Production of crimean congo hemorrhagic fever virus glycoprotein gc in eukaryotic expression system

Crimean-Congo Hemorrhagic Fever Virus is an important tick borne pathogen causing haemorrhagic fever with case fatality rate of up to 30%. The disease is gaining a wider dissemination throughout Africa, Eastern Europe and the Middle East, Eurasia and Asia. Crimean-Congo Hemorrhagic Fever Virus is a negative-sense RNA virus of the genus Nairovirus of the Bunyaviridae family. The geographic range within CCHF virus is the most extensive among the tickborne viruses affecting human health and the second most widespread of all medically important arboviruses after dengue viruses. The three genome segments encode four structural proteins—the RNA-dependent RNA polymerase (L protein) is encoded by the large (L) segment, the glycoproteins (Gn and Gc; previously referred to as G1 and G2) are encoded by the medium (M) segment, and the nucleocapsid protein (N) is encoded by the small (S) segment. Crimean Congo Hemorrhagic Fever Virus genome M segment encodes an unusually large (in comparison to members of other genera) polyprotein (1,684 amino acids in length) containing the two major structural glycoproteins, Gn and Gc, that are posttranslationally processed from precursors PreGn and PreGc by SKI-1 and SKI-1-like proteases, respectively. As the only virally encoded membrane proteins, Gn and Gc must interact with cell surface receptors, mediate the entry of virus into cells, and serve as targets for neutralizing antibodies. Although studies on the immunological properties of nucleocapsid protein in CCHFV have been found in the literature, studies on the glycoproteins Gc and Gn of this virus have yet to be scrutinized. In this study, we aimed to produce functional recombinant protein to be investigated humoral immune response against CCHFV Gc. For this purpose, GC from Kelkit strain produced and purified in Pichia pastoris and was tested in EIA and Western blot assays with CCHFV-infected human sera. In the studies, the authentic antigenicity of Gc was demonstrated in humans and rabbits. Studies have shown that P. pastoris is a suitable model organism to produce CCHFV glycoprotein Gc. Further studies conducted on the diagnoctics and immunology of CCHFV with Gc produced in P. pastoris warrented. Keywords: Crimean Congo Hemorrhagic Fever Virus; glycoprotein; yeast; Pichia pastoris