| evidence for antigenic determinants shared by the structural polypeptides of (shope) rabbit papillomavirus and human papillomavirus type 1. | | 1978 | 84435 |
| conserved polynucleotide sequences among the genomes of papillomaviruses. | the dnas of different members of the papillomavirus genus of papovaviruses were analyzed for nucleotide sequence homology. under standard hybridization conditions (tm - 28 degrees c), no homology was detectable among the genomes of human papillomavirus type 1 (hpv-1), bovine papillomavirus type 2 (bpv-2), or cottontail rabbit (shope) papillomavirus (crpv). however, under less stringent conditions (i.e., tm - 43 degrees c), stable hybrids were formed between radiolabeled dnas of crpv, bpv-1, or b ... | 1979 | 232171 |
| the isolation of cricket paralysis virus from the emperor gum moth, antheraea eucalypti scott, and its infectivity towards a range of insect species. | three virus-like particles have been isolated from diseased larvae of antheraea eucalypti. serological tests established that one of them was indistinguishable from cricket paralysis virus (crpv). crpv isolated from crickets and from antheraea were cross-infectious, and crickets could acquire lethal doses of the virus by feeding on infected antheraea larvae. in addition to two species of teleogryllus, three other species of orthoptera and nine out of ten species of lepidoptera tested were suscep ... | 1975 | 1184353 |
| molecular and biological characterization of cottontail rabbit papillomavirus variant dna sequences integrated in the vx7 carcinoma. | the transplantable vx7 carcinoma was derived from a tumor induced by a recoverable strain of cottontail rabbit papillomavirus (crpv) able to replicate in domestic rabbits. low levels of late viral gene expression have been retained through serial propagation in rabbits. we have cloned and characterized the three major types of crpv sequences integrated in this tumor, a genome-length 8-kb dna molecule and two rearranged 9- and 3.8-kb molecules. the vx7 8-kb dna displays only a few differences in ... | 1992 | 1310196 |
| identification of three transforming proteins encoded by cottontail rabbit papillomavirus. | cottontail rabbit papillomavirus (crpv) provides an animal model for human papillomaviruses associated with a high risk of cancer development. so far, nothing is known about the transforming functions of crpv genes because of the lack of an assay system. we have recently developed two systems to assay for crpv transforming functions. one is based on the finding that transformation of nih 3t3 cells by crpv is considerably increased by deleting sequences in open reading frame l2. the second one is ... | 1992 | 1310771 |
| effective vaccination against papilloma development by immunization with l1 or l2 structural protein of cottontail rabbit papillomavirus. | immunization of rabbits with either l1, the major structural protein, or l2, a minor structural protein of cottontail rabbit papillomavirus (crpv), protected against challenge with the virus. neutralizing antibodies were elicited by both the l1 and l2 trpe fusion proteins. neutralization with anti-l1 serum, however, was more efficient than with anti-l2 serum. in contrast, when tested on western blots the immune response to l2 was stronger than to l1. rabbits were also protected against crpv infe ... | 1992 | 1312271 |
| ribavirin mitigates wart growth in rabbits at early stages of infection with cottontail rabbit papillomavirus. | the challenge to develop antiviral agents effective against dna viruses such as human papillomavirus (hpv) has been dependent on finding an animal model which mimics the human forms of the disease. we have used an existing model system for the purpose of measuring the effect of antiviral drugs on the inhibition of growth of these lesions. this was based upon domestic rabbits which efficiently grow cutaneous papillomas (warts) when infected with cottontail rabbit papillomavirus (crpv). one agent ... | 1992 | 1313222 |
| metal thiolate coordination in the e7 proteins of human papilloma virus 16 and cottontail rabbit papilloma virus as expressed in escherichia coli. | the oncogenic e7 proteins of human papilloma virus (hpv 16) and of cottontail rabbit papilloma virus (crpv) have been purified from an expression system in escherichia coli. the proteins as purified from e. coli contain one tightly bound zn(ii) ion per molecule. the metal site shows facile exchange with either cd(ii) or cu(i). the hpv 16 e7 maximally bound one cd(ii) or two cu(i) ions, while the crpv e7 bound two cd(ii) or three cu(i) ions. the cd(ii) and cu(i) e7 molecules exhibited optical tra ... | 1992 | 1322900 |
| phylogenetic analysis of 48 papillomavirus types and 28 subtypes and variants: a showcase for the molecular evolution of dna viruses. | papillomaviruses are attractive models for studying the molecular evolution of dna viruses because of the large number of isolates that exhibit genomic diversity and host species and tissue specificity. to examine their relationship, we selected two amino acid sequences, one of 52 residues within the early gene e1 and the other of 44 residues within the late gene l1, which allowed insertion- and deletion-free alignment of all accessible papillomavirus sequences. we constructed phylogenetic trees ... | 1992 | 1326639 |
| the putative e5 open reading frame of cottontail rabbit papillomavirus is dispensable for papilloma formation in domestic rabbits. | in the cottontail rabbit papillomavirus (crpv)-rabbit system, recombinant crpv dna can induce papillomas. this investigation was undertaken to evaluate whether the e5 open reading frame (orf) of crpv is required for papilloma formation. the crpv genome we utilized, crpv-wa, was sequenced in the e5 region and was found to contain one deletion, two insertions, and one transition mutation compared with crpv-ks, the crpv genome that has been fully sequenced. despite these differences, an intact e5 o ... | 1992 | 1326666 |
| an in vitro system for studying the initial stages of cottontail rabbit papillomavirus infection. | cottontail rabbit papillomavirus (crpv) infection of an established cottontail epidermal cell line (sf1ep) resulted in the production of crpv-specific transcripts without concomitant morphological transformation. the most abundant transcripts corresponded in size to those of the e6 and e7 open reading frames (orfs), which are also among the commonest in domestic and cottontail rabbit papillomas. crpv rna production was both time- and dose-dependent, with rna production diminishing with decreasin ... | 1992 | 1331149 |
| preclinical system for evaluating topical podofilox treatment of papillomas: dose-response and duration of growth prior to treatment. | the objective of the present study was to assess the utility of shope rabbit papillomas as an animal model system for studying topical podofilox treatment and to evaluate dose-response relations and influence of duration of papilloma growth prior to treatment. new zealand white rabbits received inoculations of cottontail rabbit papillomavirus (crpv) virions of two dilutions at four sites total on the dorsum. two papillomas on the left side were treated with podofilox (oclassen pharmaceuticals, i ... | 1992 | 1469296 |
| an insect picornavirus may have genome organization similar to that of caliciviruses. | computer-assisted analysis of the amino acid sequence of the product encoded by the sequenced 3' portion of the cricket paralysis virus (crpv), an insect picornavirus, genome showed that this protein is homologous not to the rna-directed rna polymerases, as originally suggested, but to the capsid proteins of mammalian picornaviruses. alignment of the crpv protein sequence with those of picornavirus and calicivirus capsid proteins demonstrated that the sequenced portion of the insect picornavirus ... | 1992 | 1551442 |
| use of a rapid, efficient inoculation method to induce papillomas by cottontail rabbit papillomavirus dna shows that the e7 gene is required. | a simple inoculation method to induce papillomas efficiently with cottontail rabbit papillomavirus (crpv) dna is described. using a jet injector, recombinant crpv dna is easily delivered to 100 or more sites per rabbit and induces typical epithelial papillomas in approximately 50% of those sites. papillomas begin to form by 3 weeks and continue to develop for up to 7 weeks, a pattern similar to that reported following infection with intact virus. this system readily lends itself to investigation ... | 1991 | 1647019 |
| establishment from shope carcinoma induced in an inbred rabbit of culture cell lines with various potentials for differentiation and tumorigenicity. | shope papillomas induced by cottontail rabbit papilloma-virus (crpv) in domestic rabbits frequently regress spontaneously or, failing to do so, convert into squamous cell carcinomas at a high rate. this papilloma-carcinoma complex in rabbits provides an experimental model for human papillo-mavirus-associated malignancies. the aim of this study was to prepare an experimental system in inbred rabbits by establishing culture cell lines of the tumor. squamous cell carcinoma developed from a shope pa ... | 1991 | 1649230 |
| morphometric analysis and identification of infiltrating leucocytes in regressing and progressing shope rabbit papillomas. | spontaneous regressions of papillomavirus lesions frequently occur in both human and animal infections. the mechanism by which this occurs is currently unknown. mononuclear infiltrates are found in regressing human and rabbit papillomas. to assess the potential functional role of these infiltrates in regression, we have characterized and quantitated the cell types present in regressing rabbit lesions. forty new zealand white rabbits were inoculated with cottontail rabbit papillomavirus (crpv) at ... | 1991 | 1660041 |
| antibody-mediated neutralization in vivo of infectious papillomaviruses. | specific antibody-mediated neutralization of infectious human papillomavirus type 11 (hpv-11) was achieved in the athymic mouse xenograft system, in which hpv-11 induced morphological transformation of human foreskin. virus-specific neutralization was demonstrated by the ability of an hpv-11-specific polyclonal antiserum to neutralize hpv-11 infectivity and not bovine papillomavirus type 1 (bpv-1) or cottontail rabbit papillomavirus (crpv) infectivity. in all three virus infectivity systems, neu ... | 1990 | 1693698 |
| the open reading frame l2 of cottontail rabbit papillomavirus contains antibody-inducing neutralizing epitopes. | polyclonal antisera were generated against bacterially derived fusion proteins of the open reading frames (orfs) of the capsid proteins of cottontail rabbit papillomavirus (crpv). the carboxy-terminal two-thirds of crpv l1 and the carboxy-terminal half of crpv l2 were cloned into a bacterial expression vector and induced proteins were used as antigen and immunogen. the polyclonal antisera were tested in a series of immunological assays, including elisa, western blot, and neutralization of crpv. ... | 1991 | 1707567 |
| neutralization of crpv infectivity by monoclonal antibodies that identify conformational epitopes on intact virions. | monoclonal antibodies were generated against cottontail rabbit papillomavirus (crpv) and tested for neutralization of crpv-induced papillomas on domestic nzw rabbits. intact crpv was semi-purified on cscl gradients and used to immunize balb/c mice. hybridomas were prepared from a fusion with lymph node cells, and supernatants from growing hybridomas were analyzed by enzyme-linked immunosorbent assay (elisa) for reactivity to both intact and disrupted crpv virion antigen. supernatants from 22 cul ... | 1991 | 1722596 |
| the late region differentially regulates the in vitro transformation by cottontail rabbit papillomavirus dna in different cell types. | papilloma induced by the cottontail rabbit papillomavirus (crpv) progress at a high frequency to cancers. this property makes the crpv system unique to study the role of papillomaviruses in cancer development. in contrast to bovine papillomavirus type 1, no convenient in vitro transformation system for crpv has been available. here, we describe two in vitro systems that we have developed. transformation of nih 3t3 cells is greatly facilitated by deletions in the crpv late region. specifically, a ... | 1991 | 1849681 |
| two shope papillomavirus-associated vx2 carcinoma cell lines with different levels of keratinocyte differentiation and transplantability. | two cell lines, named vx2t and vx2r, were isolated from the transplantable vx2 carcinoma, a wholly anaplastic tumor established from a carcinoma induced by the shope cottontail rabbit papillomavirus (crpv) (j.g. kidd and p. rous, j. exp. med. 71:813-838, 1940). the crpv genome was found to be maintained and transcribed in both cell lines, as in the vx2 carcinoma. the vx2t cells retained the tumor-producing capacity in the rabbit and the low expression of epidermal keratinocyte differentiation of ... | 1985 | 2409299 |
| biodistribution of indium 111-labeled dihematoporphyrin ether in papillomas and body tissues. relevance to photodynamic therapy. | hematoporphyrin derivative and its newly purified form, dihematoporphyrin ether, have been shown to localize selectively in malignant tissues and virally induced papillomas. its use as a probe to distinguish tumors from normal tissues has been largely based on its fluorescence when activated by uv light. these findings are largely subjective, and a direct correlation to its use as a photosensitizing agent to selectively kill transformed cells when activated by an appropriate wavelength of light ... | 1989 | 2525396 |
| genetic analysis of crpv pathogenesis: the l1 open reading frame is dispensable for cellular transformation but is required for papilloma formation. | genetic studies to elucidate the role of papillomaviruses in the development and progression of tumors have been severely hampered because the viruses cannot be grown in tissue culture and therefore mutants are not available. we have employed recombinant dna for papilloma induction to identify essential sequences involved in papillomavirus pathogenesis. here, we demonstrated that deleting most of the open reading frame (orf) l2 did not affect the potential of viral cottontail rabbit papillomavir ... | 1989 | 2541552 |
| histological and molecular analysis of cottontail rabbit papillomavirus-induced papillomas treated with hematoporphyrin derivative photodynamic therapy. | the clinical regression of cottontail rabbit papillomavirus-induced cutaneous papillomas on dutch-belted rabbits following treatment with hematoporphyrin derivative photodynamic therapy was recently reported. those papillomas that underwent total regression failed to recur at 18 months. tissues from totally regressed papillomas and adjacent sites failed to reveal the presence of papilloma on histological examination. these findings were confirmed by the absence of viral dna following analysis by ... | 1988 | 2827705 |
| the two proteins encoded by the cottontail rabbit papillomavirus e6 open reading frame differ with respect to localization and phosphorylation. | cottontail rabbit papillomavirus-induced tumors contain two e6-coding transcripts. a major transcript can code for a short e6 protein initiated at aug codon 2, and a minor one could code for a long e6 initiated at aug 1. we have identified the two proteins expressed in cos-7 cells (m. barbosa and f. o. wettstein, j. virol. 61:2938-2942, 1987). the properties of the two proteins are distinctly different. the long e6 is predominantly present in the nucleus, in which it appears to be associated wit ... | 1988 | 2828659 |
| structure and genetic expression of papillomaviruses. | this article reviews the physical structures, genetic organization, expression, and regulation of papillomaviruses. in view of the extensive characterization of cellular transformation and viral functions that have been achieved in experimentally infected animals and in transformed cell cultures, the bovine papillomavirus type 1 (bpv-1) and shope cottontail rabbit papillomavirus (crpv) are compared and contrasted with the human papillomaviruses. | 1987 | 2829072 |
| study of the e2 gene product of the cottontail rabbit papillomavirus reveals a common mechanism of transactivation among papillomaviruses. | the long control region (lcr) of the cottontail rabbit papillomavirus (crpv) harbors a transcriptional promoter which can be transactivated, as reflected by cat gene expression, by cotransfection with plasmids which express the intact e2 open reading frame of crpv, human papillomavirus type 18 (hpv18), and bovine papillomavirus type 1 (bpv1). the e2 protein of crpv can also transactivate the lcrs of bpv1, hpv1, and hpv18 inserted in front of the cat gene in enhancer or promoter configuration. co ... | 1988 | 2833608 |
| identification and characterization of the crpv e7 protein expressed in cos-7 cells. | the papillomavirus e7 protein may play an important role in oncogenesis as it is the major viral protein present in human cervical cancer-derived cell lines. because of the relevance of the cottontail rabbit papillomavirus (crpv) system for the study of viral-induced malignancies, we characterized its e7 protein expressed by a heterologous strong promoter. an e7-specific antiserum was obtained by immunizing rabbits with a trp e-e7 fusion protein containing the 88 carboxyl-terminal amino acids of ... | 1988 | 2838953 |
| [papillomavirus and cancer]. | papillomaviruses are causative agents of benign tumor (papilloma) and are widely distributed in most of animals. the papillomaviruses are small dna viruses grouped in the papovavirus family. the genomes of all papillomaviruses pce double stranded circular dna of approximately 8 k. base pairs. classification of the viruses is presently based on the host range and relatedness of the nucleic acids. in the case of human papillomavirus (hpv), more than 50 types have been isolated. the amount of infor ... | 1988 | 2840032 |
| e2 of cottontail rabbit papillomavirus is a nuclear phosphoprotein translated from an mrna encoding multiple open reading frames. | the papillomavirus e2 protein is a transcription trans-activator and as such as a paramount effect on viral functions. we have identified and characterized the cottontail rabbit papillomavirus e2 protein expressed from the late simian virus 40 promoter in cos-7 cells. e2 was shown to be a highly phosphorylated 49-kilodalton protein. subcellular fractionation and indirect immunofluorescent staining indicated that e2 was located in the nuclei. e2 was expressed from a vector which contained just th ... | 1988 | 2841476 |
| structural and mutational analysis of e2 trans-activating proteins of papillomaviruses reveals three distinct functional domains. | the e2 proteins of papillomaviruses are able to transactivate the viral enhancers by interacting with the sequence accgn4cggt found in all papillomavirus long control regions. analysis of the alignment of the amino acid sequences of 10 e2 proteins reveals three distinct regions: two partially conserved domains at the n and c termini of the proteins and a region variable in size and sequence in the middle. a computer prediction of the secondary structure of the 10 sequences outlines interesting c ... | 1988 | 2846285 |
| use of retroviral vectors for mapping of splice sites in cottontail rabbit papillomavirus. | cottontail rabbit papillomavirus (crpv) genomic sequences coding for virus early functions were introduced into a retroviral vector in order to produce cdnas of the viral early region. two constructs differing in the length of control sequences preceding the e6 open reading frame were transfected into psi-2 cells and the released retroviral stock was used to infect nih3t3 cells. the proviral sequences were rescued from antibiotic g418-resistant virus-infected cells after fusion with cos cells, a ... | 1988 | 2848927 |
| promoters and processing sites within the transforming region of bovine papillomavirus type 1. | the mrnas present in bovine papillomavirus type 1 (bpv-1)-transformed c127 cells were studied by primer extension. the results show that two internal promoters are present in the e region of bpv-1 in addition to the previously identified promoter at coordinate 1 (h. ahola, a. stenlund, j. moreno-lópez, and u. pettersson, nucleic acids res. 11:2639-2650, 1983). one, located at coordinate 31, generated a set of mrnas with heterogeneous 5' ends, which may encode the major transforming protein of bp ... | 1987 | 2884331 |
| identification of the major cottontail rabbit papillomavirus late rna cap site and mapping and quantitation of an e2 and minor e6 coding mrna in papillomas and carcinomas. | the capsite of the 2.6- and 4.8-kb major late transcripts of cottontail rabbit papillomavirus (crpv) has been mapped by primer extension. a leader exon of about 300 nucleotides common to both rnas is located in the untranslated region of the genome upstream of the capsites for early transcripts. in contrast to the early capsites which are all preceded by tata boxes, no such sequence is present 30 nucleotides upstream of the late capsite. these data indicate that the switch from early to late tra ... | 1987 | 2887064 |
| a type-ii dna topoisomerase and a catenating protein from the transplantable vx2 carcinoma. | it has recently been suggested that topoisomerases could be important targets for several dna intercalating drugs used in cancer therapy. this prompted us to purify and characterize a type ii topoisomerase in a highly tumorigenic transplantable rabbit tumor isolated from a skin carcinoma associated with cottontail rabbit papillomavirus. we have found that the decatenating activity present in tumor cells was 40-100 times higher than that in the rabbit liver, while no activity could be found in sk ... | 1985 | 2982598 |
| fine structure of the cottontail rabbit papillomavirus mrnas expressed in the transplantable vx2 carcinoma. | we analyzed the polyadenylated mrnas transcribed from the cottontail rabbit papillomavirus genomes present in the domestic rabbit transplantable carcinoma line vx2, employing a combination of s1 nuclease mapping and primer extension techniques with vector m13-based single-stranded dna probes. each of the two major mrna species (1,860 and 1,110 bases long) contained two exons which corresponded to the e6-e7 and e2-e4 open reading frames. the splice donor site for these transcripts was located at ... | 1985 | 2983085 |
| genomic structure of the cottontail rabbit (shope) papillomavirus. | the nucleotide sequence of the cottontail rabbit papillomavirus (crpv or shope papillomavirus) genome has been determined. the overall organization of the genome is similar to that of the other three papillomaviruses already sequenced. the amino acid sequences of the putative viral proteins were compared to the available protein data banks. of particular interest is the homology found between the cooh terminus of the e2 putative protein of the different papillomaviruses and the viral or cellular ... | 1985 | 2984661 |
| human papillomavirus type 16 dna sequence. | the complete nucleotide sequence of hpv16 dna (7904 bp) cloned from an invasive cervical carcinoma was determined. homology comparisons allowed us to align the major open reading frames with the other published papilloma virus dna sequences. the general organization of the open reading frames is similar to that of the other four papillomavirus (bpv1, hpv1a, hpv6b, crpv) already sequenced. the sequence reveals an interruption of the reading frame coding for a suspected e1 protein. | 1985 | 2990099 |
| hematoporphyrin derivative therapy of papillomas. experimental study. | hematoporphyrin derivative has been shown to selectively localize in malignant tissues and chemically induced animal papillomas. it is a powerful photo-sensitizing agent that can cause destruction and death of tissues in which it has localized by the generation of singlet oxygen when activated by light of the appropriate wavelength (photodynamic therapy [pdt]). laryngeal papillomas are rapidly growing benign epithelial neoplasms with a clinical course marked by multiple recurrences after surgica ... | 1986 | 3000329 |
| epidermodysplasia verruciformis-associated human papillomavirus 8: genomic sequence and comparative analysis. | human papillomavirus (hpv) 8 induces skin tumors which are at high risk for malignant conversion. the nucleotide sequence of hpv8 has been determined and compared to sequences of papillomaviruses with different oncogenic potential. the general organization of the hpv8 genome is similar to that of other types. highly conserved, genus-specific sequences were found in open reading frames (orfs) e1, e2, and l1. in orfs e6, e7, and l2, hpv8 is more distantly related, but it was possible to differenti ... | 1986 | 3009874 |
| production of spliced dna copies of the cottontail rabbit papillomavirus genome in a retroviral vector. | the early region of the cottontail rabbit papillomavirus (crpv) genome has been introduced into a retroviral vector and recombinant retroviruses, produced upon transfection of the psi 2 packaging cell line, have been used to infect nih 3t3 cells. spliced derivatives of the crpv early region can be rescued from the infected cells. sequence analysis demonstrates that the major splicing event observed in rna in tumours is faithfully reproduced in this system. this splice generates a polycistronic m ... | 1986 | 3013527 |
| enhancers and trans-acting e2 transcriptional factors of papillomaviruses. | the upstream regulatory regions of human papillomavirus (hpv) types 1, 6b, 7, 11, 16, and 18, bovine papillomavirus type 1, and cottontail rabbit papillomavirus were cloned into transcriptional enhancer assay plasmids which carry the simian virus 40 early promoter lacking its own enhancer and the bacterial gene encoding chloramphenicol acetyltransferase (ec 2.3.1.28) (cat). enhancer activity, reflected by cat gene expression, was detected in all of the upstream regulatory regions tested only whe ... | 1987 | 3037119 |
| transcription of the cottontail rabbit papillomavirus early region and identification of two e6 polypeptides in cos-7 cells. | cottontail rabbit papillomavirus (crpv) early proteins are present at very low levels in virus-induced tumors and cannot be detected by immunological methods. furthermore, cells in culture are not readily transformed by the virus. to overcome these difficulties in identifying and characterizing the putative transforming protein(s) coded by the e6 open reading frame, the early cottontail rabbit papillomavirus region was expressed under the control of the late simian virus 40 promoter. mapping of ... | 1987 | 3039182 |
| physical state and transcription of the cottontail rabbit papillomavirus genome in warts and transplantable vx2 and vx7 carcinomas of domestic rabbits. | the physical state and the transcription of the genome of cottontail rabbit papillomavirus (crpv) in non-virus-producing warts and in the vx2 and vx7 transplantable carcinomas of domestic rabbits were compared. the crpv dna present in vx2 and vx7 carcinomas (10 to 20 and 100 to 200 genome equivalents per diploid cell, respectively) was found to be entirely integrated into the cellular dna, most probably as head-to-tail tandem repeats, in contrast to warts, in which viral dna (10 to 100 copies pe ... | 1984 | 6086962 |
| cottontail rabbit papillomavirus-specific transcripts in transplantable tumors with integrated dna. | the viral dna and viral transcripts of a vx2 and a vx7 transplantable carcinoma lines were analyzed. both tumor lines contain equivalent numbers of gene copies per cell of exclusively integrated viral dna. integration is in head-to-tail tandem repeats, in probably three sites and at least two integration sites are common. in both tumors, about half of the viral genomes share a 90-bp deletion. common integration sites and deletions suggest that the two tumor lines were derived from the same paren ... | 1984 | 6093372 |
| differences exist between viral transcripts in cottontail rabbit papillomavirus-induced benign and malignant tumors as well as non-virus-producing and virus-producing tumors. | five major cottontail rabbit papillomavirus-specific polyadenylated rna species with sizes of 4.8, 2.6, 2.0, 1.3, and 0.9 kilobases (kb) were found in virus-producing tumors of cottontail rabbits (the natural host for the virus). two of the rna species (sizes, 2.0 and 1.3 kb) are indistinguishable with respect to size and map position from the rna species detected previously in non-virus-producing benign and malignant tumors (nasseri et al., j. virol. 44:263-268, 1982). the 2.0-kb rna in virus-p ... | 1984 | 6206234 |
| restriction mapping and physical characterization of the cottontail rabbit papillomavirus genome in transplantable vx2 and vx7 domestic rabbit carcinomas. | | 1982 | 6281974 |
| free cottontail rabbit papillomavirus dna persists in warts and carcinomas of infected rabbits and in cells in culture transformed with virus or viral dna. | we have compared warts and carcinomas from cottontail and domestic rabbits for the presence of cottontail rabbit papillomavirus (crpv) and the status of the viral dna genome. our studies indicate that benign warts from cottontail rabbits, whether found naturally or induced in the laboratory, contain large amounts of virus and on the average 1000 copies of the virus genome per cell. both benign warts and carcinomas from domestic rabbits contain significantly reduced levels of virus relative to co ... | 1983 | 6299003 |
| papillomavirus genomes: sequences and consequences. | the complete nucleotide sequences of four papillomavirus genomes recently determined (human papillomavirus types 1a and 6b, bovine papillomavirus type 1, and the shope cottontail rabbit papillomavirus) shed light on the molecular genetics of these epitheliotropic viruses. the organization of the four genomes is very similar, and their comparative analysis suggests new hypotheses about the nature of the viral proteins, their involvement in virus structure, and their interaction with the host cell ... | 1984 | 6330226 |
| factors affecting the use of immunoosmophoresis for the detection of two insect riboviruses. | some of the factors affecting the formation of precipitin lines during immunoosmophoresis were investigated using two unrelated insect riboviruses, flock house virus (fhv) and cricket paralysis virus (crpv). precipitin lines formed in under 90 min. concentrations of 200-400 ng/ml of fhv were routinely detected but occasionally the end-point was as low as 50 ng/ml. with crpv, 1500 ng/ml was the routine detectable level. the sensitivity of the assay was largely unaffected by the presence of insect ... | 1982 | 7076782 |
| methylation of cottontail rabbit papillomavirus dna and tissue-specific expression in transgenic rabbits. | transgenic rabbits carrying multiple copies of crpv genomic dna were described previously (peng et al. (1993) j. virol. 67, 1698-1701). crpv dna was detectable in all tissues of the transgenic rabbits, however, the transcripts of crpv genes only were found in skin and skin tumors. tumor development was also restricted to skin. to study the mechanism involving tissue-specific expression of crpv genes in rabbits, cellular dnas, isolated from different normal tissues and skin tumors, were digested ... | 1995 | 7538718 |
| papillomavirus l1 capsids agglutinate mouse erythrocytes through a proteinaceous receptor. | virus-like particles (vlps) composed of l1 derived from bovine papillomavirus type 1 (bpv-1), several human papillomavirus types, or cottontail rabbit papillomavirus (crpv) agglutinated mouse but not human or rat erythrocytes. treatment of mouse erythrocytes with trypsin prevented hemagglutination (ha) by bpv-1. sera from rabbits immunized with native crpv vlps, which protect against experimental crpv infection, exhibited high titers of antibodies that inhibited crpv vlp ha activity, while sera ... | 1995 | 7541848 |
| induction of neutralizing antibodies to papillomaviruses by anti-idiotypic antibodies. | anti-idiotypic antibodies (anti-ids) were generated against three mouse monoclonal antibodies (mabs) which neutralized three different papillomaviruses. the neutralizing mabs (n-mabs) were generated against infectious human papillomavirus type 11 (hpv-11), cottontail rabbit papillomavirus (crpv), and bovine papillomavirus type 1 (bpv-1), and all recognized surface conformational epitopes that were lost upon denaturation of the virions. the polyclonal anti-ids were screened in an elisa using a pa ... | 1995 | 7542415 |
| efficacy of intravenous delta-aminolaevulinic acid photodynamic therapy on rabbit papillomas. | endogenously induced protoporphyrin ix (ppix), a metabolite of delta-aminolaevulinic acid (ala), has been evaluated as a photosensitising agent for destruction of papillomas in cottontail rabbit papillomavirus-infected dutch belted and new zealand rabbits. three factors were evaluated: (1) relative retention ratio of drug in normal tissue, papilloma and plasma over time; (2) tissue tolerance to treatment factors; and (3) efficacy of treatment protocol. three drug doses of ala were examined: 50, ... | 1995 | 7547231 |
| progression from papilloma to carcinoma is accompanied by changes in antibody response to papillomavirus proteins. | cottontail rabbit papillomavirus induces benign tumors, papillomas, in rabbits which progress at a high frequency to malignant tumors, carcinomas. cottontail rabbit papillomavirus therefore provides an experimental model for oncogenic human papillomaviruses. the nature of the antigens recognized by the host has not been identified at any stage of tumor development. here, we characterized the humoral immune response to viral antigens in cottontail and domestic rabbits at the papilloma stage, in d ... | 1993 | 7677955 |
| cottontail rabbit papillomavirus l1 protein-based vaccines: protection is achieved only with a full-length, nondenatured product. | papillomas induced by the cottontail rabbit papillomavirus (crpv) progress at a high frequency to carcinomas. in this regard, crpv and its tumors can serve as an animal model for highly oncogenic human papillomaviruses. we have previously shown that immunization with major structural protein l1 elicits neutralizing antibodies and protects rabbits from papilloma development (y.-l. lin, l.a. borenstein, r. selvakumar, r. ahmed, and f.o. wettstein, virology 187:612-619, 1992). in this study, we dem ... | 1993 | 7685411 |
| monoclonal antibody neutralization of bpv-1. | mouse monoclonal antibodies were generated against intact infectious bpv-1 virions by methods previously described (christensen et al., 1990). elisa was used to screen for reactivities to intact and/or disrupted bpv-1, crpv and hpv-11 virions. several hybridomas were initially selected that showed antibody reactivity by elisa to both intact and disrupted bpv-1, to disrupted bpv-1 only, or to intact bpv-1 virions. one monoclonal antibody, designated b1.a1, which reacted only to intact bpv-1 was s ... | 1993 | 7686316 |
| immunization with viruslike particles from cottontail rabbit papillomavirus (crpv) can protect against experimental crpv infection. | we tested the ability of vaccination with virus-like particles (vlps) to protect domestic rabbits against papillomas induced by the cottontail rabbit papillomavirus (crpv). a recombinant baculovirus system that expressed only the l1 major papillomavirus structural protein or l1 plus the minor l2 protein was used in insect cells as the source of vlps. groups of 10 rabbits were immunized with native or denatured vlps from crpv or type 1 bovine papillomavirus by using freund's adjuvant. alum was us ... | 1995 | 7745754 |
| vaccination against cutaneous and mucosal papillomavirus in cattle. | viruses are responsible for approximately 15% of human cancer worldwide. human papillomavirus and hepatitis b virus are the recognized agents of cervical and liver cancer, respectively, which together constitute 80% of all virally induced cancers. if measures could be found to bring viral infection under control, a great proportion of human cancer would be greatly reduced. experimental vaccines are being developed against papillomavirus. in principle two different types of vaccine can be envisag ... | 1994 | 7796677 |
| varied expression of major histocompatibility complex and oncogenes in shope carcinoma cell lines derived from a single tumor. | the cellular gene expression was compared in four shope carcinoma cell lines, which were derived from a single tumor and possess various potentials for differentiation and tumorigenicity. the e6 and e7 transforming genes of cottontail rabbit papillomavirus were expressed in all these cell lines, highest level of expression being in the most tumorigenic and undifferentiated cell line, where the major histocompatibility complex (mhc) class i expression was the lowest. the mhc class ii antigen, whi ... | 1995 | 7860614 |
| postattachment neutralization of papillomaviruses by monoclonal and polyclonal antibodies. | postattachment neutralization of papillomaviruses (pvs) was analyzed in three pv-infectivity models: (i) the bpv-1-induced focus-forming assay using c127 cells; (ii) in vitro abortive infection of rabbit rk-13 and sf1ep cells with crpv; and (iii) hpv-11-induced morphological transformation of human foreskin chips in the athymic mouse xenograft system. in each assay system, aliquots of infectious virus were added to the appropriate target cells and incubated at 37 degrees, followed at various pos ... | 1995 | 7871722 |
| analysis of the nucleotide sequence variation of the antigen-binding domain of dr alpha and dq alpha molecules as related to the evolution of papillomavirus-induced warts in rabbits. | we previously found that regression of skin warts induced by the shope cottontail rabbit papillomavirus in new zealand white rabbits, as well as malignant conversion of persistent warts, are linked to a restriction fragment length polymorphism of the major histocompatibility complex class ii dr alpha and dq alpha genes. to find out whether this immunogenetic control could be connected with the antigen binding and presentation function of the alpha 1 domain of class ii molecules, we have sequence ... | 1994 | 7915746 |
| comparison of the properties of the e6 and e7 genes of low- and high-risk cutaneous papillomaviruses reveals strongly transforming and high rb-binding activity for the e7 protein of the low-risk human papillomavirus type 1. | a comparative analysis of different properties of the e6 and e7 proteins of high-risk and low-risk cutaneous papillomaviruses was performed. the corresponding genomic regions of human papillomavirus types 1 and 8 (hpv1 and hpv8) and of the cottontail rabbit papillomavirus (crpv) were cloned into the eucaryotic expression vector pzipneo-sv(x)-1 and into vectors for in vitro transcription and translation. with the help of these vectors, the individual proteins were investigated for their ability t ... | 1994 | 7933087 |
| topical ctc-96 accelerates wart growth in rabbits infected with cottontail rabbit papillomavirus. | ctc-96, a cobalt containing complex, was tested as a putative topical therapeutic agent for the treatment of papillomavirus-induced tumors in our cottontail rabbit papillomavirus (crpv)-rabbit model system. following experimental infection of domestic rabbits with crpv, ctc-96 was applied to infection sites twice daily, 5 days a week for a total of 8 weeks. two levels of concentrations of aqueous ctc-96 were compared to placebo control-treated animals. with increasing dose of ctc-96 we observed ... | 1994 | 7944311 |
| photodynamic therapy using m-tetra(hydroxyphenyl) chlorin. an animal model. | to evaluate the potent photosensitizer m-tetra (hydroxyphenyl) chlorin (m-thpc) by using rabbits with cottontail rabbit papillomavirus-induced tumors and the canine larynx as model systems. | 1994 | 7980901 |
| immunization with nonstructural proteins e1 and e2 of cottontail rabbit papillomavirus stimulates regression of virus-induced papillomas. | cottontail rabbit papillomavirus is the major animal model for cancer-associated papillomaviruses. here we show that vaccination with the nonstructural proteins e1 and e2 induces the regression of virus-induced papillomas and that vaccination is equally effective when proteins are given with and without adjuvant. there was no correlation between antibody levels and regression, suggesting that tumor regression may be due to a cell-mediated response. | 1995 | 7983764 |
| papilloma formation by cottontail rabbit papillomavirus requires e1 and e2 regulatory genes in addition to e6 and e7 transforming genes. | the present study used the cottontail rabbit papillomavirus dna-rabbit system to evaluate whether the regulatory genes e1 and e2 and the transforming gene e6 are required for papilloma formation. frameshift mutations were generated in the individual genes in the context of a full-length cottontail rabbit papillomavirus genome, and the mutant dnas were intradermally inoculated into domestic rabbits. none of the mutants induced papillomas. marker rescue experiments confirmed that the defects were ... | 1994 | 8057490 |
| a suggested taxonomy and nomenclature for the cricket paralysis and drosophila c virus complex. | biophysical, biological, and serological characters are presented which in combination allow isolates of cricket paralysis virus (crpv) and drosophila c virus (dcv) to be separated and seven distinct strains of crpv to be defined. reference isolates for crpv and dcv are suggested along with a system of nomenclature that allows the passage history of a particular isolate to be easily described. | 1994 | 8176243 |
| changes in rna expression pattern during the malignant progression of cottontail rabbit papillomavirus-induced tumors in rabbits. | cottontail rabbit papillomavirus induces strictly epithelial tumors in both cottontail and domestic rabbits. a high proportion of the initial benign papillomas progress within 8 to 14 months to invasive carcinomas. with the help of mrna-specific riboprobes for e6, e7, e1, e2, l1 and l2, we investigated by in situ hybridization the rna expression pattern of cottontail rabbit papillomavirus in tissue sections of biopsies from different stages of tumor development. common features of all lesions we ... | 1994 | 8189500 |
| t-cell response to cottontail rabbit papillomavirus structural proteins in infected rabbits. | cottontail rabbit papillomavirus (crpv)-induced papillomas progress at a high frequency to carcinomas and thus can serve as a model for high-cancer-risk human papillomavirus infection. previously, we have shown that antibodies to nonstructural and structural proteins are detected in only a fraction of papilloma-bearing animals. however, the antibody response to structural proteins drastically increases as papillomas progress to carcinoma (y.-l. lin, l. a. borenstein, r. selvakumar, r. ahmed, and ... | 1994 | 8189540 |
| latent infection induced with cottontail rabbit papillomavirus. a model for human papillomavirus latency. | latent human papillomavirus infection, a very common event, is most likely the source of primary and recurrent papillomas of the respiratory and genital tracts and might also be the source of neoplastic lesions of the female genital tract and the penis. we have developed a simple model for papillomavirus latency using cottontail rabbit papillomavirus. skin of domestic rabbits was minimally scarified and inoculated with dilutions of a crude virus suspension ranging from 200 ng to 20 pg viral dna ... | 1994 | 8203458 |
| efficient self-assembly of human papillomavirus type 16 l1 and l1-l2 into virus-like particles. | the l1 genes of two human papillomavirus type 16 (hpv16) isolates derived from condylomata acuminata were used to express the l1 major capsid protein in insect cells via recombinant baculoviruses. both l1 major capsid proteins self-assembled into virus-like particles (vlp) with high efficiency and could be purified in preparative amounts on density gradients. the yield of vlp was 3 orders of magnitude higher than what has been obtained previously, using l1 derived from the prototype hpv16. dna s ... | 1993 | 8230414 |
| podofilox-induced regression of shope papillomas may be independent of host immunity. | we tested the hypothesis that infiltrating leukocytes might contribute to papilloma destruction following podofilox treatment. new zealand white (nzw) rabbits were inoculated with cottontail rabbit papillomavirus (crpv) onto abraded areas of the dorsal skin. at 21 d after viral inoculation, 5.0% podofilox solution was applied to some papillomas, whereas others were used as controls. three rabbits were sacrificed at each of three different periods after treatment initiation (1, 4, and 7 d). four ... | 1993 | 8245513 |
| the mastomys natalensis papillomavirus: nucleotide sequence, genome organization, and phylogenetic relationship of a rodent papillomavirus involved in tumorigenesis of cutaneous epithelia. | mastomys natalensis is a rodent of african origin afflicted with a very high incidence of skin tumors (keratoacanthomas and squamous carcinomas), which are associated with a papillomavirus, m. natalensis papillomavirus (mnpv). we have determined the genomic sequence of mnpv, which has a size of 7687 bp. the genomic organization is similar to that of other papillomaviruses, with open reading frames e6, e7, e1, e2, and e4 in the early and l2 and l1 in the late region. due to an unusually large hin ... | 1994 | 8291235 |
| infectious virus replication in papillomas induced by molecularly cloned cottontail rabbit papillomavirus dna. | the ability to obtain infectious papillomavirus virions from molecularly cloned dna has not been previously reported. we demonstrate here that viral genomes isolated from a recombinant++ dna clone of cottontail rabbit papillomavirus (crpv) gave rise to infectious virus when inoculated into cottontail rabbit skin. replication occurred in papillomas that formed at inoculation sites. extract of a dna-induced papilloma was serially passaged to naive rabbits with high efficiency. complete virus was f ... | 1993 | 8380092 |
| papillomavirus e7 protein binding to the retinoblastoma protein is not required for viral induction of warts. | human papillomaviruses (hpvs) are the etiologic agents responsible for benign epithelial proliferative disorders including genital warts and are a contributory factor in the pathogenesis of cervical cancer. hpvs demonstrate strict species and cell-type specificity, which is manifested by the inability of these viruses to induce disease in any species other than humans. the natural history of hpv infection in humans is closely mimicked by cottontail rabbit papillomavirus (crpv) infection in domes ... | 1993 | 8380462 |
| comparison of the binding of the human papillomavirus type 16 and cottontail rabbit papillomavirus e7 proteins to the retinoblastoma gene product. | binding of the human papillomavirus type 16 (hpv-16) e7 oncoprotein to the retinoblastoma protein (prb) is thought to be involved in the cellular transformation mediated by hpv-16. here we show that the e7 protein of the cottontail rabbit papillomavirus (crpv) binds to the same c-terminal portion of human prb as hpv-16 e7, and that both the crpv and hpv-16 e7 proteins bind specifically through similar domains to rabbit prb. furthermore, a single amino acid substitution which reduces the binding ... | 1993 | 8380832 |
| papillomas and carcinomas in transgenic rabbits carrying ej-ras dna and cottontail rabbit papillomavirus dna. | two transgenic rabbits (tri and triii) that carried cottontail rabbit papillomavirus (crpv) dna alone were identified; another (trii) carried both crpv dna and ej-ras. tri and triii developed extensive skin papillomas at about 1 month of age, and transcripts of crpv dna were detectable only in skin and/or papillomas. trii developed extensive squamous carcinomas of the skin at a very early age. transcription of both crpv dna and ej-ras was found in the skin cancers. thus, the tissue specificity o ... | 1993 | 8382316 |
| cleavage of cottontail rabbit papillomavirus e7 rna with an anti-e7 ribozyme. | we have designed and constructed a plasmid (pe7rz-1) that contains a gene for a hammerhead ribozyme that specifically cleaves cottontail rabbit papillomavirus (crpv) e7 rna sequences in vitro. the in vitro produced transcripts of pe7rz-1 cleave crpv e7 target sequences in trans at 37 degrees c. pretreatment of pe7rz-1 rna with poly-l-lysine (pll) increases the stability of the rna to greater than 2 hours in the presence of a crude papilloma cell extract and the pe7rz-1 rna/pll mixture retains ca ... | 1993 | 8387290 |
| skin test to assess immunity against cottontail rabbit papillomavirus antigens in rabbits with progressing papillomas or after papilloma regression. | this study analyzed in vivo antiviral cellular immune reactions in the shope rabbit papilloma-carcinoma model. antigens studied in experimentally infected domestic rabbits were cottontail rabbit papillomavirus particles produced with the athymic (nu/nu) mouse xenograft system and bacterial fusion proteins containing the major or minor capsid protein. recall reactions to antigens were tested by classic intracutaneous tests. positive reactions had a biphasic course. histopathology of skin test bio ... | 1993 | 8393903 |
| shope papilloma cell and leukocyte proliferation in regressing and progressing lesions. | lesions generated by infection with cottontail rabbit papillomavirus frequently undergo spontaneous regression. the purpose of this immunohistochemical study was to compare leukocyte and papilloma cell proliferation in progressing and regressing papillomas and to test the hypothesis that regression was associated with an inhibition of papilloma cell proliferation. the monoclonal antibodies (mabs) mab-019 (specific for dna/bromodeoxyuridine [brdu] complexes), ki-67 (specific for actively prolifer ... | 1993 | 8434644 |
| e2 represses the late gene promoter of human papillomavirus type 8 at high concentrations by interfering with cellular factors. | the late gene promoter p7535 of the epidermodysplasia verruciformis-associated human papillomavirus type 8 (hpv8) is regulated by the viral e2 protein. transfection experiments performed with the human skin keratinocyte cell line rts3b and p7535 reporter plasmids revealed transactivation at low amounts and a repression of basal promoter activity at high amounts of e2 expression vector. this repression was promoter specific and correlated with the amount of transiently expressed e2 protein. mutat ... | 1996 | 8523515 |
| leukocyte proliferation in vitro against cottontail rabbit papillomavirus in rabbits with persisting papillomas/cancer or after regression. | leukocyte proliferation responses to cotton-tail rabbit papillomavirus (crpv) were measured in vitro with fresh whole blood as well as with ammonium chloride lysis-separated leukocytes. the antigens used were (1) crpv particles produced in the athymic( (nu/nu) mouse xenograft system and (2) purified bacterial fusion proteins of the crpv major and minor capsid proteins l1 and l2. crpv-infected domestic rabbits with persistent papillomas or after papilloma regression, as well as uninfected control ... | 1995 | 8534129 |
| high efficiency induction of papillomas in vivo using recombinant cottontail rabbit papillomavirus dna. | plasmids containing cottontail rabbit papillomavirus (crpv) dna can induce papillomas in vivo, but efficiency has been low. the aim of the present investigation was to explore some of the technical variables involved in inoculation of rabbits with recombinant crpv dna in attempts to improve both yield and consistency of papilloma induction. it was found that induction of epidermal hyperplasia, with either a mixture of turpentine and acetone or phorbol esters, produced a marked increase in papill ... | 1995 | 8537461 |
| immunization with viruslike particles induces long-term protection of rabbits against challenge with cottontail rabbit papillomavirus. | rabbits were immunized with recombinant baculovirus-produced virus-like particles (vlps) of cottontail rabbit papillomavirus (crpv) to determine whether these antigens could induce long-term protection against experimental challenge with crpv. infectious crpv and human papillomavirus type 11 l1 vlps were used as positive and negative control immunogens, respectively. three groups of immunized animals were challenged with 10-fold serial dilutions of infectious crpv at 2 weeks, 6 months, and 12 mo ... | 1996 | 8551636 |
| protection against papillomavirus with a polynucleotide vaccine. | 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 v ... | 1996 | 8568291 |
| vaccination with yeast-expressed cottontail rabbit papillomavirus (crpv) virus-like particles protects rabbits from crpv-induced papilloma formation. | papillomaviruses infect epithelia of the skin and mucous membranes and cause benign or malignant tumours in animals and in humans. the viruses are highly species-specific, and cell culture systems for propagating human papillomaviruses (hpvs) do not exist. however, there are several animal papillomavirus models. in the cottontail rabbit papillomavirus (crpv) system, we demonstrated that recombinant crpv virus-like particles (vlps) consisting of the capsid proteins l1 or l1+l2 can be produced in ... | 1995 | 8578834 |
| particle-mediated delivery of recombinant expression vectors to rabbit skin induces high-titered polyclonal antisera (and circumvents purification of a protein immunogen). | polyclonal antibodies were generated in rabbits by delivery to skin of gold particles coated with mammalian expression vectors encoding a cytoplasmic (beta-galactosidase) or a nuclear (l1 capsid of cottontail rabbit papillomavirus) protein. one primary and one booster immunization of 30 micrograms dna per rabbit yielded specific antisera with titers from 1:24 000 to 1:120 000 in each of eight rabbits, as detected by elisa and western blot analysis. genetic immunization requires relatively small ... | 1996 | 8614644 |
| the primary target cells of the high-risk cottontail rabbit papillomavirus colocalize with hair follicle stem cells. | papillomaviruses are small dna tumor viruses with a life cycle inseparably linked to the differentiation of the pluristratified epithelium. the infection of epithelial layers of the skin may remain latent or may result in the development of benign tumors. a certain number of distinct papillomavirus types, however, cause lesions which have a high risk of progression into carcinomas, and extensive efforts have been made to understand this process. comparatively little is known about the initial ev ... | 1996 | 8627717 |
| transforming properties of the cottontail rabbit papillomavirus oncoproteins le6 and se6 and of the e8 protein. | cottontail rabbit papillomavirus induces on cottontail and domestic rabbits papillomas which progress at a high frequency to carcinoma. the virus encodes three transforming proteins; one is translated from open reading frame (orf) e7 and binds the retinoblastoma protein, and two, le6 and se6, are translated from the first and second atgs of orf e6, respectively. here we show that neither of the e6 proteins coprecipitated with p53 in vitro, nor did they bind to a recently identified e6-binding pr ... | 1996 | 8648665 |
| conserved features in papillomavirus and polyomavirus capsids. | capsids of papilloma and polyoma viruses (papovavirus family) are composed of 72 pentameric capsomeres arranged on a skewed icosahedral lattice (triangulation number of seven, t = 7). cottontail rabbit papillomavirus (crpv) was reported previously to be a t = 7laevo (left-handed) structure, whereas human wart virus, simian virus 40, and murine polyomavirus were shown to be t = 7dextro (right-handed). the crpv structure determined by cryoelectron microscopy and image reconstruction was similar to ... | 1996 | 8656427 |
| high efficiency, long-term clinical expression of cottontail rabbit papillomavirus (crpv) dna in rabbit skin following particle-mediated dna transfer. | the ability of skin to support long lasting expression of genes delivered with a particle-mediated system was evaluated in rabbits inoculated with cottontail rabbit papillomavirus (crpv) dna. the optimal delivery force for maximal gene expression in rabbit skin was determined in transient beta-galactosidase assays. forty-five sites in four rabbits were then inoculated at 350-400 p.s.i. with crpv dna. all sites (100%) formed papillomas with multiple papillomas at most sites. these results support ... | 1996 | 8692707 |
| surface conformational and linear epitopes on hpv-16 and hpv-18 l1 virus-like particles as defined by monoclonal antibodies. | a panel of 24 monoclonal antibodies (mabs) was generated against human papillomavirus (hpv) types 16 and 18 l1 virus-like particles (vlps). the mabs were screened for reactivity to a variety of vlps prepared from hpv-6, -11, -16, -18, -31, -33, -35, and -45, cottontail rabbit papillomavirus, bovine papillomavirus type 1, and a set of 35 overlapping 20-amino-acid peptides spanning the entire hpv-16 l1 gene. type-specific linear and conformational surface epitopes were detected as well as several ... | 1996 | 8806551 |
| a simplified 'coupled' probing approach for the detection of proteins on dot and western blots. | western blotting is one of the most commonly and widely used methods for identifying the presence of an antigen in biochemical studies. the present study describes a novel 'coupled blotting' approach that allows antigen on dot and western blots to be simultaneously probed with primary and secondary probing reagents. the study utilized the highly sensitive enhanced chemiluminescence (ecl) detection system, purified e7 protein of cottontail rabbit papillomavirus (crpv) and e7-specific antibodies. ... | 1996 | 8814330 |
| a molecular taxonomy for cricket paralysis virus including two new isolates from australian populations of drosophila (diptera: drosophilidae). | two new isolates of cricket paralysis virus, tar and sim, are described that were originally isolated from laboratory colonies of drosophila melanogaster and drosophila simulans respectively. using a combination of biological, serological and molecular characters it was possible to distinguish the sim isolate from all other isolates and it is thus described as a new strain; crpvsim. the tar isolate however, was indistinguishable from the crpv reference isolate crpvvic/gm/d2(2)/gm/d2(2) (teleogry ... | 1996 | 8856030 |
| the production of cricket paralysis virus in suspension cultures of insect cell lines. | the yields of cricket paralysis virus from two insect cell lines propagated in suspension culture were examined. although trichoplusia ni (tn368) cells produced more virus per cell than drosophila line 2 (dl2) cells, the smaller dl2 cells reached a higher cell density. thus the difference in production between tn368 and dl2 cultures was minimal. in mixed infections of flock house virus and cricket paralysis virus (crpv), crpv was the predominant virus produced despite being present at a much low ... | 1996 | 8858907 |
| rapid, efficient, large-scale purification of unfused, non-denatured e7 protein of cottontail rabbit papillomavirus. | cottontail rabbit papillomavirus (crpv) e7 protein is one of the :high risk' papillomavirus e7 oncoproteins that are partially insoluble in aqueous solution. an escherichia coli expression system was used for purification of crpv e7 protein in quantities sufficient for immunologic studies and structural analysis. a glutathione s-transferase (gst)-crpv e7 fusion protein was solubilized in the presence of non-ionic and ionic detergents, and isolated on an affinity column of glutathione sepharose b ... | 1996 | 8919824 |
| immortalization of inbred rabbit keratinocytes from a shope papilloma and tumorigenic transformation of the cells by ej-ras. | an immortalized cell line of keratinocytes, named spg1-3, was established from a papilloma induced from cottontail rabbit papillomavirus (crpv)-infected inbred rabbit skin. the cells have reached 60 passages in culture and are still growing well, but they are not tumorigenic in athymic mice. although crpv dna was present as extrachromosomal episomes in the papilloma from which the cell line was derived from a single colony of keratinocytes, there was no crpv dna detectable in the cells. three su ... | 1996 | 8950216 |
| intracutaneous vaccination of rabbits with the cottontail rabbit papillomavirus (crpv) l1 gene protects against virus challenge . | a dna vaccine encoding the major capsid protein l1 of cottontail rabbit papillomavirus (crpv) was constructed and administered intracutaneously (i.c.) to rabbits as supercoiled plasmids bound to gold beads using a specialized delivery device ("gene gun"). l1 dna-vaccinated rabbits developed cellular proliferative responses to crpv virus-like particles and developed high titered antibodies with neutralizing activity to crpv. following experimental challenge with crpv, all of the l1 dna-vaccinated ... | 1997 | 9178468 |
| regression of papillomas induced by cottontail rabbit papillomavirus is associated with infiltration of cd8+ cells and persistence of viral dna after regression. | cottontail rabbit papillomavirus (crpv) is a highly oncogenic papillomavirus and has been successfully used as a model to develop protective vaccines against papillomaviruses. papillomas induced by the virus may spontaneously regress, suggesting that crpv can also serve as a model to develop therapeutic vaccines. as a first step toward this goal, we have analyzed immunologic and viral aspects associated with papilloma regression and have identified several features unique to regression. immunohi ... | 1997 | 9188628 |