Bacillus toyonensis improves immune response in the mice vaccinated with recombinant antigen of bovine herpesvirus type 5

Abstract

Probiotics modulate the immune response and can increase the effectiveness of vaccines. Bacillus toyonensis is widely used as a probiotic in animal feed. The aim of this study was to assess the effects of B. toyonensis administration on the immune response to an experimental recombinant vaccine against bovine herpesvirus type 5 (BoHV-5) in mice. Mice were vaccinated with BoHV-5 recombinant glycoprotein D and supplemented with the probiotic B. toyonensis in two regimes: one group received the probiotic only during seven days prior to the initial vaccination while the second group was given the probiotic throughout the experimental period of seven weeks. Animals supplemented with probiotic B. toyonensis in two regimes showed an increase in total immunoglobulin (Ig)G, IgG1 and IgG2a levels in serum, in addition to higher titres of antibodies capable of neutralising the BoHV-5 virus than non-supplemented animals (P<0.05). Splenocytes from the supplemented mice had higher mRNA transcription levels of cytokines interleukin (IL)-4 and IL-12. These results show that the use of this probiotic may significantly contribute to the response elicited by recombinant vaccines, especially those that rely on increasing antibody and cell-mediated immune responses for efficacy. Further, the data support an immunomodulatory effect for probiotic B. toyonensis and imply that enhance effect on the immune response against a BoHV-5 recombinant vaccine in mice.

A probiotic treatment increases the immune response induced by the nasal delivery of spore-adsorbed TTFC

“…The main conclusion of this manuscript is that a probiotic treatment with B. toyonensis spores positively affects a nasal immunization with the C fragment of the tetanus toxin (TTFC) displayed by B. subtilis spores. While it was already known that B. toyonensis spores increased the immune response to a systemic vaccination [13], their efficacy as adjuvant of a mucosal vaccination was never tested before. The observed increased production of fecal sIgA and of IL-6, IL-10 and IFN-γ in the spleen of immunized animals in response to the probiotic treatment clearly points to the B. toyonensis spore as a potential mucosal adjuvant.…”

“…toyonensis BCT-7112 T used in this study was obtained from the collection of microorganisms of the Microbiology Laboratory, Biotechnology Center, Federal University of Pelotas (Brazil). Bacteria were grown in DS medium at 37ºC for 96 h as previously reported [13] and analyzed under the optical microscope for the presence of cells and spores. The cultures containing over 95% of free spores were centrifuged at 5000g for 20 min at 4 °C and the pellet suspended in phosphate buffer to a concentration of spores of approximately 2.0 × 10 7 CFU/ml.…”

“…The use of probiotics before and/or during the vaccination period to modulate the immune response [9] and increase the effectiveness of vaccines against bacterial [9,10] or viral [11,12] infections is also receiving increasing interest. In a recent study, spores of Bacillus toyonensis were shown able to increase the immune response to a parenteral vaccine against bovine herpesvirus type 5 (BoHV-5) in mice [13]. B. toyonensis, originally defined as B. cereus var.…”

“…In 1994 its use has been authorized by the European Community as a feed additive for use in poultry, cattle and rabbits [15]. Animals parenterally immunized with BoHV-5 and orally supplemented with B. toyonensis spores had higher serum IgG, IL-4 and IL-12 levels than immunized animals that did not receive the probiotic [13], suggesting this probiotic treatment as a potential alternative to the use of adjuvants.…”

Hemolysin BL from novel Bacillus toyonensis BV-17 induces antitumor activity both in vitro and in vivo

“… 13 Some research has also suggested that B. toyonensis could exert an immunomodulatory function and enhance the response of traditional vaccines in mice and pigs. 14 , 15 So far, there has been no report on its pathogenic nature. Abdulmawjood et al evaluated the enterotoxin gene expression of the Bacillus toyonensis BCT-7112 strain and found that the hblC gene was absent, therefore it was not able to form functional enterotoxins.…”