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.