scholarly journals In Vivo-Induced InvA-Like Autotransporters Ifp and InvC of Yersinia pseudotuberculosis Promote Interactions with Intestinal Epithelial Cells and Contribute to Virulence

2011 ◽  
Vol 80 (3) ◽  
pp. 1050-1064 ◽  
Author(s):  
Fabio Pisano ◽  
Annika Kochut ◽  
Frank Uliczka ◽  
Rebecca Geyer ◽  
Tatjana Stolz ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Yersinia Pseudotuberculosis ◽  
Intestinal Epithelial Cells ◽  
Bacterial Colonization ◽  
Immune Defense ◽  
Peyer's Patches ◽  
Peyer’S Patches ◽  
Intestinal Epithelial ◽  
Content Type ◽  
K 12

TheYersinia pseudotuberculosisIfp and InvC molecules are putative autotransporter proteins with a high homology to the invasin (InvA) protein. To characterize the function of these surface proteins, we expressed both factors inEscherichia coliK-12 and demonstrated the attachment of Ifp- and InvC-expressing bacteria to human-, mouse-, and pig-derived intestinal epithelial cells. Ifp also was found to mediate microcolony formation and internalization into polarized human enterocytes. TheifpandinvCgenes were not expressed underin vitroconditions but were found to be induced in the Peyer's patches of the mouse intestinal tract. In a murine coinfection model, the colonization of the Peyer's patches and the mesenteric lymph nodes of mice by theifp-deficient strain was significantly reduced, and considerably fewer bacteria reached liver and spleen. The absence of InvC did not have a severe influence on bacterial colonization in the murine infection model, and it resulted in only a slightly reduced number ofinvCmutants in the Peyer's patches. The analysis of the host immune response demonstrated that the presence of Ifp and InvC reduced the recruitment of professional phagocytes, especially neutrophils, in the Peyer's patches. These findings support a role for the adhesins in modulating host-pathogen interactions that are important for immune defense.

scholarly journals Dual Recognition of Sialic Acid and αGal Epitopes by the VP8* Domains of the Bovine Rotavirus G6P[5] WC3 and of Its Mono-reassortant G4P[5] RotaTeq Vaccine Strains

2019 ◽  
Vol 93 (18) ◽  
Author(s):  
Mia Madel Alfajaro ◽  
Ji-Yun Kim ◽  
Laure Barbé ◽  
Eun-Hyo Cho ◽  
Jun-Gyu Park ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Blood Group ◽  
Intestinal Epithelial Cells ◽  
Sialic Acids ◽  
Blood Group Antigens ◽  
Intestinal Epithelial ◽  
Content Type ◽  
Group A Rotaviruses ◽  
Group A ◽  
Small Intestinal

ABSTRACTGroup A rotaviruses, an important cause of severe diarrhea in children and young animals, initiate infection via interactions of the VP8* domain of the VP4 spike protein with cell surface sialic acids (SAs) or histo-blood group antigens (HBGAs). Although the bovine G6P[5] WC3 strain is an important animal pathogen and is also used in the bovine-human reassortant RotaTeq vaccine, the receptor(s) for the VP8* domain of WC3 and its reassortant strains have not yet been identified. In the present study, HBGA- and saliva-binding assays showed that both G6P[5] WC3 and mono-reassortant G4P[5] strains recognized the αGal HBGA. The infectivity of both P[5]-bearing strains was significantly reduced in αGal-free MA-104 cells by pretreatment with a broadly specific neuraminidase or by coincubation with the α2,6-linked SA-specificSambucus nigralectin, but not by the α2,3-linked specific sialidase or byMaackia amurensislectin. Free NeuAc and the αGal trisaccharide also prevented the infectivity of both strains. This indicated that both P[5]-bearing strains utilize α2,6-linked SA as a ligand on MA104 cells. However, the two strains replicated in differentiated bovine small intestinal enteroids and in their human counterparts that lack α2,6-linked SA or αGal HBGA, suggesting that additional or alternative receptors such as integrins, hsp70, and tight-junction proteins bound directly to the VP5* domain can be used by the P[5]-bearing strains to initiate the infection of human cells. In addition, these data also suggested that P[5]-bearing strains have potential for cross-species transmission.IMPORTANCEGroup A rotaviruses initiate infection through the binding of the VP8* domain of the VP4 protein to sialic acids (SAs) or histo-blood group antigens (HBGAs). Although the bovine G6P[5] WC3 strain is an important animal pathogen and is used as the backbone in the bovine-human reassortant RotaTeq vaccine, the receptor(s) for their P[5] VP8* domain has remained elusive. Using a variety of approaches, we demonstrated that the WC3 and bovine-human mono-reassortant G4P[5] vaccine strains recognize both α2,6-linked SA and αGal HBGA as ligands. Neither ligand is expressed on human small intestinal epithelial cells, explaining the absence of natural human infection by P[5]-bearing strains. However, we observed that the P[5]-bearing WC3 and G4P[5] RotaTeq vaccine strains could still infect human intestinal epithelial cells. Thus, the four P[5] RotaTeq vaccine strains potentially binding to additional alternative receptors may be efficient and effective in providing protection against severe rotavirus disease in human.

scholarly journals Interleukin-7 Produced by Intestinal Epithelial Cells in Response to Citrobacter rodentium Infection Plays a Major Role in Innate Immunity against This Pathogen

2015 ◽  
Vol 83 (8) ◽  
pp. 3213-3223 ◽  
Author(s):  
Wei Zhang ◽  
Jiang-Yuan Du ◽  
Qing Yu ◽  
Jun-O Jin
Keyword(s):  
Epithelial Cells ◽  
Protective Immunity ◽  
Bacterial Infections ◽  
Intestinal Epithelial Cells ◽  
Intestinal Damage ◽  
Intestinal Epithelial ◽  
Citrobacter Rodentium ◽  
Content Type ◽  
Interleukin 7

Interleukin-7 (IL-7) engages multiple mechanisms to overcome chronic viral infections, but the role of IL-7 in bacterial infections, especially enteric bacterial infections, remains unclear. Here we characterized the previously unexplored role of IL-7 in the innate immune response to the attaching and effacing bacteriumCitrobacter rodentium.C. rodentiuminfection induced IL-7 production from intestinal epithelial cells (IECs). IL-7 production from IECs in response toC. rodentiumwas dependent on gamma interferon (IFN-γ)-producing NK1.1+cells and IL-12. Treatment with anti-IL-7Rα antibody duringC. rodentiuminfection resulted in a higher bacterial burden, enhanced intestinal damage, and greater weight loss and mortality than observed with the control IgG treatment. IEC-produced IL-7 was only essential for protective immunity againstC. rodentiumduring the first 6 days after infection. An impaired bacterial clearance upon IL-7Rα blockade was associated with a significant decrease in macrophage accumulation and activation in the colon. Moreover,C. rodentium-induced expansion and activation of intestinal CD4+lymphoid tissue inducer (LTi) cells was completely abrogated by IL-7Rα blockade. Collectively, these data demonstrate that IL-7 is produced by IECs in response toC. rodentiuminfection and plays a critical role in the protective immunity against this intestinal attaching and effacing bacterium.

scholarly journals CapC, a Novel Autotransporter and Virulence Factor ofCampylobacter jejuni

2018 ◽  
Vol 84 (16) ◽  
Author(s):  
Jai W. Mehat ◽  
Simon F. Park ◽  
Arnoud H. M. van Vliet ◽  
Roberto M. La Ragione
Keyword(s):  
Public Health ◽  
Epithelial Cells ◽  
Campylobacter Jejuni ◽  
Virulence Factor ◽  
Causative Agent ◽  
Galleria Mellonella ◽  
Intestinal Epithelial Cells ◽  
Intestinal Epithelial ◽  
Content Type ◽  
Reduced Adherence

ABSTRACTCampylobacter jejuniis recognized as an important causative agent of bacterial gastroenteritis in the developed world. Despite the identification of several factors contributing to infection, characterization of the virulence strategies employed byC. jejuniremains a significant challenge. Bacterial autotransporter proteins are a major class of secretory proteins in Gram-negative bacteria, and notably, many autotransporter proteins contribute to bacterial virulence. The aim of this study was to characterize theC. jejuni81116 C8J_1278 gene (capC), predicted to encode an autotransporter protein, and examine the contribution of this factor to virulence ofC. jejuni. The predicted CapC protein has a number of features that are consistent with autotransporters, including the N-terminal signal sequence and the C-terminal β-barrel domain and was determined to localize to the outer membrane. Inactivation of thecapCgene inC. jejuni81116 andC. jejuniM1 resulted in reduced insecticidal activity inGalleria mellonellalarvae. Furthermore,C. jejuni capCmutants displayed significantly reduced adherence to and invasion of nonpolarized, partially differentiated Caco-2 and T84 intestinal epithelial cells. Gentamicin treatment showed that the reduced invasion of thecapCmutant is primarily caused by reduced adherence to intestinal epithelial cells, not by reduced invasion capability.C. jejuni capCmutants caused reduced interleukin 8 (IL-8) secretion from intestinal epithelial cells and elicited a significantly diminished immune reaction inGallerialarvae, indicating that CapC functions as an immunogen. In conclusion, CapC is a new virulence determinant ofC. jejunithat contributes to the integral infection process of adhesion to human intestinal epithelial cells.IMPORTANCECampylobacter jejuniis a major causative agent of human gastroenteritis, making this zoonotic pathogen of significant importance to human and veterinary public health worldwide. The mechanisms by whichC. jejuniinteracts with intestinal epithelial cells and causes disease are still poorly understood due, in part, to the heterogeneity ofC. jejuniinfection biology. Given the importance ofC. jejunito public health, the need to characterize novel and existing virulence mechanisms is apparent. The significance of our research is in demonstrating the role of CapC, a novel virulence factor inC. jejunithat contributes to adhesion and invasion of the intestinal epithelium, thereby in part, addressing the dearth of knowledge concerning the factors involved inCampylobacterpathogenesis and the variation observed in the severity of human infection.

scholarly journals The Oxidoreductase DsbA Plays a Key Role in the Ability of the Crohn's Disease-Associated Adherent-Invasive Escherichia coli Strain LF82 To Resist Macrophage Killing

2007 ◽  
Vol 189 (13) ◽  
pp. 4860-4871 ◽  
Author(s):  
Marie-Agnès Bringer ◽  
Nathalie Rolhion ◽  
Anne-Lise Glasser ◽  
Arlette Darfeuille-Michaud
Keyword(s):  
Escherichia Coli ◽  
Crohn’S Disease ◽  
Crohn's Disease ◽  
Epithelial Cells ◽  
Intestinal Epithelial Cells ◽  
Coli Strain ◽  
Intestinal Epithelial ◽  
Type 1 Pili ◽  
K 12

ABSTRACT Adherent-invasive Escherichia coli (AIEC) isolated from Crohn's disease patients is able to adhere to and invade intestinal epithelial cells and to replicate in mature phagolysosomes within macrophages. Here, we show that the dsbA gene, encoding a periplasmic oxidoreductase, was required for AIEC strain LF82 to adhere to intestinal epithelial cells and to survive within macrophages. The LF82-ΔdsbA mutant did not express flagella and, probably as a consequence of this, did not express type 1 pili. The role of DsbA in adhesion is restricted to the loss of flagella and type 1 pili, as forced contact between bacteria and cells and induced expression of type 1 pili restored the wild-type phenotype. In contrast, the dsbA gene is essential for AIEC LF82 bacteria to survive within macrophages, irrespective of the loss of flagella and type 1 pilus expression, and the survival ability of LF82-ΔdsbA was as low as that of the nonpathogenic E. coli K-12, which was efficiently killed by macrophages. We also provide evidence that the dsbA gene is needed for LF82 bacteria to grow and survive in an acidic and nutrient-poor medium that partly mimics the harsh environment of the phagocytic vacuole. In addition, under such stress conditions dsbA transcription is highly up-regulated. Finally, the CpxRA signaling pathway does not play a role in regulation of dsbA expression in AIEC LF82 bacteria under conditions similar to those of mature phagolysosomes.

scholarly journals Inhibition of the NF-κB Pathway in Human Intestinal Epithelial Cells by Commensal Streptococcus salivarius

2011 ◽  
Vol 77 (13) ◽  
pp. 4681-4684 ◽  
Author(s):  
Ghalia Kaci ◽  
Omar Lakhdari ◽  
Joël Doré ◽  
S. Dusko Ehrlich ◽  
Pierre Renault ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Intestinal Epithelial Cells ◽  
Intestinal Epithelial ◽  
Streptococcus Salivarius ◽  
Necrosis Factor Alpha ◽  
Content Type ◽  
Human Intestinal Epithelial Cells ◽  
Tnf Α ◽  
Factor Alpha ◽  
Necrosis Factor

ABSTRACTStreptococcus salivariusexhibited an anti-inflammatory effect on intestinal epithelial cells (IECs) and monocytes. Strains were screened using a reporter clone, HT-29/kB-luc-E, induced by tumor necrosis factor alpha (TNF-α). Supernatant from each strain downregulated NF-κB activation. The two most efficient strains produced an active metabolite (<3 kDa) which was able to downregulate the secretion of the proinflammatory chemokine interleukin-8 (IL-8).

Immunocytochemical studies of Salmonella Typhimurium invasion of porcine jejunal epithelial cells

2004 ◽  
Vol 53 (7) ◽  
pp. 691-695 ◽  
Author(s):  
Kirsten Schauser ◽  
John Elmerdahl Olsen ◽  
Lars-Inge Larsson
Keyword(s):  
Epithelial Cell ◽  
Epithelial Cells ◽  
Proximal Region ◽  
Peyer's Patches ◽  
Intestinal Cell ◽  
Jejunal Loop ◽  
Peyer’S Patches ◽  
Loop Model ◽  
Intestinal Epithelial ◽  
Subepithelial Layer

Although infection of pigs with Salmonella Typhimurium represents a serious problem, most studies on Salmonella infection have been carried out in other species. The purpose of the current study was to examine the route(s) of entry of Salmonella Typhimurium in pigs, using a jejunal loop model. The infection process was followed over 240 min using single to triple immunocytochemical detection of Salmonella and intestinal cell markers. Salmonella invasion was observed in both cytokeratin-18-positive and -negative cylindrical absorptive cells within 5–10 min. Subepithelial invasion of ordinary villi was consistently less marked than invasion of the subepithelial layer of Peyer's patches. Our results show that several epithelial cell types were invaded by Salmonella, and that Peyer's patches represent the main portal of entry in early Salmonella infection. Additionally, infection was associated with alterations in the keratin and F-actin cytoskeleton of intestinal epithelial cells, probably reflecting toxin-mediated actions. Such changes were confined to the proximal region of the jejunum, demonstrating a regional heterogeneity of intestinal epithelial cell responses to Salmonella infection.

scholarly journals Anti-Inflammatory Properties of Streptococcus salivarius, a Commensal Bacterium of the Oral Cavity and Digestive Tract

2013 ◽  
Vol 80 (3) ◽  
pp. 928-934 ◽  
Author(s):  
Ghalia Kaci ◽  
Denise Goudercourt ◽  
Véronique Dennin ◽  
Bruno Pot ◽  
Joël Doré ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Oral Cavity ◽  
Mononuclear Cells ◽  
Inflammatory Responses ◽  
Intestinal Epithelial Cells ◽  
Intestinal Epithelial ◽  
Streptococcus Salivarius ◽  
Content Type ◽  
Anti Inflammatory

ABSTRACTStreptococcus salivariusis one of the first colonizers of the human oral cavity and gut after birth and therefore may contribute to the establishment of immune homeostasis and regulation of host inflammatory responses. The anti-inflammatory potential ofS. salivariuswas first evaluatedin vitroon human intestinal epithelial cells and human peripheral blood mononuclear cells. We show that liveS. salivariusstrains inhibitedin vitrothe activation of the NF-κB pathway on intestinal epithelial cells. We also demonstrate that the liveS. salivariusJIM8772 strain significantly inhibited inflammation in severe and moderate colitis mouse models. Thesein vitroandin vivoanti-inflammatory properties were not found with heat-killedS. salivarius, suggesting a protective response exclusively with metabolically active bacteria.

scholarly journals Genetic Mechanisms Underlying the Pathogenicity of Cold-Stressed Salmonella enterica Serovar Typhimurium in Cultured Intestinal Epithelial Cells

2014 ◽  
Vol 80 (22) ◽  
pp. 6943-6953 ◽  
Author(s):  
Jigna Shah ◽  
Prerak T. Desai ◽  
Bart C. Weimer
Keyword(s):  
Epithelial Cells ◽  
Host Cell ◽  
Intestinal Epithelial Cells ◽  
Acid Stress ◽  
Intestinal Epithelial ◽  
Cell Infection ◽  
Antioxidant Genes ◽  
Content Type ◽  
Serovar Typhimurium ◽  
Adhesion And Invasion

ABSTRACTSalmonellaencounters various stresses in the environment and in the host during infection. The effects of cold (5°C, 48 h), peroxide (5 mM H2O2, 5 h) and acid stress (pH 4.0, 90 min) were tested on pathogenicity ofSalmonella. Prior exposure ofSalmonellato cold stress significantly (P< 0.05) increased adhesion and invasion of cultured intestinal epithelial (Caco-2) cells. This increasedSalmonella-host cell association was also correlated with significant induction of several virulence-associated genes, implying an increased potential of cold-stressedSalmonellato cause an infection. In Caco-2 cells infected with cold-stressedSalmonella, genes involved in the electron transfer chain were significantly induced, but no simultaneous significant increase in expression of antioxidant genes that neutralize the effect of superoxide radicals or reactive oxygen species was observed. Increased production of caspase 9 and caspase 3/7 was confirmed during host cell infection with cold-stressedSalmonella. Further, a prophage gene,STM2699, induced in cold-stressedSalmonellaand a spectrin gene, SPTAN1, induced inSalmonella-infected intestinal epithelial cells were found to have a significant contribution in increased adhesion and invasion of cold-stressedSalmonellain epithelial cells.

scholarly journals Interaction of Bifidobacterium bifidum LMG13195 with HT29 Cells Influences Regulatory-T-Cell-Associated Chemokine Receptor Expression

2012 ◽  
Vol 78 (8) ◽  
pp. 2850-2857 ◽  
Author(s):  
Patricia López ◽  
Irene González-Rodríguez ◽  
Borja Sánchez ◽  
Patricia Ruas-Madiedo ◽  
Ana Suárez ◽  
...  
Keyword(s):  
T Cell ◽  
Epithelial Cells ◽  
Intestinal Mucosa ◽  
Chemokine Receptor ◽  
Intestinal Epithelial Cells ◽  
Bifidobacterium Bifidum ◽  
Receptor Expression ◽  
Intestinal Epithelial ◽  
Content Type ◽  
Ht29 Cells

ABSTRACTProbiotics play an important role in the maintenance of the gastrointestinal barrier. In addition to direct effects on mucosal integrity, the interaction with the intestinal mucosa may have an active immunoregulatory effect. In the present work, we exposed HT29 intestinal epithelial cells to twoBifidobacteriumspecies to determine their effect on gene expression profile, enterocyte monolayer integrity, and T-cell response.Bifidobacterium breveIPLA 20004 triggered a more pronounced increase in the transepithelial resistance of the enterocyte monolayer thanBifidobacterium bifidumLMG13195. The transcriptome profile of HT29 cells cultured in the presence ofB. bifidumLMG13195 showed an increased expression of immune mediators and, interestingly, chemotactic molecules (CXCL10, CCL20, CXCL11 and CCL22) able to recruit lymphocytes. Since regulatory T cells (Treg cells) may express receptors for specific chemokines, we cultured peripheral blood mononuclear cells with supernatants of HT29 cells previously treated withBifidobacteriumstrains and analyzed FOXP3 and CD25 Treg markers and CCR6, CXCR3, CCR4, and CCR3 expression on CD4+lymphocytes. The proportion of CD25highFOXP3+cells was significantly increased after culture withB. bifidumLMG13195-conditioned HT29 supernatant. Moreover, this treatment led to the largest amount of CCR6+CXCR3−CCR4+CCR3+CD4+cells expressing high levels of CD25, corresponding to the Treg population. These results suggest that soluble factors secreted afterB. bifidumLMG13195 contact with intestinal epithelial cells favored the generation of CD4+CD25highlymphocytes expressing chemokine receptor Treg markers, thus making possible their recruitment to the intestinal mucosa.

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