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The Saccharomyces boulardii CNCM I-745 strain shows protective effects against the B. anthracis LT toxin.

Pontier-Bres R, Rampal P, Peyron JF, Munro P, Lemichez E, Czerucka D - Toxins (Basel) (2015)

Bottom Line: Exposure of polarized T84 cells to LT affected cell monolayer integrity, modified the morphology of tight junctions and induced the formation of actin stress fibers.Overnight treatment of cells with S. boulardii before incubation with LT maintained the integrity of the monolayers, prevented morphological modification of tight junctions, restricted the effects of LT on actin remodeling and delayed LT-induced MEK-2 cleavage.Mechanistically, we demonstrated that in the presence of S. boulardii, the medium is depleted of both LF and PA sub-units of LT and the appearance of a cleaved form of PA.

View Article: PubMed Central - PubMed

Affiliation: Centre Scientifique de Monaco, Monaco 98000, Monaco.

ABSTRACT
The probiotic yeast Saccharomyces boulardii (S. boulardii) has been prescribed for the prophylaxis and treatment of several infectious diarrheal diseases. Gastrointestinal anthrax causes fatal systemic disease. In the present study, we investigated the protective effects conferred by Saccharomyces boulardii CNCM I-745 strain on polarized T84 columnar epithelial cells intoxicated by the lethal toxin (LT) of Bacillus anthracis. Exposure of polarized T84 cells to LT affected cell monolayer integrity, modified the morphology of tight junctions and induced the formation of actin stress fibers. Overnight treatment of cells with S. boulardii before incubation with LT maintained the integrity of the monolayers, prevented morphological modification of tight junctions, restricted the effects of LT on actin remodeling and delayed LT-induced MEK-2 cleavage. Mechanistically, we demonstrated that in the presence of S. boulardii, the medium is depleted of both LF and PA sub-units of LT and the appearance of a cleaved form of PA. Our study highlights the potential of the S. boulardii CNCM I-745 strain as a prophylactic agent against the gastrointestinal form of anthrax.

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Protective effect of S. boulardii on LT-induced epithelium disruption. (A) Trans-epithelial resistance (TER) was measured at different time points in: control T84 monolayers (Control), T84 monolayers incubated overnight with S. boulardii alone (S.b (ON)), T84 monolayers incubated with LT alone (LT) and T84 monolayers incubated overnight with S. boulardii prior to the incubation with LT for 24 h (S.b (ON) + LT). TER values are displayed as percentages of initial values (n = 3). An asterisk denotes a significant difference versus control cells (p < 0.05, n = 3 independent experiments); (B) ZO-1 distribution was visualized in T84 monolayers control (control), incubated overnight with S. boulardii alone (S.b (ON)), monolayers incubated with LT alone for 24 h (LT 24 h), or monolayers incubated overnight with S. boulardii prior to the incubation with LT for 24 h (S.b (ON) + LT 24 h).
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toxins-07-04455-f002: Protective effect of S. boulardii on LT-induced epithelium disruption. (A) Trans-epithelial resistance (TER) was measured at different time points in: control T84 monolayers (Control), T84 monolayers incubated overnight with S. boulardii alone (S.b (ON)), T84 monolayers incubated with LT alone (LT) and T84 monolayers incubated overnight with S. boulardii prior to the incubation with LT for 24 h (S.b (ON) + LT). TER values are displayed as percentages of initial values (n = 3). An asterisk denotes a significant difference versus control cells (p < 0.05, n = 3 independent experiments); (B) ZO-1 distribution was visualized in T84 monolayers control (control), incubated overnight with S. boulardii alone (S.b (ON)), monolayers incubated with LT alone for 24 h (LT 24 h), or monolayers incubated overnight with S. boulardii prior to the incubation with LT for 24 h (S.b (ON) + LT 24 h).

Mentions: In endothelial cells, the reorganization of the actin cytoskeleton induced by LT treatment disrupts the monolayer, thereby increasing endothelial permeability [11,13,25]. To investigate the effect of LT on T84 permeability, we measured the trans-epithelial resistance (TER). As shown in Figure 2A, there was a significant decrease of 15%–20% in the TER 15–24 h after the addition of LT. After 24 h, the resistance decreased to 80%. To test a possible protective role of S. boulardii on the barrier function, we pretreated cells for 15 h with yeast cells. Under these conditions, we observed that pretreatment with S. boulardii significantly maintained the TER of LT-intoxicated monolayers compared with the control. An overnight challenge with S. boulardii as the sole treatment did not affect the TER (Figure 2A). In parallel, we investigated whether the LT-induced drop in the TER was associated with morphological modification of the tight junctions (TJs). Modification of TJ morphology was monitored by immunofluorescence staining with the zonula occludens-1 (ZO-1) marker. After 24 h of exposure to LT, T84 monolayers showed diffuse and non-linear staining patterns compared with the continuous ZO-1 staining pattern in untreated cells (Figure 2B). Interestingly, in cells pretreated with S. boulardii overnight, the continuous ZO-1 distribution was preserved (Figure 2B). An overnight challenge with S. boulardii as the sole treatment did not affect the ZO-1 staining pattern. Therefore, S. boulardii protects against the LT-induced disruption of the columnar epithelial cell barrier.


The Saccharomyces boulardii CNCM I-745 strain shows protective effects against the B. anthracis LT toxin.

Pontier-Bres R, Rampal P, Peyron JF, Munro P, Lemichez E, Czerucka D - Toxins (Basel) (2015)

Protective effect of S. boulardii on LT-induced epithelium disruption. (A) Trans-epithelial resistance (TER) was measured at different time points in: control T84 monolayers (Control), T84 monolayers incubated overnight with S. boulardii alone (S.b (ON)), T84 monolayers incubated with LT alone (LT) and T84 monolayers incubated overnight with S. boulardii prior to the incubation with LT for 24 h (S.b (ON) + LT). TER values are displayed as percentages of initial values (n = 3). An asterisk denotes a significant difference versus control cells (p < 0.05, n = 3 independent experiments); (B) ZO-1 distribution was visualized in T84 monolayers control (control), incubated overnight with S. boulardii alone (S.b (ON)), monolayers incubated with LT alone for 24 h (LT 24 h), or monolayers incubated overnight with S. boulardii prior to the incubation with LT for 24 h (S.b (ON) + LT 24 h).
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Related In: Results  -  Collection

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getmorefigures.php?uid=PMC4663514&req=5

toxins-07-04455-f002: Protective effect of S. boulardii on LT-induced epithelium disruption. (A) Trans-epithelial resistance (TER) was measured at different time points in: control T84 monolayers (Control), T84 monolayers incubated overnight with S. boulardii alone (S.b (ON)), T84 monolayers incubated with LT alone (LT) and T84 monolayers incubated overnight with S. boulardii prior to the incubation with LT for 24 h (S.b (ON) + LT). TER values are displayed as percentages of initial values (n = 3). An asterisk denotes a significant difference versus control cells (p < 0.05, n = 3 independent experiments); (B) ZO-1 distribution was visualized in T84 monolayers control (control), incubated overnight with S. boulardii alone (S.b (ON)), monolayers incubated with LT alone for 24 h (LT 24 h), or monolayers incubated overnight with S. boulardii prior to the incubation with LT for 24 h (S.b (ON) + LT 24 h).
Mentions: In endothelial cells, the reorganization of the actin cytoskeleton induced by LT treatment disrupts the monolayer, thereby increasing endothelial permeability [11,13,25]. To investigate the effect of LT on T84 permeability, we measured the trans-epithelial resistance (TER). As shown in Figure 2A, there was a significant decrease of 15%–20% in the TER 15–24 h after the addition of LT. After 24 h, the resistance decreased to 80%. To test a possible protective role of S. boulardii on the barrier function, we pretreated cells for 15 h with yeast cells. Under these conditions, we observed that pretreatment with S. boulardii significantly maintained the TER of LT-intoxicated monolayers compared with the control. An overnight challenge with S. boulardii as the sole treatment did not affect the TER (Figure 2A). In parallel, we investigated whether the LT-induced drop in the TER was associated with morphological modification of the tight junctions (TJs). Modification of TJ morphology was monitored by immunofluorescence staining with the zonula occludens-1 (ZO-1) marker. After 24 h of exposure to LT, T84 monolayers showed diffuse and non-linear staining patterns compared with the continuous ZO-1 staining pattern in untreated cells (Figure 2B). Interestingly, in cells pretreated with S. boulardii overnight, the continuous ZO-1 distribution was preserved (Figure 2B). An overnight challenge with S. boulardii as the sole treatment did not affect the ZO-1 staining pattern. Therefore, S. boulardii protects against the LT-induced disruption of the columnar epithelial cell barrier.

Bottom Line: Exposure of polarized T84 cells to LT affected cell monolayer integrity, modified the morphology of tight junctions and induced the formation of actin stress fibers.Overnight treatment of cells with S. boulardii before incubation with LT maintained the integrity of the monolayers, prevented morphological modification of tight junctions, restricted the effects of LT on actin remodeling and delayed LT-induced MEK-2 cleavage.Mechanistically, we demonstrated that in the presence of S. boulardii, the medium is depleted of both LF and PA sub-units of LT and the appearance of a cleaved form of PA.

View Article: PubMed Central - PubMed

Affiliation: Centre Scientifique de Monaco, Monaco 98000, Monaco.

ABSTRACT
The probiotic yeast Saccharomyces boulardii (S. boulardii) has been prescribed for the prophylaxis and treatment of several infectious diarrheal diseases. Gastrointestinal anthrax causes fatal systemic disease. In the present study, we investigated the protective effects conferred by Saccharomyces boulardii CNCM I-745 strain on polarized T84 columnar epithelial cells intoxicated by the lethal toxin (LT) of Bacillus anthracis. Exposure of polarized T84 cells to LT affected cell monolayer integrity, modified the morphology of tight junctions and induced the formation of actin stress fibers. Overnight treatment of cells with S. boulardii before incubation with LT maintained the integrity of the monolayers, prevented morphological modification of tight junctions, restricted the effects of LT on actin remodeling and delayed LT-induced MEK-2 cleavage. Mechanistically, we demonstrated that in the presence of S. boulardii, the medium is depleted of both LF and PA sub-units of LT and the appearance of a cleaved form of PA. Our study highlights the potential of the S. boulardii CNCM I-745 strain as a prophylactic agent against the gastrointestinal form of anthrax.

Show MeSH
Related in: MedlinePlus