- Poster presentation
- Open access
- Published:
Saccharomyces boulardii ingestion increases the humoral response of a DNA vaccine against leptospirosis in mice
BMC Proceedings volume 8, Article number: P160 (2014)
Background
DNA vaccines are a good option to generate a desired antigen using the cellular machinery of the vaccinated subject. This kind of vaccine can induce both of the humoral and cellular immune response, and show high stability and easy working, as well as offer a low-cost production. and safety for immune compromised patients [1]. However, some disadvantages, such as the low transfection rate and low immunogenicity, makes necessary the use of multiple doses [2, 3]. Therefore, several studies have been conducted trying to increase the immune response generated by the DNA vaccines. Sacharomyces boulardii, a probiotic yeast that is capable to increase the host immune response [4], was not previously evaluated as an adjuvant for DNA vaccines. Thereby, in the present study we evaluated the S. boulardii capacity to increase the humoral response of mice using DNA vaccines against a fragment of the leptospiral antigen LigAcloned in the mammalian expression plasmid pTARGET [4, 5].
Material and methods
Four to six month-old Female BALB/c mice were separated into 2 groups of 12 animals each. Group 1 (G1, control) were fed with antimicrobial-free ration; group 2 (G2) with the same ration containing 108cfu.g-1 of S. boulardii, 14 days before the first immunization, for adaptation, and during all the experiment. The immunization protocol consisted in 3 doses (days 0, 14 and 21) of 100 µg of the pTARGET/ligAni plasmid injected intramuscularly. Blood samples were collected from the retro eye venous plexus of the animals on days 0, 13, 20 and 27 for the humoral immune response evaluation of each immunization through indirect ELISA, using recombinant LigAni (5 µg.mL-1) as antigen and serum dilutions 1:30 in PBS-T.ELISA units were calculated by dividing the mean absorbance of each group by the mean absorbance of the day 0. The student's test-t was performed to determine significant differences (p < 0.05) between the groups.
Results and conclusions
Sera from G2 has shown ELISA units statistically higher than the sera from G1 after the second (p < 0.0001) and third immunization (p = 0.0264). In addition, there was nosignificant difference between the second and third immunizations of G2. This way, the results indicate that using S. boulardii as adjuvant, only two immunizations are sufficient to obtain an adequate immune response. Therefore, the S. boulardii probiotic was able to enhance the humoral immune response to a DNA vaccine against leptospirosis in mice.
References
Mazumder S, Maji M, Das A, Ali N: Potency, efficacy and durability of DNA/DNA, DNA/protein and protein/protein based vaccination using gp63 against Leishmania donovani in BALB/c mice. Plos One. 2011, 6 (2): e14644-doi:10.1371/journal.pone.0014644
Zhang X, Divangahi M, Ngai P, Santosuosso M, Millar J, Zganiacz A, Wang J, Bramson J, Xing Z: Intramuscular immunization with a monogenic plasmid DNA tuberculosis vaccine: Enhanced immunogenicity by electroporation and coexpression of GM-CSF transgene. Vaccine. 2005, 25 (7): 1342-52. doi:10.1016/j.vaccine.2006.09.089
Donnelly JJ, Wahren B, Liu MA: DNA vaccines: progress and challenges. J Immunol. 2005, 175 (2): 633-9. doi: 10.1007/s10620-005-9016-x
Buts JP, De Keyser N: Effects of Saccharomyces boulardii on intestinal mucosa. Digestive Disease and Sciences. 2006, 51 (8): 1485-1492. doi: 10.1007/s10620-005-9016-x
Thomas S, Przesdzing I, Metzke D, Schmitz J, Radbruch A, Baumgart DC: Saccharomyces boulardii inhibits lipopolysaccharide induced activation of human dendritic cells and T cell proliferation. Clin Exp Immunol1. 2009, 156 (1): 78-87. doi: 10.1111/j.1365-2249.2009.03878
Acknowledgements
We would like to thank CAPES, CNPq and FAPERGS for the financial support and scholarships.
Author information
Authors and Affiliations
Rights and permissions
Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made.
The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.
To view a copy of this licence, visit https://creativecommons.org/licenses/by/4.0/.
The Creative Commons Public Domain Dedication waiver (https://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated in a credit line to the data.
About this article
Cite this article
Silveira, M., Rosa, R., Mendonça, M. et al. Saccharomyces boulardii ingestion increases the humoral response of a DNA vaccine against leptospirosis in mice. BMC Proc 8 (Suppl 4), P160 (2014). https://doi.org/10.1186/1753-6561-8-S4-P160
Published:
DOI: https://doi.org/10.1186/1753-6561-8-S4-P160