scholarly journals Mutations in the IMD Pathway and Mustard Counter Vibrio cholerae Suppression of Intestinal Stem Cell Division in Drosophila

mBio ◽  
2013 ◽  
Vol 4 (3) ◽  
Author(s):  
Zhipeng Wang ◽  
Saiyu Hang ◽  
Alexandra E. Purdy ◽  
Paula I. Watnick
Keyword(s):  
Stem Cell ◽  
Cholera Toxin ◽  
Vibrio Cholerae ◽  
Intestinal Bacteria ◽  
The Body ◽  
Intestinal Stem Cell ◽  
Loss Of Function ◽  
Content Type ◽  
Epithelial Regeneration ◽  
Imd Pathway

ABSTRACT Vibrio cholerae is an estuarine bacterium and an intestinal pathogen of humans that causes severe epidemic diarrhea. In the absence of adequate mammalian models in which to study the interaction of V. cholerae with the host intestinal innate immune system, we have implemented Drosophila melanogaster as a surrogate host. We previously showed that immune deficiency pathway loss-of-function and mustard gain-of-function mutants are less susceptible to V. cholerae infection. We find that although the overall burden of intestinal bacteria is not significantly different from that of control flies, intestinal stem cell (ISC) division is increased in these mutants. This led us to examine the effect of V. cholerae on ISC division. We report that V. cholerae infection and cholera toxin decrease ISC division. Because IMD pathway and Mustard mutants, which are resistant to V. cholerae, maintain higher levels of ISC division during V. cholerae infection, we hypothesize that suppression of ISC division is a virulence strategy of V. cholerae and that accelerated epithelial regeneration protects the host against V. cholerae. Extension of these findings to mammals awaits the development of an adequate experimental model. IMPORTANCE Here we show that Vibrio cholerae and cholera toxin suppress intestinal stem cell (ISC) division. This is the first evidence of manipulation of ISC division by V. cholerae and demonstrates the utility of the Drosophila model in generating novel hypotheses regarding the interaction of V. cholerae with the intestinal epithelium. Furthermore, we add to the body of data suggesting that the IMD pathway and the Mustard protein modulate ISC division independently of the overall load of commensal intestinal bacteria.

scholarly journals A Genome-Wide Screen Reveals that the Vibrio cholerae Phosphoenolpyruvate Phosphotransferase System Modulates Virulence Gene Expression

2015 ◽  
Vol 83 (9) ◽  
pp. 3381-3395 ◽  
Author(s):  
Qiyao Wang ◽  
Yves A. Millet ◽  
Michael C. Chao ◽  
Jumpei Sasabe ◽  
Brigid M. Davis ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cholera Toxin ◽  
Vibrio Cholerae ◽  
Insertion Site ◽  
Virulence Gene ◽  
Loss Of Function ◽  
Phosphotransferase System ◽  
Content Type ◽  
Virulence Gene Expression ◽  
A Genome

Diverse environmental stimuli and a complex network of regulatory factors are known to modulate expression ofVibrio cholerae's principal virulence factors. However, there is relatively little known about how metabolic factors impinge upon the pathogen's well-characterized cascade of transcription factors that induce expression of cholera toxin and the toxin-coregulated pilus (TCP). Here, we used a transposon insertion site (TIS) sequencing-based strategy to identify new factors required for expression oftcpA, which encodes the major subunit of TCP, the organism's chief intestinal colonization factor. Besides identifying most of the genes known to modulatetcpAexpression, the screen yieldedptsIandptsH, which encode the enzyme I (EI) and Hpr components of theV. choleraephosphoenolpyruvate phosphotransferase system (PTS). In addition to reduced expression of TcpA, strains lacking EI, Hpr, or the associated EIIAGlcprotein produced less cholera toxin (CT) and had a diminished capacity to colonize the infant mouse intestine. The PTS modulates virulence gene expression by regulating expression oftcpPHandaphAB, which themselves control expression oftoxT, the central activator of virulence gene expression. One mechanism by which PTS promotes virulence gene expression appears to be by modulating the amounts of intracellular cyclic AMP (cAMP). Our findings reveal that theV. choleraePTS is an additional modulator of the ToxT regulon and demonstrate the potency of loss-of-function TIS sequencing screens for defining regulatory networks.

Glucomannan from Aloe vera Gel Promotes Intestinal Stem Cell-Mediated Epithelial Regeneration via the Wnt/β-Catenin Pathway

2021 ◽  
Vol 69 (36) ◽  
pp. 10581-10591
Author(s):  
Duoduo Zhang ◽  
Xingtao Zhou ◽  
Linyuan Liu ◽  
Mi Guo ◽  
Tongwen Huang ◽  
...  
Keyword(s):  
Stem Cell ◽  
Aloe Vera ◽  
Intestinal Stem Cell ◽  
Epithelial Regeneration ◽  
Aloe Vera Gel

scholarly journals Posttranslational Regulation of IL-23 Production Distinguishes the Innate Immune Responses to Live Toxigenic versus Heat-Inactivated Vibrio cholerae

mSphere ◽  
2019 ◽  
Vol 4 (4) ◽  
Author(s):  
Ana A. Weil ◽  
Crystal N. Ellis ◽  
Meti D. Debela ◽  
Taufiqur R. Bhuiyan ◽  
Rasheduzzaman Rashu ◽  
...  
Keyword(s):  
Immune Responses ◽  
Cholera Toxin ◽  
Vibrio Cholerae ◽  
Protective Immunity ◽  
Innate Immune ◽  
Posttranslational Regulation ◽  
Content Type ◽  
In Cells ◽  
Cholera Vaccines

ABSTRACT Vibrio cholerae infection provides long-lasting protective immunity, while oral, inactivated cholera vaccines (OCV) result in more-limited protection. To identify characteristics of the innate immune response that may distinguish natural V. cholerae infection from OCV, we stimulated differentiated, macrophage-like THP-1 cells with live versus heat-inactivated V. cholerae with and without endogenous or exogenous cholera holotoxin (CT). Interleukin 23A gene (IL23A) expression was higher in cells exposed to live V. cholerae than in cells exposed to inactivated organisms (mean change, 38-fold; 95% confidence interval [95% CI], 4.0 to 42; P < 0.01). IL-23 secretion was also higher in cells exposed to live V. cholerae than in cells exposed to inactivated V. cholerae (mean change, 5.6-fold; 95% CI, 4.4 to 11; P < 0.001). This increase in IL-23 secretion was more marked than for other key innate immune cytokines (e.g., IL-1β and IL-6) and dependent on exposure to the combination of both live V. cholerae and CT. While IL-23 secretion was reduced following stimulation with either heat-inactivated wild-type V. cholerae or a live isogenic ctxAB mutant of V. cholerae, the addition of exogenous CT restored IL-23 secretion in combination with the live isogenic ctxAB mutant V. cholerae, but not when it was paired with stimulation by heat-inactivated V. cholerae. The posttranslational regulation of IL-23 under these conditions was dependent on the activity of the cysteine protease cathepsin B. In humans, IL-23 promotes the differentiation of Th17 cells to T follicular helper cells, which maintain and support long-term memory B cell generation after infection. Based on these findings, the stimulation of IL-23 production may be a determinant of protective immunity following V. cholerae infection. IMPORTANCE An episode of cholera provides better protection against reinfection than oral cholera vaccines, and the reasons for this are still under study. To better understand this, we compared the immune responses of human cells exposed to live Vibrio cholerae with those of cells exposed to heat-killed V. cholerae (similar to the contents of oral cholera vaccines). We also compared the effects of active cholera toxin and the inactive cholera toxin B subunit (which is included in some cholera vaccines). One key immune signaling molecule, IL-23, was uniquely produced in response to the combination of live bacteria and active cholera holotoxin. Stimulation with V. cholerae that did not produce the active toxin or was killed did not produce an IL-23 response. The stimulation of IL-23 production by cholera toxin-producing V. cholerae may be important in conferring long-term immunity after cholera.

scholarly journals Whole-Genome Analysis of Clinical Vibrio cholerae O1 in Kolkata, India, and Dhaka, Bangladesh, Reveals Two Lineages of Circulating Strains, Indicating Variation in Genomic Attributes

mBio ◽  
2020 ◽  
Vol 11 (6) ◽  
Author(s):  
Daichi Morita ◽  
Masatomo Morita ◽  
Munirul Alam ◽  
Asish K. Mukhopadhyay ◽  
Fatema-tuz Johura ◽  
...  
Keyword(s):  
South Asia ◽  
Cholera Toxin ◽  
Vibrio Cholerae ◽  
Sub Saharan Africa ◽  
Cholera Toxin B Subunit ◽  
Whole Genome ◽  
Global Public Health ◽  
Whole Genome Analysis ◽  
Genetic Traits ◽  
Content Type

ABSTRACT Vibrio cholerae serogroup O1 is responsible for epidemic and pandemic cholera and remains a global public health threat. This organism has been well established as a resident flora of the aquatic environment that alters its phenotypic and genotypic attributes for better adaptation to the environment. To reveal the diversity of clinical isolates of V. cholerae O1 in the Bay of Bengal, we performed whole-genome sequencing of isolates from Kolkata, India, and Dhaka, Bangladesh, collected between 2009 and 2016. Comparison with global isolates by phylogenetic analysis placed the current isolates in two Asian lineages, with lineages 1 and 2 predominant in Dhaka and Kolkata, respectively. Each lineage possessed different genetic traits in the cholera toxin B subunit gene, Vibrio seventh pandemic island II, integrative and conjugative element, and antibiotic-resistant genes. Thus, although recent global transmission of V. cholerae O1 from South Asia has been attributed only to isolates of lineage 2, another distinct lineage exists in Bengal. IMPORTANCE Cholera continues to be a global concern, as large epidemics have occurred recently in Haiti, Yemen, and countries of sub-Saharan Africa. A single lineage of Vibrio cholerae O1 has been considered to be introduced into these regions from South Asia and to cause the spread of cholera. Using genomic epidemiology, we showed that two distinct lineages exist in Bengal, one of which is linked to the global lineage. The other lineage was found only in Iran, Iraq, and countries in Asia and differed from the global lineage regarding cholera toxin variant and drug resistance profile. Therefore, the potential transmission of this lineage to other regions would likely cause worldwide cholera spread and may result in this lineage replacing the current global lineage.

scholarly journals A Quinazoline-2,4-Diamino Analog Suppresses Vibrio cholerae Flagellar Motility by Interacting with Motor Protein PomB and Induces Envelope Stress

2013 ◽  
Vol 57 (8) ◽  
pp. 3950-3959 ◽  
Author(s):  
Hongxia Wang ◽  
Li Zhang ◽  
Anisia J. Silva ◽  
Jorge A. Benitez
Keyword(s):  
Cholera Toxin ◽  
Vibrio Cholerae ◽  
Motor Protein ◽  
Polar Flagellum ◽  
Flagellar Motility ◽  
Extracellular Rna ◽  
Content Type ◽  
Envelope Stress ◽  
Causative Agents ◽  
El Tor

ABSTRACTVibrio choleraestrains of serogroups O1 and O139, the causative agents of the diarrheal illness cholera, express a single polar flagellum powered by sodium motive force and require motility to colonize and spread along the small intestine. In a previous study, we described a high-throughput assay for screening for small molecules that selectively inhibit bacterial motility and identified a family of quinazoline-2,4-diamino analogs (Q24DAs) that (i) paralyzed the sodium-driven polar flagellum ofVibriosand (ii) diminished cholera toxin secreted by El Tor biotypeV. cholerae. In this study, we provide evidence that a Q24DA paralyzes the polar flagellum by interacting with the motor protein PomB. Inhibition of motility with the Q24DA enhanced the transcription of the cholera toxin genes in both biotypes. We also show that the Q24DA interacts with outer membrane protein OmpU and other porins to induce envelope stress and expression of the extracellular RNA polymerase sigma factor σE. We suggest that Q24DA-induced envelope stress could affect the correct folding, assembly, and secretion of pentameric cholera toxin in El Tor biotypeV. choleraeindependently of its effect on motility.

scholarly journals Type III Secretion Is Essential for the Rapidly Fatal Diarrheal Disease Caused by Non-O1, Non-O139 Vibrio cholerae

mBio ◽  
2011 ◽  
Vol 2 (3) ◽  
Author(s):  
Ok S. Shin ◽  
Vincent C. Tam ◽  
Masato Suzuki ◽  
Jennifer M. Ritchie ◽  
Roderick T. Bronson ◽  
...  
Keyword(s):  
Cholera Toxin ◽  
Vibrio Cholerae ◽  
Intestinal Epithelium ◽  
Type Iii Secretion ◽  
Diarrheal Disease ◽  
Secretion Systems ◽  
Content Type ◽  
Type Iii ◽  
Severe Diarrhea ◽  
Toxin Coregulated Pilus

ABSTRACTCholera is a severe diarrheal disease typically caused by O1 serogroup strains ofVibrio cholerae. The pathogenicity of all pandemicV. choleraeO1 strains relies on two critical virulence factors: cholera toxin, a potent enterotoxin, and toxin coregulated pilus (TCP), an intestinal colonization factor. However, certain non-O1, non-O139V. choleraestrains, such as AM-19226, do not produce cholera toxin or TCP, yet they still cause severe diarrhea. The molecular basis for the pathogenicity of non-O1, non-O139V. choleraehas not been extensively characterized, but many of these strains encode related type III secretion systems (TTSSs). Here, we used infant rabbits to assess the contribution of the TTSS to non-O1, non-O139V. choleraepathogenicity. We found that all animals infected with wild-type AM-19226 developed severe diarrhea even more rapidly than rabbits infected withV. choleraeO1. UnlikeV. choleraeO1 strains, which do not damage the intestinal epithelium in rabbits or humans, AM-19226 caused marked disruptions of the epithelial surface in the rabbit small intestine. TTSS proved to be essential for AM-19226 virulence in infant rabbits; an AM-19226 derivative deficient for TTSS did not elicit diarrhea, colonize the intestine, or induce pathological changes in the intestine. Deletion of either one of the two previously identified or two newly identified AM-19226 TTSS effectors reduced but did not eliminate AM-19226 pathogenicity, suggesting that at least four effectors contribute to this strain’s virulence. In aggregate, our results suggest that the TTSS-dependent virulence in non-O1, non-O139V. choleraerepresents a new type of diarrheagenic mechanism.IMPORTANCECholera, which is caused byVibrio cholerae, is an important cause of diarrheal disease in many developing countries. The mechanisms of virulence of nonpandemic strains that can cause a diarrheal illness are poorly understood. AM-19226, like several other pathogenic, nonpandemicV. choleraestrains, carries genes that encode a type III secretion system (TTSS), but not cholera toxin (CT) or toxin coregulated pilus (TCP). In this study, we used infant rabbits to study AM-19226 virulence. Infant rabbits orally inoculated with this strain rapidly developed a fatal diarrheal disease, which was accompanied by marked disruptions of the intestinal epithelium. This strain’s TTSS proved essential for its pathogenicity, and there was no diarrhea, intestinal pathology, or colonization in rabbits infected with a TTSS mutant. The effector proteins translocated by the TTSS all appear to contribute to AM-19226 virulence. Thus, our study provides insight intoin vivomechanisms by which a novel TTSS contributes to diarrheal disease caused by nonpandemic strains ofV. cholerae.

scholarly journals Effect of LexA on Chromosomal Integration of CTXϕ in Vibrio cholerae

2015 ◽  
Vol 198 (2) ◽  
pp. 268-275 ◽  
Author(s):  
Archana Pant ◽  
D Anbumani ◽  
Satyabrata Bag ◽  
Ojasvi Mehta ◽  
Pawan Kumar ◽  
...  
Keyword(s):  
Cholera Toxin ◽  
Vibrio Cholerae ◽  
Fine Tuning ◽  
Filamentous Phage ◽  
Chromosomal Integration ◽  
Content Type ◽  
Ssdna Binding ◽  
Tyrosine Recombinases ◽  
Reporter Strains ◽  
In Cells

ABSTRACTThe genesis of toxigenicVibrio choleraeinvolves acquisition of CTXϕ, a single-stranded DNA (ssDNA) filamentous phage that encodes cholera toxin (CT). The phage exploits host-encoded tyrosine recombinases (XerC and XerD) for chromosomal integration and lysogenic conversion. The replicative genome of CTXϕ produces ssDNA by rolling-circle replication, which may be used either for virion production or for integration into host chromosome. Fine-tuning of different ssDNA binding protein (Ssb) levels in the host cell is crucial for cellular functioning and important for CTXϕ integration. In this study, we mutated the master regulator gene of SOS induction,lexA, ofV. choleraebecause of its known role in controlling levels of Ssb proteins in other bacteria. CTXϕ integration decreased in cells with a ΔlexAmutation and increased in cells with an SOS-noninducing mutation,lexA(Ind−). We also observed that overexpression of host-encoded Ssb (VC0397) decreased integration of CTXϕ. We propose that LexA helps CTXϕ integration, possibly by fine-tuning levels of host- and phage-encoded Ssbs.IMPORTANCECholera toxin is the principal virulence factor responsible for the acute diarrheal disease cholera. CT is encoded in the genome of a lysogenic filamentous phage, CTXϕ.Vibrio choleraehas a bipartite genome and harbors single or multiple copies of CTXϕ prophage in one or both chromosomes. Two host-encoded tyrosine recombinases (XerC and XerD) recognize the folded ssDNA genome of CTXϕ and catalyze its integration at the dimer resolution site of either one or both chromosomes. Fine-tuning of ssDNA binding proteins in host cells is crucial for CTXϕ integration. We engineered theV. choleraegenome and created several reporter strains carrying ΔlexAorlexA(Ind−) alleles. Using the reporter strains, the importance of LexA control of Ssb expression in the integration efficiency of CTXϕ was demonstrated.

scholarly journals Smooth muscle-specific MMP17 (MT4-MMP) regulates the intestinal stem cell niche and regeneration after damage

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Mara Martín-Alonso ◽  
Sharif Iqbal ◽  
Pia M. Vornewald ◽  
Håvard T. Lindholm ◽  
Mirjam J. Damen ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Stem Cell ◽  
Smooth Muscle Cells ◽  
Stem Cell Niche ◽  
Muscle Cells ◽  
Intestinal Stem Cell ◽  
Matricellular Protein ◽  
Intestinal Epithelial ◽  
Epithelial Regeneration ◽  
Cell Niche

AbstractSmooth muscle is an essential component of the intestine, both to maintain its structure and produce peristaltic and segmentation movements. However, very little is known about other putative roles that smooth muscle cells may have. Here, we show that smooth muscle cells may be the dominant suppliers of BMP antagonists, which are niche factors essential for intestinal stem cell maintenance. Furthermore, muscle-derived factors render epithelium reparative and fetal-like, which includes heightened YAP activity. Mechanistically, we find that the membrane-bound matrix metalloproteinase MMP17, which is exclusively expressed by smooth muscle cells, is required for intestinal epithelial repair after inflammation- or irradiation-induced injury. Furthermore, we propose that MMP17 affects intestinal epithelial reprogramming after damage indirectly by cleaving diffusible factor(s) such as the matricellular protein PERIOSTIN. Together, we identify an important signaling axis that establishes a role for smooth muscle cells as modulators of intestinal epithelial regeneration and the intestinal stem cell niche.

Sign in / Sign up

Export Citation Format

Share Document