Original Research ARTICLE
Dendritic cell targeting using a DNA vaccine induces specific antibodies and CD4+ T cells to the dengue virus envelope protein domain III
- 1Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, Brazil
- 2Department of Microbiology, Immunology and Parasitology, Federal University of São Paulo, Brazil
Dengue fever has become a global threat, causing millions of infections every year. An effective vaccine against all four serotypes of dengue virus (DENV) has not been developed yet. Among the different vaccination strategies available today, DNA vaccines are safe and practical, but currently induce relatively weak immune responses in humans. In order to improve immunogenicity, antigens may be targeted to dendritic cells (DCs), the main antigen presenting cells and orchestrators of the adaptive immune response, inducing T and B cell activation. It was previously shown that a DNA vaccine encoding a fusion protein comprised of an antigen and a single-chain Fv antibody (scFv) specific for the DC endocytic receptor DEC205 induced strong immune responses to the targeted antigen. In this work, we evaluate this strategy to improve the immunogenicity of dengue virus (DENV) proteins. Plasmids encoding the scFv αDEC205, or an isotype control (scFv ISO), fused to the DENV2 envelope protein domain III (EDIII) were generated, and EDIII specific immune responses were evaluated in immunized mice. BALB/c mice were intramuscularly (i.m.) immunized three times with plasmid DNAs encoding either scDEC-EDIII or scISO-EDIII followed by electroporation. Analyses of the antibody responses indicated that EDIII fusion with scFv targeting the DEC205 receptor significantly enhanced serum anti-EDIII IgG titers that inhibited DENV2 infection. Similarly, mice immunized with the scDEC-EDIII plasmid developed a robust CD4+ T cell response to the targeted antigen, allowing the identification of two linear epitopes recognized by the BALB/c haplotype. Taken together, these results indicate that targeting DENV2 EDIII protein to DCs using a DNA vaccine encoding the scFv αDEC205 improves both antibody and CD4+ T cell responses. This strategy opens perspectives for the use of DNA vaccines that encode antigens targeted to DCs as a strategy to increase immunogenicity.
Keywords: dengue fever, Dendritic Cells, Envelope protein domain III, single chain Fv antibody, DNA vaccine
Received: 05 Oct 2018;
Accepted: 10 Jan 2019.
Edited by:Urszula Krzych, Walter Reed Army Institute of Research, United States
Reviewed by:Sri H. Ramarathinam, Monash University, Australia
Tejram Sahu, W. Harry Feinstone Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, United States
Copyright: © 2019 Zaneti, Yamamoto, Sulczewski, Almeida, Souza, Ferreira, Maeda, Sales, Rosa, Ferreira and Boscardin. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: Prof. Silvia B. Boscardin, University of São Paulo, Department of Parasitology, Institute of Biomedical Sciences, São Paulo, Brazil, email@example.com