Developing strategies for increasing the immunogenicity of DNA vaccine HIVBr18 based on fusion with human herpes virus type 1 glycoprotein and cytokine coadministration

Author(s)

Vinicius Canato Santana

• Document type: Doctoral Thesis
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Faculdade de Medicina
• Defense date: 07 jul. 2014

Examining board members

Edecio Cunha Neto; Silvia Beatriz Boscardin; Paulo Lee Ho; Maria Notomi Sato; José Ronnie Carvalho de Vasconcelos

• Advisor: Edecio Cunha Neto; Daniela Santoro Rosa

Abstract

The formulation HIVBr18, previously developed and tested, is based on a DNA vaccine encoding 18 conserved and promiscuous HIV-1 CD4 epitopes and after immunization of transgenic mice for many human HLA class II molecules using this DNA vaccine, could be observed proliferation of CD4+ and CD8+ T cells and IFN-y production directed to multiple epitopes encoded by the vaccine. We intend to explore here, strategies based on fusion or combination of epitopes encoded by HIVBr18 vaccine with glycoprotein D (gD) of HSV- 1 and also the coadministration of cytokine-encoding plasmids (pIL-2, -12, -15 and pGM -CSF) aiming to enhance immunogenicity of HIVBr18. The DNA sequence of epitopes encoded by HIVBr18 vaccine was amplified by PCR and cloned into a plasmid that contained the sequence of gD, giving rise to plasmid pVAX-gDh-HIVBr18. After mice immunization, animals immunized with this construct showed similar immune response to the group that received HIVBr18, and also the group of animals that received gDh-HIVBr18 plasmid that had been modified by exchange in peptides order to assure to the molecule a better hydrophobic distribution and allow translocation to the extracellular face of cell membrane. We constructed and injected mice with a bicistronic plasmid expressing gDh and HIVBr18, simultaneously and isolated, but no increase in the magnitude of the immune response was observed. HIVBr18 coadministration with cytokine-encoding plasmids pIL-12, pIL-15 and pGM-CSF, provides an increase in the magnitude of immune response induced against the peptides encoded by the vaccine, and similar breadth. In addition, co-immunization with pGM-CSF induced greater number of polyfunctional CD4 + T cells. We also demonstrate that, even in a low dose approach coadministration of pGM-CSF induced a higher immune response than HIVBr18 alone in the same dose. However, we observed that this cytokine is not a good adjuvant when used in combination with an adenovirus that expresses the 18 HIV-1 epitopes. (AU)

• FAPESP's process: 11/02815-6 - Development of strategies to increase the immunogenicity of the DNA vaccine HIVBr18 based on fusion with GD protein of human herpes virus type 1 (HSV-1) and coadministration of cytokines
• Grantee: vinicius canato santana
• Support type: Scholarships in Brazil - Doctorate