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48
The genome organization of the Nidovirales: similarities and differences between arteri-, toro-, and coronaviruses
- Semin Virol
, 1997
"... Viruses in the families Arteriviridae and Coronaviridae have enveloped virions which contain nonseg-mented, positive-stranded RNA, but the constituent genera differ markedly in genetic complexity and virion structure. Nevertheless, there are striking resemblances among the viruses in the organizatio ..."
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Viruses in the families Arteriviridae and Coronaviridae have enveloped virions which contain nonseg-mented, positive-stranded RNA, but the constituent genera differ markedly in genetic complexity and virion structure. Nevertheless, there are striking resemblances among the viruses in the organization and expression of their genomes, and sequence conservation among the polymerase polyproteins strongly suggests that they have a common ancestry. On this basis, the International Committee on Taxonomy of Viruses recently established a new order, Nidovirales, to contain the two families. Here, the common traits and distinguishing features of the Nidovirales are reviewed. r 1997 Academic Press KEY WORDS: arterivirus; coronavirus; torovirus; polyprotein processing; RNA recombination.
Porcine reproductive and respiratory syndrome virus comparison: divergent evolution on two continents
- J
, 1999
"... This article cites 64 articles, 31 of which can be accessed free ..."
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Cited by 47 (7 self)
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This article cites 64 articles, 31 of which can be accessed free
Identification of a novel structural protein of arteriviruses
- J
, 1999
"... Arteriviruses are positive-stranded RNA viruses with an efficiently organized, polycistronic genome. A short region between the replicase gene and open reading frame (ORF) 2 of the equine arteritis virus (EAV) genome was previously assumed to be untranslated. However, here we report that this segmen ..."
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Arteriviruses are positive-stranded RNA viruses with an efficiently organized, polycistronic genome. A short region between the replicase gene and open reading frame (ORF) 2 of the equine arteritis virus (EAV) genome was previously assumed to be untranslated. However, here we report that this segment of the EAV genome contains the 5 * part of a novel gene (ORF 2a) which is conserved in all arteriviruses. The 3 * part of EAV ORF 2a overlaps with the 5 * part of the former ORF 2 (now renamed ORF 2b), which encodes the GS glycoprotein. Both ORF 2a and ORF 2b appear to be expressed from mRNA 2, which thereby constitutes the first proven example of a bicistronic mRNA in arteriviruses. The 67-amino-acid protein encoded by EAV ORF 2a, which we have provisionally named the envelope (E) protein, is very hydrophobic and has a basic C terminus. An E protein-specific antiserum was raised and used to demonstrate the expression of the novel gene in EAV-infected cells. The EAV E protein proved to be very stable, did not form disulfide-linked oligomers, and was not N-glycosylated. Immunofluorescence and immunoelectron microscopy studies showed that the E protein associates with intracellular membranes both in EAV-infected cells and upon independent expression. An analysis of purified EAV particles revealed that the E protein is a structural protein. By using reverse genetics, we demonstrated that both the EAV E and GS proteins are essential for the production of infectious progeny virus. Arteriviruses are enveloped, positive-stranded RNA viruses
Interplay between Interferon-Mediated Innate Immunity and Porcine Reproductive and Respiratory Syndrome Virus
, 2012
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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
"... porcine reproductive and respiratory syndrome virus ..."
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porcine reproductive and respiratory syndrome virus
The M/GP5 Glycoprotein Complex of Porcine Reproductive and Respiratory Syndrome Virus Binds the Sialoadhesin Receptor in a Sialic Acid-Dependent Manner
, 2010
"... The porcine reproductive and respiratory syndrome virus (PRRSV) is a major threat to swine health worldwide and is considered the most significant viral disease in the swine industry today. In past years, studies on the entry of the virus into its host cell have led to the identification of a number ..."
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The porcine reproductive and respiratory syndrome virus (PRRSV) is a major threat to swine health worldwide and is considered the most significant viral disease in the swine industry today. In past years, studies on the entry of the virus into its host cell have led to the identification of a number of essential virus receptors and entry mediators. However, viral counterparts for these molecules have remained elusive and this has made rational development of new generation vaccines impossible. The main objective of this study was to identify the viral counterparts for sialoadhesin, a crucial PRRSV receptor on macrophages. For this purpose, a soluble form of sialoadhesin was constructed and validated. The soluble sialoadhesin could bind PRRSV in a sialic acid-dependent manner and could neutralize PRRSV infection of macrophages, thereby confirming the role of sialoadhesin as an essential PRRSV receptor on macrophages. Although sialic acids are present on the GP3, GP4 and GP5 envelope glycoproteins, only the M/GP5 glycoprotein complex of PRRSV was identified as a ligand for sialoadhesin. The interaction was found to be dependent on the sialic acid binding capacity of sialoadhesin and on the presence of sialic acids on GP5. These findings not only contribute to a better understanding of PRRSV biology, but the knowledge and tools generated in this study also hold the key to the development of a new generation of PRRSV
Phylogenetic characterization of genes encoding for glycoprotein 5 and membrane protein of PRRSV isolate HH08
"... A porcine reproductive and respiratory syndrome virus (PRRSV) was obtained from clinic samples. Genes 5 and 6 encoding for the viral glycoprotein 5 and a membrane protein of the PRRSV designated as HH08 were amplified by reverse transcription-PCR. These sequences were compared with reference sequenc ..."
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A porcine reproductive and respiratory syndrome virus (PRRSV) was obtained from clinic samples. Genes 5 and 6 encoding for the viral glycoprotein 5 and a membrane protein of the PRRSV designated as HH08 were amplified by reverse transcription-PCR. These sequences were compared with reference sequences derived from different geographical locations. The results indicated that the virus belongs to the North American type rather than European. Comparative analyses of the genetic diversity between the PRRSV isolate HH08 and other Chinese as well as foreign reference strains of PRRSV were discussed based on the sequence comparison and the topology of phylogenetic trees constructed in this study.
N-linked glycosylation of GP5 of porcine reproductive and respiratory syndrome virus is critically important for virus replication in
, 2012
"... It has been proposed that the N-linked glycan addition at certain sites in GP5 of porcine reproductive and respiratory syndrome virus (PRRSV) is important for production of infectious viruses and viral infectivity. However, such specific N-linked glycosyla-tion sites do not exist in some field PRRSV ..."
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It has been proposed that the N-linked glycan addition at certain sites in GP5 of porcine reproductive and respiratory syndrome virus (PRRSV) is important for production of infectious viruses and viral infectivity. However, such specific N-linked glycosyla-tion sites do not exist in some field PRRSV isolates. This implies that the existence of GP5-associated glycan per se is not vital to the virus life cycle. In this study, we found that mutation of individual glycosylation sites at N30, N35, N44, and N51 in GP5 did not affect virus infectivity in cultured cells. However, the mutants carrying multiple mutations at N-linked glycosylation sites in GP5 had significantly reduced virus yields compared with the wild-type (wt) virus. As a result, no viremia and antibody response were detected in piglets that were injected with a mutant without all N-linked glycans in GP5. These results suggest that the N-linked glycosylation of GP5 is critically important for virus replication in vivo. The study also showed that removal of N44-linked glycan fromGP5 increased the sensitivity of mutant virus to convalescent-phase serum samples but did not elicit a high-level neutralizing antibody response to wt PRRSV. The results obtained from the present study have made significant con-tributions to better understanding the importance of glycosylation of GP5 in the biology of PRRSV. Porcine reproductive and respiratory syndrome virus (PRRSV)is a member of the order Nidovirales, family Arteriviridae, which also includes equine arteritis virus (EAV), lactate dehydro-genase-elevating virus (LDV), and simian hemorrhagic fever virus (SHFV) (35, 38). PRRSV has been further classified into two ge-
Comparative Measurement of Cell-Mediated Immune Responses of Swine to the M and N Proteins of Porcine Reproductive and
, 2009
"... The principal objectives of this study were to develop autologous antigen-presenting cells (APCs) and to characterize the antigen-specific T-cell responses to the M and N proteins of porcine reproductive and respiratory syndrome virus (PRRSV) by using those APCs in outbred pigs. The orf6 and orf7 ge ..."
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The principal objectives of this study were to develop autologous antigen-presenting cells (APCs) and to characterize the antigen-specific T-cell responses to the M and N proteins of porcine reproductive and respiratory syndrome virus (PRRSV) by using those APCs in outbred pigs. The orf6 and orf7 genes fused with porcine granulocyte-macrophage colony-stimulating factor (GM-CSF) were cloned into the mammalian ex-pression vector to generate two plasmid DNAs, namely, pcDNA3.1-GM-CSF-PRRSV-M and pcDNA3.1-GM-CSF-PRRSV-N. Three of six pigs in two groups were repeatedly immunized with either plasmid DNA construct, and four pigs were used as controls. The recombinant M and N proteins fused with the protein transduction domain (PTD) of the human immunodeficiency virus type 1 transactivator of transcription protein were employed to generate major histocompatibility complex-matched autologous APCs from each pig. The levels of T-cell proliferation and gamma interferon (IFN-) synthesis were compared between pigs immunized with the two plasmid DNAs after stimulation of the peripheral blood mononuclear cells (PBMCs) of each pig with the autologous antigen-presenting dendritic cells and PBMCs. Higher levels of T-cell proliferation and IFN- synthesis were identified in PBMCs isolated from the pigs immunized with pcDNA3.1-GM-CSF-PRRSV-M than in those isolated from the pigs immunized with pcDNA3.1-GM-CSF-PRRSV-N. By way of contrast, serum antibodies were detected only in pigs immunized with pcDNA3.1-GM-CSF-PRRSV-N. However, no T-cell
