Molecular characterization of African swine fever virus isolates originating from outbreaks in the Russian Federation between 2007 and 2011

African swine fever is one of the most important viral diseases of pigs and which caused significant economic damage on the pig production worldwide. Nowadays, it is still present on the African continent, in Transcaucasus countries (TCC), on Island of Sardinia and in Russia. Outbreaks of the disease have been reported in Russia for the last four years, affected especially the Southern Federal District of the country. Since 2010, a new outbreak area has been observed in the Northwestern Federal District.In order to study the evolution of African swine fever virus (ASFV) isolates, strains were collected in the Russian Federation from 2007 to 2011 and investigated by means of partial sequencing and fragment length polymorphism. In detail, 7 variable regions, namely B646L, E183L, I196L, B602L, I73R/I329R, I78R/I215L and KP86R were investigated. Phylogenetic analyses revealed 100% nucleotide identity of B646L and E183L gene sequences of all examined isolates. All isolates formed one genetic cluster within genotype II. Moreover, no amplified fragment length polymorphism (AFLP) was observed for B602L, I196L, I73R/I329R, and I78R/I215L genes. The flanking primers used to amplify the KP86R gene failed to amplify a product in all the isolates. The obtained data strongly suggests that only one ASFV virus variant caused the outbreaks from 2007 to 2011 in the territory of the Russian Federation. © 2012 Elsevier B.V

In silico prediction of B- and T-cell epitopes in the CD2v protein of african swine fever virus (African swine fever virus, Asfivirus, Asfarviridae)

Introduction. African swine fever virus (ASF) is a large DNA virus that is the only member of the Asfarviridae family. The spread of the ASF virus in the territory of the Russian Federation, Eastern Europe and China indicates the ineffectiveness of existing methods of combating the disease and reinforces the urgent need to create effective vaccines. One of the most significant antigens required for the formation of immune protection against ASF is a serotype-specific CD2v protein.The purpose of the study. This study presents the results of immuno-informatics on the identification of B- and T-cell epitopes for the CD2v protein of the ASF virus using in silico prediction methods.Material and methods. The primary sequence of the CD2v protein of the ASFV virus strain Georgia 2007/1 (ID-FR682468) was analyzed in silico by programs BCPred, NetCTLpan, VaxiJen, PVS and Epitope Conservancy Analysis.Results. Using the BCPred and VaxiJen programs, 4 major B-cell immunogenic epitopes were identified. Analysis of the secretory region of ASF virus CD2v protein in NetCTLpan revealed 5 T-cell epitopes from the 32nd to the 197th position of amino acids that cross-link from the 1st to the 13th allele of the MHC-I of pigDiscussion. This study presents the results in silico prediction to identify B- and T-cell epitopes of ASF virus CD2v protein. The soluble region of the CD2v protein can be included in the recombinant polyepitope vaccine against African swine fever.Conclusion. B- and T-cell epitopes in the secretory region of the CD2v protein (from 17 to 204 aa) of ASF virus were identified by in silico prediction. An analysis of the conservatism of the identified B- and T-cell epitopes allowed us to develop a map of the distribution of immune epitopes in the CD2v protein sequence.</jats:p

2. African swine fever virus: cellular and molecular aspects

Over the last years, African swine fever virus (ASFV) has spread to several European and Asian countries, presently showing an unprecedented geographic distribution. The present chapter focuses on current knowledge and advances in the cellular/molecular features of ASFV, highlighting the gaps and future perspectives. The first half of the chapter addresses the general features of ASFV, its phylogeny and evolution, together with an overview of the viral transcription mechanisms and transcriptomics and the proteomics of ASFV-infected cells. The second half of the chapter summarises the structure and composition of the infectious ASFV particle, the mechanisms that lead to the infection and replication of the virus at the cellular level, and the viral-pig interactions. The last part of the chapter presents an overview of the currently described antiviral agents against ASFV