scholarly journals Bacteriophage EK99P-1 Alleviates Enterotoxigenic Escherichia Coli K99-Induced Barrier Dysfunction and Inflammation

Author(s):  
Narae Kim ◽  
Min jeong Gu ◽  
Yoon-Chul Kye ◽  
Young-Jun Ju ◽  
Rira Hong ◽  
...  

Abstract Background Bacteriophages have long been used as a potential alternative to antibiotics for livestock due to their ability to specifically kill enterotoxigenic Escherichia coli (ETEC), which are a major cause of diarrhea in piglets. However, the control of ETEC infection by phages within intestinal epithelial cells, and their relationship with host immune responses, remain poorly understood. Results In this study, we evaluated the effect of phage EK99P-1 against ETEC K99-infected porcine intestinal epithelial cell line (IPEC-J2). Phage EK99P-1 prevented ETEC K99-induced barrier disruption by attenuating the increased permeability mediated by the loss of tight junction proteins such as zonula occludens-1 (ZO-1), occludin, and claudin-3. ETEC K99-induced inflammatory responses, such as IL-8 secretion, were decreased by treatment with phage EK99P-1. We used a IPEC-J2/peripheral blood mononuclear cell (PBMC) Transwell co-culture system to investigate whether the modulation of barrier disruption and chemokine secretion by phage EK99P-1 in ETEC K99-infected IPEC-J2 would influence basolateral immune cells. The results showed that phage EK99P-1 reduced the mRNA expression of ETEC K99-induced pro-inflammatory cytokines, interleukin (IL)-1β and IL-8, from pPBMC collected on the basolateral side. Conclusion Together, these results suggest that phage EK99P-1 prevented ETEC K99-induced barrier dysfunction in IPEC-J2 and alleviated inflammation caused by ETEC K99 infection. Reinforcement of the intestinal barrier by phage EK99P-1 also modulates the immune cell inflammatory response.

2021 ◽  
Author(s):  
Narae Kim ◽  
Min jeong Gu ◽  
Yoon-Chul Kye ◽  
Young-Jun Ju ◽  
Rira Hong ◽  
...  

Abstract Bacteriophages have long been used as a potential alternative to antibiotics for livestock due to their ability to specifically kill ETEC, which are a major cause of diarrhea in piglets. However, the control of ETEC infection by phages within intestinal epithelial cells, and their relationship with host immune responses, remain poorly understood. In this study, we evaluated the effect of phage EK99P-1 against ETEC K99-infected IPEC-J2. Phage EK99P-1 prevented ETEC K99-induced barrier disruption by attenuating the increased permeability mediated by the loss of tight junction proteins such as ZO-1, occludin, and claudin-3. ETEC K99-induced inflammatory responses, such as IL-8 secretion, were decreased by treatment with phage EK99P-1. We used a IPEC-J2/PBMC Transwell co-culture system to investigate whether the modulation of barrier disruption and chemokine secretion by phage EK99P-1 in ETEC K99-infected IPEC-J2 would influence basolateral immune cells. The results showed that phage EK99P-1 reduced the mRNA expression of ETEC K99-induced pro-inflammatory cytokines, IL-1β and IL-8, from PBMC collected on the basolateral side. Together, these results suggest that phage EK99P-1 prevented ETEC K99-induced barrier dysfunction in IPEC-J2 and alleviated inflammation caused by ETEC K99 infection. Reinforcement of the intestinal barrier by phage EK99P-1 also modulates the immune cell inflammatory response.


2021 ◽  
Author(s):  
Qiao Li ◽  
Yanhong Chen ◽  
Changning Yu ◽  
Paula Azevedo ◽  
Joshua Gong ◽  
...  

Abstract Background: Enterotoxigenic Escherichia coli (ETEC) F4 commonly colonizes the small intestine and releases enterotoxins that impair the intestinal barrier function and trigger inflammatory responses. Although Bacillus licheniformis (B. licheniformis) has been reported to enhance intestinal health, it remains to be seen whether there is a functional role of B. licheniformis in intestinal inflammatory response in intestinal porcine epithelial cell line (IPEC-J2) when stimulated with ETEC F4.Methods: In the present study, the effects of B. licheniformis PF9 on the release of pro-inflammation cytokines, cell integrity and nuclear factor-κB (NF-κB) activation were evaluated in ETEC F4-induced IPEC-J2 cells.Results: B. licheniformis PF9 treatment was capable of remarkably attenuating the expression levels of inflammation cytokines tumor necrosis factor-α (TNF-α), interleukin (IL)-8, and IL-6 during ETEC F4 infection. Furthermore, the gene expression of Toll-like receptor 4 (TLR4)-mediated upstream related genes of NF-κB signaling pathway has been significantly inhibited. These changes were accompanied by a significant decreased phosphorylation of p65 NF-κB during ETEC F4 infection with B. licheniformis PF9 treatment. The immunofluorescence and western blot analysis revealed that B. licheniformis PF9 increased the expression levels of zona occludens 1 (ZO-1) and occludin (OCLN) in ETEC F4-infected IPEC-J2 cells. Meanwhile, the B. licheniformis PF9 could alleviate the epithelial barrier function assessed by the trans-epithelial electrical resistance (TEER) and cell permeability assay. Interestingly, B. licheniformis PF9 protect IPEC-J2 cells against ETEC F4 infection by decreasing the gene expressions of virulence-related factors (including luxS, estA, estB, and elt) in ETEC F4.Conclusions: Collectively, our results suggest that B. licheniformis PF9 might reduce inflammation-related cytokines through blocking the NF-κB signaling pathways. Besides, B. licheniformis PF9 displayed a significant role in the enhancement of IPEC-J2 cell integrity.


2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Xiaoxi Liu ◽  
Fenghua Liu ◽  
Yunfei Ma ◽  
Huanrong Li ◽  
Xianghong Ju ◽  
...  

Puerarin, baicalin and berberine hydrochloride are the main components of Gegen Qinlian Decoction, which has been used to treat diarrhoea in China for hundreds of years, yet the biological function and molecular mechanism of these components are not clear. To investigate the effects of puerarin, baicalin, and berberine hydrochloride on the regulation of porcine intestinal epithelial cells (IPEC-J2 cells) infected with enterotoxigenic Escherichia coli (ETEC). IPEC-J2 cells were pretreated with puerarin (200 μg/mL), baicalin (1 μg/mL), and berberine hydrochloride (100 μg/mL) at 37°C for 3 h and then coincubated with the F4ac ETEC bacterial strain 200 at 37°C for 3 h. ETEC infection damaged the structure of IPEC-J2 cells, upregulated mucin 4 (P < 0.01) and mucin 13 mRNA (P < 0.05) expression, increased the apoptosis rate (P < 0.05), and promoted inflammatory responses (IL-6 and CXCL-2 mRNA expression) in IPEC-J2 cells by activating the nuclear factor-κB (NF-κB) signaling pathway. Pretreatment with puerarin, baicalin, and berberine hydrochloride improved the structure and morphology of IPEC-J2 cells and inhibited ETEC adhesion by downregulating specific adhesion molecules. Pretreatment with baicalin decreased the inflammatory response; pretreatment with baicalin and berberine hydrochloride decreased the inflammatory response mediated by the NF-κB signaling pathway. Pretreatment with puerarin, baicalin, and berberine hydrochloride protected IPEC-J2 cells from ETEC infection by inhibiting bacterial adhesion and inflammatory responses.


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