Dataset Information

Multi-Omics Characterization of the Virulence Potential of Bacillus thuringiensis Subspecies using an in vitro intestinal epithelial model

ABSTRACT: The soil bacterium Bacillus thuringiensis (Bt) can produce spores and crystals composed of toxins with insecticidal activity. Due to these properties, some Bt strains have been developed as biopesticides for pest control, with a high value to restrict the use of chemical insecticides. However, Bt strains belong to the Bacillus cereus (Bc) group, sharing some virulence genes encoding diarrheal enterotoxins like hemolysin BL (Hbl), non-hemolytic enterotoxin (Nhe) and cytotoxin K (Cyt-K2). These toxins are known to be involved in foodborne outbreaks (FBOs) caused by Bc sensu stricto contamination. For this reason, it has been suggested that Bt may also provoke FBOs and it is therefore crucial to evaluate their virulence potential and to characterize their effects on humans. For this purpose, differentiated human intestinal Caco-2 cells, able to mimic the human intestinal barrier, have been treated with serial dilutions of the culture supernatant of five different Bt strains used as biopesticides. No cytotoxicity was induced with all Bt supernatants after 24 h treatment in contrast to Bacillus cytotoxicus (Bcyt) supernatants. Interleukin 8 (IL-8) secretion increased sharply in both groups, suggesting possible concerns with chronic inflammation. To investigate the molecular effects of Bt supernatants on Caco-2 cells, untargeted proteomics and metabolomics were performed on both cell media and lysates with 3 non-cytotoxic concentrations. Proteomics and metabolomics highlighted common perturbations on oxidative phosphorylation (OXPHOS) and lipid metabolism for both Bt and Bcyt supernatants exposures. Proteins linked to acute inflammation decreased only with Bcyt exposure. Bt supernatants and not Bcyt supernatants caused a shedding of CD59 and CD55, inhibitors of the complement system, from the cell membrane into the culture medium. This showed that Bt supernatants can increase the vulnerability of intestinal cells to their own immune system. Proteomics also revealed the heterogeneity of toxin abundance in the supernatants of the different Bt subspecies, demonstrating the importance of taking subspecies into account when assessing the risks associated with their use as biopesticides.

INSTRUMENT(S):

ORGANISM(S): Homo Sapiens (human)

TISSUE(S): Caco-2 Cell, Enterocyte

SUBMITTER: Thibaut LEGER

LAB HEAD: Thibaut Léger

PROVIDER: PXD060628 | Pride | 2026-07-02

REPOSITORIES: Pride

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Multi-omics characterisation of the virulence and inflammatory potential of Bacillus thuringiensis in an in vitro intestinal epithelial model.

Alilat Sarah S Lanceleur Rachelle R Bonis Mathilde M Pairaud Sylvie S De Almeida Natália Pinto NP Vial Gaëlle G Sarda Xavier X Firmesse Olivier O Fessard Valérie V Liuu Sophie S Léger Thibaut T

The Science of the total environment 20260404

The soil bacterium Bacillus thuringiensis (Bt) can produce spores and crystals composed of toxins with insecticidal activity. Due to these properties, some Bt strains have been developed as biopesticides for pest control, offering an alternative to chemical insecticides. However, Bt strains belong to the Bacillus cereus (Bc) group and share some virulence genes encoding diarrhoeal enterotoxins such as Hemolysin BL (Hbl), Non-haemolytic enterotoxin (Nhe) and Cytotoxin K (Cyt-K2). These toxins are ...[more]

PMID: 41932230

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Project description:The soil bacterium Bacillus thuringiensis (Bt) can produce spores and crystals composed of toxins with insecticidal activity. Due to these properties, some Bt strains have been developed as biopesticides for pest control, with a high value to restrict the use of chemical insecticides. However, Bt strains belong to the Bacillus cereus (Bc) group, sharing some virulence genes encoding diarrheal enterotoxins like hemolysin BL (Hbl), non-hemolytic enterotoxin (Nhe) and cytotoxin K (Cyt-K2). These toxins are known to be involved in foodborne outbreaks (FBOs) caused by Bc sensu stricto contamination. For this reason, it has been suggested that Bt may also provoke FBOs and it is therefore crucial to evaluate their virulence potential and to characterize their effects on humans. For this purpose, differentiated human intestinal Caco-2 cells, able to mimic the human intestinal barrier, have been treated with serial dilutions of the culture supernatant of five different Bt strains used as biopesticides. No cytotoxicity was induced with all Bt supernatants after 24 h treatment in contrast to Bacillus cytotoxicus (Bcyt) supernatants. Interleukin 8 (IL-8) secretion increased sharply in both groups, suggesting possible concerns with chronic inflammation. To investigate the molecular effects of Bt supernatants on Caco-2 cells, untargeted proteomics and metabolomics were performed on both cell media and lysates with 3 non-cytotoxic concentrations. Proteomics and metabolomics highlighted common perturbations on oxidative phosphorylation (OXPHOS) and lipid metabolism for both Bt and Bcyt supernatants exposures. Proteins linked to acute inflammation decreased only with Bcyt exposure. Bt supernatants and not Bcyt supernatants caused a shedding of CD59 and CD55, inhibitors of the complement system, from the cell membrane into the culture medium. This showed that Bt supernatants can increase the vulnerability of intestinal cells to their own immune system. Proteomics also revealed the heterogeneity of toxin abundance in the supernatants of the different Bt subspecies, demonstrating the importance of taking subspecies into account when assessing the risks associated with their use as biopesticides.

Project description:Background: Resveratrol has been demonstrated to exert pleiotropic health beneficial effects. Among the various mechanisms of action antioxidant, anti-inflammatory, cardio- and cancer-protective outcomes have been reported. Particularly, an important function of this natural compound against atherosclerosis has been postulated and the action of resveratrol on lipids and lipoprotein levels seems to be of relevance in this pathology, but also for other metabolic diseases. Accordingly, taking into consideration the straight contact of resveratrol with the intestine, this study aimed to gain insights into the protective effects of trans-resveratrol on enterocyte physiology and metabolism in proinflammatory conditions. For this purpose, a DNA microarray analysis was conducted in Caco-2 cells where global gene expression profile at intestinal level was screened. Cells were pretreated with 50 Î¼Î? of trans-resveratrol and, subsequently, lipopolysaccharide (LPS) was added for 48 h. Results: The microarray analysis revealed 121 genes differentially expressed between resveratrol-treated and non-treated cells (B> 0). Four genes, inhibitor of DNA binding 1(ID1), histidine-rich glycoprotein (HRG), NADPH oxidase (NOX1) and sprouty homolog 1 (SPRY), were upregulated by LPS treatment, but significantly downregulated with trans-resveratrol pretreatment (padj< 0.05). Moreover, genes implicated in pathways related to lipid metabolism, such as synthesis of lipids (z-score= -1.195) and concentration of cholesterol (z-score= -0.109), were markedly downregulated by trans-resveratrol. Other genes implicated in lipid metabolism, but also in cell death and survival function, such as transcription factors KrÃ¼ppel-like factor 5 (KLF5) and amphiregulin (AREG), were also significantly inhibited by trans-resveratrol pretreatment. RT-qPCR-data confirmed the microarray results. Special mention deserves acyl-CoA synthetase long-chain family member 3 (ACSL3) and endothelial lipase (LIPG), which were downregulated by the stilbene and have been previously associated with fatty acid synthesis and obesity in other tissues. Conclusions: This study envisages that trans-resveratrol might exert important anti-lipogenic effect at intestinal level under proinflammatory conditions, which have not been previously described. The experiment was conducte in Caco-2 cells. There were three experimental groups (n=5), Caco-2 cells stimulated with lipopolysaccharides (LPS), Caco-2 cells stimulated with LPS and pre-treated with trans-resveratrol (LPS+RSV) and non-treated Caco-2 cells.

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			Action	DRS
	BHI-01-01.mgf	Mgf
	BHI-01-01.raw	Raw
	BHI-01-02.mgf	Mgf
	BHI-01-02.raw	Raw
	BHI-01-03.mgf	Mgf