RESUMO
The ability of lactobacilli isolated from feedlot cattle environment to differentially modulate the innate immune response triggered by Toll-like receptors (TLRs) activation in bovine intestinal epithelial (BIE) cells was evaluated. BIE cells were stimulated with Lactobacillus mucosae CRL2069, Lactobacillus acidophilus CRL2074, Lactobacillus fermentum CRL2085 or Lactobacillus rhamnosus CRL2084 and challenged with heat-stable pathogen associated molecular patterns (PAMPs) from enterotoxigenic Escherichia coli (ETEC) to induce the activation of TLR4 or with polyinosinic:polycytidylic acid (poly(I:C)) to activate TLR3. Type I interferons, cytokines, chemokines and negative regulators of TLR signalling were studied by RT-PCR. L. mucosae CRL2069 significantly reduced the expression of interleukin (IL)-8 and monocyte chemoattractant protein (MCP)-1 in BIE cells in the context of TLR3 activation. L. mucosae CRL2069 also reduced the expression of tumour necrosis factor-α, IL-ß, MCP-1, and IL-8 in heat-stable ETEC PAMPs-challenged BIE cells. In addition, reduced expressions of IL-6, MCP-1, and IL-8 were found in BIE cells stimulated with L. rhamnosus CRL2084, although its effect was significantly lower than that observed for the CRL2069 strain. The reduced levels of pro-inflammatory factors in BIE cells induced by the CRL2069 and CRL2085 strains was related to their ability of increasing the expression of TLR negative regulators. L. mucosae CRL2069 significantly improved the expression of A20-binding inhibitor of NFκ-B activation 3 (ABIN-3), interleukin-1 receptor-associated kinase M (IRAK-M) and mitogen-activated protein kinase 1 (MKP-1) while L. rhamnosus CRL2084 augmented ABIN-3 expression in BIE cells. The results of this work suggest that among the studied strains, L. mucosae CRL2069 was able to regulate TLR3-mediated innate immune response and showed a remarkable capacity to modulate TLR4-mediated inflammation in BIE cells. The CRL2069 strain induce the up-regulation of three TLR negative regulators that would influence nuclear factor kB and mitogen-activated protein kinases signalling pathways while reducing the expression of pro-inflammatory cytokines and chemokines. Therefore, L. mucosae CRL2069 is an interesting immunobiotic candidate for the protection of the bovine host against TLR-mediated intestinal inflammatory damage.
Assuntos
Células Epiteliais/imunologia , Células Epiteliais/microbiologia , Imunidade Inata , Intestinos/imunologia , Lactobacillales/imunologia , Probióticos/administração & dosagem , Receptores Toll-Like/imunologia , Animais , Bovinos , Linhagem Celular , Quimiocinas/genética , Quimiocinas/imunologia , Citocinas/genética , Citocinas/imunologia , Inflamação , Mucosa Intestinal/imunologia , Intestinos/citologia , Lactobacillales/isolamento & purificação , Lactobacillus/imunologia , Lactobacillus acidophilus/imunologia , Lacticaseibacillus rhamnosus/imunologia , Transdução de Sinais , Receptor 3 Toll-Like/genética , Receptor 3 Toll-Like/imunologia , Receptor 4 Toll-Like/genética , Receptor 4 Toll-Like/imunologia , Receptores Toll-Like/genéticaRESUMO
Previously, we reported that the non-viable immunomodulatory Bifidobacterium infantis MCC12 and Bifidobacterium breve MCC1274 strains (paraimmunobiotic bifidobacteria) were able to increase the protection against rotavirus infection in bovine intestinal epithelial (BIE) cells. In order to gain insight into the influence of paraimmunobiotic bifidobacteria on the innate antiviral immune response of BIE cells, their effect on the transcriptomic response triggered by Toll-like receptor 3 (TLR3) activation was investigated. By using microarray technology and qPCR analysis, we obtained a global overview of the immune genes involved in the innate antiviral immune response in BIE cells. Activation of TLR3 by poly(I:C) in BIE cells significantly increased the expression of interferon (IFN)-α and IFN-ß, several interferon-stimulated genes, cytokines, and chemokines. It was also observed that both paraimmunobiotic bifidobacteria differently modulated immune genes expression in poly(I:C)-challenged BIE cells. Most notable changes were found in genes involved in antiviral defence (IFN-ß, MX1, OAS1X, MDA5, TLR3, STAT2, STAT3), cytokines (interleukin (IL)-6), and chemokines (CCL2, CXCL2, CXCL6) that were significantly increased in bifidobacteria-treated BIE cells. B. infantis MCC12 and B. breve MCC1274 showed quantitative and qualitative differences in their capacities to modulate the innate antiviral immune response in BIE cells. B. breve MCC1274 was more efficient than the MCC12 strain to improve the production of type I IFNs and antiviral factors, an effect that could be related to its higher ability to protect against rotavirus replication in BIE cells. Interestingly, B. infantis MCC12 showed a remarkable anti-inflammatory effect. The MCC12 strain was more efficient to reduce the expression of inflammatory cytokines and chemokines (IL-16, IL-20, CX3CL1) when compared with B. breve MCC1274. These results provided valuable information for the deeper understanding of the antiviral immune response of intestinal epithelial cells as well as the host-paraimmunobiotic interaction in the bovine host.