RESUMO
Salmonella Typhimurium (ST313) has caused an epidemic of invasive disease in sub-Saharan Africa and has been recently identified in Brazil. As the virulence of this ST is poorly understood, the present study aimed to (i) perform the RNA-seq in vitro of S. Typhimurium STm30 (ST313) grown in Luria-Bertani medium at 37°C; (ii) compare it with the RNA-seq of the S. Typhimurium SL1344 (ST19) and S. Typhimurium STm11 (ST19) strains under the same growing conditions; and (iii) examine the colonization capacity and expression of virulence genes and cytokines in murine colon. The STm30 (ST313) strain exhibited stronger virulence and was associated with a more inflammatory profile than the strains SL1344 (ST19) and STm11 (ST19), as demonstrated by transcriptome and in vivo assay. The expression levels of the hilA, sopD2, pipB, and ssaS virulence genes, other Salmonella pathogenicity islands SPI-1 and SPI-2 genes or effectors, and genes of the cytokines IL-1ß, IFN-γ, TNF-α, IL-6, IL-17, IL-22, and IL-12 were increased during ST313 infection in C57BL/6J mice. In conclusion, S. Typhimurium STm30 (ST313) isolated from human feces in Brazil express higher levels of pathogenesis-related genes at 37°C and has stronger colonization and invasion capacity in murine colon due to its high expression levels of virulence genes, when compared with the S. Typhimurium SL1344 (ST19) and STm11 (ST19) strains. STm30 (ST313) also induces stronger expression of pro-inflammatory cytokines in this organ, suggesting that it causes more extensive tissue damage.
Assuntos
Colo/microbiologia , Infecções por Salmonella/imunologia , Infecções por Salmonella/microbiologia , Salmonella typhimurium/patogenicidade , Animais , Brasil , Colo/imunologia , Citocinas/genética , Citocinas/imunologia , Fezes/microbiologia , Ilhas Genômicas , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Infecções por Salmonella/genética , Salmonella typhimurium/genética , Salmonella typhimurium/isolamento & purificação , Salmonella typhimurium/fisiologia , VirulênciaRESUMO
Probiotics have been associated with a variety of health benefits. They can act as adjuvant to enhance specific immune response. Bacterial cell wall (CW) molecules are key structures that interact with host receptors promoting probiotic effects. The adjuvant capacity underlying this sub-cellular fraction purified from Lactobacillus casei CRL431 and L. paracasei CNCMI-1518 remains to be characterized. We interrogated the molecular and cellular events after oral feeding with probiotic-derived CW in addition to heat-inactivated Salmonella Typhimurium and their subsequent protective capacity against S. Typhimurium challenge. Intact probiotic bacteria were orally administered for comparison. We find that previous oral feeding with probiotics or their sub-cellular fraction reduce bacterial burden in spleen and liver after Salmonella challenge. Antibody responses after pathogen challenge were negligible, characterized by not major changes in the antibody-mediated phagocytic activity, and in the levels of total and Salmonella-specific intestinal sIgA and serum IgG, respectively. Conversely, the beneficial effect of probiotic-derived CW after S. Typhimurium challenge were ascribed to a Th1-type cell-mediated immunity which was characterized by augmentation of the delayed-type hypersensitivity response. The cell-mediated immunity associated with the oral feeding with probiotic-derived CW was accompanied with a Th1-cell polarizing cytokines, distinguished by increase IFN-γ/IL-4 ratio. Similar results were observed with the intact probiotics. Our study identified molecular events associated with the oral administration of sub-cellular structures derived from probiotics and their adjuvant capacity to exert immune modulatory function.
Assuntos
Parede Celular/imunologia , Lacticaseibacillus casei/imunologia , Lacticaseibacillus paracasei/imunologia , Probióticos/administração & dosagem , Infecções por Salmonella/imunologia , Salmonella typhimurium/imunologia , Células Th1/imunologia , Adjuvantes Imunológicos/administração & dosagem , Administração Oral , Animais , Anticorpos Antibacterianos/sangue , Citocinas/imunologia , Imunidade Celular , Lacticaseibacillus casei/química , Lacticaseibacillus paracasei/química , Macrófagos/imunologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , FagocitoseRESUMO
BACKGROUND: Anti-inflammatory properties have been attributed to latex proteins of the medicinal plant Calotropis procera. PURPOSE: A mixture of cysteine peptidases (LPp2) from C. procera latex was investigated for control of inflammatory mediators and inflammation in a mouse model of Salmonella infection. METHODS: LPp2 peptidase activity was confirmed by the BANA assay. Cytotoxicity assays were conducted with immortalized macrophages. Peritoneal macrophages (pMØ) from Swiss mice were stimulated with lipopolysaccharide (LPS) in 96-well plates and then cultured with nontoxic concentrations of LPp2. Swiss mice intravenously received LPp2 (10 mg/kg) and then were challenged intraperitoneally with virulent Salmonella enterica Ser. Typhimurium. RESULTS: LPp2 was not toxic at dosages lower than 62.2 µg/mL. LPp2 treatments of pMØ stimulated with LPS impaired mRNA expression of pro-inflammatory cytokines IL-1ß, TNF-α, IL-6 and IL-10. LPp2 increased the intracellular bacterial killing in infected pMØ. Mice given LPp2 had a lower number of leukocytes in the peritoneal cavity in comparison to control groups 6 h after infection. The bacterial burden and histological damage were widespread in target organs of mice receiving LPp2. CONCLUSION: We conclude that LPp2 contains peptidases with strong anti-inflammatory properties, which may render mice more susceptible to early disseminated infection caused by Salmonella.
Assuntos
Anti-Inflamatórios/farmacologia , Calotropis/química , Peptídeo Hidrolases/farmacologia , Proteínas de Plantas/farmacologia , Infecções por Salmonella/tratamento farmacológico , Salmonella typhimurium/efeitos dos fármacos , Animais , Anti-Inflamatórios/isolamento & purificação , Regulação da Expressão Gênica , Interleucina-10/genética , Interleucina-10/imunologia , Interleucina-1beta/genética , Interleucina-1beta/imunologia , Interleucina-6/genética , Interleucina-6/imunologia , Látex/química , Lipopolissacarídeos/antagonistas & inibidores , Lipopolissacarídeos/farmacologia , Macrófagos Peritoneais/efeitos dos fármacos , Macrófagos Peritoneais/imunologia , Camundongos , Peptídeo Hidrolases/isolamento & purificação , Componentes Aéreos da Planta/química , Extratos Vegetais/química , Proteínas de Plantas/isolamento & purificação , Plantas Medicinais , Cultura Primária de Células , Infecções por Salmonella/imunologia , Infecções por Salmonella/microbiologia , Infecções por Salmonella/patologia , Salmonella typhimurium/imunologia , Salmonella typhimurium/patogenicidade , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/imunologiaRESUMO
AIMS: This study compared the capacity of strains of Salmonella enterica serovars Enteritidis and Dublin isolated in Brazil to invade epithelial cells, to be internalized by and survive within macrophages, and to stimulate cytokine release in vitro. METHODS AND RESULTS: Both serovars infected 75 and 73% Caco-2 (human) and MDBK (bovine) epithelial cells respectively. Salmonella Dublin and S. Enteritidis (i) were internalized at the respective rates of 79·6 and 65·0% (P ≤ 0·05) by U937 (human) macrophages, and 70·4 and 66·9% by HD11 (chicken) macrophages; and (ii) multiplied at the respective rates of 3·2- and 2·7-fold within U937 cells, and 1·9- and 1·1-fold (P ≤ 0·05) within HD11 cells respectively. Seventy per cent of 10 S. Dublin strains stimulated IL-8 production, while 70% of S. Enteritidis strains enhanced production of IL-1ß, IL-6, IL-8, IL-10, IL-12p70 and TNF in Caco-2 cells. CONCLUSIONS: Compared with S. Enteritidis, S. Dublin had stronger ability to survive within macrophages and induced weak cytokine production, which may explain the higher incidence of invasive diseases caused by S. Dublin in humans. SIGNIFICANCE AND IMPACT OF THE STUDY: This study compared S. enterica serovars Enteritidis and Dublin to provide comparative data about the profile of the two serovars in cells from humans, the common host and their respective natural animal hosts and vice versa in order to check the differences between these two phylogenetically closely related serovars that share antigenic properties but present different phenotypic behaviours.
Assuntos
Citocinas/metabolismo , Células Epiteliais/microbiologia , Macrófagos/microbiologia , Infecções por Salmonella/imunologia , Infecções por Salmonella/microbiologia , Salmonella enterica/imunologia , Salmonella enterica/patogenicidade , Animais , Brasil , Células CACO-2 , Bovinos , Galinhas , Células Epiteliais/imunologia , Humanos , Macrófagos/imunologia , Viabilidade Microbiana , Sorogrupo , Células U937RESUMO
OBJECTIVE: To test the hypothesis that fermentable fiber prevents Salmonella typhimurium infection-associated symptoms by enhancing innate and adaptive immune system in neonatal pigs. METHODS: Two-d-old piglets (n=120) were randomized to receive either a nutritionally complete sow milk replacer formula (CON), or supplemented with methylcellulose (MCEL-non-fermentable), soy polysaccharides (SPS-moderately fermentable), or fructooligosaccharides (FOS-highly fermentable). On d7, piglets received an oral gavage of S. typhimurium-798, and continued receiving the same diets up to 48h post-infection. Ileal mucosal samples were obtained for further analyses. RESULTS: A reduction in chloride secretion was observed in FOS when compared to other diets (p<0.0003). The number of ileal sulfo-acidomucins was higher (p<0.05) in FOS before infection compared with other diets. NFkB was inhibited in FOS following infection (p<0.05), when compared with CON. IL-1ß expression was increased at 4h post-infection (p<0.05) in CON; however, this response was attenuated in the fiber groups. IL-6 expression was higher (p<0.05) in CON post- infection, higher in SPS at 24h (p<0.05), but unchanged in MCEL and FOS when compared to pre-infection values. FOS had a higher expression of neutrophil-chemoattractant IL-8 before infection (p<0.05) compared to other groups. CONCLUSION: The reduction in chloride secretion, proinflammatory cytokines expression and NFkB activation, and increased number of sulfo-acidomucins, and IL-8 expression in the fiber groups, indicates that the degree of fermentability impacts the innate and adaptive immune system, and could be the mechanisms by which dietary fibers reduce S. typhimurium infection-associated-symptoms in neonatal pigs and apply these results to infants.
Assuntos
Fibras na Dieta/administração & dosagem , Fermentação , Oligossacarídeos/administração & dosagem , Infecções por Salmonella/prevenção & controle , Imunidade Adaptativa/imunologia , Animais , Animais Recém-Nascidos , Citocinas/imunologia , Fibras na Dieta/farmacologia , Imunidade Inata/imunologia , Metilcelulose/administração & dosagem , Metilcelulose/farmacologia , Oligossacarídeos/farmacologia , Polissacarídeos/administração & dosagem , Polissacarídeos/farmacologia , Distribuição Aleatória , Infecções por Salmonella/imunologia , Salmonella typhimurium/isolamento & purificação , Glycine max/química , SuínosRESUMO
BACKGROUND: Calotropis procera latex protein fraction (LP) was previously shown to protect animals from septic shock. Further investigations showed that LP modulate nitric oxide and cytokines levels. OBJECTIVES: To evaluate whether the protective effects of LP, against lethal bacterial infection, is observed in its subfractions (LPPII and LPPIII). METHODS: Subfractions (5 and 10 mg/kg) were tested by i.p. administration, 24 h before challenging with lethal injection (i.p.) of Salmonella Typhimurium. LPPIII (5 mg/kg) which showed higher survival rate was assayed to evaluate bacterial clearance, histopathology, leukocyte recruitment, plasma coagulation time, cytokines and NO levels. FINDINGS: LPPIII protected 70% of animals of death. The animals given LPPIII exhibited reduced bacterial load in blood and peritoneal fluid after 24 h compared to the control. LPPIII promoted macrophage infiltration in spleen and liver. LPPIII restored the coagulation time of infected animals, increased IL-10 and reduced NO in blood. MAIN CONCLUSIONS: LPPIII recruited macrophages to the target organs of bacterial infection. This addressed inflammatory stimulus seems to reduce bacterial colonisation in spleen and liver, down regulate bacterial spread and contribute to avoid septic shock.
Assuntos
Antibacterianos/uso terapêutico , Calotropis/química , Homeostase/efeitos dos fármacos , Inflamação/tratamento farmacológico , Látex/química , Extratos Vegetais/farmacologia , Proteínas de Plantas/uso terapêutico , Infecções por Salmonella/tratamento farmacológico , Animais , Antibacterianos/isolamento & purificação , Antibacterianos/farmacologia , Regulação para Baixo , Proteínas de Plantas/isolamento & purificação , Proteínas de Plantas/farmacologia , Infecções por Salmonella/imunologia , Infecções por Salmonella/microbiologiaRESUMO
Citrus by-products are inexpensive sources of polyphenols, important bioactive compounds with wide pharmaceutical and food applications. This study aimed to investigate the effect of enzymatic treatment of citrus by-products on the polyphenolic profile of extracts and assess the influence of extracts on the growth and adhesion of probiotics and foodborne pathogenic bacteria and on the inflammatory response of epithelial cells. Enzyme-assisted extraction altered the polyphenolic profile (as assessed by HPLC-DAD), increasing the content of aglycone flavanones (naringenin and hesperetin). Enzymatic extracts and aglycone flavanones exhibited higher antibacterial and prebiotic activities than non-enzymatic extracts and glycoside flavanones. However, a higher content of aglycones was not associated with higher anti-adhesion activity. Citrus extracts significantly (P ≤ 0.05) decreased the inflammatory response of Caco-2 cells to Salmonella Typhimurium adhesion. These results support the sustainable reuse of citrus agroindustrial wastes and indicate the potential of citrus extracts in preventing infection by foodborne pathogenic bacteria and inducing proliferation of probiotics in foods and the gut environment.
Assuntos
Aderência Bacteriana/efeitos dos fármacos , Citrus/química , Citocinas/imunologia , Extratos Vegetais/farmacologia , Antibacterianos/análise , Antibacterianos/isolamento & purificação , Antibacterianos/farmacologia , Células CACO-2 , Cromatografia Líquida de Alta Pressão , Flavanonas/análise , Flavanonas/isolamento & purificação , Flavanonas/farmacologia , Frutas/química , Humanos , Extratos Vegetais/análise , Extratos Vegetais/isolamento & purificação , Infecções por Salmonella/imunologia , Infecções por Salmonella/microbiologia , Salmonella typhimurium/efeitos dos fármacos , Salmonella typhimurium/crescimento & desenvolvimento , Salmonella typhimurium/fisiologia , Resíduos/análiseRESUMO
Probiotics form a promising strategy to maintain intestinal health. Milks fermented with probiotic strains, such as the Lactobacillus paracasei ST11, are largely commercialized in Brazil and form a low-cost alternative to probiotic pharmaceutical formulations. In this study, we assessed the probiotic effects of milk fermented by L. paracasei ST11 (administered through fermented milk) in a Salmonella typhimurium infection model in BALB/c mice. We observed in this murine model that the applied probiotic conferred protective effects against S. typhimurium infection, since its administration reduced mortality, weight loss, translocation to target organs (liver and spleen) and ileum injury. Moreover, a reduction in the mRNA expression of pro-inflammatory cytokines such as IFN-γ, IL-6, TNF-α and IL-17 in animals that received the probiotic before challenge was observed. Additionally, the ileum microbiota was better preserved in these animals. The present study highlights a multifactorial protective aspect of this commercial probiotic strain against a common gastrointestinal pathogen.
Assuntos
Produtos Fermentados do Leite , Resistência à Doença/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Lacticaseibacillus paracasei/fisiologia , Probióticos/farmacologia , Infecções por Salmonella/prevenção & controle , Animais , Peso Corporal/efeitos dos fármacos , Dieta , Resistência à Doença/genética , Resistência à Doença/imunologia , Regulação da Expressão Gênica/imunologia , Íleo/efeitos dos fármacos , Íleo/imunologia , Íleo/microbiologia , Interferon gama/genética , Interferon gama/imunologia , Interleucina-17/genética , Interleucina-17/imunologia , Interleucina-6/genética , Interleucina-6/imunologia , Fígado/efeitos dos fármacos , Fígado/imunologia , Fígado/microbiologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Infecções por Salmonella/imunologia , Infecções por Salmonella/microbiologia , Infecções por Salmonella/mortalidade , Salmonella typhimurium/efeitos dos fármacos , Salmonella typhimurium/crescimento & desenvolvimento , Salmonella typhimurium/patogenicidade , Baço/efeitos dos fármacos , Baço/imunologia , Baço/microbiologia , Análise de Sobrevida , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/imunologiaRESUMO
BACKGROUND Calotropis procera latex protein fraction (LP) was previously shown to protect animals from septic shock. Further investigations showed that LP modulate nitric oxide and cytokines levels. OBJECTIVES To evaluate whether the protective effects of LP, against lethal bacterial infection, is observed in its subfractions (LPPII and LPPIII). METHODS Subfractions (5 and 10 mg/kg) were tested by i.p. administration, 24 h before challenging with lethal injection (i.p.) of Salmonella Typhimurium. LPPIII (5 mg/kg) which showed higher survival rate was assayed to evaluate bacterial clearance, histopathology, leukocyte recruitment, plasma coagulation time, cytokines and NO levels. FINDINGS LPPIII protected 70% of animals of death. The animals given LPPIII exhibited reduced bacterial load in blood and peritoneal fluid after 24 h compared to the control. LPPIII promoted macrophage infiltration in spleen and liver. LPPIII restored the coagulation time of infected animals, increased IL-10 and reduced NO in blood. MAIN CONCLUSIONS LPPIII recruited macrophages to the target organs of bacterial infection. This addressed inflammatory stimulus seems to reduce bacterial colonisation in spleen and liver, down regulate bacterial spread and contribute to avoid septic shock.
Assuntos
Animais , Proteínas de Plantas/uso terapêutico , Infecções por Salmonella/tratamento farmacológico , Extratos Vegetais/farmacologia , Calotropis/química , Homeostase/efeitos dos fármacos , Inflamação/tratamento farmacológico , Látex/química , Antibacterianos/uso terapêutico , Proteínas de Plantas/isolamento & purificação , Proteínas de Plantas/farmacologia , Infecções por Salmonella/imunologia , Infecções por Salmonella/microbiologia , Regulação para Baixo , Antibacterianos/isolamento & purificação , Antibacterianos/farmacologiaRESUMO
In recent years, cancer immunotherapy has undergone great advances because of our understanding of the immune response and the mechanisms through which tumor cells evade it. A century after the first immunotherapy attempt based on bacterial products described by William Coley, the use of live attenuated bacterial vectors has become a promising alternative in the fight against cancer. This review describes the role of live attenuated Salmonella enterica as an oncolytic and immunotherapeutic agent, due to its high affinity for tumor tissue and its ability to activate innate and adaptive antitumor immune response. Furthermore, its potential use as delivery system of tumor antigens and immunomodulatory molecules that induce tumor regression is also reviewed.