Saccharomyces boulardii improves humoral immune response to DNA vaccines against leptospirosis.

This study evaluated Saccharomyces boulardii capacity to improve the humoral and cellular immune responses using DNA vaccines coding for the leptospiral protein fragments LigAni and LigBrep. BALB/c mice were fed with rodent-specific feed containing 108 colony-forming units of Saccharomyces boulardii per gram. Animals were immunized three times intramuscularly with 100 µg of pTARGET plasmids containing the coding sequences for the above mentioned proteins. Control group animals received no probiotic feed but were immunized the same way. Antibody titers were measured by indirect ELISA. Expression levels of IL-4, IL-10, IL-12, IL-17, IFN-γ, and TGF-β were determined by qRT-PCR from RNA extracted from whole blood, after an intraperitoneal boost with 50 μg of the recombinant proteins. Antibody titers increased significantly after the second and third application when pTARGET/ligAni and pTARGET/ligBrep, were used to vaccinate the animals in comparison with the control group (p<0.05). In addition, there was a significant increase in the expression of the IL-10 in mice immunized with pTARGET/ligBrep and fed with Saccharomyces boulardii. The results suggested Saccharomyces boulardii has an immunomodulator effect in DNA vaccines, mainly by stimulating the humoral response, which is often limited in this kind of vaccines. Therefore, the use of Saccharomyces boulardii as immunomodulator represents a new alternative strategy for more efficient DNA vaccination. PMID: 2800882...
Source: Journal of Medical Microbiology - Category: Microbiology Authors: Tags: J Med Microbiol Source Type: research