Salmonella Type III Effector AvrA Stabilizes Cell Tight Junctions to Inhibit Inflammation in Intestinal Epithelial Cells

AbstractSmall non-coding RNA RyhB is a key regulator of iron homeostasis in bacteria by sensing iron availability in the environment. Although RyhB is known to influence bacterial virulence by interacting with iron metabolism related regulators, its interaction with virulence genes, especially the Type III secretion system (T3SS), has not been reported. Here, we demonstrate that two RyhB paralogs of Salmonella enterica serovar Enteritidis upregulate Type III secretion system (T3SS) effectors, and consequently affect Salmonella invasion into intestinal epithelial cells. Specifically, we found that RyhB-1 modulate Salmonella response to stress condition of iron deficiency and hypoxia, and stress in simulated intestinal environment (SIE). Under SIE culture conditions, both RyhB-1 and RyhB-2 are drastically induced and directly upregulate the expression of T3SS effector gene sipA by interacting with its 5′ untranslated region (5′ UTR) via an incomplete base-pairing mechanism. In addition, the RyhB paralogs upregulate the expression of T3SS effector gene sopE. By regulating the invasion-related genes, RyhBs in turn affect the ability of S. Enteritidis to adhere to and invade into intestinal epithelial cells. Our findings provide evidence that RyhBs function as critical virulence factors by directly regulating virulence-related gene expression. Thus, inhibition of RyhBs may be a potential strategy to attenuate Salmonella.

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The effect of berberine in vitro on tight junctions in human Caco-2 intestinal epithelial cells

Fitoterapia ◽

10.1016/j.fitote.2009.02.005 ◽

2009 ◽

Vol 80 (4) ◽

pp. 241-248 ◽

Cited By ~ 36

Author(s):

Lili Gu ◽

Ning Li ◽

Qiurong Li ◽

Qiang Zhang ◽

Chengyang Wang ◽

...

Keyword(s):

Epithelial Cells ◽

Tight Junctions ◽

Intestinal Epithelial Cells ◽

Intestinal Epithelial

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Cell Polarization and Epigenetic Status Shape the Heterogeneous Response to Type III Interferons in Intestinal Epithelial Cells

Frontiers in Immunology ◽

10.3389/fimmu.2017.00671 ◽

2017 ◽

Vol 8 ◽

Cited By ~ 21

Author(s):

Sudeep Bhushal ◽

Markus Wolfsmüller ◽

Tharini A. Selvakumar ◽

Lucas Kemper ◽

Dagmar Wirth ◽

...

Keyword(s):

Epithelial Cells ◽

Intestinal Epithelial Cells ◽

Cell Polarization ◽

Intestinal Epithelial ◽

Type Iii

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Type III Interferon Restriction by Porcine Epidemic Diarrhea Virus and the Role of Viral Protein nsp1 in IRF1 Signaling

Journal of Virology ◽

10.1128/jvi.01677-17 ◽

2017 ◽

pp. JVI.01677-17 ◽

Cited By ~ 24

Author(s):

Qingzhan Zhang ◽

Hanzhong Ke ◽

Anthony Blikslager ◽

Takashi Fujita ◽

Dongwan Yoo

Keyword(s):

Epithelial Cells ◽

Porcine Epidemic Diarrhea Virus ◽

Nuclear Translocation ◽

Intestinal Epithelial Cells ◽

Cell Model ◽

Intestinal Epithelial ◽

Diarrhea Virus ◽

Type Iii ◽

Porcine Epidemic Diarrhea ◽

Type Iii Ifn

Type III interferons (IFN-λs) play a vital role to maintain the antiviral state of the mucosal epithelial surface in the gut, and in turn, enteric viruses may have evolved to evade the type III IFN responses during infection. To study of the possible immune evasion of porcine epidemic diarrhea virus (PEDV) from type III IFN response, a line of porcine intestinal epithelial cells was developed as a cell model for PEDV replication. IFN-λ1 and IFN-λ3 inhibited the PEDV replication, indicating the anti-PEDV activity of type III IFNs. Of the 21 PEDV proteins, nsp1, nsp3, nsp5, nsp8, nsp14, nsp15, nsp16, ORF3, E, M, and N were found to suppress the type III IFN activities, and the IRF1 signaling mediated the suppression. PEDV specifically inhibited IRF1 nuclear translocation. Peroxisome is the innate antiviral signaling platform for activation of IRF1-mediated IFN-λ production, and peroxisomes were found to decrease in number in PEDV-infected cells. PEDV nsp1 blocked the nuclear translocation of IRF1 and reduced the number of peroxisomes to suppress IRF1-mediated type III IFNs. Mutational studies showed the conserved residues of nsp1 were crucial for IRF1-mediated IFN-λ suppression. Our study for the first time provides the evidence that the porcine enteric virus PEDV downregulates and evades the IRF1-mediated type III IFN responses by reducing the peroxisomes.IMPORTANCEPorcine epidemic diarrhea virus (PEDV) is a highly contagious enteric coronavirus emerged in swine in the US and has caused severe economic losses. PEDV targets the intestinal epithelial cells in the gut, and intestinal epithelial cells selectively induce and respond to the production of type III interferons (IFNs). However, little is known about modulation of type III IFN response by PEDV in the intestinal epithelial cells. In this study, we established a porcine intestinal epithelial cell model for PEDV replication. We found that PEDV inhibited the IRF1-mediated type III IFN production by decreasing the peroxisomes in number in the porcine intestinal epithelial cells. We also demonstrated that the conserved residues in the PEDV nsp1 protein were crucial for IFN suppression. This study for the first time showed the PEDV evasion of type III IFN response in the intestinal epithelial cells. It provides valuable information on the host cell-virus interactions not only for PEDV but also other enteric viral infections in swine.

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Trafficking of Shigella Lipopolysaccharide in Polarized Intestinal Epithelial Cells

The Journal of Cell Biology ◽

10.1083/jcb.145.4.689 ◽

1999 ◽

Vol 145 (4) ◽

pp. 689-698 ◽

Cited By ~ 42

Author(s):

Wandy L. Beatty ◽

Stéphane Méresse ◽

Pierre Gounon ◽

Jean Davoust ◽

Joëlle Mounier ◽

...

Keyword(s):

Epithelial Cells ◽

Tight Junctions ◽

Apical Membrane ◽

Intestinal Epithelial Cells ◽

Fluid Phase ◽

Apical Surface ◽

Intestinal Epithelial ◽

Electron Microscopic ◽

Basolateral Side ◽

Endocytic Compartments

Bacterial lipopolysaccharide (LPS) at the apical surface of polarized intestinal epithelial cells was previously shown to be transported from the apical to the basolateral pole of the epithelium (Beatty, W.L., and P.J. Sansonetti. 1997. Infect. Immun. 65:4395–4404). The present study was designed to elucidate the transcytotic pathway of LPS and to characterize the endocytic compartments involved in this process. Confocal and electron microscopic analyses revealed that LPS internalized at the apical surface became rapidly distributed within endosomal compartments accessible to basolaterally internalized transferrin. This compartment largely excluded fluid-phase markers added at either pole. Access to the basolateral side of the epithelium subsequent to trafficking to basolateral endosomes occurred via exocytosis into the paracellular space beneath the intercellular tight junctions. LPS appeared to exploit other endocytic routes with much of the internalized LPS recycled to the original apical membrane. In addition, analysis of LPS in association with markers of the endocytic network revealed that some LPS was sent to late endosomal and lysosomal compartments.

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JAM4, a Junctional Cell Adhesion Molecule Interacting with a Tight Junction Protein, MAGI-1

Molecular and Cellular Biology ◽

10.1128/mcb.23.12.4267-4282.2003 ◽

2003 ◽

Vol 23 (12) ◽

pp. 4267-4282 ◽

Cited By ~ 116

Author(s):

Susumu Hirabayashi ◽

Makiko Tajima ◽

Ikuko Yao ◽

Wataru Nishimura ◽

Hiroki Mori ◽

...

Keyword(s):

Cell Adhesion ◽

Epithelial Cells ◽

Tight Junctions ◽

Adhesion Molecule ◽

Intestinal Epithelial Cells ◽

Cell Junctions ◽

Intestinal Epithelial ◽

Cell Contacts ◽

L Cells ◽

Junction Protein

ABSTRACT MAGI-1 is a membrane-associated guanylate kinase protein at tight junctions in epithelial cells. It interacts with various molecules and functions as a scaffold protein at cell junctions. We report here a novel MAGI-1-binding protein that we named junctional adhesion molecule 4 (JAM4). JAM4 belongs to an immunoglobulin protein family. JAM4 was colocalized with ZO-1 in kidney glomeruli and in intestinal epithelial cells. Biochemical in vitro studies revealed that JAM4 bound to MAGI-1 but not to ZO-1, whereas JAM1 did not bind to MAGI-1. JAM4 and MAGI-1 interacted with each other and formed clusters in COS-7 cells when coexpressed. JAM4 mediated calcium-independent homophilic adhesion and was accumulated at cell-cell contacts when expressed in L cells. MAGI-1, ZO-1, and occludin were recruited to JAM4-based cell contacts. JAM4 also reduced the permeability of CHO cell monolayers. MAGI-1 strengthened JAM4-mediated cell adhesion in L cells and sealing effects in CHO cells. These findings suggest that JAM4 together with MAGI-1 provides an adhesion machinery at tight junctions, which may regulate the permeability of kidney glomerulus and small intestinal epithelial cells.

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Critical role of type III interferon in controlling SARS-CoV-2 infection, replication and spread in primary human intestinal epithelial cells

10.1101/2020.04.24.059667 ◽

2020 ◽

Cited By ~ 13

Author(s):

Megan L. Stanifer ◽

Carmon Kee ◽

Mirko Cortese ◽

Sergio Triana ◽

Markus Mukenhirn ◽

...

Keyword(s):

Epithelial Cells ◽

De Novo ◽

Intestinal Epithelial Cells ◽

Critical Role ◽

Type I ◽

Intestinal Epithelial ◽

Virus Particles ◽

Type Iii ◽

Human Intestinal Epithelial Cells ◽

Type Iii Interferon

SummarySARS-CoV-2 is an unprecedented worldwide health problem that requires concerted and global approaches to better understand the virus in order to develop novel therapeutic approaches to stop the COVID-19 pandemic and to better prepare against potential future emergence of novel pandemic viruses. Although SARS-CoV-2 primarily targets cells of the lung epithelium causing respiratory infection and pathologies, there is growing evidence that the intestinal epithelium is also infected. However, the importance of the enteric phase of SARS-CoV-2 for virus-induced pathologies, spreading and prognosis remains unknown. Here, using both colon-derived cell lines and primary non-transformed colon organoids, we engage in the first comprehensive analysis of SARS-CoV-2 lifecycle in human intestinal epithelial cells. Our results demonstrate that human intestinal epithelial cells fully support SARS-CoV-2 infection, replication and production of infectious de-novo virus particles. Importantly, we identified intestinal epithelial cells as the best culture model to propagate SARS-CoV-2. We found that viral infection elicited an extremely robust intrinsic immune response where, interestingly, type III interferon mediated response was significantly more efficient at controlling SARS-CoV-2 replication and spread compared to type I interferon. Taken together, our data demonstrate that human intestinal epithelial cells are a productive site of SARS-CoV-2 replication and suggest that the enteric phase of SARS-CoV-2 may participate in the pathologies observed in COVID-19 patients by contributing in increasing patient viremia and by fueling an exacerbated cytokine response.

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