| transformation by hamster polyomavirus: identification and functional analysis of the early genes. | a strategy involving polymerase chain reaction amplification of cdnas was designed to study the expression of the hamster polyomavirus (hapv) early region in hapv-transformed rat fibroblasts, productively hapv-infected cells, and hapv-induced lymphoma. we identified three mrnas resulting from alternative splicing of open reading frames leading to coding capacities for three polypeptides with molecular weights similar to those of the murine polyomavirus large t, middle t (mt), and small t (st) an ... | 1992 | 1312640 |
| early gene expression in lymphoma-associated hamster polyomavirus viral genomes. | hamster polyomavirus (hapv) is the causal agent of hair follicle epithelioma in hamsters belonging to a colony bred in berlin-buch. these tumors shed virus particles that are assembled in the keratinized layer of the epidermis. by contrast, hapv induces lymphomas after inoculation into newborn hamsters from a distinct colony bred in potsdam. these lymphoid tumors accumulate massive amounts of episomal viral genomes characterized by deletions that alter specifically the regulatory and the late co ... | 1992 | 1312694 |
| identification and characterization of the hamster polyomavirus middle t antigen. | hamster polyomavirus (hapv) is associated with lymphoid and hair follicle tumors in syrian hamsters. the early region of hapv has the potential to encode three polypeptides (which are related to the mouse polyomavirus early proteins) and can transform fibroblasts in vitro. we identified the hapv middle t antigen (hamt) as a 45-kda protein. like its murine counterpart, hamt was associated with serine/threonine phosphatase, phosphatidylinositol-3 kinase, and protein tyrosine kinase activities. how ... | 1991 | 1709702 |
| analysis of the hamster polyomavirus infection in vitro: host-restricted productive cycle. | in a search for a host fully permissive for the hamster polyomavirus (hapv) productive cycle in cell culture, the replication of the viral genome has been assayed in a panel of murine and hamster cell types. these experiments led to the conclusion that hamster cells represent the most permissive host for hapv dna replication although some murine cells also permit replication of the viral dna. a single burst of infectious particles is demonstrable in some replication-competent cells, but the outc ... | 1990 | 2164724 |
| the hamster polyomavirus--a brief review of recent knowledge. | the hamster polyomavirus was first isolated by graffi et al. in berlin-buch from skin epithelioma arising spontaneously in the buch syrian hamster colony. virus particles are assembled in the nuclei of keratinized cell layer. the genome organization is identical to the murine polyomavirus genetic map including, in particular, the existence of a coding capacity for an early gene product analogous to the middle t antigen. the virus and the cloned dna can immortalize primary cells and transform est ... | 1990 | 2167650 |
| the hamster polyomavirus transforming properties. | the hamster papovavirus (hapv) is a polyomavirus isolated from hair follicle tumor arising spontaneously in newborn hamsters which can also induce lymphoma and leukemia. this tissue specificity displayed in vivo can be bypassed in vitro since hapv carries the full transforming properties of a polyomavirus (immortalization and transformation). we report here the phenotypic characterization of cells that were selected as immortalized or transformed and express constitutively the hapv early genes. ... | 1988 | 3285292 |
| kinetics of p56lck and p60src src homology 2 domain binding to tyrosine-phosphorylated peptides determined by a competition assay or surface plasmon resonance. | src homology 2 (sh2) domains are phosphotyrosine-binding modules found within various signal-transducing proteins. we have determined by 125i competition assay and surface plasmon resonance that the sh2 domains of src and lck bind to a variety of phosphopeptides with similar affinity and specificity. both bound with highest affinity [kd(app) approximately 3.7 nm; ka = 2.4 x 10(5) m-1 x s-1; kd = 1.2 x 10(-3) s-1] a phosphopeptide having a tyr(p)-glu-glu-ile motif found in the hamster polyomaviru ... | 1993 | 7685110 |
| episomal amplification or chromosomal integration of the viral genome: alternative pathways in hamster polyomavirus-induced lymphomas. | the state and expression of the hamster polyomavirus genome in a large panel of virus-induced lymphomas have been investigated. the viral genome is present within tumor cells either as abundant nonrandomly deleted extrachromosomal copies or as a single copy integrated into cellular dna. we show that these two physical states are likely to be functionally equivalent: first, deletion and integration of the viral genome both inactivate the late coding region; second, the amount of viral early rnas ... | 1995 | 7707533 |
| induction of interleukin-2 transcription by the hamster polyomavirus middle t antigen: a role for fyn in t cell signal transduction. | the transforming protein of mouse polyomavirus, the mouse middle t antigen (momt), and its counterpart in the hamster polyomavirus, the hamster middle t antigen (hamt), interact with a number of cellular proteins. among these are members of the src family of tyrosine kinases, the phosphatidylinositol 3-kinase, the serine/threonine phosphatase pp2a and the adaptor protein shc (in the case of momt). however, both the relative affinity of these antigens for the members of the src family and the tum ... | 1995 | 7875200 |
| in vivo replication of the hamster polyomavirus genome and generation of specific deletions in the process of lymphomagenesis. | hamster polyomavirus (hapv) causes lymphomas when injected into newborn hamsters. these tumors are virus-free but accumulate large amounts of deleted extrachromosomal viral genomes. in order to identify the major sites of virus replication in animals, we have monitored the hapv dna present in different organs at various times after injection. the data demonstrate that viral replication preferentially occurs in lymphoid organs. lymphoma-associated viral genomes display specific deletions. pcr ana ... | 1994 | 8057443 |
| viral genomes maintained extrachromosomally in hamster polyomavirus-induced lymphomas display a cell-specific replication in vitro. | hamster polyomavirus causes lymphomas when injected into newborn syrian hamsters. large amounts of extrachromosomal viral genomes are accumulated in the lymphoma cells. these genomes are characterized by deletions affecting the late coding region as well as a specific part of the noncoding regulatory region. by contrast with wild-type genomes, lymphoma-associated genomes replicate in a lymphoblastoid cell line but not in a fibroblastic cell line. the deletion acts in a cis-dominant manner and is ... | 1993 | 8230439 |
| distinct segments of the hamster polyomavirus regulatory region have differential effects on dna replication. | the replication of plasmids containing various fragments of the hamster polyomavirus (hapv) dna non-coding region was tested in a permissive hamster cell line. we first investigated the importance of some methodological parameters including the time course and the amount of transfecting plasmid dna and have shown that these factors can greatly influence the relative amount of newly replicated dna accumulated within the transfected cells. taking these into account, quantitative comparisons could ... | 1993 | 8380834 |
| mutations within the hamster polyomavirus large t antigen domain involved in prb binding impair virus productive cycle and immortalization capacity. | hamster polyomavirus (hapv) causes lymphoma and leukemia when injected into newborn syrian hamsters and achieves full transformation of rodent fibroblasts in vitro. it offers a comprehensive model to study at a molecular level the contributions of the viral oncogenes to neoplastic transformation in vitro and in the animal. we have investigated the ability of hapv large t antigen to form a complex with the product of the retinoblastoma gene (prb) in vitro. in this report, we demonstrate that hapv ... | 1993 | 8382359 |
| in vivo replication of hamster polyomavirus dna displays lymphotropism in hamsters susceptible to lymphoma induction. | using the whole body section hybridization technique, we monitored the organ- and age-specific pattern of replication of hamster polyomavirus (hapv) dna in a colony of syrian hamsters, which are susceptible to lymphoma induction. three phases of viral infection and replication could be distinguished: first, a phase of acute infection characterized by high levels of replication of hapv dna in the haemopoietic organs and the liver. this culminated 5 to 7 days post-infection (p.i.); second, at 10 d ... | 1996 | 8811016 |
| hamster polyomavirus-encoded proteins: gene cloning, heterologous expression and immunoreactivity. | the hamster polyomavirus (hapv) is associated with spontaneously appearing skin epithelioma of the syrian hamster z3 strain. virus particles prepared from the skin epithelioma cause lymphoma and leukemia when injected into newborn hamsters from a distinct syrian hamster colony (hap); in contrast to the skin epithelioma the hemopoietic tumors are virus free but accumulate viral dna. to study the humoral immune response of hapv-infected z3 hamsters we produced recombinant hapv proteins in escheric ... | 1996 | 8883364 |
| functional interaction between the sh2 domain of fyn and tyrosine 324 of hamster polyomavirus middle-t antigen. | middle-t antigen of mouse polyomavirus (momt) associates with the cellular tyrosine kinases c-src, c-yes, and fyn, while middle-t antigen of hamster polyomavirus (hamt) exclusively binds fyn. this interaction is essential for polyomavirus-mediated transformation of cells in culture and tumor formation in animals. here we show that the kinase domain of fyn is sufficient for association with momt but not for binding of hamt. we further demonstrate that a fyn mutant lacking the sh2 domain is able t ... | 1997 | 8985339 |
| the n terminus of hamster polyomavirus middle t antigen carries a determinant for specific activation of p59c-fyn. | transformation by rodent polyomaviruses is mediated primarily by middle t antigen, a membrane-bound protein that does not carry an intrinsic enzymatic activity but interacts and subverts the activity of cellular regulators of proliferation. the multiple protein partners of murine polyomavirus (py) middle t antigen include the tyrosine kinases c-src and, to a lesser extent, c-fyn and c-yes. by contrast, the hamster polyomavirus (hapv) middle t antigen selectively activates the c-fyn gene product. ... | 1997 | 8995669 |
| generation of lymphoma-type variant hamster polyomavirus genomes in hamsters susceptible to lymphoma induction. | the hamster polyomavirus (hapv) induces either hair follicle epitheliomas or lymphomas in either z3 or hap respectively. syrian hamsters. in the lymphomas specifically deleted "lymphoma-type" (lt) hapv genomes are accumulated. in the present study the temporal pattern of generation of hapv (lt) dna was investigated in context of the development of lymphomas in neonatally infected hap hamsters. the generation of hapv (lt) dna was first detectable during the postnatal phase of high level replicati ... | 1997 | 9155872 |
| signalling by src family kinases: lessons learnt from dna tumour viruses. | virus replication and spreading in a host population depends on highly specific interactions of viral proteins with infected cells, resulting in subversion of multiple cellular signal transduction pathways. for instance, viral proteins cause cell cycle progression of the infected host cell in order to establish a cellular environment favourable for virus replication. of equal importance for successful virus propagation is virus-mediated attenuation of a host's immune response. many of the pathwa ... | 1997 | 9376219 |
| yeast cells allow high-level expression and formation of polyomavirus-like particles. | polyomavirus-derived virus-like particles (vlps) have been described as potential carriers for encapsidation of nucleic acids in gene therapy. although vlps can be generated in e. coli or insect cells, the yeast expression system should be advantageous as it is well established for the biotechnological generation of products for human use, especially because they are free of toxins hazardous for humans. we selected the yeast saccharomyces cerevisiae for expression of the major capsid protein vp1 ... | 1999 | 10223341 |
| capsid protein-encoding genes of hamster polyomavirus and properties of the viral capsid. | on the basis of its genome organization the hamster polyomavirus (hapv) is closely related to the murine polyomavirus py. but hapv infection, in contrast to py infection, gives rise to two different tumor types; depending on the hamster strain used for infection, hapv induces either epitheliomas or lymphomas. although the hapv virions were shown to be similar to those of py and sv40, more precise information about the structure and protein composition of the hapv capsid was still missing. here w ... | 1999 | 10334036 |
| formation of immunogenic virus-like particles by inserting epitopes into surface-exposed regions of hamster polyomavirus major capsid protein. | we generated highly immunogenic virus-like particles that are based on the capsid protein vp1 of the hamster polyomavirus (hapv-vp1) and harbor inserted foreign epitopes. the hapv-vp1 regions spanning amino acids 81-88 (position 1), 222/223 (2), 244-246 (3), and 289-294 (4) were predicted to be surface exposed. an epitope of the pre-s1 region of the hepatitis b virus (designated s1; amino acid sequence dpafr) was introduced into the predicted positions of vp1. all vp1/s1 fusion proteins were exp ... | 2000 | 10891404 |
| an immunodominant, cross-reactive b-cell epitope region is located at the c-terminal part of the hamster polyomavirus major capsid protein vp1. | the vp1 represents the major capsid protein of the hamster polyomavirus (hapv). here we describe the mapping of epitopes along the vp1 using escherichia coli-expressed vp1-dihydrofolate reductase (dhfr) fusion proteins and pepscan analysis. by use of dhfr fusion proteins an immunodominant region was localized in the c-terminal part of vp1 between amino acids 320-384. further epitopes are located in the regions amino acids 1-133 and amino acids 133-320, respectively. there were no obvious differe ... | 2000 | 11192300 |
| the hamster polyomavirus--a brief review of recent knowledge. | the hamster polyomavirus (hapv) was first described in 1967 as a virus associated with skin epithelioma of the syrian hamster. the tumors appear spontaneously in a hamster colony bred in berlin-buch (hab). virus particles isolated from skin epitheliomas cause lymphoma and leukemia when injected into newborn hamsters from a distinct colony bred in potsdam, germany (hap). the viral genome has been totally sequenced and the overall genetic organization establishes hapv as a member of the polyomavir ... | 2001 | 11210944 |
| hamster polyomavirus infection in a pet syrian hamster (mesocricetus auratus). | an approximately 8-week-old pet syrian hamster (mesocricetus auratus) with a 1-week history of dyspnea, hyporexia, and ataxia was submitted for necropsy. on gross examination, the hamster had multiple abdominal adhesions and enlargement of the mesenteric lymph node. histologic evaluation revealed multicentric lymphoma of the liver, jejunum, mesenteric lymph node, testicular fat pad, and epididymis. based on the hamster's age and the type and distribution of the lymphoma, a presumptive diagnosis ... | 2001 | 11467479 |
| polyomavirus infection in hamsters and trichoepitheliomas/cutaneous adnexal tumours. | multiple skin nodules, with histological features of adnexal tumours consistent with trichoepithelioma, were observed on the head and trunk of syrian hamsters. skin biopsies from 20 hamsters from five different colonies were affected, and two of the affected hamsters also had lymphoma. two owners reported that 16 of 70 hamsters and 50 of 100 hamsters in their colonies had similar skin lesions. these tumours have previously been associated in laboratory colonies with hamster polyomavirus (hapv) i ... | 2002 | 12137418 |
| chimeric bacteriophage fr virus-like particles harboring the immunodominant c-terminal region of hamster polyomavirus vp1 induce a strong vp1-specific antibody response in rabbits and mice. | the late region of the hamster polyomavirus (hapyv, former hapv) genome encodes three structural proteins vp1, vp2, and vp3, where vp1 represents the major capsid protein of 384 amino acids. screening of sera from hapyv-infected papilloma-bearing and papilloma-free hamsters demonstrated the immunodominant features of all three capsid proteins. for both groups of hamsters in the c-terminal region of vp1 immunodominant b-cell epitopes were identified in the regions between amino acids 305 and 351 ... | 2002 | 12513932 |
| generation of recombinant virus-like particles of human and non-human polyomaviruses in yeast saccharomyces cerevisiae. | non-viral methods of gene transfer have been preferred in gene therapy approaches for several reasons, particularly for their safety, simplicity and convenience in introducing heterologous dna into cells. polyomavirus virus-like particles (vlps) represent a promising carrier for encapsidation of foreign nucleic acids for gene therapy. for the development of such gene delivery systems as well as for providing reagents for improving virus diagnostics, an efficient yeast expression system for the g ... | 2002 | 12602348 |
| inhibitory effects of rosmarinic acid on lck sh2 domain binding to a synthetic phosphopeptide. | in the course of screening inhibitors from the methanol (meoh) extracts of 168 medicinal plants against lymphocyte cell-specific kinase (lck) src -homology 2 (sh2) binding to a synthetic phosphotyrosine-containing peptide (phosphopeptide), we isolated rosmarinic acid from the meoh extract of prunella vulgaris, which showed specific inhibitory activity. the ic 50 value for lck sh2 binding to phosphopeptide (sgsgeepqpyeeipi) of hamster polyomavirus middle-sized tumor (hmt py324) was 7 microm. howe ... | 2003 | 12898421 |
| segments of puumala hantavirus nucleocapsid protein inserted into chimeric polyomavirus-derived virus-like particles induce a strong immune response in mice. | insertion of a short-sized epitope at four different sites of yeast-expressed hamster polyomavirus major capsid protein vp1 has been found to result in the formation of chimeric virus-like particles. here, we demonstrate that the insertion of 45 or 120 amino acid-long segments from the n-terminus of puumala hantavirus nucleocapsid protein into sites 1 (amino acids 80-89) and 4 (amino acids 288-295) of vp1 allowed the highly efficient formation of virus-like particles. in contrast, expression lev ... | 2004 | 15018662 |
| generation of monoclonal antibodies of desired specificity using chimeric polyomavirus-derived virus-like particles. | foreign protein sequences presented on hamster polyomavirus (hapyv) major capsid protein vp1-derived virus-like particles (vlps) have been demonstrated to be highly immunogenic. the current study was aimed to evaluate vp1-derived chimeric vlps as tools for hybridoma technology to generate monoclonal antibodies (mabs) of desired specificity. chimeric vlps containing inserts of different size and origin were used as immunogens. chimeric vlps carrying a 9 amino acid (aa)-long cytotoxic t-cell epito ... | 2006 | 16516908 |
| size and position of truncations in the carboxy-terminal region of major capsid protein vp1 of hamster polyomavirus expressed in yeast determine its assembly capacity. | the hamster polyomavirus major capsid protein vp1 was modified in its carboxy-terminal region by consecutive truncations and single amino acid exchanges. the ability of yeast-expressed vp1 variants to form virus-like particles (vlps) strongly depended on the size and position of the truncation. vp1 variants lacking 21, 69, and 79 amino acid (aa) residues in their carboxy-terminal region efficiently formed vlps similar to those formed by the unmodified vp1 (diameter 40-45 nm). in contrast, vp1 de ... | 2006 | 16575481 |
| comparing phylogenetic codivergence between polyomaviruses and their hosts. | seventy-two full genomes corresponding to nine mammalian (67 strains) and two avian (5 strains) polyomavirus species were analyzed using maximum likelihood and bayesian methods of phylogenetic inference. our fully resolved and well-supported (bootstrap proportions > 90%; posterior probabilities = 1.0) trees separate the bird polyomaviruses (avian polyomavirus and goose hemorrhagic polyomavirus) from the mammalian polyomaviruses, which supports the idea of spitting the genus into two subgenera. s ... | 2006 | 16731904 |
| virus-like particles derived from major capsid protein vp1 of different polyomaviruses differ in their ability to induce maturation in human dendritic cells. | as polyomavirus major capsid protein vp1-derived virus-like particles (vlps) have been demonstrated to be highly immunogenic, we studied their interaction with human dendritic cells (hdcs). exposure of hdcs to vlps originating from murine (mpyv) or hamster polyomavirus (hapyv) induced hdc maturation. in contrast, exposure of hdcs to vlps derived from human polyomaviruses (bk and jc) and simian virus 40 (sv40) only marginally induced dc maturation. the hdcs stimulated by hapyv- or mpyv-derived vl ... | 2006 | 16904154 |
| hamster polyomavirus-derived virus-like particles are able to transfer in vitro encapsidated plasmid dna to mammalian cells. | the authentic major capsid protein 1 (vp1) of hamster polyomavirus (hapyv) consists of 384 amino acid (aa) residues (42 kda). expression from an additional in-frame initiation codon located upstream from the authentic vp1 open reading frame (at position -4) might result in the synthesis of a 388 aa-long, amino-terminally extended vp1 (aa -4 to aa 384; vp1(ext)). in a plasmid-mediated drosophila schneider (s2) cell expression system, both vp1 derivatives as well as a vp1(ext) variant with an amin ... | 2007 | 16927120 |
| chimeric polyomavirus-derived virus-like particles: the immunogenicity of an inserted peptide applied without adjuvant to mice depends on its insertion site and its flanking linker sequence. | we inserted the sequence of the carcinoembryonic antigen-derived t cell epitope cap-1-6d (cea) into different positions of the hamster polyomavirus major capsid protein vp1. independently from additional flanking linkers, yeast-expressed vp1 proteins harboring the cea insertion between vp1 amino acid residues 80 and 89 (site 1) or 288 and 295 (site 4) or simultaneously at both positions assembled to chimeric virus-like particles (vlps). balb/c mice immunized with adjuvant-free vlps developed vp1 ... | 2007 | 17931115 |
| cellular and humoral immunogenicity of hamster polyomavirus-derived virus-like particles harboring a mucin 1 cytotoxic t-cell epitope. | in this study, we examined hamster polyomavirus (hapyv) major capsid protein vp1-derived virus-like particles (vlps) as a carrier for a human tumor-associated cytotoxic t lymphocyte (ctl) epitope. the vp1 tolerated the insertion of an hla-*a2-restricted ctl epitope from human mucin 1 (muc1) into two sites independently and simultaneously, without interfering with assembly of chimeric vlps. chimeric vlps did not differ in the entry pathway or maturation potential of human dendritic cells (hdcs) c ... | 2008 | 18355119 |
| production in yeast of pseudotype virus-like particles harboring functionally active antibody fragments neutralizing the cytolytic activity of vaginolysin. | abstract: | 2011 | 22171920 |
| induction of insert-specific immune response in mice by hamster polyomavirus vp1 derived virus-like particles carrying lcmv gp33 ctl epitope. | hamster polyomavirus (hapyv) major capsid protein vp1 based chimeric virus-like particles (vlps) carrying model gp33 ctl epitope derived from lymphocytic choriomeningitis virus (lcmv) were generated in yeast and examined for their capability to induce ctl response in mice. chimeric vp1-gp33 vlps were effectively processed in antigen presenting cells in vitro and in vivo and induced antigen-specific cd8+ t cell proliferation. mice immunized only once with vp1-gp33 vlps without adjuvant developed ... | 2011 | 21864590 |
| evaluation of trichodysplasia spinulosa-associated polyomavirus capsid protein as a new carrier for construction of chimeric virus-like particles harboring foreign epitopes. | recombinant virus-like particles (vlps) represent a promising tool for protein engineering. recently, trichodysplasia spinulosa-associated polyomavirus (tspyv) viral protein 1 (vp1) was efficiently produced in yeast expression system and shown to self-assemble to vlps. in the current study, tspyv vp1 protein was exploited as a carrier for construction of chimeric vlps harboring selected b and t cell-specific epitopes and evaluated in comparison to hamster polyomavirus vp1 protein. chimeric vlps ... | 2015 | 26230706 |
| production and biomedical applications of virus-like particles derived from polyomaviruses. | virus-like particles (vlps), aggregates of capsid proteins devoid of viral genetic material, show great promise in the fields of vaccine development and gene therapy. these particles spontaneously self-assemble after heterologous expression of viral structural proteins. this review will focus on the use of virus-like particles derived from polyomavirus capsid proteins. since their first recombinant production 27 years ago these particles have been investigated for a myriad of biomedical applicat ... | 2013 | 23999392 |
| iga antibody production by intrarectal immunization of mice using recombinant major capsid protein of hamster polyomavirus. | viral proteins are highly antigenic and known as potent stimulators of adaptive immune responses. this mechanism is often used for biotechnological applications in monoclonal antibody production resulting in high-affinity igg antibodies in most cases. the aim of this study was to increase antigen-specific iga antibody levels in mice in order to generate monoclonal iga antibodies by hybridoma technology. for this purpose, hamster polyomavirus (hapyv) major capsid protein vp1 was used to immunize ... | 2012 | 24688770 |
| survey of molecular chaperone requirement for the biosynthesis of hamster polyomavirus vp1 protein in saccharomyces cerevisiae. | a number of viruses utilize molecular chaperones during various stages of their life cycle. it has been shown that members of the heat-shock protein 70 (hsp70) chaperone family assist polyomavirus capsids during infection. however, the molecular chaperones that assist the formation of recombinant capsid viral protein 1 (vp1)-derived virus-like particles (vlps) in yeast remain unclear. a panel of yeast strains with single chaperone gene deletions were used to evaluate the chaperones required for ... | 2016 | 27038828 |
| construction of polyomavirus-derived pseudotype virus-like particles displaying a functionally active neutralizing antibody against hepatitis b virus surface antigen. | virus-like particles (vlps) can be efficiently produced by heterologous expression of viral structural proteins in yeast. due to their repetitive structure, vlps are extensively used for protein engineering and generation of chimeric vlps with inserted foreign epitopes. hamster polyomavirus vp1 represents a promising epitope carrier. however, insertion of large sized protein sequences may interfere with its self-assembly competence. the co-expression of polyomavirus capsid protein vp1 with minor ... | 2015 | 26370129 |
| genome sequences of a rat polyomavirus related to murine polyomavirus, rattus norvegicus polyomavirus 1. | we amplified and sequenced six complete genomes of a polyomavirus from feral norway rats (rattus norvegicus) and from a long-term breeding colony derived from norway rats. this virus, which is closely related to hamster polyomavirus and murine polyomavirus, may contribute to understanding the evolutionary history of rodent polyomaviruses. | 2015 | 26337891 |
| the use of chimeric virus-like particles harbouring a segment of hantavirus gc glycoprotein to generate a broadly-reactive hantavirus-specific monoclonal antibody. | monoclonal antibodies (mabs) against viral glycoproteins have important diagnostic and therapeutic applications. in most cases, the mabs specific to viral glycoproteins are raised against intact virus particles. the biosynthesis of viral glycoproteins in heterologous expression systems such as bacteria, yeast, insect or mammalian cells is often problematic due to their low expression level, improper folding and limited stability. to generate mabs against hantavirus glycoprotein gc, we have used ... | 2014 | 24513568 |
| antibodies bound to aβ oligomers potentiate the neurotoxicity of aβ by activating microglia. | beta amyloid (aβ) oligomers are thought to contribute to the pathogenesis of alzheimer’s disease. however, clinical trials using aβ immunization were unsuccessful due to strong brain inflammation, the mechanisms of which are poorly understood. in this study we tested whether monoclonal antibodies to oligomeric aβ would prevent the neurotoxicity of aβ oligomers in primary neuronal-glial cultures. however, surprisingly,the antibodies dramatically increased the neurotoxicity of aβ. antibodies bound ... | 2013 | 23745639 |
| lymphoma outbreak in a gash:sal hamster colony. | we have detected a high incidence of lymphomas in a colony of gash:sal syrian golden hamsters (mesocricetus auratus). this strain is characterised by its ability to present convulsive crises of audiogenic origin. almost 16 % (90 males and 60 females) of the 975 animals were affected during a 5-year period by the development of a progressing lymphoid tumour and exhibited similar clinical profiles characterised by lethargy, anorexia, evident abdominal distension, and a rapid disease progression re ... | 2013 | 23719671 |
| the use of recombinant pseudotype virus-like particles harbouring inserted target antigen to generate antibodies against cellular marker p16ink4a. | protein engineering provides an opportunity to generate new immunogens with desired features. previously, we have demonstrated that hamster polyomavirus major capsid protein vp1-derived virus-like particles (vlps) are highly immunogenic and can be employed for the insertion of foreign epitopes at certain surface-exposed positions. in the current study, we have designed pseudotype vlps consisting of an intact vp1 protein and vp2 protein fused with the target antigen--cellular marker p16(ink4a)--a ... | 2012 | 22629125 |
| hamster polyomavirus research: past, present, and future. | hamster polyomavirus (mesocricetus auratus polyomavirus 1, hapyv) was discovered as one of the first rodent polyomaviruses at the end of the 1960s in a colony of syrian hamsters (mesocricetus auratus) affected by skin tumors. natural hapyv infections have been recorded in syrian hamster colonies due to the occurrence of skin tumors and lymphomas. hapyv infections of syrian hamsters represent an important and pioneering tumor model. experimental infections of syrian hamsters of different colonies ... | 2021 | 34068409 |