| virulence and genotype-associated infectivity of interferon-treated macrophages by porcine reproductive and respiratory syndrome viruses. | the polarization into m1 and m2 macrophages (mφ) is essential to understand mφ function. consequently, the aim of this study was to determine the impact of ifn-γ (m1), il-4 (m2) and ifn-β activation of mφ on the susceptibility to genotype 1 and 2 porcine reproductive respiratory syndrome (prrs) virus (prrsv) strains varying in virulence. to this end, monocyte-derived mφ were generated by culture during 72h and polarization was induced for another 24h by addition of ifn-γ, il-4 or ifn-β. mφ were ... | 2014 | 24220223 |
| the spread of type 2 porcine reproductive and respiratory syndrome virus (prrsv) in north america: a phylogeographic approach. | the emergence and spread of type 2 porcine reproductive and respiratory syndrome virus (type 2 prrsv) in north america is heavily influenced by the multiple site production system used in the hog industry. however, it is unclear how anthropogenic factors such has this have shaped the current spatial distribution of prrsv genotypes. we employed bayesian phylogeographic analyses of 7040 orf5 sequences to reveal the recent geographical spread of type 2 prrsv in north america. the directions and int ... | 2013 | 24210109 |
| a novel porcine reproductive and respiratory syndrome virus vector system that stably expresses enhanced green fluorescent protein as a separate transcription unit. | here we report the rescue of a recombinant porcine reproductive and respiratory syndrome virus (prrsv) carrying an enhanced green fluorescent protein (egfp) reporter gene as a separate transcription unit. a copy of the transcription regulatory sequence for orf6 (trs6) was inserted between the n protein and 3'-utr to drive the transcription of the egfp gene and yield a general purpose expression vector. successful recovery of prrsv was obtained using an rna polymerase ii promoter to drive transcr ... | 2013 | 24176053 |
| sodium tanshinone iia sulfonate inhibits porcine reproductive and respiratory syndrome virus via suppressing n gene expression and blocking virus-induced apoptosis. | porcine reproductive and respiratory syndrome virus (prrsv) causes significant economic loss in the swine industry. currently, there is no effective way to prevent prrsv infection. sodium tanshinone iia sulfonate (sts), a natural compound derived from salvia miltiorrhiza, was shown to possess anti-prrsv activity, but the underlying mechanisms remain unclear. the objective of this study was to investigate the effect of sts on prrsv-induced cell apoptosis and prrsv n protein expression pattern. | 2014 | 24158620 |
| porcine reproductive and respiratory syndrome virus inhibition of interferon-β transcription by irf3-independent mechanisms in marc-145 cells in early infection. | interferon β is an important antiviral molecule whose expression is triggered through recognition of viral components by pattern recognition receptors via a cascade of signaling molecules, while viruses could target these molecules to evade from innate immunity. ifn regulatory factor 3 (irf3) plays a crucial role in innate immune responses. here, we demonstrate that prrsv infection did not induce ifn-β gene transcription in marc-145 cells, but inhibited poly (i:c) stimulated ifn-β gene transcrip ... | 2013 | 24148827 |
| positive effects of porcine il-2 and il-4 on virus-specific immune responses induced by the porcine reproductive and respiratory syndrome virus (prrsv) orf5 dna vaccine in swine. | the purpose of this study was to investigate the effects of porcine interleukin (il)-2 and il-4 genes on enhancing the immunogenicity of a porcine reproductive and respiratory syndrome virus orf5 dna vaccine in piglets. eukaryotic expression plasmids pcdna-orf5, pcdna-il-2, and pcdna-il-4 were constructed and then expressed in marc-145 cells. the effects of these genes were detected using an indirect immunofluorescent assay and reverse transcription polymerase chain reaction (rt-pcr). characteri ... | 2014 | 24136204 |
| dietary plant extracts improve immune responses and growth efficiency of pigs experimentally infected with porcine reproductive and respiratory syndrome virus. | a study was conducted to evaluate the effects of 3 different plant extracts on growth performance and immune responses of weaned pigs experimentally infected with porcine reproductive and respiratory syndrome virus (prrsv). a total of 64 weaned pigs (7.8 ± 0.3 kg bw), free of prrsv, were randomly allotted to 1 of 8 treatments in a 2 × 4 factorial arrangement with a randomized complete block design. pigs were blocked by initial bw. sex and ancestry were equalized across treatments. the first fact ... | 2013 | 24126276 |
| genetic dissection of complete genomes of type 2 prrs viruses isolated in denmark over a period of 15 years. | type 2 porcine reproductive and respiratory syndrome virus (prrsv) was first detected in europe in 1996 co-incident with the introduction of a live attenuated vaccine. since then, only limited orf5 and orf7 sequences of type 2 prrs viruses have been reported throughout europe. in the present study, the genetic and antigenic diversity of 11 complete genomes and 49 orf5 and 55 orf7 nucleotide sequences obtained from 57 viruses in denmark from 2003 to 2012 were examined. the genetic identity of the ... | 2013 | 24125764 |
| complete genome sequences of porcine reproductive and respiratory syndrome viruses: perspectives on their temporal and spatial dynamics. | porcine reproductive and respiratory syndrome virus (prrsv) has been investigated extensively at the molecular level. nevertheless, genome wide study on the temporal and spatial dynamics of the virus is non-existed. to explore this topic, we determined complete coding genome sequences for four prrsv isolates and analyzed them together with 122 global published ones using the bayesian coalescent approach as well as bayesian inferences and maximum likelihood methods. all eu-type viruses belonged t ... | 2013 | 24122560 |
| phenotypic modulation and cytokine profiles of antigen presenting cells by european subtype 1 and 3 porcine reproductive and respiratory syndrome virus strains in vitro and in vivo. | porcine reproductive and respiratory syndrome virus (prrsv) causes continuous problems in the pig industry, due to high costs of outbreaks and reduced welfare of diseased pigs. the severity of infection is, partly, dependent on the virus strain. recently isolated eastern-european subtype 3 strains are more pathogenic than the widespread subtype 1 strains. there is, however, almost no information available about the mechanisms involved in the pathogenicity of these subtype 3 strains. the objectiv ... | 2013 | 24120935 |
| phylogenetic analysis and molecular characteristics of 17 porcine reproductive and respiratory syndrome virus isolates in southern china from 2010 to 2011. | we analyzed the complete genomic sequences of 17 porcine reproductive and respiratory syndrome virus (prrsv) isolates from southern china obtained between 2010 and 2011 and found that four of seven isolates from 2011 were closely related to the jxa1-r strain (vaccine virus of jxa1). this close relationship between field isolates and china domestic vaccine viruses has not been reported to date. the occurrence of vaccine-like viruses potentially creates a threat for the pig breeding industry and b ... | 2013 | 24113000 |
| antibody-dependent enhancement of prrsv infection down-modulates tnf-α and ifn-β transcription in macrophages. | porcine reproductive and respiratory syndrome (prrs) is an infectious disease, resulting in important economic losses in pig farming. previous studies have shown that fcγ receptor (fcγr)-mediated entry of infectious prrsv immune complexes into macrophages plays a pivotal role in the pathogenesis of the disease. this study demonstrates that prrsv was able to suppress the transcription of key antiviral genes tumor necrosis factor-α (tnf-α) and interferon-β (ifn-β), when infection was via the ade p ... | 2013 | 24099951 |
| pathogenesis and prevention of placental and transplacental porcine reproductive and respiratory syndrome virus infection. | porcine reproductive and respiratory syndrome virus (prrsv)-induced reproductive problems are characterized by embryonic death, late-term abortions, early farrowing and increase in number of dead and mummified fetuses, and weak-born piglets. the virus recovery from fetal tissues illustrates transplacental infection, but despite many studies on the subject, the means by which prrsv spreads from mother to fetus and the exact pathophysiological basis of the virus-induced reproductive failure remain ... | 2013 | 24099529 |
| highly divergent strains of porcine reproductive and respiratory syndrome virus incorporate multiple isoforms of nonstructural protein 2 into virions. | viral structural proteins form the critical intermediary between viral infection cycles within and between hosts, function to initiate entry, participate in immediate early viral replication steps, and are major targets for the host adaptive immune response. we report the identification of nonstructural protein 2 (nsp2) as a novel structural component of the porcine reproductive and respiratory syndrome virus (prrsv) particle. a set of custom α-nsp2 antibodies targeting conserved epitopes within ... | 2013 | 24089566 |
| purifying selection in porcine reproductive and respiratory syndrome virus orf5a protein influences variation in envelope glycoprotein 5 glycosylation. | porcine reproductive and respiratory syndrome virus orf5a protein is encoded in an alternate open reading frame upstream of the major envelope glycoprotein (gp5) in subgenomic mrna5. bioinformatic analysis of 3466 type 2 prrsv sequences showed that the two proteins have co-evolved through a fine balance of purifying codon usage to maintain a conserved rq-rich motif in orf5a protein, while eliciting a variable n-linked glycosylation motif in the alternative gp5 reading frame. conservation of the ... | 2013 | 24084290 |
| chinese and vietnamese strains of hp-prrsv cause different pathogenic outcomes in united states high health swine. | an infectious clone of a highly pathogenic prrsv strain from vietnam (rsrv07) was prepared and was demonstrated to contain multiple amino acid differences throughout the genome when compared to chinese highly pathogenic prrsv strain rjxwn06. virus rescued from the rsrv07 infectious clone was compared to rjxwn06 and us type 2 prototype strain vr-2332 to examine the effects of virus genotype and phenotype on in vitro growth, and virus challenge dose on in vivo pathogenicity and host response. afte ... | 2013 | 24074587 |
| enhancing neutralizing antibody production by an interferon-inducing porcine reproductive and respiratory syndrome virus strain. | porcine reproductive and respiratory syndrome (prrs) virus (prrsv) continues to cause substantial economic losses to the global swine industry. prrsv appears to inhibit synthesis of type i interferons (ifns), such as ifn-α and -β, which are critical for the innate immunity and play an important role in the modulation of adaptive immunity. an atypical prrsv strain, a2mc2, is able to induce type i ifns in vitro. in this study, a2mc2 induction of neutralizing antibodies in vivo was compared with th ... | 2013 | 24063978 |
| antibody response and maternal immunity upon boosting prrsv-immune sows with experimental farm-specific and commercial prrsv vaccines. | the porcine reproductive and respiratory syndrome virus (prrsv) causes reproductive failure in sows and respiratory disease in pigs of all ages. despite the frequent use of vaccines to maintain prrsv immunity in sows, little is known on how the currently used vaccines affect the immunity against currently circulating and genetically divergent prrsv variants in prrsv-immune sows, i.e. sows that have a pre-existing prrsv-specific immunity due to previous infection with or vaccination against the v ... | 2013 | 24041768 |
| a novel baculovirus vector shows efficient gene delivery of modified porcine reproductive and respiratory syndrome virus antigens and elicits specific immune response. | porcine reproductive and respiratory syndrome (prrs) is an economically devastating epizootic of porcine species. current vaccines are inadequate to control the disease burden and outbreaks in the field. we report a novel baculovirus vaccine vector with white spot syndrome virus immediate early 1 shuttle promoter, with strong activity in both insect cells and mammalian cells, for immunization against prrsv. the insect cell cultured baculovirus vector produces prrsv envelope glycoproteins orf2a, ... | 2013 | 24035590 |
| comparison of viremia of type ii porcine reproductive and respiratory syndrome virus in naturally infected pigs by zip nucleic acid probe-based real-time pcr. | porcine reproductive and respiratory syndrome virus (prrsv) is a rna virus with high genetic variation. this virus causes significant economic losses in most pig-producing countries. the clinical presentation of prrsv ranges from asymptomatic to devastating. in this study, we developed a sensitive and specific zip nucleic acid probe-based real-time pcr assay to evaluate the viremia of natural prrsv-infected pigs in taiwan. serum samples were collected from 577 pigs aged 5-12 weeks. these include ... | 2013 | 24028493 |
| genetic typing of porcine reproductive and respiratory syndrome virus isolates from central european countries. | all thirty-three but one porcine reproductive and respiratory syndrome virus (prrsv) isolate originating from pigs in austria, czech republic and slovakia were typed on the basis of partial orf5 sequence as prrsv-1, subtype eu-1. the single isolate of prrsv-2 originated from slovakia. | 2013 | 24020763 |
| fresh pork and porcine reproductive and respiratory syndrome virus: factors related to the risk of disease transmission. | porcine reproductive and respiratory syndrome virus (prrs) is a highly infectious virus. experimentally, the disease can be induced in naïve pigs by the oral, intranasal and intramuscular routes. depending on the virulence of the strain of the virus and the age of the pig, peak viremia can occur within 7 days of infection, and live virus can be isolated from blood or lymph nodes for several months post-infection. young pigs tend to develop higher titres of viremia than older pigs infected by the ... | 2015 | 24016101 |
| effect of collection material and sample processing on pig oral fluid testing results. | the effect of sampling material, sample processing, and collection order on the detection of analytes in pig oral fluid specimens was evaluated. oral fluid samples were collected from 104 pens of commercial wean-to-finish pigs using ropes made of three different materials. processed (centrifuged and filtered) and unprocessed oral fluid samples were tested using commercial elisas for porcine reproductive and respiratory syndrome virus (prrsv) antibodies and total igm, iga, and igg. unprocessed sa ... | 2013 | 24011474 |
| molecular evolution of porcine reproductive and respiratory syndrome virus isolates from central china. | to investigate the genetic diversity of prevailing porcine reproductive and respiratory syndrome virus (prrsv) in henan province of china, 61 orf5 gene sequences, originating from henan province during 2003-2010, were subjected to amino acid variation and phylogenetic analysis. the analyzed prrsv orf5 sequences carried evidence of one unique recombination event. phylogenetic analysis revealed that all henan isolates belonged to type 2 genotype and were divided into two subgroups. the dominant is ... | 2013 | 23998927 |
| evolutionary dynamics of a highly pathogenic type 2 porcine reproductive and respiratory syndrome virus: analyses of envelope protein-coding genes. | porcine reproductive and respiratory syndrome virus (prrsv) has long been an economically devastating swine viral disease. the recent emergence of a highly pathogenic type 2 prrsv with high mobility and mortality in china, spreading in vietnam, laos, and thailand has placed neighbouring countries at risk. this study applied a codon-based extension of the bayesian relaxed clock model and the fixed effects maximum-likelihood method to investigate and compare the evolutionary dynamics of type 2 prr ... | 2015 | 23981823 |
| blood antioxidant enzymes (sod, gpx), biochemical and haematological parameters in pigs naturally infected with porcine reproductive and respiratory syndrome virus. | porcine reproductive and respiratory syndrome (prrs) has become one of the most economically important diseases for the swine industry worldwide. the objective of the study was to determine selected blood antioxidant enzymes (glutathione peroxidase (gpx), superoxide dismutase (sod)), biochemical and haematological parameters in prrs positive and negative pigs of three different categories, mainly to test oxidative stress hypothesis in pigs naturally infected with prrs virus. ninety prrs positive ... | 2013 | 23971206 |
| [establishment of a porcine cd151 transgenic pk-15 cell line susceptible to porcine reproductive and respiratory syndrome virus]. | in order to study the role of porcine cd151 in infection of porcine cells by porcine reproductive and respiratory syndrome virus (prrsv), we established a porcine cd151 transgenic pk-15 cell line. | 2013 | 23957156 |
| variable interference with interferon signal transduction by different strains of porcine reproductive and respiratory syndrome virus. | porcine reproductive and respiratory syndrome virus (prrsv) is a positive-sense single-strand rna virus that has contributed to substantial losses to the swine industry. the objective of this study was to examine the interference of interferon (ifn)-activated signaling by prrsv viral proteins and compare the effects of several prrsv strains on the ifn signaling. three non-structural proteins (nsp 1β, 7 and 12) and two structural proteins (gp3 and n) of vr-2385 were found to significantly inhibit ... | 2013 | 23953026 |
| porcine reproductive and respiratory syndrome virus nonstructural protein 4 induces apoptosis dependent on its 3c-like serine protease activity. | porcine reproductive and respiratory syndrome (prrs) is a highly contagious disease in pigs caused by prrs virus (prrsv). although prrsv infection-induced cell apoptosis has been established, the related viral protein is still unknown. here, we reported that prrsv nonstructural protein 4 (nsp4) was a critical apoptosis inducer. nsp4 could activate caspase-3, -8, and -9. using truncated constructs without different domains in nsp4, we demonstrated that the full-length of nsp4 structure was requir ... | 2013 | 23936003 |
| validation and further characterization of a major quantitative trait locus associated with host response to experimental infection with porcine reproductive and respiratory syndrome virus. | infectious diseases are costly to the swine industry; porcine reproductive and respiratory syndrome (prrs) is the most devastating. in earlier work, a quantitative trait locus associated with resistance/susceptibility to prrs virus was identified on sus scrofa chromosome 4 using approximately 560 experimentally infected animals from a commercial cross. the favorable genotype was associated with decreased virus load and increased weight gain (wg). the objective here was to validate and further ch ... | 2014 | 23914972 |
| comparison of specimens for detection of porcine reproductive and respiratory syndrome virus infection in boar studs. | porcine reproductive and respiratory syndrome virus (prrsv)-contaminated semen from boars is a route of transmission to females, and early detection of prrsv infection in boars is a key component in sow farm biosecurity. the purpose of this study was to determine the optimum diagnostic specimen(s) for the detection of acute prrsv infection in boars. individually housed boars (n = 15) were trained for semen and oral fluid collection and then vaccinated with a commercial prrsv modified live virus ... | 2015 | 23895185 |
| mutagenesis analysis of porcine reproductive and respiratory syndrome virus nonstructural protein 7. | nonstructural protein 7 (nsp7), which is flanked by nsp6 and nsp8, is one of the most conserved nonstructural proteins of porcine reproductive and respiratory syndrome virus (prrsv). nonstructural protein (nsp)-specific antibodies are produced in high titers in response to virus replication, especially against nsp1a, nsp1b, nsp2, and nsp7. however, many regional aspects of nsp7 are still veiled, such as its impact on viral replication and virulence or the immunological mechanism between virus an ... | 2013 | 23892545 |
| characterization of a serologic marker candidate for development of a live-attenuated diva vaccine against porcine reproductive and respiratory syndrome virus. | diva (differentiating infected from vaccinated animals) vaccines have proven extremely useful for control and eradication of infectious diseases in livestock. we describe here the characterization of a serologic marker epitope, so-called epitope-m201, which can be a potential target for development of a live-attenuated diva vaccine against porcine reproductive and respiratory syndrome virus (prrsv). epitope-m201 is located at the carboxyl terminus (residues 161-174) of the viral m protein. the e ... | 2013 | 23892102 |
| a fast and robust method for full genome sequencing of porcine reproductive and respiratory syndrome virus (prrsv) type 1 and type 2. | prrsv is a positive-sense rna virus with a high degree of genetic variability among isolates. for diagnostic sensitivity and vaccine design it is essential to monitor prrsv genetic diversity. however, to date only a few full genome sequences of prrsv isolates have been made publicly available. in the present study, fast and robust methods for long range rt-pcr amplification and subsequent next generation sequencing (ngs) were developed and validated on nine type 1 and nine type 2 prrsv viruses. ... | 2013 | 23891870 |
| complete genome sequence of a novel deletion porcine reproductive and respiratory syndrome virus strain. | porcine reproductive and respiratory syndrome virus hz-31 strain is different from any other previously sequenced porcine reproductive and respiratory syndrome virus strains. it contains a 59-amino acid (aa) discontinuous deletion in aa 467 to 474, aa 498 to 519, and aa 533 to 561 of nsp2. here, we report the complete genome sequence of this novel chinese virulent prrsv variant. | 2013 | 23887914 |
| recombination is associated with an outbreak of novel highly pathogenic porcine reproductive and respiratory syndrome viruses in china. | in 2009 to 2010, there was a marked increase in the number of infections with highly pathogenic porcine reproductive and respiratory syndrome virus (hp-prrsv) in china. through phylogenetic analysis, we show that viruses from this outbreak originated from a single recombination event, illustrating the potential importance of this process for disease emergence. | 2013 | 23885071 |
| in vitro antiviral activity and underlying molecular mechanisms of dipotassium glycyrrhetate against porcine reproductive and respiratory syndrome virus. | porcine reproductive and respiratory syndrome virus (prrsv) has caused large economic losses in the swine industry. currently, there is no effective way to prevent prrsv infection. in this study, we investigated the inhibitory effect of dipotassium glycyrrhetate (dg), a derivative of glycyrrhetinic acid, on prrsv infection ability. | 2013 | 23872789 |
| development and application of a blocking enzyme-linked immunosorbent assay (elisa) to differentiate antibodies against live and inactivated porcine reproductive and respiratory syndrome virus. | the aim of this study was to establish a method that could differentiate antibodies against live and inactivated vaccines of porcine reproductive and respiratory syndrome virus (prrsv). a blocking elisa (b-elisa) was established using the prrsv non-structural protein, nsp9, as the antigen and a monoclonal antibody, 2d6, against the nsp9 protein as the capture antibody. the test was validated by using 415 clinical sera in the b-elisa compared to a commercial kit based on the indirect elisa using ... | 2013 | 23871220 |
| functional characterization of porcine lsm14a in ifn-β induction. | human lsm14a has recently been found as a processing body-associated sensor of intracellular viral nucleic acids and triggers signaling for type i ifn expression. here porcine lsm14a (plsm14a) was cloned from the pk-15 cells. the plsm14a orf is 1392 bp in length, encoding 463 amino acids. the putative plsm14a contains a sm-like domain and two arginine-glycine-glycine (rgg) boxes. the plsm14a has high identity at the amino acid level to those of bovine, human and mouse (93.5-97.4%) and is transcr ... | 2013 | 23871214 |
| epidemiological study of air filtration systems for preventing prrsv infection in large sow herds. | porcine reproductive and respiratory syndrome virus (prrsv) is the most economically significant pathogen in the us swine industry. aerosol transmission among herds is a major concern in pig dense regions and filtration of incoming air, in combination with standard biosecurity procedures, has been demonstrated to prevent transmission of prrsv into susceptible herds. to quantify the impact of air filtration on reducing risk of prrsv outbreaks, we compared the incidence rate of new prrsv introduct ... | 2013 | 23870693 |
| dynamics and evolution of porcine reproductive and respiratory syndrome virus (prrsv) orf5 following modified live prrsv vaccination in a prrsv-infected herd. | the objective of this study was to investigate the dynamics and evolution of porcine reproductive and respiratory syndrome virus (prrsv) orf5 following the use of a modified live prrsv (mlv) vaccine. a prrsv-positive farm with coexistence of types 1 and 2 and no history of mlv vaccination was investigated. vaccination with a type 2 mlv (ingelvac prrs mlv, boehringer ingelheim, usa) was implemented. all sows were vaccinated at monthly intervals for two consecutive months and then every third mont ... | 2014 | 23851653 |
| involvement of unfolded protein response, p53 and akt in modulation of porcine reproductive and respiratory syndrome virus-mediated jnk activation. | our previous study has shown that activation of jnk plays a critical role in porcine reproductive and respiratory syndrome virus (prrsv)-mediated apoptosis. in this follow-up study, we further investigated the mechanisms involved in modulation of prrsv-mediated jnk activation and apoptosis. we found that unfolded protein response (upr) was induced in response to prrsv infection which in turn triggered jnk activation and apoptosis. we also found that p53 and akt were activated at the early stage ... | 2013 | 23850458 |
| experimental infection and comparative genomic analysis of a highly pathogenic prrsv-hbr strain at different passage levels. | a highly pathogenic strain of porcine reproductive and respiratory syndrome virus (prrsv-hbr) was passaged on marc-145 cells for 125 passages. in order to elucidate the change in virulence of prrsv-hbr strain during the process of passage in vitro, swine infection experiment was performed with the viruses of low (f5 and f10) and high passage (f125). in addition, to identify the mutations related to the change in virulence of prrsv-hbr strain, we compared and analyzed the genomic sequences of the ... | 2013 | 23850443 |
| pk-15 cells transfected with porcine cd163 by piggybac transposon system are susceptible to porcine reproductive and respiratory syndrome virus. | the piggybac (pb) transposon system is a non-viral dna-transfer system in which a transposase directs integration of a pb transposon into a ttaa site in the genome. transgenic expression of porcine cd163 is necessary and sufficient to confer non-permissive cells susceptible to infection with porcine reproductive and respiratory syndrome virus (prrsv). such permissive cells can be used as a tool for prrsv cellular receptor and other studies. one of the problems in studying prrsv is the lack of po ... | 2013 | 23835031 |
| swifn-β promotes genetic mutation of porcine reproductive and respiratory syndrome virus in marc-145. | this result, for the first time, demonstrates that under swine interferon-β (swifn-β) immune pressure molecular variation of porcine reproductive and respiratory syndrome virus (prrsv) accelerates. prrsv-a1 strain was continuously propagated in marc-145 cells primed with swifn-β for 20 passages to develop rrrsv-a1βf20 strains while prrsv-a1f20 was control without swifn-β respectively. nsp2, orf3, orf5 and orf6 genes of these strains were amplified, cloned and sequenced. sequencing analysis indic ... | 2013 | 23834966 |
| broadening the heterologous cross-neutralizing antibody inducing ability of porcine reproductive and respiratory syndrome virus by breeding the gp4 or m genes. | porcine reproductive and respiratory syndrome virus (prrsv) is one of the most economically important swine pathogens, which causes reproductive failure in sows and respiratory disease in piglets. a major hurdle to control prrsv is the ineffectiveness of the current vaccines to confer protection against heterologous strains. since both gp4 and m genes of prrsv induce neutralizing antibodies, in this study we molecularly bred prrsv through dna shuffling of the gp4 and m genes, separately, from si ... | 2013 | 23826108 |
| the signal sequence of type ii porcine reproductive and respiratory syndrome virus glycoprotein 3 is sufficient for endoplasmic reticulum retention. | the glycoprotein 3 (gp3) of type ii porcine reproductive and respiratory syndrome virus has the characteristic domains of a membrane protein. however, this protein has been reported to be retained in the endoplasmic reticulum (er) rather than transported to the plasma membrane of the cell. in this study, we performed confocal laser scanning microscopy analysis of variants of gp3 and found that the signal sequence of the gp3 led to confinement of gp3 in the er, while the functional ortransmembran ... | 2013 | 23820208 |
| antiviral effect of dietary germanium biotite supplementation in pigs experimentally infected with porcine reproductive and respiratory syndrome virus. | germanium biotite (gb) is an aluminosilicate mineral containing 36 ppm germanium. the present study was conducted to better understand the effects of gb on immune responses in a mouse model, and to demonstrate the clearance effects of this mineral against porcine reproductive and respiratory syndrome virus (prrsv) in experimentally infected pigs as an initial step towards the development of a feed supplement that would promote immune activity and help prevent diseases. in the mouse model, dietar ... | 2013 | 23814470 |
| poly(i:c) inhibits porcine reproductive and respiratory syndrome virus replication in marc-145 cells via activation of ifit3. | porcine reproductive and respiratory syndrome virus (prrsv) is a major cause of heavy economic losses in many swine-producing regions. current vaccination strategies and antiviral drugs provide only limited protection. interferon (ifn)-induced protein with tetratricopeptide repeats 3 (ifit3) has been characterized as the product of a novel antiviral gene and as an important modulator in innate immunity. however, the role of ifit3 in prrsv infection is scarcely understood. in this study, polyinos ... | 2013 | 23791982 |
| an intact sialoadhesin (sn/siglec1/cd169) is not required for attachment/internalization of the porcine reproductive and respiratory syndrome virus. | surface expression of siglec1, also known as sialoadhesin or cd169, is considered a primary determinant of the permissiveness of porcine alveolar macrophages for infection by porcine reproductive and respiratory syndrome virus (prrsv). in vitro, the attachment and internalization of prrsv are dependent on the interaction between sialic acid on the virion surface and the sialic acid binding domain of the siglec1 gene. to test the role of siglec1 in prrsv infection, a siglec1 gene knockout pig was ... | 2013 | 23785195 |
| development and validation of an assay to detect porcine reproductive and respiratory syndrome virus-specific neutralizing antibody titers in pig oral fluid samples. | porcine reproductive and respiratory syndrome virus (prrsv)-specific neutralizing antibodies (na) are important for clearing the virus. pen-based pig oral fluid samples for disease surveillance are gaining in importance due to the ease of collection and low cost. the aim of this study was to develop a prrsv-specific na assay to determine na titers in pig oral fluid samples. at first, we standardized the prrsv na assay using pen-based pig oral fluid samples collected over a period of 3 months fro ... | 2013 | 23784856 |
| molecular epidemiology of prrsv in south china from 2007 to 2011 based on the genetic analysis of orf5. | porcine reproductive and respiratory syndrome virus (prrsv) has proven to be highly genetically variable; however, comprehensive information regarding the virus's genetic diversity in south china is limited. in this study, a total of 3199 clinical samples were collected from 267 pig farms suspected of prrsv infection between 2007 and 2011. the orf5 genes of 51 prrsv-positive samples were sequenced and analyzed. the 51 study strains were divided into three primary subgenotypes. fourty-five of the ... | 2013 | 23770054 |
| ctla4 mediated targeting enhances immunogenicity against prrsv in a dna prime/killed virus boost strategy. | porcine reproductive and respiratory syndrome virus (prrsv) is the causative agent of porcine reproductive and respiratory syndrome (prrs), causing heavy economic losses to the swine industry all over the world. as current vaccination strategies could only confer limited and incomplete protection against prrsv infection, a safe and efficient prrsv vaccine is urgently needed. vaccination with cytotoxic-t-lymphocyte-associated protein 4 (ctla4) and antigen fusion expression plasmid which could tar ... | 2013 | 23764470 |
| plga nanoparticle entrapped killed porcine reproductive and respiratory syndrome virus vaccine helps in viral clearance in pigs. | porcine reproductive and respiratory syndrome (prrs) is a chronic viral disease of pigs, has been posing a huge economic concern to pig industry worldwide. in this study, we developed biodegradable plga [poly(d,l-lactide-co-glycolide)] nanoparticle-entrapped killed prrsv vaccine (nano-kag), and administered intranasally to pigs once and evaluated the immune correlates. in nano-kag vaccinated homologous virus challenged pigs, complete clearance of viremia was observed in 2 weeks, associated with ... | 2013 | 23764272 |
| targeted mutations in a highly conserved motif of the nsp1β protein impair the interferon antagonizing activity of porcine reproductive and respiratory syndrome virus. | non-structural protein 1β (nsp1β) of porcine reproductive and respiratory syndrome virus (prrsv) contains a papain-like cysteine protease (plpβ) domain and has been identified as the main viral protein antagonizing the host innate immune response. in this study, nsp1β was determined to suppress the expression of reporter genes as well as to suppress 'self-expression' in transfected cells, and this activity appeared to be associated with its interferon (ifn) antagonist function. to knock down the ... | 2013 | 23761406 |
| survival of porcine reproductive and respiratory syndrome virus in pork products. | there is a risk of virus transmission through contaminated pork, and many viruses are considered potential hazards for both humans and livestock. the risk of transmission may be elevated with importation/exportation of meat between countries globally. survival of porcine reproductive and respiratory syndrome virus (prrsv) in different pork products has not been studied. the present study evaluated prrsv survival in four different products: fresh sausage, ham, bacon, and acidified sausage prepare ... | 2013 | 23760750 |
| signal peptide cleavage from gp5 of prrsv: a minor fraction of molecules retains the decoy epitope, a presumed molecular cause for viral persistence. | porcine reproductive and respiratory syndrome virus (prrsv) is the major pathogen in the pig industry. variability of the antigens and persistence are the biggest challenges for successful control and elimination of the disease. gp5, the major glycoprotein of prrsv, is considered an important target of neutralizing antibodies, which however appear only late in infection. this was attributed to the presence of a "decoy epitope" located near a hypervariable region of gp5. this region also harbors ... | 2013 | 23755249 |
| microrna 181 suppresses porcine reproductive and respiratory syndrome virus (prrsv) infection by targeting prrsv receptor cd163. | we previously showed that microrna 181 (mir-181) can inhibit prrsv replication by directly targeting its genomic rna. here, we report that mir-181 can downregulate the prrsv receptor cd163 in blood monocytes and porcine alveolar macrophages (pams) through targeting the 3' untranslated region (utr) of cd163 mrna. downregulation of cd163 leads to the inhibition of prrsv entry into pams and subsequently suppresses prrsv infection. our findings indicate that delivery of mir-181 can be used as antivi ... | 2013 | 23740977 |
| porcine, murine and human sialoadhesin (sn/siglec-1/cd169): portals for porcine reproductive and respiratory syndrome virus entry into target cells. | porcine sialoadhesin (psn; a sialic acid-binding lectin) and porcine cd163 (pcd163) are molecules that facilitate infectious entry of porcine reproductive and respiratory syndrome virus (prrsv) into alveolar macrophages. in this study, it was shown that murine sn (msn) and human sn (hsn), like psn, can promote prrsv infection of pcd163-expressing cells. intact sialic acid-binding domains are crucial, since non-sialic acid-binding mutants of psn, msn and hsn did not promote infection. endodomain- ... | 2013 | 23740482 |
| financial implications of installing air filtration systems to prevent prrsv infection in large sow herds. | air filtration systems implemented in large sow herds have been demonstrated to decrease the probability of having a porcine reproductive and respiratory syndrome virus (prrsv) outbreak. however, implementation of air filtration represents a considerable capital investment, and does not eliminate the risk of new virus introductions. the specific objectives of the study were: 1) to determine productivity differences between a cohort of filtered and non-filtered sow farms; and 2) to employ those p ... | 2013 | 23735427 |
| a possible strategy to produce pigs resistant to porcine reproductive and respiratory syndrome virus. | the purpose of this study was to enhance the production of transgenic cloned embryos with porcine reproductive and respiratory syndrome virus (prrsv) shrna expression cassettes. to construct transgenic vector with expression targeting against prrsv, prrsv shrna expression cassettes were inserted into pegfp-n1 and the ability of resulting recombinant plasmid pegfp-g1 inhibiting virus replication was examined in marc-145 cells. results showed that prrsv replication could be significantly inhibited ... | 2013 | 23732571 |
| in vitro screening for compounds derived from traditional chinese medicines with antiviral activities against porcine reproductive and respiratory syndrome virus. | seventeen compounds derived from traditional chinese medicines (tcms) were tested for their antiviral activity against porcine reproductive and respiratory syndrome virus (prrsv) in vitro. visualization with the cytopathologic effect (cpe) assay and the 3-(4, 5-dimethyithiazol- 2-yl)-2,5-diphenyltetrazolium bromide test were used to determine the 50% cytotoxic concentration (cc50) and 50% effective concentration (ec50) in cultured marc-145 cells. among the tested compounds, chlorogenic acid and ... | 2013 | 23727804 |
| recombinant chimeric vaccine composed of prrsv antigens and truncated pseudomonas exotoxin a (pe-k13). | a pseudomonas exotoxin (pe-kdel)-based chimeric subunit vaccine system was recently developed using a reverse vaccinology technique. in this study, the plasmids containing pe-prrs chimeric subunits were constructed that composed of porcine reproductive and respiratory syndrome virus (prrsv) antigen moieties, a ligand moiety and a pseudomonas exotoxin a deleted domain iii (pe (δiii)), and a carboxyl terminal moiety that includes a polypeptide with amino acid sequence kdel (k3). the pe-prrs combin ... | 2013 | 23712024 |
| porcine reproductive and respiratory syndrome virus infection is associated with an increased number of sn-positive and cd8-positive cells in the maternal-fetal interface. | it is already known that porcine reproductive and respiratory syndrome virus (prrsv) infection in lungs changes a local cell pattern and cytokine profile. however, there is no information about cellular and immunological events upon prrsv infection in the maternal-fetal interface yet. the altered number and/or function of macrophages and nk cells in the maternal-fetal interface during infection may have a functional importance for virus replication. in addition, local cellular and immunological ... | 2013 | 23707347 |
| cryptoporus volvatus extract inhibits porcine reproductive and respiratory syndrome virus (prrsv) in vitro and in vivo. | porcine reproductive and respiratory syndrome virus (prrsv) is an important arterivirus that can cause significant losses in swine industry. at present, there are no adequate control strategies against prrsv. thus, there is an urgent need for new treatment regimens that have efficacious antiviral activity to compensate for vaccines. cryptoporus volvatus commonly serves as an anti-infective agent in tradational chinese medicines. in this report, we exploited whether the aqueous extract from the f ... | 2013 | 23704937 |
| comparative pathogenesis of type 1 (european genotype) and type 2 (north american genotype) porcine reproductive and respiratory syndrome virus in infected boar. | porcine reproductive and respiratory syndrome virus (prrsv) now has two main genotypes, genotype 1 (european) and genotype 2 (north american). there is a lack of data on the comparison of pathogenicity of the two genotypes in boars. the objectives of the present study were to evaluate the amount of prrsv present in semen over time and compare the viral distribution and microscopic lesions of type 1 and type 2 prrsv-infected boars. | 2013 | 23687995 |
| impact of genotype 1 and 2 of porcine reproductive and respiratory syndrome viruses on interferon-α responses by plasmacytoid dendritic cells. | porcine reproductive and respiratory syndrome (prrs) virus (prrsv) infections are characterized by prolonged viremia and viral shedding consistent with incomplete immunity. type i interferons (ifn) are essential for mounting efficient antiviral innate and adaptive immune responses, but in a recent study, north american prrsv genotype 2 isolates did not induce, or even strongly inhibited, ifn-α in plasmacytoid dendritic cells (pdc), representing "professional ifn-α-producing cells". since inhibit ... | 2013 | 23675981 |
| porcine reproductive and respiratory syndrome virus activates inflammasomes of porcine alveolar macrophages via its small envelope protein e. | porcine reproductive and respiratory syndrome virus (prrsv) infection results in extensive tissue inflammation and damage, which are believed to be responsible for increased susceptibility to secondary infection and even for death. however, its pathogenic mechanisms are not fully understood. to explore the mechanism underlying the prrsv-induced tissue inflammation and damage, we investigated whether prrsv activates porcine alveolar macrophage (pam) inflammasomes which mediate por-il-1β maturatio ... | 2013 | 23664331 |
| complete genome sequence of a european genotype porcine reproductive and respiratory syndrome virus in china. | here, we report a novel european genotype porcine reproductive and respiratory syndrome virus (prrsv) strain with 15 nucleotide deletions in the nonstructural protein 2 region and 3 nucleotide deletions in the overlapping regions of the open reading frame 3 (orf3) and orf4 regions. this study will aid in further exploration of the genetic and antigenic diversity of the european genotype of the prrsv in china. | 2013 | 23661475 |
| genetic analysis of orf5 porcine reproductive and respiratory syndrome virus isolated in vietnam. | porcine reproductive and respiratory syndrome virus (prrsv) is one of the most economically important swine pathogens because it is highly infectious and causes economic losses due to decreased pig productivity. in this study, the 603 bp complete major envelope protein encoding gene (orf5) of 32 field prrsv isolates from vietnam collected during 2008-2012 were sequenced and analyzed. multiple nucleotide (nt) and deduced amino acid (aa) alignments of orf5 were performed on the 32 isolates: the re ... | 2013 | 23650891 |
| induction of stat1 phosphorylation at serine 727 and expression of proinflammatory cytokines by porcine reproductive and respiratory syndrome virus. | porcine reproductive and respiratory syndrome virus (prrsv) is a viral pathogen that causes acute respiratory illnesses in young pigs. since 1987, prrsv has contributed substantial economic losses to the swine industry. elevation of proinflammatory cytokines in prrsv-infected pigs is thought to contribute to prrsv pathogenesis. in this study, prrsv vr-2385, a type 2 strain with moderate virulence, was found to induce phosphorylation of signal transducer and activator of transcription 1 (stat1) a ... | 2013 | 23637938 |
| comparative expression of toll-like receptors and inflammatory cytokines in pigs infected with different virulent porcine reproductive and respiratory syndrome virus isolates. | porcine reproductive and respiratory syndrome virus (prrsv) is largely responsible for heavy economic losses in the swine industry worldwide because of its high mutation rate and subsequent emergence of virulent strains. however, the immunological and pathological responses of pigs to prrsv strains with different virulence have not been completely elucidated. | 2013 | 23631691 |
| [expression and identification of truncated nsp7 protein of north american and europe genotype porcine reproductive and respiratory syndrome virus]. | porcine reproductive and respiratory syndrome virus (prrsv) non-structural protein 7 (nsp7) plays an important role in the induction of host humoral immune response and could serve as an ideal antigen for serological genotyping assay for prrsv based on the significant difference in immunoreactivities of north american (na) and european (eu) prrsv nsp7. in this study, nsp7 of na and eu prrsvwas separately expressed and purified using prokaryotic expression system. the purified recombinant nsp7 pr ... | 2013 | 23631115 |
| genetic diversity of porcine reproductive and respiratory syndrome virus in korea. | the high genetic diversity of porcine reproductive and respiratory syndrome virus (prrsv) has been an obstacle to developing an effective vaccine for porcine reproductive and respiratory syndrome (prrs). this study was performed to assess the degree of genetic diversity among prrsvs from korean pig farms where wasting and respiratory syndrome was observed from 2005 to 2009. samples from 786 farms were tested for the presence of prrsv using reverse transcription pcr protocol. a total of 117 farms ... | 2013 | 23628658 |
| non-structural protein 2 of the porcine reproductive and respiratory syndrome (prrs) virus: a crucial protein in viral pathogenesis, immunity and diagnosis. | porcine reproductive and respiratory syndrome (prrs) is a swine disease of significant economic importance that causes reproductive and respiratory problems in pigs. the replicase non-structural protein 2 (nsp2) of the porcine reproductive and respiratory syndrome virus (prrsv) is recognized as the most variable region within the prrsv genome. this review discusses the molecular characteristics and biological and immunological functions of the prrsv nsp2 and its involvement in the virus's pathog ... | 2013 | 23591056 |
| immune response to orf5a protein immunization is not protective against porcine reproductive and respiratory syndrome virus infection. | porcine reproductive and respiratory syndrome virus (prrsv) is an enveloped rna virus responsible for prrs in swine, a disease with globally significant animal welfare and economic concerns. there is no specific treatment and variably effective immune protection. molecular mechanisms responsible for virulence, pathogenesis and protective immune response remain poorly understood. these factors limit progress toward development of effective measures for prevention and treatment of prrs. a novel pr ... | 2013 | 23578707 |
| pig immune response to general stimulus and to porcine reproductive and respiratory syndrome virus infection: a meta-analysis approach. | the availability of gene expression data that corresponds to pig immune response challenges provides compelling material for the understanding of the host immune system. meta-analysis offers the opportunity to confirm and expand our knowledge by combining and studying at one time a vast set of independent studies creating large datasets with increased statistical power. in this study, we performed two meta-analyses of porcine transcriptomic data: i) scrutinized the global immune response to diff ... | 2013 | 23552196 |
| kinetics of the porcine reproductive and respiratory syndrome virus (prrsv) humoral immune response in swine serum and oral fluids collected from individual boars. | the object of this study was to describe and contrast the kinetics of the humoral response in serum and oral fluid specimens during acute porcine reproductive and respiratory syndrome virus (prrsv) infection. the study involved three trials of 24 boars each. boars were intramuscularly inoculated with a commercial modified live virus (mlv) vaccine (trial 1), a type 1 prrsv field isolated (trial 2), or a type 2 prrsv field isolate (trial 3). oral fluid samples were collected from individual boars ... | 2013 | 23537175 |
| impact of genetic variation and geographic distribution of porcine reproductive and respiratory syndrome virus on infectivity and pig growth. | the porcine reproductive and respiratory syndrome (prrs) is a devastating disease for the pig industry. in this study, we analysed the genetic variability of prrs virus (prrsv) as well as the relationship between the genetic variability, the geographical and temporal distribution of the prrsv strains. moreover, we investigated the association between the glycosylation patterns in prrsv sequences and pigs growth. | 2013 | 23537091 |
| probability of detecting porcine reproductive and respiratory syndrome virus infection using pen-based swine oral fluid specimens as a function of within-pen prevalence. | pen-based oral fluid sampling has proven to be an efficient method for surveillance of infectious diseases in swine populations. to better interpret diagnostic results, the performance of oral fluid assays (antibody- and nucleic acid-based) must be established for pen-based oral fluid samples. therefore, the objective of the current study was to determine the probability of detecting porcine reproductive and respiratory syndrome virus (prrsv) infection in pen-based oral fluid samples from pens o ... | 2013 | 23536612 |
| toll-like receptor ligands enhance the protective effects of vaccination against porcine reproductive and respiratory syndrome virus in swine. | porcine reproductive and respiratory syndrome virus (prrsv) is mainly responsible for the heavy economic losses in pig industry in the world. current vaccination strategies provide only a limited protection. previous studies have demonstrated the immunostimulatory adjuvant effects of toll-like receptor (tlr) ligands, synthetic double-stranded rna polyriboinosinic polyribocytidylic [poly(i:c)], lipoteichoic acid (lta) and cl097 in humans and animals. to study the effects of these compounds on the ... | 2013 | 23523335 |
| suppression of nk cell-mediated cytotoxicity against prrsv-infected porcine alveolar macrophages in vitro. | the adaptive immunity against prrsv has already been studied in depth, but only limited data are available on the innate immune responses against this pathogen. in the present study, we analyzed the interaction between porcine natural killer (nk) cells and prrsv-infected primary porcine alveolar macrophages (pams), since nk cells are one of the most important components of innate immunity and pams are primary target cells of prrsv infection. nk cytotoxicity assays were performed using enriched n ... | 2013 | 23522639 |
| complete genome sequence of a novel natural recombinant porcine reproductive and respiratory syndrome virus isolated from a pig farm in yunnan province, southwest china. | | 2013 | 23516219 |
| conserved nucleotides in the terminus of the 3' utr region are important for the replication and infectivity of porcine reproductive and respiratory syndrome virus. | the 3' untranslated region (3' utr), including the poly (a) tail, reportedly plays an important role in arterivirus replication, but the roles of the cis-acting elements present in the 3' utr of porcine reproductive and respiratory syndrome virus (prrsv) remain largely unknown. in the present study, pcr-based mutagenic analysis was conducted on the 3' utr of prrsv infectious full-length cdna clone paprrs to investigate the structure and function of the conserved terminal nucleotides between the ... | 2013 | 23512575 |
| plasmids expressing porcine interferon gamma up-regulate pro-inflammatory cytokine and co-stimulatory molecule expression which are suppressed by porcine reproductive and respiratory syndrome virus. | porcine reproductive and respiratory syndrome virus (prrsv) suppresses the pro-inflammatory immune response following infection of myeloid antigen-presenting cells. a reduced pro-inflammatory immune response modulates prrsv replication, clinical disease, and persistent infection of the virus. numerous efforts have been made to enhance the pro-inflammatory immune response to prrsv, but only a few attempts have so far elicited satisfactory results. the present study aims to evaluate in vitro the p ... | 2013 | 23507439 |
| in vitro inactivation of porcine reproductive and respiratory syndrome virus and pseudorabies virus by slightly acidic electrolyzed water. | slightly acidic electrolyzed water (saew, ph 5.0-6.5) is a novel disinfectant with environmentally friendly broad spectrum microbial decontamination properties which could have significant utility on farm. two of the most important pathogenic viruses in pigs are porcine reproductive and respiratory syndrome virus (prrsv) and pseudorabies virus (prv). the aim of this study was to evaluate the viricidal effectiveness of saew against prrsv and prv in vitro under different available chlorine concent ... | 2013 | 23489846 |
| effect of saliva stabilisers on detection of porcine reproductive and respiratory syndrome virus in oral fluid by quantitative reverse transcriptase real-time pcr. | this study evaluated the effect of extraction-amplification methods, storage temperature and saliva stabilisers on detection of porcine reproductive and respiratory syndrome virus (prrsv) rna by quantitative reverse transcriptase real-time pcr (qrt-pcr) in porcine oral fluid. the diagnostic performance of different extraction-amplification methods was examined using a dilution series of oral fluid spiked with prrsv. to determine rna stability, porcine oral fluid, with or without commercially ava ... | 2013 | 23489844 |
| pathogenesis of korean type 1 (european genotype) porcine reproductive and respiratory syndrome virus in experimentally infected pregnant gilts. | the aims of this study were to determine (1) the pathogenesis of experimental infection with a korean type 1 porcine reproductive and respiratory syndrome virus (prrsv) by defining the viral distribution and the sites of viral replication and (2) the relationship between viral replication and apoptosis in stillborn fetuses and live born piglets from infected pregnant gilts. at 3 weeks ante partum, four pregnant gilts were inoculated intranasally with korean type 1 prrsv. stillborn fetuses from t ... | 2013 | 23489681 |
| ligation of porcine fc gamma receptor i inhibits levels of antiviral cytokine in response to prrsv infection in vitro. | prrsv infection ade facilitates the attachment and internalization of the virus onto macrophages through fc receptor-mediated endocytosis. fcγri is the activating receptor with a tyrosine-based activating motif (itam) in its cytoplasmic tail, where up-regulates phagocytosis. however, porcine fcγri's role in the antiviral immune response to prrsv infection has not been studied. in this study, our results indicated that selective activation of porcine fcγri in pam cells down-regulated significantl ... | 2013 | 23454095 |
| replacement of the heterologous 5' untranslated region allows preservation of the fully functional activities of type 2 porcine reproductive and respiratory syndrome virus. | the 5' untranslated region (utr) is believed to be vital for the replication of porcine reproductive and respiratory syndrome virus (prrsv), yet its functional mechanism remains largely unknown. in this study, to define the cis-acting elements for viral replication and infectivity, the 5' utr swapping chimeric clones ptlv8 and pshsp5 were constructed based on two different genotypes full-length infectious cdna clone paprrs and pshe backbones. between them, vtlv8 could be rescued from ptlv8 and h ... | 2013 | 23453581 |
| immunohistochemical characterization of type ii pneumocyte proliferation after challenge with type i porcine reproductive and respiratory syndrome virus. | the aim of this study was to characterize histologically and immunohistochemically the lung lesions developing in growing pigs, 10 and 21 days after experimental challenge with a field strain of porcine reproductive and respiratory syndrome virus (prrsv). lung lesions were scored for (1) pneumocyte hypertrophy and hyperplasia, (2) septal mononuclear infiltration, (3) intra-alveolar necrotic debris, (4) intra-alveolar inflammatory cell accumulation and (5) perivascular inflammatory cell accumulat ... | 2016 | 23453491 |
| porcine reproductive and respiratory syndrome virus nsp1β inhibits interferon-activated jak/stat signal transduction by inducing karyopherin-α1 degradation. | porcine reproductive and respiratory syndrome virus (prrsv) inhibits the interferon-mediated antiviral response. type i interferons (ifns) induce the expression of ifn-stimulated genes by activating phosphorylation of both signal transducer and activator of transcription 1 (stat1) and stat2, which form heterotrimers (interferon-stimulated gene factor 3 [isgf3]) with interferon regulatory factor 9 (irf9) and translocate to the nucleus. prrsv nsp1β blocks the nuclear translocation of the isgf3 com ... | 2013 | 23449802 |
| effects on boar semen quality after infection with porcine reproductive and respiratory syndrome virus: a case report. | the effect of porcine reproductive and respiratory syndrome virus (prrsv) on semen quality was examined in a group of 11 spontaneously infected boars in a commercial boar stud. semen samples were collected 4 weeks prior to 4 weeks post-infection (wpi). infection with prrsv of the european genotype subtype 1 (eu-1) was verified by specific quantitative real-time polymerase chain reaction (rt-pcr) in 36% of the serum samples. all boars seroconverted before 4 wpi and remained in normal condition th ... | 2013 | 23442207 |
| pathogenesis of type 1 (european genotype) porcine reproductive and respiratory syndrome virus in male gonads of infected boar. | the objective of this study was to determine the pathogenesis of experimental infection with a type 1 porcine reproductive and respiratory syndrome virus (prrsv) by defining the sites of viral replication and apoptosis in male gonads from infected boars for a period of 21 days after intranasal inoculation. microscopically, hypospermatogenesis and abundant germ cell depletion and death were observed in the testes. such germ cell death occurs by apoptosis, as determined by a characteristic histolo ... | 2013 | 23435841 |
| predicted peptides from non-structural proteins of porcine reproductive and respiratory syndrome virus are able to induce ifn-γ and il-10. | this work describes peptides from non-structural proteins (nsp) of porcine reproductive and respiratory syndrome virus (prrsv) predicted as potential t cell epitopes by bioinfornatics and tested for their ability to induce ifn-γ and il-10 responses. pigs immunized with either genotype 1 or genotype 2 prrsv attenuated vaccines (n=5/group) and unvaccinated pigs (n = 4) were used to test the peptides. swine leukocyte antigen haplotype of each pig was also determined. pigs were initially screened fo ... | 2013 | 23435238 |
| two natural recombinant highly pathogenic porcine reproductive and respiratory syndrome viruses with different pathogenicities. | highly pathogenic porcine reproductive and respiratory syndrome virus (hp-prrsv) is a variant of type 2 prrsv with high virulence. genetic and pathogenic characteristics of hp-prrsv vary rapidly during the evolution. in this study, we determined the complete genome of a hp-prrsv isolate designated 10fuj-2, which shared 98.34 % nucleotide identity with hp-prrsv reference strain jxa1. genomic analyses by phylogenetic tree and recombination detection program confirmed 10fuj-2 to be a recombinant wi ... | 2013 | 23430712 |
| the zinc-finger domain was essential for porcine reproductive and respiratory syndrome virus nonstructural protein-1α to inhibit the production of interferon-β. | porcine reproductive and respiratory syndrome virus (prrsv) has caused one of the most economically devastating and pandemic diseases of swine. previous studies have documented that prrsv nonstructural protein-1α (nsp1α) was an interferon antagonist, but the mechanism by which nsp1α inhibited the interferon (ifn)-β production was unclear. here, by site-directed mutagenesis of the predicted zinc-coordinating residues of the zinc-finger (zf) domain of nsp1α or by deletion of the zf domain of nsp1α ... | 2013 | 23428052 |
| immunization of pigs with a type 2 modified live prrsv vaccine prevents the development of a deadly long lasting hyperpyrexia in a challenge study with highly pathogenic prrsv jx143. | porcine reproductive and respiratory syndrome virus (prrsv) has been confirmed to be the underlying cause of the so-called 'porcine high fever disease' (phfd), a disease that emerged in china in 2006 and subsequently spread over south east asia. the aim of this study was to investigate whether animals challenged with the chinese highly pathogenic prrsv jx143 would be protected by vaccination with single dose of a type 2 modified live virus (mlv) vaccine. forty-four pigs 17-19 days of age were we ... | 2013 | 23422144 |
| bayesian analysis of risk factors for infection with a genotype of porcine reproductive and respiratory syndrome virus in ontario swine herds using monitoring data. | porcine reproductive and respiratory syndrome (prrs) has a worldwide distribution. this economically important endemic disease causes reproductive failure in breeding stock and respiratory tract illness in young pigs. in ontario restricted fragment length polymorphism (rflp) 1-18-4 has been determined as one of the most common virus genotypes. individual-level models (ilms) for infectious diseases, fitted in a bayesian mcmc framework, have been used to describe both the spatial and temporal spre ... | 2013 | 23416041 |
| immunization with dna vaccines containing porcine reproductive and respiratory syndrome virus open reading frames 5, 6, and 7 may be related to the exacerbation of clinical disease after an experimental challenge. | pigs were immunized with dna plasmids containing different open reading frames (orfs) of a porcine reproductive and respiratory syndrome virus (prrsv) genotype i strain. one group was injected with three inoculations of orf7, a second group was immunized with three inoculations of plasmids containing orf5 and orf6, and a third group was kept as controls. later, +21 days after the last inoculation, animals were challenged with the homologous strain. after the challenge, prrsv-specific interferon ... | 2013 | 23409932 |