**In silico Designed Ebola Virus T-Cell Multi-Epitope DNA Vaccine Constructions Are Immunogenic in Mice**

**Sergei I. Bazhan \*, Denis V. Antonets, Larisa I. Karpenko, Svetlana F. Oreshkova, Olga N. Kaplina, Ekaterina V. Starostina, Sergei G. Dudko, Sofia A. Fedotova and Alexander A. Ilyichev**

State Research Center of Virology and Biotechnology "Vector", Koltsovo, 630559 Novosibirsk Region, Russia; antonec@nprog.ru (D.V.A.); karpenko@vector.nsc.ru (L.I.K.); sv\_oresh@mail.ru (S.F.O.);

okaplina@vector.nsc.ru (O.N.K.); starostina\_ev@vector.nsc.ru (E.V.S.); s.g.dudko@gmail.com (S.G.D.);

hz.smoke.on.the.water@gmail.com (S.A.F.); ilyichev@vector.nsc.ru (A.A.I.)

**\*** Correspondence: bazhan@vector.nsc.ru; Tel.: +7-383-363-47-00 (ext. 2001)

Received: 5 March 2019; Accepted: 27 March 2019; Published: 29 March 2019

**Abstract:** *Background*: The lack of effective vaccines against Ebola virus initiates a search for new approaches to overcoming this problem. The aim of the study was to design artificial polyepitope T-cell immunogens—candidate DNA vaccines against Ebola virus and to evaluate their capacity to induce a specific immune response in a laboratory animal model. *Method*: Design of two artificial polyepitope T-cell immunogens, one of which (EV.CTL) includes cytotoxic and the other (EV.Th)—T-helper epitopes of Ebola virus proteins was carried out using original TEpredict/PolyCTLDesigner software. Synthesized genes were cloned in pcDNA3.1 plasmid vector. Target gene expression was estimated by synthesis of specific mRNAs and proteins in cells transfected with recombinant plasmids. Immunogenicity of obtained DNA vaccine constructs was evaluated according to their capacity to induce T-cell response in BALB/c mice using IFNγ ELISpot and ICS. *Results*: We show that recombinant plasmids pEV.CTL and pEV.Th encoding artificial antigens provide synthesis of corresponding mRNAs and proteins in transfected cells, as well as induce specific responses both to CD4+ and CD8+ T-lymphocytes in immunized animals. *Conclusions*: The obtained recombinant plasmids can be regarded as promising DNA vaccine candidates in future studies of their capacity to induce cytotoxic and protective responses against Ebola virus.

**Keywords:** ebola virus disease; artificial T-cell antigens; DNA vaccine constructs; computer design; gene expression; immunogenicity
