Efeito de diferentes estímulos produzidos por Bacillus toyonensis BCT-7112T em macrófagos murinos RAW 264.7

Abstract

Probiotics are defined as “Live microorganisms that, when administered in certain types, confer health benefits on the host”. Among the beneficial effects provided to the host by probiotics are immunomodulation and the influence on other organs of the body, in addition to those belonging to the gastrointestinal system. Bacillus spp. they are gram-positive, sporulating, and may be obligatorily or optionally aerobic Species of this genus have been used as a probiotic for less than 30 years. Studies carried out in the Microbiology laboratory of the Faculty of Biotechnology of the Federal University of Pelotas on the probiotic and immunomodulating activity of Bacillus toyonensis BCT-7112T have a potential immunomodulatory effect through an increase in the cellular and humoral immune response. However, studies that investigate in detail an interaction between B.toyonensis and the immune system are still scarce. Thus, the aim of the present study was to analyze the effect of different stimuli of Bacillus toyonensis BCT-7112T (vegetative cell, live and inactivated spores, DNA and culture supernatant) on murine macrophage cell line RAW 264.7 by 1, 8 and 24 hours . The relative transcription of messenger RNA for the cytokines TNFα, IL10 and IL4; NFkβ nuclear factor; and TLR2 receptor, was evaluated by the technique of real-time PCR (qPCR). The results obtained demonstrated that components of the B. toyonensis BCT-7112T culture are able to immunomodulate the RAW 264.7 macrophage lineage in vitro. Furthermore, it was observed that this modulation is not standard and is altered according to the stimulus used, or that it instigates a more detailed investigation of the immunomodulatory properties of each of the treatments used. In this way, it is possible to reaffirm the role of B. toyonensis BCT-7112T, not only of its vegetative cell, but also of its spore, DNA and supernatant, as a potential immunomodulator. Live stimuli (i.e, live vegetative cells and spore) increased the transcription of the proinflammatory factors TNFα and TLR2 and also NFkβ, respectively, in addition to also increasing the transcription of IL10. These same inactivated stimuli, on the other hand, reduced the transcription of proinflammatory factors and increased that of the anti-inflammatory cytokines IL10 and IL4. There are potential applications that can range from the use of this microorganism as a vaccine adjuvant to the use of its components with probiotics, which can benefit both human and animal health.