RESULTS OF Fc-PROTEIN FUSION TECHNOLOGY APPLICATION FOR VACCINE DESIGN AGAINST INFECTIOUS DISEASES OF ANIMALS AND HUMAN

The main criteria for current vaccines design are effectiveness, efficaciousness and safety. Increasing requirements for vaccine safety and purity push forward not only classical vaccine development, but also new generation vaccine technology, including sub-unit, recombinant, anti-idiotypic, DNA vaccines etc. This recombinant technology has already demonstrated its advantage, efficaciousness and safety in a large field of therapeutic and curative drug development for animal and human (S. Khan et al., 2016). In 2011, six novel drugs were created based on the new Fc-fusion protein technology. Most of the newly developed drugs affect receptor-ligand interactions, acting as antagonists by blocking direct receptor binding, i.e. Enbrel (etanercept; Amgen, USA), Zaltrap (aflibercept; Sanofi, France), Arcalyst (rilonacept; Regeneron, USA), or as agonists for direct stimulation of receptor function which augment immune response as Amevive (alefacept, Astellas, USA) does, or decrease immune response as Nplate (romiplostim; Amgen, USA) does. In this review, we pay attention to the most relevant results from the last few years for virus and bacterial vaccine designed based on Fc-fusion technology. The Fc-chimeras are hybrid sequences in which Fc-fragment of IgG (Fc-IgG) and targeted therapeutic protein are fused in an entire protein molecule (V. Pechtner et al., 2017). In this fusion, the hinge region of Fc-IgG is a flexible spacer between therapeutic protein and conservative part of IgG. It helps to minimize potential negative effect of two functional domains to each other. Therapeutic drugs based on Fc-fusion proteins are divided in three types, the receptor-Fc, peptide-Fc, and monomer-Fc. The Fc-fused proteins have tremendous therapeutic potential, since Fc domain in this molecules helps to specifically augment the pharmaco-dynamics values. Presence of Fc-domain in hybrid molecules prolongs half elimination of protein from plasma, which extends drug therapeutic activity and slows down kidney clearance for large molecules. Here, we summarize the most significant experimental data of Fc-fusion technology application against such pathogens as human immunodeficiency virus (D. Capon et al., 1989), Ebola virus (K. Konduru et al., 2011), Dengue virus (M.Y. Kim et al., 2018), influenza virus (L. Du et al., 2011), Mycobacterium tuberculosis (S. Soleimanpour et al., 2015), classical swine fever virus (Z. Liu et al., 2017). We also discuss the critical aspects of mechanism of action, drug design and Fc-fused protein production. Targeted activation of effector systems boosts protective potential of immuno-genic molecules and broadens its application. The interest of this review is focused on an application of Fc-fused proteins as potential vaccines against infectious human and animal diseases. We also briefly discuss the perspectives of Fc-fused antigens for novel effective medicine developments using African swine fever virus as an example

[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 (IDFR682468) 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 pig Discussion. 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

Analysis of the African Swine Fever Virus Immunomodulatory Proteins

Molecular epidemiology of viral infections traditionally based on the analysis of changes in individual genes or genetic markers. The analysis of the African swine fever virus (ASFV) genes encoding immunomodulatory proteins is an important tool for studying the diversity and evolution of the virus. In this work, we carried out a structural and phylogenetic analysis of the ASF virus immunomodulatory proteins 5EL (A238L gene), I14L (Dp71L gene), K11L (I329L gene). The degree of nucleotide substitutions of the ASFV concatenated genes A238L, I329L and Dp71L revealed purifying (stabilizing) selection at the nucleotide sequences level. The variability characteristic of the selected group of ASFV genes is of great interest for the genetic differences search in immunomodulatory proteins. The sequencing results of the A238L, I329L and Dp71L genes and their phylogenetic analysis showed that these genes are conservative among a large group of ASFV genes. The I329L gene is a genetic marker of common origin. The East African strains (Genotype X) of Dp71L gene have two forms: a long (184 amino acids) and a short (from 70 to 72 amino acids) and is formed by fusion of the 13L and 14L. All ASF virus Russian isolates isolated in 2016–2017 were identical to the reference strain ASFV/Georgia/wb/2007. Characterization of variability 5EL protein, I14L, K11L may be serve to identify target sites in the ASFV genome and to develop vaccines. The obtained data allow to evaluate the genetic diversity of the ASFV immunomodulatory proteins and the dynamics of their evolution, to predict the possible participation of the A238L, I329L and Dp71L genes in the virulence of various ASFV strains