HPV33 L1 are mainly located on the tip of the capsomere and that several hyper variable loops contribute to form these conformational epitopes. Knowledge of the antigenic structure of HPV is crucial for designing hybrid particles as a basis for intertypic HPV vaccines.
-
Heparan sulfate proteoglycans interact exclusively with conformationally intact HPV L1 assemblies: basis for a virus-like particle ELISA.
Journal of medical virology, 2004Co-Authors: Oliver Rommel, Claudia Fligge, Hans-christoph Selinka, Joakim Dillner, Christian Bergsdorf, Xiaohong Wang, Martin SappAbstract:In this article, we demonstrate that interaction of human papillomavirus-like particles (HPV-VLPs) with the putative glucosaminoglycan binding receptor is strictly dependent on conformational integrity. Such conformations are present on VLPs and capsomeres but not on monomers of the major Capsid Protein, L1, confirming reports that capsomeres can induce virus-neutralizing antibodies. Furthermore, we show the suitability of this specific interaction for development of VLP-based enzyme-linked immunosorbent assays (ELISAs), using heparin for indirect coupling of VLPs to microtiter plates, which may add an intrinsic quality control. This avoids presentation of linear, often highly cross-reactive epitopes of L1. In addition, heparin specifically interacts with a wide variety of HPV types, making it a prime candidate for a universal capture molecule.
Tadahito Kanda - One of the best experts on this subject based on the ideXlab platform.
-
Thiol-reactive reagents inhibits intracellular trafficking of human papillomavirus type 16 pseudovirions by binding to cysteine residues of major Capsid Protein L1.
Virology journal, 2007Co-Authors: Yoshiyuki Ishii, Keiko Tanaka, Kazunari Kondo, Tamae Matsumoto, Fumiko Shinkai-ouchi, Ken ' Ichi Hagiwara, Tadahito KandaAbstract:A human papillomavirus (HPV) virion is composed of Capsid Proteins L1 and L2. Several cysteine residues are located on L1 of various HPVs at markedly similar relative positions, suggesting their important functions. Although the authentic virions cannot be studied with cultured cells, surrogate pseudovirions consisting of Capsid and reporter plasmid are available for studies dealing with infectivity. HPV type16-pseudovirions (16PVs) were found to lose their infectivity after incubation with thiol-reactive reagents [biotin polyethyleneoxide iodoacetamide (BPEOIA), 5,5'-dithiobis(2-nitrobenzoic acid) (DTNB), N-ethylmaleimide (NEM), 4-(N-maleimido)benzyl-trimethylammonium iodide (MBTA), and [2-(trimethylammonium)ethyl] methanethiosulfonate bromide (MTSET)]. A labelled streptavidin was detected to bind to the complex of BPEOIA and L1 of the 16PVs incubated with BPEOIA. The analysis of molecular mass of trypsin-fragments derived from the complex of the BPEOIA and L1 indicated that BPEOIA bound to at least C146, C225, and C229. No appreciable change of the 16PVs carrying DTNB or NEM was detected by sedimentation analysis or electron microscopy. The 16PVs carrying DTNB or NEM were able to bind to and enter HeLa cells but degraded before they reached the perinuclear region. HPV16 L1 C146, C225, and C229 have free thiol, which are accessible to BPEOIA, DTNB, NEM, MBTA, and MTSET. Binding of DTNB or NEM to the thiols may cause conformational changes that result in the inhibition of the entry and trafficking of the 16PVs.
-
Human Papillomavirus 16 Minor Capsid Protein L2 Helps Capsomeres Assemble Independently of Intercapsomeric Disulfide Bonding
Virus Genes, 2005Co-Authors: Yoshiyuki Ishii, Saori Ozaki, Keiko Tanaka, Tadahito KandaAbstract:The human papillomavirus (HPV) capsomeres (pentamers of major Capsid Protein L1), which constitute along with L2 the virion Capsid, can assemble themselves alone into the L1-Capsid particles in vivo and in vitro , depending on intercapsomeric disulfide bonds. To study a possible role of L2 in Capsid assembly, we examined the interaction between HPV16 L2 and capsomeres under the conditions that inhibit the formation of disulfide bonds in vitro and in vivo . The purified L2 bound to free capsomeres prepared by disassembling L1-Capsids but not to the L1-Capsids in vitro . And the L2 was found to help capsomeres assemble into smaller Capsid-like particles independently of intercapsomeric disulfide bonding. Similar particles were obtained from the Sf9 cells co-infected with baculoviruses expressing L2 and an L1 mutant that lacks a C-terminal cysteine (C428S) and can form capsomeres but no Capsids when expressed alone. These findings suggest that L2, which is known to bind both viral DNA and L1, may contribute to the formation of the virion by linking viral DNA and capsomeres and by helping capsomeres assemble before the virion Capsid structure is completed by dintercapsomeric disulfide bonding.
-
Mutational analysis of human papillomavirus type 16 major Capsid Protein L1: the cysteines affecting the intermolecular bonding and structure of L1-Capsids.
Virology, 2003Co-Authors: Yoshiyuki Ishii, Keiko Tanaka, Tadahito KandaAbstract:Abstract Human papillomavirus 16 major Capsid Protein L1 (composed of 505 amino acids (aa) including 12 cysteines) assembles by itself into virion-like icosahedral particles (L1-Capsids), each of which is dissociated into 72 pentameric capsomeres when intermolecular disulfide bonds are disrupted. To identify the cysteines affecting the bonding and the structural integrity of the L1-Capsids, we constructed a series of L1 mutants with substitution of serine for cysteine, which were expressed from recombinant baculoviruses in the insect Sf9 cells. From infected cells, the self-assembled L1-Capsid fractions were purified by CsCl-equilibrium centrifugation and examined for velocity sedimentation profiles, for the presence of intermolecular bonding by SDS–PAGE with or without a reducing agent, for morphology under an electron microscope, and for susceptibility to trypsin digestion. Mutants C175S (C at aa 175 was replaced with S) and C185S were sedimented in sucrose-density gradients slightly slower than the wild type (WT) Capsids, and mutant C428S stayed near the top as WT-capsomeres did. In the nonreducing SDS gel, where WT-Capsids were separated into two bands of L1-trimers and L1-dimers, the C175S-trimer band was not detected, the C185S-dimer band was much less dense, and the C428S-trimer and C428S-dimer bands were not detected. Thus, it seems likely that C175, C185, and C428 are involved in L1 trimerization, in L1 dimerization, and in both, respectively. Morphologically, the C175S, C185S, and C428S fractions appeared to consist mostly of heterogeneous rod-shaped tubules, of smaller spherical particles, and of only capsomeres, respectively, whereas C102S, C229S, and C379S resembled WT. The C161S, C175S, C185S, C229S, C379S, and C428S Capsids were more sensitive to degradation caused by trypsin than WT. The results indicate that C175, C185, and C428 are required for the normal assembly of L1-Capsids through trimerization and dimerization of L1 bound by the intercapsomeric disulfide bonds between cysteines, and that C161, C229, and C379 are necessary for the integrity of L1-Capsids probably through intramolecular bonding.
-
dna vaccination of mice with plasmid expressing human papillomavirus 6 major Capsid Protein L1 elicits type specific antibodies neutralizing pseudovirions constructed in vitro
Journal of Medical Virology, 2000Co-Authors: Koji Matsumoto, Kei Kawana, Hiroyuki Yoshikawa, Yuji Taketani, Kunito Yoshiike, Tadahito KandaAbstract:Human papillomavirus 6 (HPV 6) causes benign condylomata. As a model for HPV vaccine development, we tested a HPV 6 DNA vaccine candidate, constructed by subcloning the major Capsid Protein (L1) gene into an expression plasmid having the cytomegalovirus promoter, for its immunogenicity in BALB/c mice. Three intracutaneous inoculations of the plasmid with a gene gun at 2-week intervals elicited anti-L1 serum antibodies. The antibodies were found to recognize highly type-specific, conformation-dependent epitopes, including those to neutralize pseudovirions capable of inducing β-galactosidase in infected monkey COS-1 cells. The data support the idea that immunization with DNA capable of expressing HPV L1 can be used as an HPV vaccine strategy for humans. J. Med. Virol. 60:200–204, 2000. © 2000 Wiley-Liss, Inc.
-
DNA vaccination of mice with plasmid expressing human papillomavirus 6 major Capsid Protein L1 elicits type-specific antibodies neutralizing pseudovirions constructed in vitro.
Journal of medical virology, 2000Co-Authors: Koji Matsumoto, Kei Kawana, Hiroyuki Yoshikawa, Yuji Taketani, Kunito Yoshiike, Tadahito KandaAbstract:Human papillomavirus 6 (HPV 6) causes benign condylomata. As a model for HPV vaccine development, we tested a HPV 6 DNA vaccine candidate, constructed by subcloning the major Capsid Protein (L1) gene into an expression plasmid having the cytomegalovirus promoter, for its immunogenicity in BALB/c mice. Three intracutaneous inoculations of the plasmid with a gene gun at 2-week intervals elicited anti-L1 serum antibodies. The antibodies were found to recognize highly type-specific, conformation-dependent epitopes, including those to neutralize pseudovirions capable of inducing beta-galactosidase in infected monkey COS-1 cells. The data support the idea that immunization with DNA capable of expressing HPV L1 can be used as an HPV vaccine strategy for humans.
Benes L. Trus - One of the best experts on this subject based on the ideXlab platform.
-
The papillomavirus major Capsid Protein L1.
Virology, 2013Co-Authors: Christopher B Buck, Patricia M Day, Benes L. TrusAbstract:The elegant icosahedral surface of the papillomavirus virion is formed by a single Protein called L1. Recombinant L1 Proteins can spontaneously self-assemble into a highly immunogenic structure that closely mimics the natural surface of native papillomavirus virions. This has served as the basis for two highly successful vaccines against cancer-causing human papillomaviruses (HPVs). During the viral life cycle, the Capsid must undergo a variety of conformational changes, allowing key functions including the enCapsidation of the ~8 kb viral genomic DNA, maturation into a more stable state to survive transit between hosts, mediating attachment to new host cells, and finally releasing the viral DNA into the newly infected host cell. This brief review focuses on conserved sequence and structural features that underlie the functions of this remarkable Protein.
-
Two antibodies that neutralize papillomavirus by different mechanisms show distinct binding patterns at 13 Å resolution
Journal of Molecular Biology, 1998Co-Authors: Frank P. Booy, Heather L. Greenstone, Richard B S Roden, John T Schiller, Benes L. TrusAbstract:Abstract Complexes between bovine papillomavirus type 1 (BPV1) and examples of two sets of neutralizing, monoclonal antibodies (mAb) to the major Capsid Protein (L1) were analyzed by low-dose cryo-electron microscopy and three-dimensional (3D) image reconstruction to 13 A resolution. mAb #9 is representative of a set of neutralizing antibodies that can inhibit viral binding to the cell surface, while mAb 5B6 is representative of a second set that efficiently neutralizes papillomaviruses without significantly inhibiting viral binding to the cell surface. The 3D reconstructions reveal that mAb #9 binds to L1 molecules of both pentavalent and hexavalent capsomeres. In contrast, 5B6 binds only to hexavalent capsomeres, reflecting the significant structural or environmental differences for the 5B6 epitope in the 12 pentavalent capsomeres. Epitope localization shows that mAb #9 binds monovalently to the tips of capsomeres whereas 5B6 binds both monovalently and bivalently to the sides of hexavalent capsomeres approximately two-thirds of the way down from the outer tips, very close to the putative stabilizing intercapsomere connections. The absence of mAb 5B6 from the pentavalent capsomeres and its inability to prevent viral binding to the cell surface suggest that receptor binding may occur at one or more of the 12 virion vertices.
-
Novel structural features of bovine papillomavirus Capsid revealed by a three-dimensional reconstruction to 9 Å resolution
Nature Structural Biology, 1997Co-Authors: Benes L. Trus, Heather L. Greenstone, Michael Vrhel, Richard B S Roden, John T Schiller, Frank P. BooyAbstract:The three-dimensional structure of bovine papillomavirus has been determined to 9 Å resolution by reconstruction of high resolution, low dose cryo-electron micrographs of quench-f rozen virions. Although hexavalent and pentavalent capsomeres form star-shaped pentamers of the major Capsid Protein L1, they have distinct high-resolution structures. Most prominently, a 25 Å hole in the centre of hexavalent capsomeres is occluded in the pentavalent capsomeres. This raises the possibility that the L2 minor Capsid Protein is located in the centre of the pentavalent capsomeres. Inter-capsomere connections ∼10 Å in diameter were clearly resolved. These link adjacent capsomeres and are reminiscent of the helical connections that stabilize polyomavirus.
-
Novel structural features of bovine papillomavirus Capsid revealed by a three-dimensional reconstruction to 9 Å resolution
Nature structural biology, 1997Co-Authors: Benes L. Trus, Heather L. Greenstone, Michael Vrhel, Richard B S Roden, John T Schiller, Frank P. BooyAbstract:The three-dimensional structure of bovine papillomavirus has been determined to 9 A resolution by reconstruction of high resolution, low dose cryo-electron micrographs of quench-frozen virions. Although hexavalent and pentavalent capsomeres form star-shaped pentamers of the major Capsid Protein L1, they have distinct high-resolution structures. Most prominently, a 25 A hole in the centre of hexavalent capsomeres is occluded in the pentavalent capsomeres. This raises the possibility that the L2 minor Capsid Protein is located in the centre of the pentavalent capsomeres. Inter-capsomere connections approximately 10 A in diameter were clearly resolved. These link adjacent capsomeres and are reminiscent of the helical connections that stabilize polyomavirus.
Richard B S Roden - One of the best experts on this subject based on the ideXlab platform.
-
Cervarix: a vaccine for the prevention of HPV 16, 18-associated cervical cancer.
Biologics : targets & therapy, 2008Co-Authors: Archana Monie, Chien Fu Hung, Richard B S RodenAbstract:Cervical cancer continues to be the second largest cause of cancer deaths in women worldwide. Persistent infection with high-risk types of human papillomavirus (HPV) is a necessary cause of cervical cancer. Thus, prophylactic vaccination against HPV is an attractive strategy to prevent cervical cancer. Current strategies for the development of safe and effective preventive vaccines are based on the induction of neutralizing antibodies against the major Capsid Protein, L1 of HPV. Cervarix™ is one of the preventive HPV vaccines that has been approved in the Europe and Australia and is currently under review by the US Food and Drug Administration. Cervarix is composed of HPV16 and HPV18 L1 virus-like particles (VLPs) formulated in ASO4 adjuvant. Vaccination with Cervarix has been shown to protect women against a high proportion of precursor lesions of cervical cancer caused by these two HPV types. This review explores the various features of this new vaccine candidate and discusses the future directions in the field of HPV vaccine development.
-
Two antibodies that neutralize papillomavirus by different mechanisms show distinct binding patterns at 13 Å resolution
Journal of Molecular Biology, 1998Co-Authors: Frank P. Booy, Heather L. Greenstone, Richard B S Roden, John T Schiller, Benes L. TrusAbstract:Abstract Complexes between bovine papillomavirus type 1 (BPV1) and examples of two sets of neutralizing, monoclonal antibodies (mAb) to the major Capsid Protein (L1) were analyzed by low-dose cryo-electron microscopy and three-dimensional (3D) image reconstruction to 13 A resolution. mAb #9 is representative of a set of neutralizing antibodies that can inhibit viral binding to the cell surface, while mAb 5B6 is representative of a second set that efficiently neutralizes papillomaviruses without significantly inhibiting viral binding to the cell surface. The 3D reconstructions reveal that mAb #9 binds to L1 molecules of both pentavalent and hexavalent capsomeres. In contrast, 5B6 binds only to hexavalent capsomeres, reflecting the significant structural or environmental differences for the 5B6 epitope in the 12 pentavalent capsomeres. Epitope localization shows that mAb #9 binds monovalently to the tips of capsomeres whereas 5B6 binds both monovalently and bivalently to the sides of hexavalent capsomeres approximately two-thirds of the way down from the outer tips, very close to the putative stabilizing intercapsomere connections. The absence of mAb 5B6 from the pentavalent capsomeres and its inability to prevent viral binding to the cell surface suggest that receptor binding may occur at one or more of the 12 virion vertices.
-
the papillomavirus minor Capsid Protein l2 induces localization of the major Capsid Protein L1 and the viral transcription replication Protein e2 to pml oncogenic domains
Journal of Virology, 1998Co-Authors: Richard B S Roden, Douglas R Lowy, John T SchillerAbstract:We have used immunofluorescent staining and confocal microscopy to examine the subcellular localization of structural and nonstructural bovine papillomavirus (BPV) Proteins in cultured cells that produce infectious virions. When expressed separately, L1, the major Capsid Protein, showed a diffuse nuclear distribution while L2, the minor Capsid Protein, was found to localize to punctate nuclear regions identified as promonocytic leukemia Protein (PML) oncogenic domains (PODs). Coexpression of L1 and L2 induced a relocation of L1 into the PODs, leading to the colocalization of L1 and L2. The effect of L2 expression on the distribution of the nonstructural viral Proteins E1 and E2, which are required for maintenance of the genome and viral DNA synthesis, was also examined. The localization of the E1 Protein was unaffected by L2 expression. However, the pattern of anti-E2 staining was dramatically altered in L2-expressing cells. Similar to L1, E2 was shifted from a dispersed nuclear locality into the PODs and colocalized with L2. The recruitment of full-length E2 by L2 occurred in the absence of other viral components. L2 was shown previously to be essential for the generation of infectious BPV. Our present results provide evidence for a role for L2 in the organization of virion components by recruiting them to a distinct nuclear domain. This L2-dependent colocalization probably serves as a mechanism to promote the assembly of papillomaviruses either by increasing the local concentration of virion constituents or by providing the physical architecture necessary for efficient packaging and assembly. The data also suggest a role for a nonstructural viral Protein, E2, in virion assembly, specifically the recruitment of the viral genome to the sites of assembly, through its high-affinity interaction with specific sequences in the viral DNA.
-
Novel structural features of bovine papillomavirus Capsid revealed by a three-dimensional reconstruction to 9 Å resolution
Nature Structural Biology, 1997Co-Authors: Benes L. Trus, Heather L. Greenstone, Michael Vrhel, Richard B S Roden, John T Schiller, Frank P. BooyAbstract:The three-dimensional structure of bovine papillomavirus has been determined to 9 Å resolution by reconstruction of high resolution, low dose cryo-electron micrographs of quench-f rozen virions. Although hexavalent and pentavalent capsomeres form star-shaped pentamers of the major Capsid Protein L1, they have distinct high-resolution structures. Most prominently, a 25 Å hole in the centre of hexavalent capsomeres is occluded in the pentavalent capsomeres. This raises the possibility that the L2 minor Capsid Protein is located in the centre of the pentavalent capsomeres. Inter-capsomere connections ∼10 Å in diameter were clearly resolved. These link adjacent capsomeres and are reminiscent of the helical connections that stabilize polyomavirus.
-
Novel structural features of bovine papillomavirus Capsid revealed by a three-dimensional reconstruction to 9 Å resolution
Nature structural biology, 1997Co-Authors: Benes L. Trus, Heather L. Greenstone, Michael Vrhel, Richard B S Roden, John T Schiller, Frank P. BooyAbstract:The three-dimensional structure of bovine papillomavirus has been determined to 9 A resolution by reconstruction of high resolution, low dose cryo-electron micrographs of quench-frozen virions. Although hexavalent and pentavalent capsomeres form star-shaped pentamers of the major Capsid Protein L1, they have distinct high-resolution structures. Most prominently, a 25 A hole in the centre of hexavalent capsomeres is occluded in the pentavalent capsomeres. This raises the possibility that the L2 minor Capsid Protein is located in the centre of the pentavalent capsomeres. Inter-capsomere connections approximately 10 A in diameter were clearly resolved. These link adjacent capsomeres and are reminiscent of the helical connections that stabilize polyomavirus.