In silico design of influenza a virus artificial epitope-based T-cell antigens and the evaluation of their immunogenicity in mice

Abstract

The polyepitope strategy is promising approach for successfully creating a broadly protective flu vaccine, which targets T-lymphocytes (both CD4+ and CD8+) to recognise the most conserved epitopes of viral proteins. In this study, we employed a computer-aided approach to develop several artificial antigens potentially capable of evoking immune responses to different virus subtypes. These antigens included conservative T-cell epitopes of different influenza A virus proteins. To design epitope-based antigens we used experimentally verified information regarding influenza virus T-cell epitopes from the Immune Epitope Database (IEDB) (http://www.iedb.org). We constructed two “human” and two “murine” variants of polyepitope antigens. Amino acid sequences of target polyepitope antigens were designed using our original TEpredict/PolyCTLDesigner software. Immunogenic and protective features of DNA constructs encoding “murine” target T-cell immunogens were studied in BALB/c mice. We showed that mice groups immunised with a combination of computer-generated “murine” DNA immunogens had a 37.5% survival rate after receiving a lethal dose of either A/California/4/2009 (H1N1) virus or A/Aichi/2/68 (H3N2) virus, while immunisation with live flu H1N1 and H3N2 vaccine strains provided protection against homologous viruses and failed to protect against heterologous viruses. These results demonstrate that mechanisms of cross-protective immunity may be associated with the stimulation of specific T-cell responses. This study demonstrates that our computer-aided approach may be successfully used for rational designing artificial polyepitope antigens capable of inducing virus-specific T-lymphocyte responses and providing partial protection against two different influenza virus subtypes.

Communicated by Ramaswamy H. Sarma

Graphical Abstract

Keywords:

• In silico design
• T-cell epitope-based antigens
• influenza virus
• DNA vaccine
• immunogenicity

Disclosure statement

The authors declare that they have no known competing financial interests or personal relationships that may appear to influence the work reported in this paper.

Authors’ contributions

Denis Antonets and Sergei Bazhan designed vaccine constructions, planned the experiments and analyzed and interpreted the data. Denis Antonets wrote scripts and programs. Tatiana Ilyicheva and Larisa Karpenko planned experiments, and analyzed and interpreted data. Olga Kaplina, Ekaterina Starostina, Vasiliy Marchenko, Olga Volkova, and Anastasiya Bakulina conducted experimental work and acquired data. The manuscript was written by Sergei Bazhan, Denis Antonets, Tatiana Ilyicheva, and Larisa Karpenko. All authors read and approved the final manuscript. All authors attest they meet ICMJE criteria for authorship.

Additional information

Funding

The study was funded by the Russian Science Foundation Grant [15-15-00047] and partly by the state assignment of FBRI SRC VB “Vector”, Rospotrebnadzor