Enhancement of Immune Responses by Guanosine-Based Particles in DNA Plasmid Formulations against Infectious Diseases

J Immunol Res. 2019 May 22:2019:3409371. doi: 10.1155/2019/3409371. eCollection 2019.

Abstract

Immunogenicity of DNA vaccines can be efficiently improved by adding adjuvants into their formulations. In this regard, the application of nano- and microparticles as vaccines adjuvants, or delivery systems, provides a powerful tool in designing modern vaccines. In the present study, we examined the role of "Supramolecular Hacky Sacks" (SHS) particles, made via the hierarchical self-assembly of a guanosine derivative, as a novel immunomodulator for DNA plasmid preparations. These plasmids code for the proteins HIV-1 Gag (pGag), the wild-type vaccinia virus Western Reserve A27 (pA27L), or a codon-optimized version of the latter (pOD1A27Lopt), which is also linked to the sequence of the outer domain-1 (OD1) from HIV-1 gp120 protein. We evaluated the enhancement of the immune responses generated by our DNA plasmid formulations in a murine model through ELISpot and ELISA assays. The SHS particles increased the frequencies of IFN-γ-producing cells in mice independently immunized with pGag and pA27L plasmids. Moreover, the addition of SHS to pGag and pA27L DNA plasmid formulations enhanced the production of IFN-γ (Th1-type) over IL-4 (Th2-type) cellular immune responses. Furthermore, pGag and pA27L plasmids formulated with SHS, triggered the production of antigen-specific IgG in mice, especially the IgG2a isotype. However, no improvement of either of those adaptive immune responses was observed in mice receiving pOD1A27Lopt+SHS. Here, we demonstrated that SHS particles have the ability to improve both arms of adaptive immunity of plasmid coding "wild-type" antigens without additional strategies to boost their immunogenicity. To the best of our knowledge, this is the first report of SHS guanosine-based particles as DNA plasmid adjuvants.

MeSH terms

  • AIDS Vaccines / genetics
  • AIDS Vaccines / immunology
  • Animals
  • Antibody Specificity / immunology
  • Cytokines / biosynthesis
  • Enzyme-Linked Immunospot Assay
  • Female
  • Guanosine* / chemistry
  • HIV Antibodies / immunology
  • HIV-1 / immunology
  • Humans
  • Immunity, Humoral
  • Immunization
  • Immunogenicity, Vaccine
  • Immunoglobulin G / immunology
  • Interferon-gamma / biosynthesis
  • Mice
  • Nanoparticles* / chemistry
  • Plasmids* / chemistry
  • Plasmids* / genetics
  • Plasmids* / immunology
  • Vaccines, DNA / chemistry
  • Vaccines, DNA / genetics
  • Vaccines, DNA / immunology*

Substances

  • AIDS Vaccines
  • Cytokines
  • HIV Antibodies
  • Immunoglobulin G
  • Vaccines, DNA
  • Guanosine
  • Interferon-gamma