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Journal of Immunology Research
Volume 2017, Article ID 7407136, 16 pages
Research Article

Fusion to Flaviviral Leader Peptide Targets HIV-1 Reverse Transcriptase for Secretion and Reduces Its Enzymatic Activity and Ability to Induce Oxidative Stress but Has No Major Effects on Its Immunogenic Performance in DNA-Immunized Mice

1Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
2Gamaleja Research Center of Epidemiology and Microbiology, Moscow, Russia
3Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
4Chemistry Department, Belozersky Research Institute of Physico-Chemical Biology of Lomonosov Moscow State University, Moscow, Russia
5Linköping University, Linköping, Sweden
6Riga Stradins University, Riga, Latvia
7M.P. Chumakov Institute of Poliomyelitis and Viral Encephalities, Russian Academy of Sciences, Moscow, Russia

Correspondence should be addressed to Anastasia Latanova; moc.liamg@avonatalaa

Received 28 December 2016; Accepted 13 April 2017; Published 22 June 2017

Academic Editor: Masha Fridkis-Hareli

Copyright © 2017 Anastasia Latanova et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Reverse transcriptase (RT) is a key enzyme in viral replication and susceptibility to ART and a crucial target of immunotherapy against drug-resistant HIV-1. RT induces oxidative stress which undermines the attempts to make it immunogenic. We hypothesized that artificial secretion may reduce the stress and make RT more immunogenic. Inactivated multidrug-resistant RT (RT1.14opt-in) was N-terminally fused to the signal providing secretion of NS1 protein of TBEV (Ld) generating optimized inactivated Ld-carrying enzyme RT1.14oil. Promotion of secretion prohibited proteasomal degradation increasing the half-life and content of RT1.14oil in cells and cell culture medium, drastically reduced the residual polymerase activity, and downmodulated oxidative stress. BALB/c mice were DNA-immunized with RT1.14opt-in or parental RT1.14oil by intradermal injections with electroporation. Fluorospot and ELISA tests revealed that RT1.14opt-in and RT1.14oil induced IFN-γ/IL-2, RT1.14opt-in induced granzyme B, and RT1.14oil induced perforin production. Perforin secretion correlated with coproduction of IFN-γ and IL-2 (). Both DNA immunogens induced strong anti-RT antibody response. Ld peptide was not immunogenic. Thus, Ld-driven secretion inferred little change to RT performance in DNA immunization. Positive outcome was the abrogation of polymerase activity increasing safety of RT-based DNA vaccines. Identification of the molecular determinants of low cellular immunogenicity of RT requires further studies.