Mumps Virus SH Protein Inhibits NF-κB Activation by Interacting with Tumor Necrosis Factor Receptor 1, Interleukin-1 Receptor 1, and Toll-Like Receptor 3 Complexes.

The mumps virus (MuV) small hydrophobic protein (SH) is a type I membrane protein expressed in infected cells. SH has been reported to interfere with innate immunity by inhibiting tumor necrosis factor alpha (TNF-α)-mediated apoptosis and NF-κB activation. To elucidate the underlying mechanism, we generated recombinant MuVs (rMuVs) expressing the SH protein with an N-terminal FLAG epitope or lacking SH expression due to the insertion of three stop codons into the gene.

Seroprevalence of human polyomavirus 9 and cross-reactivity to African green monkey-derived lymphotropic polyomavirus.

Human polyomavirus 9 (HPyV9) was discovered recently in immunocompromised patients and shown to be genetically closely related to B-lymphotropic polyomavirus (LPyV). No serological data are available for HPyV9, but human antibodies against LPyV have been reported previously. To investigate the seroepidemiology of HPyV9 and the sero-cross-reactivity between HPyV9 and LPyV, a capsomer-based IgG ELISA was established using the major capsid protein VP1 of HPyV9 and LPyV.

Analysis of porcine circovirus type 1 detected in Rotarix vaccine.

A metagenomic analysis of live human vaccines has recently demonstrated the presence of porcine circovirus type 1 (PCV1) DNA in the paediatric vaccine Rotarix used in the prevention of acute gastroenteritis. Using real-time PCR for PCV1, titres of PCV1 DNA in several batches of Rotarix were found to be in the order of 6-7 log(10) copies per dose. Pre-treatment of the reconstituted vaccine with the nuclease Benzonase, followed by extraction of nucleic acid and quantification of PCV1 DNA by real-time PCR, revealed that there was no loss of PCV1 DNA titre compared to untreated controls, suggesting that the porcine viral DNA was present in the vaccine in an encapsidated form.

Mumps virus small hydrophobic protein targets ataxin-1 ubiquitin-like interacting protein (ubiquilin 4).

The small hydrophobic (SH) protein of mumps virus has been reported to interfere with innate immunity by inhibiting tumour necrosis factor alpha-mediated apoptosis. In a yeast two-hybrid screen we have identified the ataxin-1 ubiquitin-like interacting protein (A1Up) as a cellular target of the SH protein. A1Up contains an amino-terminal ubiquitin-like (UbL) domain, a carboxy-terminal ubiquitin-associated (UbA) domain and two stress-inducible heat shock chaperonin-binding (Sti1) motifs.

Porcine circoviruses--small but powerful.

When porcine circovirus type 1 (PCV1) was isolated more than 40 years ago as a non-pathogenic contaminant of a porcine kidney cell line, enthusiasm and curiosity kept within reasonable limits. Virologists became more interested, when a second variant was isolated and termed PCV2, because PCV2 is linked to postweaning multisystemic wasting disease (PMWS), a new emerging multifactorial disease in swine. Both PCV1 and PCV2 are small and rather simply organized and express only few proteins.

Measles viruses of genotype H1 evade recognition by vaccine-induced neutralizing antibodies targeting the linear haemagglutinin noose epitope.

The linear haemagglutinin noose epitope (HNE; aa 379-410) is a protective B-cell epitope and considered to be highly conserved in both the vaccine and the wild-type measles virus (MeV) haemagglutinin (H) proteins. Vaccine virus-derived monoclonal antibodies (mAbs) BH6 and BH216, which target the HNE, neutralized MeVs of genotypes B3, C2, D4, D5, D6, D7 and D8, and the vaccine strain Edmonston Zagreb. In the case of genotype H1, only strain Berlin.

Cloning and expression of a truncated pigeon circovirus capsid protein suitable for antibody detection in infected pigeons.

Infections with pigeon circovirus (PiCV) (also termed columbid circovirus) occur in meat and racing pigeons (Columba livia) of all ages and have been reported worldwide. A PiCV infection is associated with immunosuppression and the development of young pigeon disease syndrome. An indirect enzyme-linked immunosorbent assay (ELISA) for the detection of virus-specific serum antibody was developed for research purposes.

Interaction of the replication proteins and the capsid protein of porcine circovirus type 1 and 2 with host proteins.

Porcine circovirus type 2 (PCV2) is an important pathogen in swine, whereas porcine circovirus type 1 (PCV1) is apathogenic. To analyze the interactions between PCV and its host, we have used a yeast two-hybrid assay to identify cellular proteins interacting with Cap and Rep proteins of both PCV genotypes. Six cellular proteins were found to interact with Cap (MKRN1, gC1qR, Par-4, NAP1, NPM1 and Hsp40) and three with Rep (ZNF265, TDG and VG5Q).

Gene expression of the human Torque Teno Virus isolate P/1C1.

Torque Teno Virus (TTV) has been assigned to the floating genus Anellovirus. TTV ssDNA genomes have a size of 3.6 to 3.

Functional analysis of cis- and trans-acting replication factors of porcine circovirus type 1.

The replication proteins Rep and Rep' of porcine circovirus type 1 (PCV1) are both capable of introducing and resealing strand discontinuities at the viral origin of DNA replication in vitro underlying genome amplification by rolling-circle replication. The PCV1 origin of replication encompasses the minimal binding site (MBS) of the Rep and Rep' proteins and an inverted repeat with the potential to form a stem-loop. In this study, both elements of the PCV1 origin were demonstrated to be essential for viral replication in transfected cells.

Demonstration of nicking/joining activity at the origin of DNA replication associated with the rep and rep' proteins of porcine circovirus type 1.

The replication of porcine circovirus type 1 (PCV1) is thought to occur by rolling-circle replication (RCR), whereby the introduction of a single-strand break generates a free 3'-hydroxyl group serving as a primer for subsequent DNA synthesis. The covalently closed, single-stranded genome of PCV1 replicates via a double-stranded replicative intermediate, and the two virus-encoded replication-associated proteins Rep and Rep' have been demonstrated to be necessary for virus replication. However, although postulated to be involved in RCR-based virus replication, the mechanism of action of Rep and Rep' is as yet unknown.

Infection studies on human cell lines with porcine circovirus type 1 and porcine circovirus type 2.

Background: The lack of human donor organs in allotransplantation has led to a proposal for the use of porcine tissues and organs as alternative therapeutic material for humans. Besides immunological problems like graft rejection, one of the major concerns is the transmission of porcine microorganisms as viruses, bacteria and fungi to a human recipient.

Methods: Human cell lines have been infected with porcine circovirus type 1 (PCV1) and porcine circovirus type 2 (PCV2) to investigate whether PCV can infect and replicate in human epithelial cells and lymphocytes.

Molecular biology of Porcine circovirus: analyses of gene expression and viral replication.

The rep gene of Porcine circovirus type 1 directs the synthesis of two proteins. The full-length protein Rep is 312 amino acids in size, the spliced variant Rep' is truncated (168 aa) and exon 2 is frame-shifted. Replication of PCV1 DNA depends on synthesis of both proteins.

New reporter gene-based replication assay reveals exchangeability of replication factors of porcine circovirus types 1 and 2.

Two types of porcine circovirus (PCV), which differ in their pathogenicity, are known. PCV type 2 (PCV2) is the etiological agent of postweaning multisystemic wasting syndrome in swine, while PCV1 has not yet been linked to a disease. Corroborating earlier observations in PCV1, transcript mapping revealed that the rep gene of PCV2 encodes two products, the full-length protein Rep and the spliced version Rep' and that the simultaneous expression of Rep and Rep' proteins is essential for initiation of replication of PCV2.