SepA Enhances<i>Shigella</i>Invasion of Epithelial Cells by Degrading Alpha-1 Antitrypsin and Producing a Neutrophil Chemoattractant

Meza-Segura, Mario; Birtley, James R.; Maldonado‐Contreras, Ana; Mueller, Christian; Simin, Karl; Stern, Lawrence J.; McCormick, Beth A.

doi:10.1128/mbio.02833-21

Cited by 12 publications

(9 citation statements)

References 100 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, the fact that PMN still migrated under IL-8 blocking conditions indicates that signals other than IL-8 are likewise involved in this process. In a series of articles, McCormick and colleagues interrogated molecules and bacterial components involved in Shigella -PMN responses in T84 cells ( 56 – 59 ); the group reported the contribution of hepoxilin A3, a product of the cleavage of arachidonic acid via 12/15-lipoxygenase ( 56 ) and the requirement of S. flexneri plasmid-encoded virulence effectors for PMN migration ( 60 – 62 ). In contrast, Perdomo et al found intermediate PMN migration in T84 monolayers exposed to a noninvasive (plasmid-cured) Shigella strain ( 54 ).…”

Section: Discussionmentioning

confidence: 99%

Epithelial and Neutrophil Interactions and Coordinated Response toShigellain a Human Intestinal Enteroid-Neutrophil Coculture Model

Lemme-Dumit

Doucet

Zachos

et al. 2022

mBio

View full text Add to dashboard Cite

Studies of mucosal immunity and microbial host cell interaction have traditionally relied on animal models and in vitro tissue culture using immortalized cancer cell lines, which yield nonphysiological and often unreliable results. Herein, we report the development and characterization of an ex vivo enteroid-PMN coculture consisting of normal human intestinal epithelium and a mechanistic interrogation of PMN and epithelial cell interaction and function in the context of Shigella infection.

show abstract

Section: Discussionmentioning

confidence: 99%

Epithelial and Neutrophil Interactions and Coordinated Response toShigellain a Human Intestinal Enteroid-Neutrophil Coculture Model

Lemme-Dumit

Doucet

Zachos

et al. 2022

mBio

View full text Add to dashboard Cite

show abstract

“…The effect of EAEC 042-infection on the gut barrier was investigated by evaluating the expression of ZO-1 tight junctions and β-catenin adherence junction proteins, on the ileum and colon, after 7 days post-challenge and uninfected mice (control group) by immunofluorescence. As illustrated in Figure 5 , ZO-1 localization remained unaltered in both ileum and colon tissues, suggesting that tight junctions are not affected at this stage of EAEC 042 infection and confirming that tEAEC, which is not an invasive pathogen, does not disrupt the epithelial barrier integrity as do S. enterica serovar Typhimurium and Shigella flexneri , both invasive bacteria ( Tafazoli et al., 2003 ; Meza-segura et al., 2021 ). On the other hand, EAEC 042 infection influenced β-catenin expression in the ileum since it was observed not only in the latero-basal cell region, adherence junction, and control tissues but also in the apical cell region ( Figure 6 ).…”

Section: Resultsmentioning

confidence: 57%

A Novel Adult Murine Model of Typical Enteroaggregative Escherichia coli Infection Reveals Microbiota Dysbiosis, Mucus Secretion, and AAF/II-Mediated Expression and Localization of β-Catenin and Expression of MUC1 in Ileum

Morán-García

López-Saucedo²,

Becerra³

et al. 2022

Front. Cell. Infect. Microbiol.

Self Cite

View full text Add to dashboard Cite

Typical enteroaggregative Escherichia coli (tEAEC) is a diarrheagenic E. coli pathotype associated with pediatric and traveler’s diarrhea. Even without diarrhea, EAEC infections in children also lead to increased gut inflammation and growth shortfalls. EAEC strain’s defining phenotype is the aggregative adherence pattern on epithelial cells attributable to the aggregative adherence fimbriae (AAF). EAEC only causes diarrhea in humans; therefore, not much is known of the exact intestinal region of infection and damage or its interactions with intestinal enterocytes in vivo and in situ. This study aimed to develop a new tEAEC mouse model of infection, characterize the microbiota of infected mice, and evaluate in situ the expression of host adherence and surface molecules triggering EAEC infection and the role of the EAEC AAF-II in adherence. Six-week-old C57BL/6 mice, without previous antibiotic treatment, were orally challenged with EAEC 042 strain or EAEC 042 AAF-II mutant (ΔAAF/II) strain, or DAEC-MXR strain (diffusely adherent E. coli clinical isolate), and with saline solution (control group). Paraffin sections of the colon and ileum were stained with H&E and periodic acid-Schiff. ZO-1, β-catenin, MUC1, and bacteria were analyzed by immunofluorescence. EAEC-infected mice, in comparison with DAEC-MXR-infected and control mice, significantly lost weight during the first 3 days. After 7 days post-infection, mucus production was increased in the colon and ileum, ZO-1 localization remained unaltered, and morphological alterations were more pronounced in the ileum since increased expression and apical localization of β-catenin in ileal enterocytes were observed. EAEC-infected mice developed dysbiosis 21 days post-infection. At 4 days post-infection, EAEC strain 042 formed a biofilm on ileal villi and increased the expression and apical localization of β-catenin in ileal enterocytes; these effects were not seen in animals infected with the 042 ΔAAF/II strain. At 3 days post-infection, MUC1 expression on ileal enterocytes was mainly detectable among infected mice and colocalized with 042 strains on the enterocyte surface. We developed a novel mouse model of EAEC infection, which mimics human infection, not an illness, revealing that EAEC 042 exerts its pathogenic effects in the mouse ileum and causes dysbiosis. This model is a unique tool to unveil early molecular mechanisms of EAEC infection in vivo and in situ.

show abstract

“…However, the fact that PMN still migrated under IL-8 blocking conditions indicates that signals other than IL-8 are likewise involved in this process. In a series of articles, McCormick and colleagues interrogated molecules and bacterial components involved in Shigella -PMN responses in T84 cells (56–59); the group reported the contribution of hepoxilin A3, a product of the cleavage of arachidonic acid via 12/15-lipoxygenase (56) and the requirement of S. flexneri plasmid-encoded virulence effectors for PMN migration (60–62). In contrast, Sansonetti et al found intermediate PMN migration in T84 monolayers exposed to a non-invasive (plasmid curated) Shigella strain (54).…”

Section: Discussionmentioning

confidence: 99%

Epithelial and neutrophil interactions and coordinated response toShigellain a human intestinal enteroid-neutrophil co-culture model

Lemme-Dumit

Doucet

Zachos

et al. 2020

Preprint

View full text Add to dashboard Cite

Polymorphonuclear neutrophils (PMN) respond to inflammation and infection in the gut. The physical and molecular interactions between the human intestinal epithelium and PMN in the gut mucosa and their coordinated responses to enteric pathogens, are poorly understood. We have established a PMN-enteroid co-culture model consisting of human intestinal stem-cell derived enteroid monolayers and peripheral blood PMN. The model was characterized in terms of tissue structure, barrier function, cell phenotype, production of cytokines, and innate immune responses. Shigella was used as a model enteric pathogen to interrogate PMN and epithelial cell interactions and innate immunity. PMN added to the enteroid monolayers increased production of IL-8 and rapidly transmigrated across the epithelial cell layer. PMN immune phenotype was distinctly modified in the gut microenvironment via molecular signals and direct epithelial cell contact. Apical exposure to Shigella increased PMN migration and production of IL-6 by co-cultured cells. PMN became activated and efficiently phagocytosed bacteria at the apical epithelial cell surface. The co-culture model revealed PMN-epithelial cell direct communication, tissue-driven PMN phenotypic adaptation and enhancement of anti-microbial function. This novel ex vivo epithelial cell-PMN co-culture system is relevant for mechanistic interrogation of host-microbe interactions and innate immune responses and the evaluation of preventive/therapeutic tools.

show abstract

SepA EnhancesShigellaInvasion of Epithelial Cells by Degrading Alpha-1 Antitrypsin and Producing a Neutrophil Chemoattractant

Abstract: Shigella is the second leading cause of diarrheal death globally. In this study, we identified the host protein targets of SepA, Shigella ’s major protein secreted in culture.

Cited by 12 publications

References 100 publications

Epithelial and Neutrophil Interactions and Coordinated Response toShigellain a Human Intestinal Enteroid-Neutrophil Coculture Model

Epithelial and Neutrophil Interactions and Coordinated Response toShigellain a Human Intestinal Enteroid-Neutrophil Coculture Model

A Novel Adult Murine Model of Typical Enteroaggregative Escherichia coli Infection Reveals Microbiota Dysbiosis, Mucus Secretion, and AAF/II-Mediated Expression and Localization of β-Catenin and Expression of MUC1 in Ileum

Epithelial and neutrophil interactions and coordinated response toShigellain a human intestinal enteroid-neutrophil co-culture model

Contact Info

Product

Resources

About