O-Antigen Delays Lipopolysaccharide Recognition and Impairs Antibacterial Host Defense in Murine Intestinal Epithelial Cells

The picornavirus Aichi virus (AiV) is a non-enveloped RNA virus that causes acute gastroenteritis symptoms, such as diarrhea, abdominal pain, nausea, vomiting, and fever. Antiviral host defense involves the fast response of type I interferon (IFN) and the secretion of inflammatory cytokines against pathogens. However, the intestinal inflammatory and antiviral response to AiV infection is poorly understood. This study evaluated the antiviral activity of intestinal epithelial cells (IECs), which form a single-cell layer separating the bowel wall from pathogens. Isolated primary mouse IECs were subjected to AiV infection and virion production, inducing the mRNA expression of type I/type III IFNs and inflammatory cytokines. The mechanism involved induced the expression of phospho-IFN regulatory factor 3 and mitochondrial antiviral-signaling protein of type I IFN signaling. These findings were also observed in AiV-infected human colon carcinoma cells. In summary, a viral productive and pathogenic infection of AiV in primary murine IECs is validated.

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Nitric Oxide Production by Human Intestinal Epithelial Cells and Competition for Arginine as Potential Determinants of Host Defense Against the Lumen-Dwelling PathogenGiardia lamblia

The Journal of Immunology ◽

10.4049/jimmunol.164.3.1478 ◽

2000 ◽

Vol 164 (3) ◽

pp. 1478-1487 ◽

Cited By ~ 155

Author(s):

Lars Eckmann ◽

Fabrice Laurent ◽

T. Dianne Langford ◽

Michael L. Hetsko ◽

Jennifer R. Smith ◽

...

Keyword(s):

Nitric Oxide ◽

Epithelial Cells ◽

Host Defense ◽

Intestinal Epithelial Cells ◽

Nitric Oxide Production ◽

Intestinal Epithelial ◽

Oxide Production ◽

Human Intestinal Epithelial Cells

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Factors affecting the colonization of isolated rabbit intestinal epithelial cells by Vibrio cholerae 01 in vitro

Canadian Journal of Microbiology ◽

10.1139/m89-103 ◽

1989 ◽

Vol 35 (6) ◽

pp. 642-645 ◽

Cited By ~ 3

Author(s):

D. Sasmal ◽

B. Guhathakurta ◽

S. N. Sikdar ◽

A. Datta

Keyword(s):

Epithelial Cell ◽

Epithelial Cells ◽

Vibrio Cholerae ◽

Intestinal Epithelial Cell ◽

Intestinal Epithelial Cells ◽

Growth Media ◽

Intestinal Epithelial ◽

Factors Affecting ◽

O Antigen

The adhesive capability of Vibrio cholerae 01 strains to isolated rabbit intestinal epithelial cells was maximally expressed when the bacteria were grown in synthetic broth and was enhanced by the presence of Ca2+ in the growth media. N-Acetyl-D-glucosamine could inhibit the adhesion of the bacteria to rabbit intestinal epithelial cells as could lipopolysaccharide O-antigen from Vibrio cholerae 01 and lectin from Triticum vulgaris. Since the lipopolysaccharide is known to contain N-acetyl-D-glucosamine and because the lectin from Triticum vulgaris shows specificity for this sugar, it is probable that N-acetyl-D-glucosamine is actively involved in the adhesion of Vibrio cholerae 01 to isolated rabbit intestinal epithelial cells.Key words: adhesion, Vibrio cholerae 01, rabbit intestinal epithelial cell.

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Transient Suppression of Shigella flexneri Type 3 Secretion by a Protective O-Antigen-Specific Monoclonal IgA

mBio ◽

10.1128/mbio.00042-11 ◽

2011 ◽

Vol 2 (3) ◽

Cited By ~ 22

Author(s):

Stephen J. Forbes ◽

Tia Bumpus ◽

Elizabeth A. McCarthy ◽

Blaise Corthésy ◽

Nicholas J. Mantis

Keyword(s):

Epithelial Cells ◽

Mucosal Immunity ◽

Intestinal Epithelial Cells ◽

Shigella Flexneri ◽

Secretory Iga ◽

Bacterial Invasion ◽

Intestinal Epithelial ◽

Content Type ◽

O Antigen ◽

Type 3

ABSTRACTMucosal immunity to the enteric pathogenShigella flexneriis mediated by secretory IgA (S-IgA) antibodies directed against the O-antigen (O-Ag) side chain of lipopolysaccharide. While secretory antibodies against the O-Ag are known to prevent bacterial invasion of the intestinal epithelium, the mechanisms by which this occurs are not fully understood. In this study, we report that the binding of a murine monoclonal IgA (IgAC5) to the O-Ag ofS. flexneriserotype 5a suppresses activity of the type 3 secretion (T3S) system, which is necessary forS. flexnerito gain entry into intestinal epithelial cells. IgAC5’s effects on the T3S were rapid (5 to 15 min) and were coincident with a partial reduction in the bacterial membrane potential and a decrease in intracellular ATP levels. Activity of the T3S system returned to normal levels 45 to 90 min following antibody treatment, demonstrating that IgAC5’s effects were transient. Nonetheless, these data suggest a model in which the association of IgA with the O-Ag ofS. flexneripartially de-energizes the T3S system and temporarily renders the bacterium incapable of invading intestinal epithelial cells.IMPORTANCESecretory IgA (S-IgA) serves as the first line of defense against enteric infections. However, despite its well-recognized role in mucosal immunity, relatively little is known at the molecular level about how this class of antibody functions to prevent pathogenic bacteria from penetrating the epithelial barrier. It is generally assumed that S-IgA functions primarily by “immune exclusion,” a phenomenon in which the antibody binds to microbial surface antigens and thereby promotes bacterial agglutination, entrapment in mucus, and physical clearance from the gastrointestinal tract via peristalsis. The results of the present study suggest that in addition to serving as a physical barrier, S-IgA may have a direct impact on the ability of microbial pathogens to secrete virulence factors required for invasion of intestinal epithelial cells.

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Three-dimensional organization and functional relationships of endocytotic compartments in pig intestinal epithelial cells

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100123283 ◽

1992 ◽

Vol 50 (1) ◽

pp. 576-577

Author(s):

Julian P. Heath ◽

Buford L. Nichols ◽

László G. Kömüves

Keyword(s):

Electron Microscopy ◽

Epithelial Cells ◽

Intestinal Epithelial Cells ◽

Three Dimensional ◽

Intestinal Epithelial ◽

Cell Surfaces ◽

Basal Surface ◽

Functional Relationships

The newborn pig intestine is adapted for the rapid and efficient absorption of nutrients from colostrum. In enterocytes, colostral proteins are taken up into an apical endocytotic complex of channels that transports them to target organelles or to the basal surface for release into the circulation. The apical endocytotic complex of tubules and vesicles clearly is a major intersection in the routes taken by vesicles trafficking to and from the Golgi, lysosomes, and the apical and basolateral cell surfaces.Jejunal tissues were taken from piglets suckled for up to 6 hours and prepared for electron microscopy and immunocytochemistry as previously described.

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