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Adenosine deaminases that act on RNA (ADARs) have been reported to be functional on various viruses. ADAR1 may exhibit antiviral or proviral activity depending on the type of virus. Human immunodeficiency virus (HIV)-1 is the most well-studied lentivirus with respect to its interaction with ADAR1, and variable results have been reported. In this study, we demonstrated that equine ADAR1 (eADAR1) was a positive regulator of equine infectious anemia virus (EIAV), another lentivirus of the Retroviridae family. First, eADAR1 significantly promoted EIAV replication, and the enhancement of viral protein expression was associated with the long terminal repeat ( LTR ) and Rev response element ( RRE ) regions. Second, the RNA binding domain 1 of eADAR1 was essential only for enhancing LTR -mediated gene expression. Third, in contrast with APOBEC proteins, which have been shown to reduce lentiviral infectivity, eADAR1 increased the EIAV infectivity. This study indicated that eADAR1 was proviral rather than antiviral for EIAV. [ABSTRACT FROM AUTHOR]

Recently pseudorabies outbreaks have occurred in many vaccinated farms in China. To identify genetic characteristics of pseudorabies virus (PRV) strains, we obtained the genomic sequences of PRV strains HeN1 and JS, which were compared to 4 PRV genomes and 729 partial gene sequences. PRV strains isolated in China showed marked sequence divergence compared to European and American strains. Phylogenetic analysis revealed that for the first time PRV can be divided into 2 distinct clusters, with Chinese strains being genotype II and PRVs isolated from other countries being genotype I. Restriction fragment length polymorphism analysis confirmed differences between HeN1 and Bartha strains, as did the presence of unique insertion/deletion polymorphisms and microsatellites. This divergence between the two genotypes may have been generated from long-term, independent evolution, which could also explain the low efficacy of the Bartha vaccine in protecting pigs infected with genotype II PRV. [ABSTRACT FROM AUTHOR]

Abstract: Major efforts have been put forth for the development of effective rotavirus vaccines including transgenic plant vaccines. Previous studies have reported that rotavirus VP7 maintains its neutralizing immunity when it is transformed into the potato genome. The present study was aimed at investigating the hereditary stability of VP7-transformed potatoes over fifty generations. The VP7 gene was stably transcribed and expressed in potato cells as detected by RT-PCR and Western blotting. Humeral and mucosal responses were successfully induced in BALB/c mice fed with the fiftieth generation transformed potato tubers. There were no significant differences in serum IgG and fecal IgA between the mice fed with the first and fiftieth generation potatoes (P >0.05). Profiles of cytokines such as IFN-gamma, IL-2, IL-4, IL-5 and TGF-beta in immunized mice showed a naive T-cells bias to Th1 and Th3 polarization. Moreover, specific CTL responses were also detected in C57BL/6 mice fed with transformed potatoes. This research represents a significant step towards the development of rotavirus vaccines derived from a transgenic plant that can be obtained by long-term and large-scale vegetative reproduction. To our knowledge, this is the first finding regarding vaccines derived from plants that can be propagated for many generations. [Copyright &y& Elsevier]

Rotaviruses (RV) are a common cause of severe diarrhea in young children, resulting in nearly one million deaths worldwide annually. Rotavirus VP7 was the rotavirus neutralizing protein. Previous study reported that VP7 DNA vaccine can induce high levels of IgG in mice but cannot protect mice against challenge (Choi, A.H., Basu, M., Rae, M.N., McNeal, M.M., Ward, R.L., 1998. Virology 250, 230–240). We found that rotavirus VP7 could maintain its neutralizing immunity when it was transformed into the potato genome. Mice immunized with the transformed tubers successfully elicited serum IgG and mucosal IgA specific for VP7. The mucosal IgA titer was as high as 1000, while serum IgG titer was only 600. Neutralizing assays indicated that IgA could neutralize rotavirus. These results indicate the potential usefulness of plants for production and delivery of edible rotavirus vaccines. [Copyright &y& Elsevier]