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Hvid H, Skydsgaard M, Jensen NK, Viuff BM, Jensen HE, Oleksiewicz MB, Kvist PH. Artificial Intelligence-Based Quantification of Epithelial Proliferation in Mammary Glands of Rats and Oviducts of Göttingen Minipigs. Toxicol Pathol 2020; 49:912-927. [PMID: 32840183 DOI: 10.1177/0192623320950633] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Quantitative assessment of proliferation can be an important endpoint in toxicologic pathology. Traditionally, cell proliferation is quantified by labor-intensive manual counting of positive and negative cells after immunohistochemical staining for proliferation markers (eg, Ki67, bromo-2'-deoxyuridine, or proliferating cell nuclear antigen). Currently, there is a lot of interest in replacing manual evaluation of histology end points with image analysis tools based on artificial intelligence. The aim of the present study was to explore if a commercially available image analysis software can be used to quantify epithelial proliferative activity in rat mammary gland and minipig oviduct. First, algorithms based on artificial intelligence were trained to detect epithelium in each tissue. Areas of BrdU- or Ki67-positive nuclei and negative nuclei were subsequently quantified with threshold analysis. Artificial intelligence-based and manually counted labelling indices were strongly correlated and equally well detected the estrous cycle influence on proliferation in mammary gland and oviduct epithelium, as well as the dramatically increased proliferation in rat mammary glands after treatment with estradiol and progesterone. In conclusion, quantification of epithelial proliferation in two reproductive tissues can be achieved in a reliable fashion using image analysis software based on artificial intelligence, thus avoiding time- and labor-intensive manual counting, requiring trained operators.
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Affiliation(s)
- Henning Hvid
- Pathology & Imaging, 1450Novo Nordisk A/S, Måløv, Denmark
| | | | | | | | - Henrik E Jensen
- Section of Pathology, University of Copenhagen, Kobenhavn, Denmark
| | | | - Peter H Kvist
- Pathology & Imaging, 1450Novo Nordisk A/S, Måløv, Denmark
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Oleksiewicz MB, Thorup I, Nielsen HS, Andersen HV, Hegelund AC, Iversen L, Guldberg TS, Brinck PR, Sjogren I, Thinggaard UK, Jørgensen L, Jensen MB. Generalized Cellular Hypertrophy is Induced by a Dual-Acting PPAR Agonist in Rat Urinary Bladder Urothelium In Vivo. Toxicol Pathol 2016; 33:552-60. [PMID: 16076770 DOI: 10.1080/01926230500214657] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Some developmental dual-acting PPARα/γ agonists, such as ragaglitazar, have shown carcinogenic effects in the rodent urinary bladder urothelium after months-years of dosing. We examined early (precancerous) changes in the bladder urothelium of rats orally dosed with ragaglitazar, using a newly developed flow cytometric method. Following 3 weeks of oral ragaglitazar dosing, increases in physical size occurred in a generalized fashion in rat bladder urothelial cells, determined by flow cytometry. Protein/DNA measurements confirmed increased protein content of urothelial cells in the bladder, and hypertrophy was observed in the kidney pelvis urothelium by histopathology. In animals exhibiting urothelial hypertrophy, no cell cycle changes were detected in parallel samples of bladder urothelium. Interestingly, urothelial cells from normal rats were found to constitute a unique type of noncycling population, with high G2/M fractions. In summary, our findings showed that in the urothelium of ragaglitazar-treated animals, hypertrophy (increased size and protein content per cell) was an early change, that affected the whole bladder urothelial cell population. The urothelial hypertrophy was primary, i.e., occurred in the absence of similarly pronounced changes in cell cycle distributions. To our knowledge, this is the first report of a direct hypertrophic effect of a PPAR agonist. Urothelial hypertrophy might be a relevant early biological endpoint in mechanistic studies regarding the bladder-carcinogenic effect of PPAR agonists.
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Affiliation(s)
- Martin B Oleksiewicz
- Novo Nordisk A/S, Novo Nordisk Park, Department of Virology and Molecular Toxicology, Maalov, Denmark.
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Oleksiewicz MB, Steenhard NR, Hansen JES. Modernizing stockpiles of medical countermeasures against smallpox: Benefits, risks, and knowledge gaps. Am J Disaster Med 2015; 10:109-20. [PMID: 26312493 DOI: 10.5055/ajdm.2015.0195] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
OBJECTIVE New smallpox medical countermeasures are entering the marketplace, offering the opportunity to modernize existing stockpiles. However, new smallpox countermeasures are developed under the animal rule, meaning that human efficacy data are lacking, and human safety data may be limited. Also, stockpile modernization would require prioritization of increasingly limited public funds. Approaches to address these issues are needed. METHODS Smallpox vaccine data were gathered by literature search. The financial value of vaccination in the face of an outbreak was evaluated using a threatbased cost/benefit analysis model, involving i) estimation of the efficacy of new smallpox vaccines based on available clinical data on virus-neutralizing seroconversion in vaccinees, ii) estimation of the likelihood for a smallpox outbreak in Denmark, and iii) estimation of the expected life-saving effects of postevent vaccination. RESULTS The authors estimated that i) the likelihood of a smallpox outbreak in Denmark is very low (one event in 200,000 years), ii) the expected efficacy of currently available and new vaccines is 95 and 75 percent, respectively, iii) the expected frequency of serious side effects from vaccination is between 100 and 10,000 fold lower for new than for existing vaccines, depending on modes of action. CONCLUSIONS Despite the very low likelihood for a smallpox outbreak, the potentially large consequences combined with the protective effect of vaccination make maintenance of the smallpox vaccine stockpile justified and valuable. For vaccination in the face of a smallpox outbreak, a high efficacy rather than a lowered rate of adverse effects would maximize the number of lives saved.
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Oleksiewicz MB, Steenhard NR, Hansen JES. Author's response. Am J Disaster Med 2015; 10:363-366. [PMID: 27352451] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
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Lundby A, Bolvig P, Hegelund AC, Hansen BF, Worm J, Lützen A, Billestrup N, Bonnesen C, Oleksiewicz MB. Surface-expressed insulin receptors as well as IGF-I receptors both contribute to the mitogenic effects of human insulin and its analogues. J Appl Toxicol 2014; 35:842-50. [DOI: 10.1002/jat.3082] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Revised: 09/13/2014] [Accepted: 09/15/2014] [Indexed: 11/09/2022]
Affiliation(s)
- Anders Lundby
- Department of Biomedical Sciences; University of Copenhagen; Blegdamsvej 3 2200 Copenhagen N Denmark
| | - Pernille Bolvig
- Diabetes Research Unit, Novo Nordisk A/S; Novo Nordisk Park 2760 Maaloev Denmark
| | | | - Bo F. Hansen
- Diabetes Research Unit, Novo Nordisk A/S; Novo Nordisk Park 2760 Maaloev Denmark
| | - Jesper Worm
- Diabetes Research Unit, Novo Nordisk A/S; Novo Nordisk Park 2760 Maaloev Denmark
| | - Anne Lützen
- Diabetes Research Unit, Novo Nordisk A/S; Novo Nordisk Park 2760 Maaloev Denmark
| | - Nils Billestrup
- Department of Biomedical Sciences; University of Copenhagen; Blegdamsvej 3 2200 Copenhagen N Denmark
| | - Christine Bonnesen
- Diabetes Research Unit, Novo Nordisk A/S; Novo Nordisk Park 2760 Maaloev Denmark
| | - Martin B. Oleksiewicz
- Centre for Biosecurity and Biopreparedness; Statens Serum Institute; Artillerivej 5 2300 Copenhagen S Denmark
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Stadejek T, Stankevicius A, Murtaugh MP, Oleksiewicz MB. Molecular evolution of PRRSV in Europe: current state of play. Vet Microbiol 2013; 165:21-8. [PMID: 23528651 DOI: 10.1016/j.vetmic.2013.02.029] [Citation(s) in RCA: 140] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2012] [Revised: 02/22/2013] [Accepted: 02/27/2013] [Indexed: 11/18/2022]
Abstract
Porcine reproductive and respiratory syndrome virus (PRRSV) is a major threat to European swine production. The existence of extensive genetic variation in endemic strains and the presence of highly virulent strains in other geographic regions pose the threat of devastating epidemic outbreaks. Here we describe the current knowledge of genetic variation in European PRRSV isolates, the implications for PRRSV evolution, and the presence of multiple genetic lineages of Type 2 (North American genotype) isolates in Europe. In Type 1 (European genotype) PRRSV, three genetic subtypes are recognized and a fourth subtype appears to be present. Type 2 PRRSV was considered to be genetically homogenous in Europe due to a unique presence of an introduced vaccine strain, but independent introductions of virulent Type 2 field viruses are now evident. In Type 1 PRRSV, only subtype 1 (Lelystad virus-like) circulates in Central and Western Europe and globally. In Eastern Europe, all subtypes are present. The subtypes of Type 1 PRRSV also exhibit length differences in the nucleocapsid protein, ranging in size from 124 to 132 amino acids depending on subtype. This size heterogeneity is unparalleled in the nucleocapsid proteins of Type 2 PRRSV or other viruses. Surprisingly, it affects the C-terminus, otherwise thought to be under strong structural constraints. Finally, divergent subtypes of Type 1 PRRSV have produced high rates of false-negative RT-PCR results in diagnostic tests, and may also degrade the reliability of serodiagnostic assays using the nucleocapsid protein antigen. In summary, the extensive genetic diversity of Type 1 PRRSV is of relevance for understanding nucleocapsid protein structure/function relationships. Further, the extensive genetic diversity of Type 1 PRRSV in Europe, and the presence of diverse Type 2 PRRSV strains, together emphasize the importance of relevant validation of PRRSV diagnostics. More extensive and systematic molecular phylogeny studies are needed to fully understand PRRSV diversity in Europe, to provide swine producers with reliable diagnostics, and to better assess the potential consequences of endemic spread and exotic introductions.
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Affiliation(s)
- Tomasz Stadejek
- Department of Pathology and Veterinary Diagnostics, Faculty of Veterinary Medicine, Warsaw University of Life Sciences - SGGW, Nowoursynowska 159c, 02-776 Warsaw, Poland.
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Knudsen L, Hansen BF, Jensen P, Pedersen TÅ, Vestergaard K, Schäffer L, Blagoev B, Oleksiewicz MB, Kiselyov VV, De Meyts P. Agonism and antagonism at the insulin receptor. PLoS One 2012; 7:e51972. [PMID: 23300584 PMCID: PMC3531387 DOI: 10.1371/journal.pone.0051972] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2011] [Accepted: 11/14/2012] [Indexed: 11/29/2022] Open
Abstract
Insulin can trigger metabolic as well as mitogenic effects, the latter being pharmaceutically undesirable. An understanding of the structure/function relationships between insulin receptor (IR) binding and mitogenic/metabolic signalling would greatly facilitate the preclinical development of new insulin analogues. The occurrence of ligand agonism and antagonism is well described for G protein-coupled receptors (GPCRs) and other receptors but in general, with the exception of antibodies, not for receptor tyrosine kinases (RTKs). In the case of the IR, no natural ligand or insulin analogue has been shown to exhibit antagonistic properties, with the exception of a crosslinked insulin dimer (B29-B’29). However, synthetic monomeric or dimeric peptides targeting sites 1 or 2 of the IR were shown to be either agonists or antagonists. We found here that the S961 peptide, previously described to be an IR antagonist, exhibited partial agonistic effects in the 1–10 nM range, showing altogether a bell-shaped dose-response curve. Intriguingly, the agonistic effects of S961 were seen only on mitogenic endpoints (3H-thymidine incorporation), and not on metabolic endpoints (14C-glucose incorporation in adipocytes and muscle cells). The agonistic effects of S961 were observed in 3 independent cell lines, with complete concordance between mitogenicity (3H-thymidine incorporation) and phosphorylation of the IR and Akt. Together with the B29-B’29 crosslinked dimer, S961 is a rare example of a mixed agonist/antagonist for the human IR. A plausible mechanistic explanation based on the bivalent crosslinking model of IR activation is proposed.
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Affiliation(s)
- Louise Knudsen
- Receptor Systems Biology Laboratory, Hagedorn Research Institute, Gentofte, Denmark.
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Oleksiewicz MB, Nagy G, Nagy E. Anti-bacterial monoclonal antibodies: Back to the future? Arch Biochem Biophys 2012; 526:124-31. [DOI: 10.1016/j.abb.2012.06.001] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2012] [Revised: 06/01/2012] [Accepted: 06/02/2012] [Indexed: 01/08/2023]
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Knudsen KJ, Nelander Holm GM, Krabbe JS, Listov-Saabye N, Kiehr B, Dufva M, Svendsen JE, Oleksiewicz MB. Driving gradual endogenous c-myc overexpression by flow-sorting: intracellular signaling and tumor cell phenotype correlate with oncogene expression. Arch Toxicol 2011; 83:1061-74. [PMID: 19730820 DOI: 10.1007/s00204-009-0463-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2009] [Accepted: 08/20/2009] [Indexed: 11/28/2022]
Abstract
Insulin-exposed rat mammary cancer cells were flow sorted based on a c-myc reporter plasmid encoding a destabilized green fluorescent protein. Sorted cells exhibited gradual increases in c-myc levels. Cells overexpressing c-myc by only 10% exhibited phenotypic changes attributable to c-myc overexpression, such as cell cycle disturbances, increased cell size, and overexpression of the S6 ribosomal protein. Cells overexpressing c-myc by 70% exhibited additional phenotypic changes typical of c-myc overexpression, such as increased histone H3 phosphorylation, and reduced adherence. Sorted cells also exhibited overexpression of the IGF-1R, and slightly elevated expression of the IR. Increased susceptibility to the mitogenic effect of insulin was seen in a small proportion of the sorted cells, and insulin was more effective in activating the p44/42 MAPK pathway, but not the PI3K pathway, in the sorted cells than in the nonsorted cell population. To our knowledge, this is the first in vitro system allowing functional coupling between mitogenic signaling by a well-defined growth factor and gradual overexpression of the normal, endogenous c-myc gene. Thus, our flow-sorting approach provides an alternative modeling of the receptor-mediated carcinogenic process, compared to the currently used approaches of recombinant constitutive or conditional overexpression of oncogenic transmembrane receptor tyrosine kinases or oncogenic transcription factors.
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Affiliation(s)
- Kasper Jermiin Knudsen
- Institute for Micro and Nanotechnology, Technical University of Denmark, Lyngby, Denmark
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Hvid H, Fels JJ, Kirk RK, Thorup I, Jensen HE, Hansen BF, Oleksiewicz MB. In Situ Phosphorylation of Akt and ERK1/2 in Rat Mammary Gland, Colon, and Liver Following Treatment with Human Insulin and IGF-1. Toxicol Pathol 2011; 39:623-40. [DOI: 10.1177/0192623311406936] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
High doses of insulin and the insulin analog AspB10 have been reported to increase mammary tumor incidence in female rats likely via receptor-mediated mechanisms, possibly involving enhanced IGF-1 receptor activation. However, insulin and IGF-1 receptor functionality and intracellular signaling in the rat mammary gland in vivo is essentially unexplored. The authors investigated the effect of a single subcutaneous dose of 600 nmol/kg human insulin or IGF-1 on Akt and ERK1/2 phosphorylation in rat liver, colon, and mammary gland. Rat tissues were examined by Western blotting and immunohistochemistry by phosphorylation-specific antibodies. Insulin as well as IGF-1 caused Akt phosphorylation in mammary epithelial cells, with myoepithelial and basal epithelial cells being most sensitive. IGF-1 caused stronger Akt phosphorylation than insulin in mammary gland epithelial cells. Phosphorylation of ERK1/2 was not influenced by insulin or IGF-1. Rather, in liver and mammary gland P-ERK1/2 appeared to correlate with estrous cycling, supporting that ERK1/2 has important physiological roles in these two organs. In short, these findings supported that the rat mammary gland epithelium expresses functional insulin and IGF-1 receptors and that phosphorylation of Akt as well as ERK1/2 may be of value in understanding the effects of exogenous insulin in the rat mammary gland and colon.
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Affiliation(s)
- Henning Hvid
- Department of Veterinary Disease Biology, Faculty of Life Sciences, University of Copenhagen, Denmark
- Pathology, Novo Nordisk A/S, Copenhagen, Denmark
| | | | - Rikke K. Kirk
- Histology and Delivery, Novo Nordisk A/S, Copenhagen, Denmark
| | - Inger Thorup
- Pathology, Novo Nordisk A/S, Copenhagen, Denmark
| | - Henrik E. Jensen
- Department of Veterinary Disease Biology, Faculty of Life Sciences, University of Copenhagen, Denmark
| | - Bo F. Hansen
- Insulin Biology, Novo Nordisk A/S, Copenhagen, Denmark
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Hvid H, Thorup I, Oleksiewicz MB, Sjögren I, Jensen HE. An alternative method for preparation of tissue sections from the rat mammary gland. ACTA ACUST UNITED AC 2011; 63:317-24. [DOI: 10.1016/j.etp.2010.02.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2009] [Revised: 01/29/2010] [Accepted: 02/15/2010] [Indexed: 11/29/2022]
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Hvid H, Ekstrøm CT, Vienberg S, Oleksiewicz MB, Klopfleisch R. Identification of stable and oestrus cycle-independent housekeeping genes in the rat mammary gland and other tissues. Vet J 2010; 190:103-8. [PMID: 20952231 DOI: 10.1016/j.tvjl.2010.09.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2010] [Revised: 08/24/2010] [Accepted: 09/01/2010] [Indexed: 10/18/2022]
Abstract
The function and development of the rat mammary gland is dependent on the oestrus cycle. Normalization of gene expression in mammary gland samples assessed by quantitative RT-PCR therefore requires housekeeping genes (HKGs) which are stably expressed during the oestrus cycle. mRNA expression of 10 HKGs was measured in the rat mammary gland at different phases of the oestrus cycle. In addition, mRNA expression of the HKGs was measured in a panel of other rat tissues comprising laser microdissected mammary gland alveolar lobules and interlobular connective tissue and macrodissected mammary gland, liver, skeletal muscle, colon and ovary samples. Expression and ranking of HKGs varied between tissues and oestrus cycle phases and several HKGs were necessary for normalization between samples. In the mammary gland samples, three HKGs (Sdha, Tbp, and Atp5b) were identified as the optimal combination of stably expressed genes across oestrus cycle phases. For normalization between samples from the entire panel of rat tissues, eight HKGs (Rps18, Eef1a1, B2m, Actb, Tbp, Hprt, Pgk1, and Sdha) were identified as the optimal combination. These HKGs are of general relevance for studies comparing gene expression between different rat tissues.
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Affiliation(s)
- Henning Hvid
- Department of Veterinary Disease Biology, University of Copenhagen, Denmark.
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Oleksiewicz MB, Bonnesen C, Hegelund AC, Lundby A, Holm GMN, Jensen MB, Krabbe JS. Comparison of intracellular signalling by insulin and the hypermitogenic AspB10 analogue in MCF-7 breast adenocarcinoma cells. J Appl Toxicol 2010; 31:329-41. [DOI: 10.1002/jat.1590] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2010] [Revised: 08/16/2010] [Accepted: 08/16/2010] [Indexed: 12/17/2022]
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Egerod FL, Brünner N, Svendsen JE, Oleksiewicz MB. PPARalpha and PPARgamma are co-expressed, functional and show positive interactions in the rat urinary bladder urothelium. J Appl Toxicol 2010; 30:151-62. [PMID: 19757489 DOI: 10.1002/jat.1481] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Some dual-acting PPARalpha + gamma agonists cause cancer in the rat urinary bladder, in some cases overrepresented in males, by a mechanism suggested to involve chronic stimulation of PPARalpha and PPARgamma, i.e. exaggerated pharmacology. By western blotting, we found that the rat urinary bladder urothelium expressed PPARalpha at higher levels than the liver and heart, and comparable to kidney. Urothelial expression of PPARgamma was above that of fat, heart, skeletal muscle and kidney. Male rats exhibited a higher PPARalpha/PPARgamma expression balance in the bladder urothelium than did female rats. Rats were treated by gastric gavage with rosiglitazone (PPARgamma agonist), fenofibrate (PPARalpha agonist) or a combination of rosiglitazone and fenofibrate for 7 days. In the urothelium, the transcription factor Egr-1 was induced to significantly higher levels in rats co-administered rosiglitazone and fenofibrate than in rats administered either rosiglitazone or fenofibrate alone. Egr-1 was also induced in the heart and liver of rats treated with fenofibrate, but a positive interaction between rosiglitazone and fenofibrate with regards to Egr-1 induction was only seen in the urothelium. Thus, in the rat urinary bladder urothelium, PPARalpha and PPARgamma were expressed at high levels, were functional and exhibited positive interactions. Interestingly, fenofibrate induced the peroxisome membrane protein PMP70 not only in liver, but also in the bladder urothelium, opening the possibility that oxidative stress may contribute to rat urothelial carcinogenesis by dual-acting PPARalpha + gamma agonists.
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Egerod FL, Svendsen JE, Hinley J, Southgate J, Bartels A, Brünner N, Oleksiewicz MB. PPAR alpha and PPAR gamma coactivation rapidly induces Egr-1 in the nuclei of the dorsal and ventral urinary bladder and kidney pelvis urothelium of rats. Toxicol Pathol 2010; 37:947-58. [PMID: 20008548 DOI: 10.1177/0192623309351723] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
To facilitate studies of the rat bladder carcinogenicity of dual-acting PPAR alpha+gamma agonists, we previously identified the Egr-1 transcription factor as a candidate carcinogenicity biomarker and developed rat models based on coadministration of commercially available specific PPAR alpha and PPAR gamma agonists. Immunohistochemistry for Egr-1 with a rabbit monoclonal antibody demonstrated that male vehicle-treated rats exhibited minimal urothelial expression and specifically, no nuclear signal. In contrast, Egr-1 was induced in the nuclei of bladder, as well as kidney pelvis, urothelia within one day (2 doses) of oral dosing of rats with a combination of 8 mg/kg rosiglitazone and 200 mg/kg fenofibrate (specific PPAR gamma and PPAR alpha agonists, respectively). These findings were confirmed by Western blotting using a different Egr-1 antibody. Egr-1 was induced to similar levels in the dorsal and ventral bladder urothelium, arguing against involvement of urinary solids. Egr-1 induction sometimes occurred in a localized fashion, indicating physiological microheterogeneity in the urothelium. The rapid kinetics supported that Egr-1 induction occurred as a result of pharmacological activation of PPAR alpha and PPAR gamma, which are coexpressed at high levels in the rat urothelium. Finally, our demonstration of a nuclear localization supports that the Egr-1 induced by PPAR alpha and PPAR gamma coactivation in the rat urothelium may be biologically active.
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Hvid H, Klopfleisch R, Vienberg S, Hansen BF, Thorup I, Jensen HE, Oleksiewicz MB. Unique expression pattern of the three insulin receptor family members in the rat mammary gland: dominance of IGF-1R and IRR over the IR, and cyclical IGF-1R expression. J Appl Toxicol 2010; 31:312-28. [DOI: 10.1002/jat.1627] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Henning Hvid
- Department of Veterinary Disease Biology; Faculty of Life Sciences; University of Copenhagen; Denmark
- Pathology; Novo Nordisk A/S; Copenhagen Denmark
| | | | - Sara Vienberg
- Insulin Biology; Novo Nordisk A/S; Copenhagen Denmark
| | - Bo F. Hansen
- Insulin Biology; Novo Nordisk A/S; Copenhagen Denmark
| | | | - Henrik E. Jensen
- Department of Veterinary Disease Biology; Faculty of Life Sciences; University of Copenhagen; Denmark
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Listov-Saabye N, Jensen MB, Kiehr B, Hansen EW, Svendsen JE, Lundby A, Holm GMN, Oleksiewicz MB. MCF-7 human mammary adenocarcinoma cells exhibit augmented responses to human insulin on a collagen IV surface. J Appl Toxicol 2009; 29:470-7. [PMID: 19338014 DOI: 10.1002/jat.1428] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Human mammary cell lines are extensively used for preclinical safety assessment of insulin analogs. However, it is essentially unknown how mitogenic responses can be optimized in mammary cell-based systems. We developed an insulin mitogenicity assay in MCF-7 human mammary adenocarcinoma cells, under low serum (0.1% FCS) and phenol red-free conditions, with 3H thymidine incorporation as endpoint. Based on EC50 values determined from 10-fold dilution series, beta-estradiol was the most potent mitogen, followed by human IGF-1, human AspB10 insulin and native human insulin. AspB10 insulin was significantly more mitogenic than native insulin, validating the ability of the assay to identify hypermitogenic human insulin analogs. With MCF-7 cells on a collagen IV surface, the ranking of mitogens was maintained, but fold mitogenic responses and dynamic range and steepness of dose-response curves were increased. Also, PI3K pathway activation by insulin was enhanced on a collagen IV surface. This study provided the first determination and ranking of the mitogenic potencies of standard reference compounds in an optimized MCF-7 assay. The optimized MCF-7 assay described here is of relevance for in vitro toxicological testing and carcinogenicity safety assessment of new insulin compounds.
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Affiliation(s)
- Nicolai Listov-Saabye
- Copenhagen University, Institute for Pharmacology and Pharmacotherapy, Universitetsparken 2, 2100 København Ø, Denmark
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Bonnesen C, Nelander GM, Hansen BF, Jensen P, Krabbe JS, Jensen MB, Hegelund AC, Svendsen JE, Oleksiewicz MB. Synchronization in G0/G1 enhances the mitogenic response of cells overexpressing the human insulin receptor A isoform to insulin. Cell Biol Toxicol 2009; 26:293-307. [PMID: 19898946 PMCID: PMC2896650 DOI: 10.1007/s10565-009-9142-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2009] [Accepted: 10/22/2009] [Indexed: 01/01/2023]
Abstract
Evaluating mitogenic signaling specifically through the human insulin receptor (IR) is relevant for the preclinical safety assessment of developmental insulin analogs. It is known that overexpression of IR sensitizes cells to the mitogenic effects of insulin, but it is essentially unknown how mitogenic responses can be optimized to allow practical use of such recombinant cell lines for preclinical safety testing. We constitutively overexpressed the short isoform of the human insulin receptor (hIR-A, exon 11-negative) in L6 rat skeletal myoblasts. Because the mitogenic effect of growth factors such as insulin is expected to act in G0/G1, promoting S-phase entry, we developed a combined topoinhibition + serum deprivation strategy to explore the effect of G0/G1 synchronization as an independent parameter in the context of serum deprivation, the latter being routinely used to reduce background in mitogenicity assays. G0/G1 synchronization significantly improved the mitogenic responses of L6-hIR cells to insulin, measured by 3H-thymidine incorporation. Comparison with the parental L6 cells using phospho-mitogen-activated protein kinase, phospho-AKT, as well as 3H-thymidine incorporation end points supported that the majority of the mitogenic effect of insulin in L6-hIR cells was mediated by the overexpressed hIR-A. Using the optimized L6-hIR assay, we found that the X-10 insulin analog was more mitogenic than native human insulin, supporting that X-10 exhibits increased mitogenic signaling through the hIR-A. In summary, this study provides the first demonstration that serum deprivation may not be sufficient, and G0/G1 synchronization may be required to obtain optimal responsiveness of hIR-overexpressing cell lines for preclinical safety testing.
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Egerod FL, Bartels A, Fristrup N, Borre M, Ørntoft TF, Oleksiewicz MB, Brünner N, Dyrskjøt L. High frequency of tumor cells with nuclear Egr-1 protein expression in human bladder cancer is associated with disease progression. BMC Cancer 2009; 9:385. [PMID: 19878561 PMCID: PMC2774864 DOI: 10.1186/1471-2407-9-385] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2009] [Accepted: 10/30/2009] [Indexed: 12/23/2022] Open
Abstract
Background Egr-1 (early growth response-1 transcription factor) has been proposed to be involved in invasion and metastasis processes of human bladder cancer, but Egr-1 protein expression levels in human bladder cancer have not been investigated. In the present study we investigated the expression levels of Egr-1 protein in early stages of human bladder cancer and correlated it to later progression. Methods Expression of Egr-1 protein in human bladder cancer was examined by immunohistochemistry, on a tissue microarray constructed from tumors from 289 patients with non-muscle invasive urothelial bladder cancer. Results The frequency of tumor cells with nuclear Egr-1 immunolabelling correlated to bladder cancer stage, grade and to later progression to muscle-invasive bladder cancer (T2-4). Stage T1 tumors exhibited significantly higher frequencies of tumor cells with nuclear Egr-1 immunolabelling than Ta tumors (P = 0.001). Furthermore, Kaplan-Meier survival analysis showed that a high frequency of tumor cells with nuclear Egr-1 immunolabelling was significantly associated with a higher risk of progression to stage T2-4 (log-rank test, P = 0.035). Tumor cells with nuclear Egr-1 immunolabelling were found to localize at the tumor front in some of the tumor biopsies. Conclusion The results from this study support a potential involvement of Egr-1 in the progression from non-muscle invasive bladder cancers to muscle invasive bladder cancer.
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Chopra B, Georgopoulos NT, Nicholl A, Hinley J, Oleksiewicz MB, Southgate J. Structurally diverse peroxisome proliferator-activated receptor agonists induce apoptosis in human uro-epithelial cells by a receptor-independent mechanism involving store-operated calcium channels. Cell Prolif 2009; 42:688-700. [PMID: 19614673 DOI: 10.1111/j.1365-2184.2009.00628.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
OBJECTIVES Peroxisome proliferator-activated receptors (PPARs) are implicated in epithelial cell proliferation and differentiation, but investigation has been confounded by potential off-target effects of some synthetic PPAR ligands. Our aim was to determine mechanisms underlying the pro-apoptotic effect of synthetic PPAR agonists in normal human bladder uro-epithelial (urothelial) cells and to reconcile this with the role of PPARs in urothelial cytodifferentiation. MATERIALS AND METHODS Normal human urothelial (NHU) cells were grown as non-immortal lines in vitro and exposed to structurally diverse agonists ciglitazone, troglitazone, rosiglitazone (PPARgamma), ragaglitazar (PPARalpha/gamma), fenofibrate (PPARalpha) and L165041 (PPARbeta/delta). RESULTS NHU cells underwent apoptosis following acute exposure to ciglitazone, troglitazone or ragaglitazar, but not fenofibrate, L165041 or rosiglitazone, and this was independent of ERK or p38 MAP-kinase activation. Pro-apoptotic agonists induced sustained increases in intracellular calcium, whereas removal of extracellular calcium altered the kinetics of ciglitazone-mediated calcium release from sustained to transient. Cell death was accompanied by plasma-membrane disruption, loss of mitochondrial membrane-potential and caspase-9/caspase-3 activation. PPARgamma-mediated apoptosis was unaffected following pre-treatment with PPARgamma antagonist T0070907 and was strongly attenuated by store-operated calcium channel (SOC) inhibitors 2-APB and SKF-96365. CONCLUSIONS Our results provide a mechanistic basis for the ability of some PPAR agonists to induce death in NHU cells and demonstrate that apoptosis is mediated via PPAR-independent mechanisms, involving intracellular calcium changes, activation of SOCs and induction of the mitochondrial apoptotic pathway.
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Affiliation(s)
- B Chopra
- Department of Biology, Jack Birch Unit of Molecular Carcinogenesis, University of York, York, UK
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Oleksiewicz MB, Southgate J, Iversen L, Egerod FL. Rat Urinary Bladder Carcinogenesis by Dual-Acting PPARalpha + gamma Agonists. PPAR Res 2009; 2008:103167. [PMID: 19197366 PMCID: PMC2632771 DOI: 10.1155/2008/103167] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2008] [Accepted: 10/07/2008] [Indexed: 12/25/2022] Open
Abstract
Despite clinical promise, dual-acting activators of PPARalpha and gamma (here termed PPARalpha+gamma agonists) have experienced high attrition rates in preclinical and early clinical development, due to toxicity. In some cases, discontinuation was due to carcinogenic effect in the rat urothelium, the epithelial layer lining the urinary bladder, ureters, and kidney pelvis. Chronic pharmacological activation of PPARalpha is invariably associated with cancer in rats and mice. Chronic pharmacological activation of PPARgamma can in some cases also cause cancer in rats and mice. Urothelial cells coexpress PPARalpha as well as PPARgamma, making it plausible that the urothelial carcinogenicity of PPARalpha+gamma agonists may be caused by receptor-mediated effects (exaggerated pharmacology). Based on previously published mode of action data for the PPARalpha+gamma agonist ragaglitazar, and the available literature about the role of PPARalpha and gamma in rodent carcinogenesis, we propose a mode of action hypothesis for the carcinogenic effect of PPARalpha+gamma agonists in the rat urothelium, which combines receptor-mediated and off-target cytotoxic effects. The proposed mode of action hypothesis is being explored in our laboratories, towards understanding the human relevance of the rat cancer findings, and developing rapid in vitro or short-term in vivo screening approaches to faciliate development of new dual-acting PPAR agonist compounds.
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Affiliation(s)
| | - Jennifer Southgate
- Jack Birch Unit of Molecular Carcinogenesis, Department of Biology, University of York, York YO10 5YW, UK
| | - Lars Iversen
- Biopharm Toxicology and Safety Pharmacology, Novo Nordisk A/S, 2760 Maalov, Denmark
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Egerod FL, Nielsen HS, Iversen L, Thorup I, Storgaard T, Oleksiewicz MB. Biomarkers for early effects of carcinogenic dual-acting PPAR agonists in rat urinary bladder urotheliumin vivo. Biomarkers 2008; 10:295-309. [PMID: 16240504 DOI: 10.1080/13547500500218682] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Small-molecule agonists of the peroxisome proliferator-activated receptor (PPAR) alpha and gamma isoforms (dual-acting PPAR agonists) can cause urothelial cancers in rodents. Rats were dosed orally for 16 days with bladder carcinogenic (ragaglitazar) as well as non-bladder carcinogenic (fenofibrate and rosiglitazone) PPAR agonists and protein changes were assayed in the urinary bladder urothelium by Western blotting. Dose levels reflected 10-20 x human exposure, and the ragaglitazar dose was in the carcinogenic range. Ragaglitazar induced expression of the transcription factor Egr-1, phosphorylation of the c-Jun transcription factor and phosphorylation of the ribosomal S6 protein were observed. These changes were also observed in rats dosed with either rosiglitazone or fenofibrate. However, the protein changes were stronger (Egr-1 induction) or of a longer duration (S6 phosphorylation) in ragaglitazar-treated animals. Animals co-administered fenofibrate (a specific PPARalpha agonist) and rosiglitazone (a specific PPARgamma agonist) exhibited Egr-1 and S6 protein changes more similar to those induced by ragaglitazar (a dual-acting PPARalpha/gamma agonist) than either fenofibrate or rosiglitazone alone. The findings suggest that ragaglitazar causes Egr-1, c-Jun and S6 protein changes in the urothelium by a mechanism involving PPARalpha as well as PPARgamma, and that the Egr-1, c-Jun and S6 protein changes might have potential biomarker value.
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Affiliation(s)
- F L Egerod
- Preclinical Development, Novo Nordisk A/S, Maalov, Denmark
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Oleksiewicz MB, Schaal-Jensen R, Kiehr B, Krabbe JS, Sommer C. Preclinical toxicity biomarkers for combination treatment with clotting factors rFXIII and rFVIIa. Biomarkers 2008; 12:424-44. [PMID: 17564847 DOI: 10.1080/13547500701308597] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Combination treatment with the clotting factors recombinant activated factor VII (rFVIIa), serine protease, and recombinant factor XIII (rFXIII), protransglutaminase, is being explored for haemostatic therapy. We performed a single-dose toxicology study in the cynomolgus monkey, with four dose groups receiving 0.1 + 0.34 mg kg(-1) (group 1), 0.33 + 1.12 mg kg(-1) (group 2), 1.67 + 5.60 mg kg(-1) (group 3) and 5.00 + 16.80 mg kg(-1) (group 4) of a rFVIIa + rFXIII combination. In the three lower dose groups, no clinical, histopathological or blood chemistry changes were observed. In group 4, the animals died at 4 h post-dosing, with histopathology revealing a systemic coagulopathy resembling, but distinct from, disseminated intravascular coagulation. Due to the absence of toxicity warning signs, toxicity biomarkers were identified by a Western blot-based screening of approximately 20 plasma proteins known to be involved in the clotting cascade. Three of the examined proteins were specifically affected by rFVIIa + rFXIII treatment. Fibronectin and fibrinogen exhibited dose-dependent reductions from less than 10% reduction (group 2) to more than 90% reduction (group 4). These reductions were reversible, and specific. For vitronectin, a dose-dependent conversion to the 65-kDa form was found to occur in groups 3 and 4. Thus, fibrinogen, fibronectin and vitronectin represent the first biomarkers for clotting factor toxicity.
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Oleksiewicz MB, Kjeldal HO, Klenø TG. Identification of stool proteins in C57BL/6J mice by two-dimensional gel electrophoresis and MALDI-TOF mass spectrometry. Biomarkers 2008; 10:29-40. [PMID: 16097391 DOI: 10.1080/13547500500038775] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Gastrointestinal disease is a major cause of mortality in humans and animals, and the detection of disease-associated protein in stool is an established diagnostic method in this context. Yet, no data currently exists about the protein composition of mammalian faeces. Using a newly developed two-dimensional (2D) gel method, 28 of the most abundant proteins in murine faeces were identified. Mammalian faeces contains protein from multiple species (from the individual, from gastrointestinal bacteria, from food, etc.). Yet, it was found that the majority of mouse stool proteins were of mouse origin, with a minority of proteins being derived from food (in particular soybean glycinin and conglycinin) and bacteria (flagellin). Most mouse proteins were proteases and saccharidases derived from the exocrine pancreas. In addition, two unexpected mouse proteins were identified: one was a newly described mucin-like protein from intestinal goblet cells (FcgammaBP); the other was the secreted form of carbonic anhydrase (type VI) from salivary gland. The data suggest that 2D analysis of faecal protein is likely to provide meaningful information about the physiological stage of the gastrointestinal tract. Compared with studies based on biopsies, faecal protein analysis may reduce the number of laboratory animals, and might also allow quicker bridging from animal studies to humans, where biopsy material is more difficult to obtain and is less relevant for general practice use.
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Affiliation(s)
- M B Oleksiewicz
- Department of Virology and Molecular Toxicology, Novo Nordisk A/S, Novo Nordisk Park, Måløv, Denmark.
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Stadejek T, Oleksiewicz MB, Scherbakov AV, Timina AM, Krabbe JS, Chabros K, Potapchuk D. Definition of subtypes in the European genotype of porcine reproductive and respiratory syndrome virus: nucleocapsid characteristics and geographical distribution in Europe. Arch Virol 2008; 153:1479-88. [DOI: 10.1007/s00705-008-0146-2] [Citation(s) in RCA: 132] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2008] [Accepted: 05/22/2008] [Indexed: 11/29/2022]
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Chopra B, Hinley J, Oleksiewicz MB, Southgate J. Trans-Species Comparison of PPAR and RXR Expression by Rat and Human Urothelial Tissues. Toxicol Pathol 2008; 36:485-95. [DOI: 10.1177/0192623308315672] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Because some investigational peroxisome proliferator-activated receptors (PPAR) agonists cause tumors in the lower urinary tract of rats, we compared normal human and rat urothelium in terms of PPAR and retinoid X receptor (RXR) expression and proliferation-associated phenotypes. In situ, few human but most rat urothelial cells were Ki67 positive, indicating fundamental differences in cell cycle control. Rat and human urothelia expressed all 3 PPAR and the RXRα and RXRβ isoforms in a predominantly nuclear localization, indicating that they may be biologically active. However, immunolocalization differences were observed between species. First, whereas PPARα and PPARβ/δ were expressed throughout the human bladder or ureteric urothelium, in the rat urothelium PPARα was primarily, and PPARβ/δ exclusively, restricted to superficial cells. Second, RXRβ was restricted to intermediate and superficial layers of the human urothelium but tended to be absent from the rat superficial cells. Third, PPARγ expression was present throughout the urothelia of both species but was most intense in the superficial human urothelium. Species differences were also observed in the expression of PPAR and RXR isoforms between cultured rat and human urothelial cells and in the smooth muscle. Our findings highlight the unique coexpression of multiple PPAR and RXR isoforms by urothelium and suggest that species differences in PPAR function between rat and human urothelia may be explored in an in vitro setting.
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Affiliation(s)
- Bikramjit Chopra
- Jack Birch Unit of Molecular Carcinogenesis, Department of Biology, University of York, York, Y010 5YW, UK
| | - Jennifer Hinley
- Jack Birch Unit of Molecular Carcinogenesis, Department of Biology, University of York, York, Y010 5YW, UK
| | | | - Jennifer Southgate
- Jack Birch Unit of Molecular Carcinogenesis, Department of Biology, University of York, York, Y010 5YW, UK
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27
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Schaal-Jensen R, Kiehr B, Boesen HT, Krabbe JS, Sommer C, Jacobsen H, Oleksiewicz MB. Characterization of high molecular weight plasma protein complexes induced by clotting factor rFXIII-treatment in the cynomolgus monkey. J Thromb Haemost 2007; 5:2070-8. [PMID: 17650079 DOI: 10.1111/j.1538-7836.2007.02695.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND In cynomolgus monkeys, suprapharmacological doses of clotting recombinant factor XIII (rFXIII) cause a generalized coagulopathy, associated with formation of circulating high molecular weight protein complexes (HMEX). HMEX consist of plasma protein substrates cross-linked by FXIII transglutaminase activity. OBJECTIVE To characterize HMEX, with a view to develop safety biomarker assays. METHODS Cynomolgus monkeys received single i.v. injections with vehicle or rFXIII at 1, 3 and 10 mg kg(-1). Plasma HMEX were analyzed by sodium dodecylsulfate-polyacrylmide gel electrophoresis, silver staining, Western blotting and quantitative dissociation-enhanced lanthanide fluoroimmunoassay. Plasma FXIII antigen was analyzed by quantitative ELISA. Human HMEX were made in vitro, by spiking plasma with thrombin-activated rFXIII. RESULTS Maximal circulating HMEX levels were reached within 1 h of rFXIII treatment, and remained stable over 24 h. HMEX above 250 kDa contained fibrinogen alpha-chains and fibronectin. Fibrinogen gamma-chain was detected only in HMEX below 250 kDa. The total plasma concentration of HMEX was in the low microg mL(-1) range, distributed on less than 20 main species. Human and cynomolgus HMEX were similar. HMEX formation increased with rFXIII dose in a disproportionate manner, with 3-fold and fortyfold increases in HMEX exposure associated with rFXIII dose increments from 1 to 3 and 3 to 10 mg kg(-1), respectively. CONCLUSIONS The disproportionate HMEX formation parallels the steep toxicity dose response previously reported for rFXIII in cynomolgus monkeys, supporting a mechanistical role for HMEX in the generalized coagulopathy seen in rFXIII toxicity. Our findings support that HMEX constitute candidate (potential) safety biomarkers in rFXIII treatment.
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Abstract
BACKGROUND Fluorescence-activated cell sorting (FACS) is an attractive technique for gene or protein expression studies in rare cell populations. For cell types where specific surface markers are not known, intracellular markers can be used. However, this approach is currently held to be difficult, as the required fixation and permeabilization may cause protein modification and RNA degradation. METHODS AND RESULTS Using the rat thyroid gland as model, rare (parafollicular) and frequent (follicular) endocrine cell types were sorted based on immunostaining for intracellular calcitonin peptide and thyroglobulin protein expression. The sorted cells were compatible with Western blot analysis of proteins, immunoassay detection of calcitonin peptide hormone and RT-PCR. CONCLUSION We developed a robust FACS protocol that allows flow sorting of rare cells from dissociated organ material, based on intracellular markers. Our FACS protocol is compatible with downstream analysis of proteins, peptides, and mRNA in the sorted cells.
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Affiliation(s)
- Ulrik Moerch
- Department of Virology and Molecular Toxicology, Novo Nordisk A/S, Maaloev, Denmark
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Stadejek T, Oleksiewicz MB, Potapchuk D, Podgórska K. Porcine reproductive and respiratory syndrome virus strains of exceptional diversity in eastern Europe support the definition of new genetic subtypes. J Gen Virol 2006; 87:1835-1841. [PMID: 16760385 DOI: 10.1099/vir.0.81782-0] [Citation(s) in RCA: 123] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Porcine reproductive and respiratory syndrome virus (PRRSV) ORF5 and ORF7 sequences from Belarus were found to be of the European (EU) genotype, but grouped separately from all other EU genotype sequences described so far, including live-attenuated EU genotype PRRSV vaccines and Italian EU genotype sequences, some of which have been associated with reduced vaccine efficacy. Also, the Belarusian EU-PRRSV exhibited extreme ORF7 size polymorphism, ranging from 375 nt (the smallest EU genotype ORF7 yet described) to 393 nt (the largest ORF7 yet described for any arterivirus). With the Belarusian sequences, the diversity of EU genotype PRRSV now exceeds that of the North American (US) genotype PRRSV, suggesting a European origin of PRRSV. Finally, a very sharp geographical demarcation of highly diverse EU genotype PRRSV was observed along the eastern Polish border. The new Belarusian sequences have relevance for vaccine and diagnostic-antigen design and show that sequence analysis of PRRSV from more eastern parts of Europe may offer further insights into the emergence and evolution of PRRSV.
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Affiliation(s)
- T Stadejek
- National Veterinary Research Institute, Al. Partyzantów 57, 24-100 Puławy, Poland
| | - M B Oleksiewicz
- Novo Nordisk A/S, Virology and Molecular Toxicology, Novo Nordisk Park, 2760 Måløv, Denmark
| | - D Potapchuk
- S. N. Vyshelesskij Institute of Experimental Veterinary Medicine, National Academy of Sciences of Belarus, 2 Vyshelesskij Street, Minsk 223020, Belarus
| | - K Podgórska
- National Veterinary Research Institute, Al. Partyzantów 57, 24-100 Puławy, Poland
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Stadejek T, Mittelholzer C, Oleksiewicz MB, Paweska J, Belák S. Highly diverse type of equine arteritis virus (EAV) from the semen of a South African donkey: short communication. Acta Vet Hung 2006; 54:263-70. [PMID: 16841763 DOI: 10.1556/avet.54.2006.2.12] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Equine arteritis virus (EAV) was detected by RT-nested PCR in semen samples from a naturally infected South African donkey. Sequence analysis of the amplified ORF5 fragment revealed only 60 to 70% nucleotide identity to a panel of EAV reference sequences. The unique donkey EAV sequence was also found to be stable during passage in horses. The sequence data reported in this study indicate that the South African donkey variant might represent a new genotype of EAV. The distinct genetic properties of the South African asinine strain of EAV suggest a divergent evolution of this arterivirus in various host species or, alternatively, a possible role for African donkeys in the emergence of EAV in horses.
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Affiliation(s)
- T Stadejek
- Department of Swine Diseases, The National Veterinary Research Institute, 24-100 Puławy, Partyzantów 57, Poland.
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Moerch U, Haahr Hansen M, Vest Hansen NJ, Rasmussen LK, Oleksiewicz MB, Frandsen TP, Haurum JS, Bregenholt S. Allergen-specific polyclonal antibodies reduce allergic disease in a mouse model of allergic asthma. Int Arch Allergy Immunol 2006; 140:261-9. [PMID: 16699287 DOI: 10.1159/000093283] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2005] [Accepted: 01/10/2006] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Recombinant allergen-specific immunoglobulin G (IgG) antibody therapy can reduce allergic asthma symptoms by inhibiting the immunoglobulin E (IgE)-mediated allergic response. This study investigated the effect of intranasally administered allergen-specific monoclonal (mAb) and polyclonal (pAb) antibody on airway inflammation and hyperresponsiveness (AHR) in a mouse model of human asthma. METHODS Ovalbumin (OVA)-specific IgG2b antibodies were generated by phage display using spleens from OVA-immunized mice, and screening against OVA and finally expressed in CHO cells. Sensitized mice were treated intranasally with either a recombinant anti-OVA mAb (gc32) or a polyclonal preparation comprising seven selected antibodies (including gc32). Control mice received diluent only, OVA only, a control polymeric IgG or dexamethasone. Following challenge with nebulized OVA, investigators assessed airway inflammation by histology and cellular composition of the bronchoalveolar fluid, and methacholine-induced airway hyperresponsiveness (AHR). Serum levels of total and OVA-specific IgE were measured by ELISA. RESULTS Sensitized mice developed airway inflammation and AHR in response to OVA challenge. Intranasally administered OVA-specific murine polyclonal or monoclonal IgG2b antibodies both reduced OVA-induced lung inflammation. Polyclonal, but not anti-OVA mAb, also reduced AHR and eosinophil influx into the airway lumen. Both anti-OVA antibody preparations reduced levels of specific IgE with no effect on total IgE levels. CONCLUSIONS Intranasal treatment with allergen-specific pAb reduces pulmonary inflammation and AHR in a mouse model of allergic asthma, but allergen-specific mAb reduces inflammation only. Allergen-specific recombinant pAb offers a potentially valuable therapeutic approach to the management of allergic asthma.
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Meijer PJ, Andersen PS, Haahr Hansen M, Steinaa L, Jensen A, Lantto J, Oleksiewicz MB, Tengbjerg K, Poulsen TR, Coljee VW, Bregenholt S, Haurum JS, Nielsen LS. Isolation of Human Antibody Repertoires with Preservation of the Natural Heavy and Light Chain Pairing. J Mol Biol 2006; 358:764-72. [PMID: 16563430 DOI: 10.1016/j.jmb.2006.02.040] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2005] [Revised: 02/13/2006] [Accepted: 02/14/2006] [Indexed: 10/25/2022]
Abstract
The humoral immune system in higher vertebrates is unique in its ability to generate highly diverse antibody responses against most pathogens as well as against certain malignancies. Several technologies have been developed to exploit this vast source of potentially therapeutic antibodies, including hybridoma technology, phage display and yeast display. Here, we present a novel, high-throughput technology (the Symplex Technology) for rapid direct cloning and identification of human antigen-specific high-affinity antibodies from single antibody-producing cells of immune individuals. The utility of the technology was demonstrated by isolation of diverse sets of unique high-affinity antibodies against tetanus toxoid and influenza virus from immunized volunteers. Hence, the Symplex Technology is a new method for the rapid isolation of high-affinity antibodies directly from humans.
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Affiliation(s)
- Per-Johan Meijer
- Symphogen A/S, Elektrovej, Building 375, DK-2800 Lyngby, Denmark
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Oleksiewicz MB, Stadejek T, Maćkiewicz Z, Porowski M, Pejsak Z. Discriminating between serological responses to European-genotype live vaccine and European-genotype field strains of porcine reproductive and respiratory syndrome virus (PRRSV) by peptide ELISA. J Virol Methods 2005; 129:134-44. [PMID: 15992937 DOI: 10.1016/j.jviromet.2005.05.017] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2005] [Revised: 05/16/2005] [Accepted: 05/17/2005] [Indexed: 11/17/2022]
Abstract
A peptide ELISA was developed based on an immunodominant and hypervariable epitope in the ORF4 envelope glycoprotein of porcine reproductive and respiratory syndrome virus (PRRSV). The peptide sequence was derived from the Porcilis live-attenuated PRRSV vaccine strain (genotype 1, European). Antibodies induced by the field PRRSVs currently circulating in Poland were not detected by the Porcilis ORF4 peptide ELISA. In contrast, Porcilis-vaccinated animals seroconverted in the ORF4 peptide ELISA at 21 days post-vaccination. Maximal titers were seen 30-92 days post-vaccination; most sera had endpoint titers between 1:1000 and 1:100,000. In a paired format, where sera were assayed in two separate ELISAs using ORF4 peptides derived from the genetically very closely related Porcilis and Lelystad PRRSV strains, it was possible to differentiate between antibodies induced by these two viruses. The Porcilis and Lelystad ORF4 peptide ELISAs had sensitivities of 89 and 100%, respectively. Thus, ORF4 peptide ELISA afforded specific detection of antibodies induced by an European-genotype live-attenuated vaccine PRRSV strain (Porcilis). The results suggest that specific ORF4 peptide ELISAs can be custom-made for European-genotype PRRSV strains, using general peptide design criteria described in this work. Thus, ORF4 ELISAs may be generally useful, to monitor safety and operational aspects of European-genotype live-attenuated PRRSV vaccine virus use in populations with circulating field European-genotype PRRSVs.
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Affiliation(s)
- Martin B Oleksiewicz
- Novo Nordisk A/S, Virology and Molecular Toxicology, Novo Nordisk Park, Måløv, Denmark
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Abstract
In humans and cattle, multiple injections of murine monoclonal antibodies (m-mAbs) induce anti-mouse antibody responses. The objectives of the present study were to investigate whether a similar response could be seen when pigs were subjected to m-mAb therapy, and to study the kinetics of such a response. In two separate animal experiments, long-term treatment was performed with m-mAbs at low-dose levels and therapeutic levels, respectively. Two specific m-mAbs that recognized cognate antigen in the pigs (CD4 and CD8 surface antigens on T-lymphocytes) and two irrelevant control m-mAbs having no cognate antigen in the pigs were used. Enzyme-linked immunosorbent assays (ELISA) were used to quantitate the circulating m-mAbs, as well as the induced pig anti-mouse antibodies (PAMA), in serum samples from m-mAb-treated pigs. As expected, we generally saw vigorous PAMA responses within 10 days after the start of m-mAb treatment with the specific m-mAbs. However, the different mAbs showed striking differences in the kinetics and levels of PAMA responses, differences that might be ascribed to the m-mAb formulation and epitope specificity. In conclusion, treatment of pigs with m-mAbs against T-cell surface antigens induced rapid PAMA responses. This may influence and possibly decrease the effect of the m-mAb treatment by narrowing the time period where m-mAbs can efficiently be used for cell depletion.
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Affiliation(s)
- Louise Lohse
- Danish Institute for Food and Veterinary Research, Department of Virology, Lindholm, Kalvehave, Denmark
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35
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Oleksiewicz MB, Snijder EJ, Normann P. Phage display of the Equine arteritis virus nsp1 ZF domain and examination of its metal interactions. J Virol Methods 2004; 119:159-69. [PMID: 15158598 DOI: 10.1016/j.jviromet.2004.04.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2004] [Revised: 04/01/2004] [Accepted: 04/06/2004] [Indexed: 10/26/2022]
Abstract
A putative zinc finger (ZF) domain in the Equine arteritis virus (EAV) nsp1 protein was described recently to be required for viral transcription. The nsp1 ZF (50 aa) was expressed on the surface of M13KE gIII phage, fused to the N terminus of the phage pIII protein. To evaluate the functionality of the ZF domain, a binding assay was developed, based on the use of immobilized Ni(2+) ions (Ni-NTA). Phages displaying ZF bound significantly better to Ni-NTA than did phages displaying negative-control peptides, which also contained metal-coordinating residues. Also, binding of ZF-displaying phages could be inhibited by an anti-nsp1 serum, or by mutation of residues predicted to be important for zinc coordination. Finally, binding was abolished by low concentrations (0.1%) Tween 20, and rescued by including Zn(2+), Ni(2+) or Cu(2+), but not Mg(2+), in the binding buffer, suggesting that formation of secondary structure was involved in binding of the ZF to Ni-NTA. These findings provide the first experimental evidence that the putative nsp1 ZF domain can coordinate divalent metal ions, and that this property is associated with the secondary structure of the domain. The Ni-NTA binding assay developed in the present study may have general applications in the study of other ZF domains.
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Affiliation(s)
- M B Oleksiewicz
- Dept. of Applied Trinomics, Novo Nordisk Park, Måløv, Denmark.
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Oleksiewicz MB, Rasmussen TB, Normann P, Uttenthal A. Determination of the sequence of the complete open reading frame and the 5'NTR of the Paderborn isolate of classical swine fever virus. Vet Microbiol 2003; 92:311-25. [PMID: 12554101 DOI: 10.1016/s0378-1135(02)00424-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The classical swine fever (CSF) epidemic in the Netherlands in 1997-1998 lasted 14 months, during which 429 infected and 1300 at risk herds were culled, at an estimated economical cost of 2 billion US dollars. Despite the overwhelming scale of the epizootic, the CSF virus (CSFV) strain causing the outbreak has remained largely uncharacterized. The Dutch epizootic is epidemiologically linked to a small CSF outbreak in 1997, in Paderborn in Germany. E2 and partial 5' NTR sequencing has shown that the index Paderborn isolate, and several Dutch isolates taken during the 1997-1998 epizootic, are virtually identical, confirming that the Paderborn isolate triggered the Dutch outbreak, and furthermore showing that this single isolate was stable throughout the whole Dutch outbreak (the above reviewed in [C. Terpstra, A. J. de Smit, Veterinary Microbiol. 77 (2000) 3-15]). We determined the nucleotide sequence of the 5' NTR (by 5' RACE) and the complete open reading frame of the Paderborn isolate (GenBank AY072924). Our sequence was identical to previously published partial 5'NTR and E2 sequences for the index Paderborn 1997 and Dutch 1997 (Venhorst) isolates, confirming the identity of the virus we sequenced. Phylogenetic analysis based on the complete open reading frame showed that Paderborn is genetically very different from common European laboratory reference strains. Neutralization studies showed that Paderborn is also antigenically very different from common laboratory strains such as Alfort 187. Paderborn is the only recent European CSFV field isolate for which a complete sequence is available, and given Paderborns genetic and antigenic uniqueness, the Paderborn sequence may have practical use for diagnostic and vaccine antigen development.
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Affiliation(s)
- Martin B Oleksiewicz
- Department of Virology, Danish Veterinary Institute, Lindholm DK-4771 Kalvehave, Denmark
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Uttenthal A, Storgaard T, Oleksiewicz MB, de Stricker K. Experimental infection with the Paderborn isolate of classical swine fever virus in 10-week-old pigs: determination of viral replication kinetics by quantitative RT-PCR, virus isolation and antigen ELISA. Vet Microbiol 2003; 92:197-212. [PMID: 12523982 DOI: 10.1016/s0378-1135(02)00364-4] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
We performed experimental infection in 10-week-old pigs with the Paderborn isolate of classical swine fever virus (CSFV). Despite being epidemiologically linked to the major CSFV outbreak in The Netherlands in 1997, the in vivo replication kinetics of this isolate have to our knowledge not been described in detail previously. We found that oronasal infection with 10(4.7) TCID(50) produced mortality in three out of five pigs after 29-31 days, and severe clinical symptoms in one out of five pigs, while one out of five pigs exhibited no clinical symptoms. At this infection dose, pigs had viral RNA (monitored by quantitative reverse transcription (RT)-PCR) in serum as soon as 2 days post-infection, and excretion of infectious virus (monitored by sentinel pigs) appeared to be virtually concomitant with viremia onset. While virus RNA was cleared from the serum of most pigs after 1-2 weeks, some pigs had viral RNA in serum for more than 30 days, and exhibited only mild clinical symptoms. We observed an excellent correlation between clinical symptoms and viral RNA loads in serum, while serum antibody levels were low. Clinically affected pigs had up to 1000-fold higher serum viral RNA loads than did pigs without clinical symptoms. At this level of infection, and this age group, the Paderborn isolate exhibited a strikingly wide range of replication patterns, which might be relevant to the spread of the virus through susceptible pig populations, and the severity of the 1997-1998 outbreak.
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Affiliation(s)
- Ase Uttenthal
- Danish Veterinary Institute, Lindholm, DK-4771, Kalvehave, Denmark.
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Nielsen HS, Liu G, Nielsen J, Oleksiewicz MB, Bøtner A, Storgaard T, Faaberg KS. Generation of an infectious clone of VR-2332, a highly virulent North American-type isolate of porcine reproductive and respiratory syndrome virus. J Virol 2003; 77:3702-11. [PMID: 12610145 PMCID: PMC149535 DOI: 10.1128/jvi.77.6.3702-3711.2003] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A full-length cDNA clone of the prototypical North American porcine reproductive and respiratory syndrome virus (PRRSV) isolate VR-2332 was assembled in the plasmid vector pOK(12). To rescue infectious virus, capped RNA was transcribed in vitro from the pOK(12) clone and transfected into BHK-21C cells. The supernatant from transfected monolayers were serially passaged on Marc-145 cells and porcine pulmonary alveolar macrophages. Infectious PRRSV was recovered on Marc-145 cells as well as porcine pulmonary macrophages; thus, the cloned virus exhibited the same cell tropism as the parental VR-2332 strain. However, the cloned virus was clearly distinguishable from the parental VR-2332 strain by an engineered marker, a BstZ17I restriction site. The full-length cDNA clone had 11 nucleotide changes, 2 of which affected coding, compared to the parental VR-2332 strain. Additionally, the transcribed RNA had an extra G at the 5' end. To examine whether these changes influenced viral replication, we examined the growth kinetics of the cloned virus in vitro. In Marc-145 cells, the growth kinetics of the cloned virus reflected those of the parental isolate, even though the titers of the cloned virus were consistently slightly lower. In experimentally infected 5.5-week-old pigs, the cloned virus produced blue discoloration of the ears, a classical clinical symptom of PRRSV. Also, the seroconversion kinetics of pigs infected with the cloned virus and VR-2332 were very similar. Hence, virus derived from the full-length cDNA clone appeared to recapitulate the biological properties of the highly virulent parental VR-2332 strain. This is the first report of an infectious cDNA clone based on American-type PRRSV. The availability of this cDNA clone will allow examination of the molecular mechanisms behind PRRSV virulence and attenuation, which might in turn allow the production of second-generation, genetically engineered PRRSV vaccines.
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Affiliation(s)
- H S Nielsen
- Danish Veterinary Institute, Lindholm, Denmark
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40
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Stadejek T, Stankevicius A, Storgaard T, Oleksiewicz MB, Belák S, Drew TW, Pejsak Z. Identification of radically different variants of porcine reproductive and respiratory syndrome virus in Eastern Europe: towards a common ancestor for European and American viruses. J Gen Virol 2002; 83:1861-1873. [PMID: 12124450 DOI: 10.1099/0022-1317-83-8-1861] [Citation(s) in RCA: 136] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
We determined 22 partial porcine reproductive and respiratory syndrome virus (PRRSV) ORF5 sequences, representing pathogenic field strains mainly from Poland and Lithuania, and two currently available European-type live PRRSV vaccines. Also, the complete ORF7 of two Lithuanian and two Polish strains was sequenced. We found that Polish, and in particular Lithuanian, PRRSV sequences were exceptionally different from the European prototype, the Lelystad virus, and in addition showed a very high national diversity. The most diverse present-day European-type PRRSV sequences were from Poland (2000) and Lithuania (2000), and exhibited only 72.2% nucleotide identity in the investigated ORF5 sequence. While all sequences determined in the present study were clearly of European type, inclusion of the new Lithuanian sequences in the genealogy resulted in a common ancestor for the European type virus significantly closer to the American-type PRRSV than previously seen. In addition, the length of the ORF7 of the Lithuanian strains was 378 nucleotides, and thus intermediate between the sizes of the prototypical EU-type (387 nucleotides) and US-type (372 nucleotides) ORF7 lengths. These findings for the Lithuanian PRRSV sequences provide support for the hypothesis that the EU and US genotypes of PRRSV evolved from a common ancestor. Also, this is the first report of ORF7 protein size polymorphism in field isolates of EU-type PRRSV.
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Affiliation(s)
- T Stadejek
- National Veterinary Research Institute, Al. Partyzantów 57, 24-100 Puławy, Poland1
| | - A Stankevicius
- National Veterinary Research Institute, Al. Partyzantów 57, 24-100 Puławy, Poland1
| | - T Storgaard
- Danish Veterinary Institute for Virus Research, Lindholm, 4771 Kalvehave, Denmark2
| | - M B Oleksiewicz
- Danish Veterinary Institute for Virus Research, Lindholm, 4771 Kalvehave, Denmark2
| | - S Belák
- National Veterinary Institute, Department of Virology, Biomedical Center, Box 585, S-751 23 Uppsala, Sweden3
| | - T W Drew
- Veterinary Laboratories Agency (Weybridge), Addlestone, Surrey KT15 3NB, UK4
| | - Z Pejsak
- National Veterinary Research Institute, Al. Partyzantów 57, 24-100 Puławy, Poland1
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Forsberg R, Storgaard T, Nielsen HS, Oleksiewicz MB, Cordioli P, Sala G, Hein J, Bøtner A. The genetic diversity of European type PRRSV is similar to that of the North American type but is geographically skewed within Europe. Virology 2002; 299:38-47. [PMID: 12167339 DOI: 10.1006/viro.2002.1450] [Citation(s) in RCA: 116] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Porcine reproductive and respiratory syndrome virus (PRRSV) is a recently emerged pathogen. Two PRRSV genotypes exist, North American and European, which are only 55-70% identical at the nucleotide level. Previous studies have shown high nucleotide diversity in the North American genotype and low nucleotide diversity in the European genotype. Here, we analyzed the ORF5 and ORF7 genes for a large number of new European type PRRSV isolates in conjunction with existing database sequences. This new analysis showed that contrary to previous assumptions, genetic diversity is at least as high in the European genotype as in the North American genotype. Furthermore, we showed that genetic diversity of European type PRRSV has a marked geographical pattern, with exceptionally high genetic diversity among Italian sequences. The geographical pattern of diversity in relation to the epidemiology of PRRSV in Europe is discussed. Discrepancies between ORF5- and ORF7-based genealogies were observed, and further analysis of the data set confirmed the presence of recombination. We were therefore able to report the first observation of recombination in wild-type isolates of European genotype PRRSV.
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Affiliation(s)
- Roald Forsberg
- Department of Ecology and Genetics, University of Aarhus, Denmark
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42
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Oleksiewicz MB, Bøtner A, Normann P. Porcine B-cells recognize epitopes that are conserved between the structural proteins of American- and European-type porcine reproductive and respiratory syndrome virus. J Gen Virol 2002; 83:1407-1418. [PMID: 12029156 DOI: 10.1099/0022-1317-83-6-1407] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
By selecting phage display libraries with immune sera from experimentally infected pigs, porcine B-cell epitopes in the open reading frame (ORF) 2, 3, 5 and 6 proteins of European-type porcine reproductive and respiratory syndrome virus (PRRSV) were identified. The sequences of all the epitopes were well conserved in European-type PRRSV and even between European- and American-type PRRSV. Accordingly, sera from pigs infected with American-type PRRSV cross-reacted with the European-type epitopes. Thus, this study showed, for the first time, the presence of highly conserved epitopes in the matrix protein and envelope glycoproteins of PRRSV. ORF5 and 6 epitopes localized to protein parts that are predicted to be hidden in PRRSV virions. In contrast, ORF2 and 3 epitopes localized to putative protein ectodomains. Due to the interesting localization, the sequence surrounding the ORF2 and 3 epitopes was subjected to closer scrutiny. A heptad motif, VSRRIYQ, which is present in a single copy in ORF2 and 3 proteins, was identified; this arrangement is completely conserved in all European-type PRRSV sequences available. The VSRRIYQ repeat motif colocalized closely with one of the ORF2 epitopes and secondary structure modelling showed that this segment of the ORF2 protein could form an amphipathic helix. Intriguingly, a mutation associated with virulence/attenuation of an American vaccine strain of PRRSV also localized to this ORF2 protein segment and affected the hydrophobic face of the predicted amphipathic helix. Further work is needed to determine whether these findings delineate a functional domain in the PRRSV ORF2 protein.
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Affiliation(s)
- M B Oleksiewicz
- The Danish Veterinary Institute for Virus Research, Lindholm, 4771 Kalvehave, Denmark1
| | - A Bøtner
- The Danish Veterinary Institute for Virus Research, Lindholm, 4771 Kalvehave, Denmark1
| | - P Normann
- The Danish Veterinary Institute for Virus Research, Lindholm, 4771 Kalvehave, Denmark1
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Oleksiewicz MB, Kristensen B, Ladekjaer-Mikkelsen AS, Nielsen J. Development of a rapid in vitro protein refolding assay which discriminates between peptide-bound and peptide-free forms of recombinant porcine major histocompatibility class I complex (SLA-I). Vet Immunol Immunopathol 2002; 86:55-77. [PMID: 11943330 DOI: 10.1016/s0165-2427(02)00015-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The extracellular domains of swine leukocyte antigen class I (SLA-I, major histocompatibility complex protein class I) were cloned and sequenced for two haplotypes (H4 and H7) which do not share any alleles based on serological typing, and which are the most important in Danish farmed pigs. The extracellular domain of SLA-I was connected to porcine beta2 microglobulin by glycine-rich linkers. The engineered single-chain proteins, consisting of fused SLA-I and beta2 microglobulin, were overexpressed as inclusion bodies in Escherichia coli. Also, variants were made of the single-chain proteins, by linking them through glycine-rich linkers to peptides representing T-cell epitopes from classical swine fever virus (CSFV) and foot-and-mouth disease virus (FMDV). An in vitro refold assay was developed, using a monoclonal anti-SLA antibody (PT85A) to gauge refolding. The single best-defined, SLA-I restricted porcine CD8(+) T-cell epitope currently known is a 9-residue peptide from the polyprotein of CSFV (J. Gen. Virol. 76 (1995) 3039). Based on results with the CSFV epitope and two porcine haplotypes (H4 and H7), the in vitro refold assay appeared able to discriminate between peptide-free and peptide-occupied forms of SLA-I. It remains to be seen whether the rapid and technically very simple in vitro refold assay described here will prove generally applicable for the screening of virus-derived peptides for SLA-I binding.
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Affiliation(s)
- M B Oleksiewicz
- Danish Veterinary Institute for Virus Research, 4771 Kalvehave, Lindholm, Denmark.
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Nielsen J, Bøtner A, Bille-Hansen V, Oleksiewicz MB, Storgaard T. Experimental inoculation of late term pregnant sows with a field isolate of porcine reproductive and respiratory syndrome vaccine-derived virus. Vet Microbiol 2002; 84:1-13. [PMID: 11731155 PMCID: PMC7117428 DOI: 10.1016/s0378-1135(01)00450-3] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The use of a live attenuated porcine reproductive and respiratory syndrome virus (PRRSV) vaccine in piglets has been associated with reproductive disorders in non-vaccinated sows. Vaccine-derived virus (VDV) has been isolated from foetuses, stillborn pigs, and dead piglets, indicating that the live vaccine spread from vaccinated piglets to non-vaccinated sows, and that the virus might be implicated in the severe reproductive problems observed. In the present study, one such VDV isolate was used to experimentally infect pregnant sows in the last trimester. The chosen isolate, which had more than 99.6% identity to the attenuated vaccine virus, originated from the lungs of a stillborn pig from a swine herd with a sudden high level of stillborn pigs and increased piglet mortality in the nursing period. Intranasal inoculation of sows with the virus isolate resulted in congenital infection, foetal death, and preweaning pig mortality. As such, the present study showed that vaccine-derived PRRSV can cause disease in swine consistent with PRRS.
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Affiliation(s)
- J Nielsen
- Danish Veterinary Institute for Virus Research, Lindholm, DK-4771 Kalvehave, Denmark.
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45
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van Vugt JJFA, Storgaard T, Oleksiewicz MB, Bøtner A. High frequency RNA recombination in porcine reproductive and respiratory syndrome virus occurs preferentially between parental sequences with high similarity. J Gen Virol 2001; 82:2615-2620. [PMID: 11602772 DOI: 10.1099/0022-1317-82-11-2615] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Two types of porcine reproductive and respiratory syndrome virus (PRRSV) exist, a North American type and a European type. The co-existence of both types in some countries, such as Denmark, Slovakia and Canada, creates a risk of inter-type recombination. To evaluate this risk, cell cultures were co-infected with either a North American and a European type of PRRSV or two diverse types of European isolate. Subsequently, an approximately 600 bp region of the PRRSV genome was tested for recombination by quantitative real-time RT-PCR. Between 0.1 and 2.5% RNA recombination was found between the European isolates, but no recombination was detected between the European and North American types. Calculation of the maximum theoretical risk of European-American recombination, based on the sensitivity of the RT-PCR system, revealed that RNA recombination between the European and North American types of PRRSV is at least 10 000 times less likely to occur than RNA recombination between diverse European isolates.
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Affiliation(s)
- Joke J F A van Vugt
- Danish Veterinary Institute for Virus Research, Lindholm, DK-4771 Kalvehave, , Denmark1
| | - Torben Storgaard
- Danish Veterinary Institute for Virus Research, Lindholm, DK-4771 Kalvehave, , Denmark1
| | - Martin B Oleksiewicz
- Danish Veterinary Institute for Virus Research, Lindholm, DK-4771 Kalvehave, , Denmark1
| | - Anette Bøtner
- Danish Veterinary Institute for Virus Research, Lindholm, DK-4771 Kalvehave, , Denmark1
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46
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Forsberg R, Oleksiewicz MB, Petersen AM, Hein J, Bøtner A, Storgaard T. A molecular clock dates the common ancestor of European-type porcine reproductive and respiratory syndrome virus at more than 10 years before the emergence of disease. Virology 2001; 289:174-9. [PMID: 11689039 DOI: 10.1006/viro.2001.1102] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The disease caused by porcine reproductive and respiratory syndrome virus (PRRSV) emerged independently and almost simultaneously in Europe (1990) and North America (1987). The original reservoir of the virus and the date it entered the pig populations is not known. In this study, we demonstrate an accurate molecular clock for the European PRRSV ORF 3 gene, place the root in the genealogy, estimate the rate of nucleotide substitution, and date the most recent common viral ancestor of the data set to 1979; more than 10 years before the onset of the European epidemic. Based on these findings, we conclude that PRRSV virus most likely entered the pig population some time before the epidemic emergence of the virus, and hence, that emergence of European-type PRRSV is not the result of a recent species transmission event. Together, our results show that ORF3 sequencing is a valuable epidemiologic tool for examining the emergence and spread of PRRSV in Europe. As such, the panel of well-characterized and highly divergent ORF3 sequences described in this study provides a reference point for future molecular epidemiologic studies.
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Affiliation(s)
- R Forsberg
- Department of Ecology and Genetics, University of Aarhus, Denmark
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47
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Oleksiewicz MB, Bøtner A, Normann P. Semen from boars infected with porcine reproductive and respiratory syndrome virus (PRRSV) contains antibodies against structural as well as nonstructural viral proteins. Vet Microbiol 2001; 81:109-25. [PMID: 11376957 DOI: 10.1016/s0378-1135(01)00341-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The seminal excretion of antibodies against porcine reproductive and respiratory syndrome virus (PRRSV) was examined in a group of five boars experimentally infected by the nasopharyngeal route. By using phage-displayed peptide epitopes from the PRRSV replicase and envelope glycoproteins as ELISA antigen, we were able to separately and specifically assay antibody responses against structural and nonstructural viral proteins. Antibodies against structural as well as nonstructural viral proteins were consistently found in the semen of all boars, beginning from 1-4 weeks postinfection. This is the first report documenting the presence of anti-PRRSV antibodies in boar semen. Seminal antiviral IgA was also detected, and we observed a correlation between seminal IgA responses against nonstructural viral proteins, and the duration of PRRSV RNA excretion in semen. The implications of these findings for the diagnostics and pathogenesis of venereal PRRSV infection are discussed.
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Affiliation(s)
- M B Oleksiewicz
- Danish Veterinary Institute for Virus Research, Lindholm, 4771 Kalvehave, Denmark.
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48
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Nielsen HS, Oleksiewicz MB, Forsberg R, Stadejek T, Bøtner A, Storgaard T. Reversion of a live porcine reproductive and respiratory syndrome virus vaccine investigated by parallel mutations. J Gen Virol 2001; 82:1263-1272. [PMID: 11369869 DOI: 10.1099/0022-1317-82-6-1263] [Citation(s) in RCA: 143] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A live attenuated porcine reproductive and respiratory syndrome (PRRS) vaccine virus has been shown to revert to virulence under field conditions. In order to identify genetic virulence determinants, ORF1 from the attenuated vaccine virus and three Danish vaccine-derived field isolates was sequenced and compared with the parental strain of the vaccine virus (VR2332). This revealed five mutations that had occurred independently in all three vaccine-derived field isolates, indicating strong parallel selective pressure on these positions in the vaccine virus when used in swine herds. Two of these parallel mutations were direct reversions to the parental VR2332 sequence and were situated in a papain-like cysteine protease domain and in the helicase domain. The remaining parallel mutations might be seen as second-site compensatory mutations for one or more of the mutations that accumulated in the vaccine virus sequence during cell-culture adaptation. Evaluation of the remaining mutations in the ORF1 sequence revealed stronger selective pressure for amino acid conservation during spread in pigs than during vaccine production. Furthermore, it was found that the selective pressure did not change during the time period studied. The implications of these findings for PRRS vaccine attenuation and reversion are discussed.
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Affiliation(s)
- Henriette S Nielsen
- Danish Veterinary Institute for Virus Research, Lindholm, DK-4771 Kalvehave, Denmark1
| | - Martin B Oleksiewicz
- Danish Veterinary Institute for Virus Research, Lindholm, DK-4771 Kalvehave, Denmark1
| | - Roald Forsberg
- Institute of Biological Science, University of Aarhus, Aarhus, Denmark2
| | | | - Anette Bøtner
- Danish Veterinary Institute for Virus Research, Lindholm, DK-4771 Kalvehave, Denmark1
| | - Torben Storgaard
- Danish Veterinary Institute for Virus Research, Lindholm, DK-4771 Kalvehave, Denmark1
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Oleksiewicz MB, Bøtner A, Toft P, Normann P, Storgaard T. Epitope mapping porcine reproductive and respiratory syndrome virus by phage display: the nsp2 fragment of the replicase polyprotein contains a cluster of B-cell epitopes. J Virol 2001; 75:3277-90. [PMID: 11238854 PMCID: PMC114121 DOI: 10.1128/jvi.75.7.3277-3290.2001] [Citation(s) in RCA: 132] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
We screened phage display libraries of porcine reproductive and respiratory syndrome virus (PRRSV) protein fragments with sera from experimentally infected pigs to identify linear B-cell epitopes that are commonly recognized during infection in vivo. We identified 10 linear epitope sites (ES) 11 to 53 amino acids in length. In the replicase polyprotein, a total of eight ES were identified, six of which localized to the Nsp2 replicase polyprotein processing end product. In the structural proteins, a total of two ES were identified, in the ORF3 and ORF4 minor envelope glycoproteins. The ORF4 ES was previously identified by monoclonal antibody mapping (J. J. M. Meulenberg, A. P. van Nieuwstadt, A. van Essen-Zandenbergen, and J. P. M. Langeveld, J. Virol. 71:6061-6067, 1997), but its immunogenicity had not been examined in pigs. We found that six experimentally PRRSV-infected pigs consistently had very high antibody titers against the ORF4 ES. In some animals, sera diluted 1:62,500 still gave weak positive enzyme immunoassay reactivity against the ORF4 ES. This hitherto unrecognized immunodominance likely caused phages displaying the ORF4 ES to outcompete phages displaying other ES during library screening with porcine sera and accounted for our failure to identify more than two ES in the structural genes of PRRSV. Genetic analysis showed that variable ES were also the most immunogenic in vivo. Serological analysis indicated differences in the immunoglobulin A responses between short-term and longer-term viremic pigs towards some ES. The implications of these findings for PRRSV diagnostics and immunopathogenesis are discussed.
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Affiliation(s)
- M B Oleksiewicz
- Danish Veterinary Institute for Virus Research, Lindholm, 4771 Kalvehave, Denmark
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Alexandersen S, Oleksiewicz MB, Donaldson AI. The early pathogenesis of foot-and-mouth disease in pigs infected by contact: a quantitative time-course study using TaqMan RT-PCR. J Gen Virol 2001; 82:747-755. [PMID: 11257178 DOI: 10.1099/0022-1317-82-4-747] [Citation(s) in RCA: 107] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Foot-and-mouth disease (FMD) is a highly contagious, economically important virus disease of cloven-hoofed animals. The objective of the present study was to examine the early pathogenesis of FMD in pigs by a quantitative time-course study. Under experimental conditions, recipient pigs were infected by contact with donor pigs affected by FMD. Every 24 h from day 1 to day 4 after exposure, two recipient pigs were selected randomly, killed and necropsied. A range of tissues were analysed by a quantitative TaqMan RT-PCR method and by titration of FMD virus on primary bovine thyroid cells. The titres of virus determined by assay in cell culture and calculated from the quantitative TaqMan data correlated strongly (r>0.9), thereby establishing the validity of the TaqMan calculations. The data indicated that the replication of virus in the lungs contributes only in small part to airborne virus excretion. Sites in the pharynx, trachea and nasal mucosa are probably more important in that regard. The sites of earliest virus infection and possibly replication in recipient pigs appeared to be in the pharynx (soft palate, tonsil and floor of pharynx). The data indicated that FMD virus replication in pigs is rapid and that the majority of virus amplification occurs in the skin. A model for the progression of infection is proposed, indicating initial spread from the pharyngeal region, through regional lymph nodes and via the blood to epithelial cells, resulting in several cycles of virus amplification and spread.
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Affiliation(s)
- Soren Alexandersen
- Institute for Animal Health, Pirbright Laboratory, Ash Road, Pirbright, Woking, Surrey GU24 0NF, UK1
| | - Martin B Oleksiewicz
- Institute for Animal Health, Pirbright Laboratory, Ash Road, Pirbright, Woking, Surrey GU24 0NF, UK1
| | - Alex I Donaldson
- Institute for Animal Health, Pirbright Laboratory, Ash Road, Pirbright, Woking, Surrey GU24 0NF, UK1
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