Alternative inactivated poliovirus vaccines adjuvanted with Quillaja brasiliensis or Quil-a saponins are equally effective in inducing specific immune responses

PLoS One. 2014 Aug 22;9(8):e105374. doi: 10.1371/journal.pone.0105374. eCollection 2014.

Abstract

Inactivated polio vaccines (IPV) have an important role at the final stages of poliomyelitis eradication programs, reducing the risks associated with the use of attenuated polio vaccine (OPV). An affordable option to enhance vaccine immunogenicity and reduce costs of IPV may be the use of an effective and renewable adjuvant. In the present study, the adjuvant activity of aqueous extract (AE) and saponin fraction QB-90 from Quillaja brasiliensis using poliovirus antigen as model were analyzed and compared to a preparation adjuvanted with Quil-A, a well-known saponin-based commercial adjuvant. Experimental vaccines were prepared with viral antigen plus saline (control), Quil-A (50 µg), AE (400 µg) or QB-90 (50 µg). Sera from inoculated mice were collected at days 0, 28, 42 and 56 post-inoculation of the first dose of vaccine. Serum levels of specific IgG, IgG1 and IgG2a were significantly enhanced by AE, QB-90 and Quil-A compared to control group on day 56. The magnitude of enhancement was statistically equivalent for QB-90 and Quil-A. The cellular response was evaluated through DTH and analysis of IFN-γ and IL-2 mRNA levels using in vitro reestimulated splenocytes. Results indicated that AE and QB-90 were capable of stimulating the generation of Th1 cells against the administered antigen to the same extent as Quil-A. Mucosal immune response was enhanced by the vaccine adjuvanted with QB-90 as demonstrated by increases of specific IgA titers in bile, feces and vaginal washings, yielding comparable or higher titers than Quil-A. The results obtained indicate that saponins from Q. brasiliensis are potent adjuvants of specific cellular and humoral immune responses and represent a viable option to Quil-A.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adjuvants, Immunologic*
  • Animals
  • Antibodies, Viral / immunology
  • Antibody Specificity / immunology
  • Antigens, Viral / immunology
  • Cytokines / genetics
  • Cytokines / metabolism
  • Disease Models, Animal
  • Female
  • Gene Expression
  • Hypersensitivity, Delayed / immunology
  • Immunity, Mucosal
  • Immunization
  • Immunoglobulin A / immunology
  • Immunoglobulin G / immunology
  • Mice
  • Poliomyelitis / genetics
  • Poliomyelitis / immunology
  • Poliomyelitis / prevention & control*
  • Poliovirus Vaccine, Inactivated / immunology*
  • Quillaja / chemistry
  • Quillaja / immunology*
  • Quillaja Saponins
  • Saponins / immunology*

Substances

  • Adjuvants, Immunologic
  • Antibodies, Viral
  • Antigens, Viral
  • Cytokines
  • Immunoglobulin A
  • Immunoglobulin G
  • Poliovirus Vaccine, Inactivated
  • Quillaja Saponins
  • Saponins
  • Quil A

Grants and funding

This work was funded by the Brazilian Agencies National Comission for Improvement of Higher Education Personnel (www.capes.gov.br, Capes-Udelar number CGCI 040/2011) to GG and National Council for Scientific and Technological Development (www.cnpq.br, CNPq number 306079/2013-5) to AGFN. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.