scholarly journals Vibrio deploys Type 2 secreted lipase to esterify cholesterol with host fatty acids and mediate cell egress

2019 ◽  
Author(s):  
Marcela de Souza Santos ◽  
Suneeta Chimalapati ◽  
Ann Ray ◽  
Wan-Ru Lee ◽  
Giomar Rivera-Cancel ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Vibrio Parahaemolyticus ◽  
Cell Biology ◽  
Host Cells ◽  
Lipid Biochemistry ◽  
Secretion Systems ◽  
Host Cytoplasm ◽  
Mediate Cell ◽  
Secreted Lipase ◽  
Esterify Cholesterol

AbstractPathogens find diverse niches for survival inside host cells where replication occurs in a relatively protected environment. Vibrio parahaemolyticus, a facultative intracellular pathogen, uses its type 3 secretion system 2 (T3SS2) to invade and replicate inside host cells. However, after extensive analysis, the T3SS2 pathogenicity island appeared to lack a mechanism for egress of this bacterium from the invaded host cell. Using a combination of cell biology, microbial genetics and lipid biochemistry, we found that VPA0226, a constitutively secreted lipase, is required for escape of Vibrio parahaemolyticus from host cells. Remarkably, this lipase must be delivered into the host cytoplasm where it preferentially uses fatty acids associated with innate immune response (i.e. arachidonic acid, 20:4) to esterify cholesterol, weakening the plasma membrane and allowing egress of the bacteria. This study reveals the resourcefulness of microbes and the interplay between virulence systems to evolve an ingenious scheme for survival and escape.Impact StatementConsidering the course of a pathogen’s evolution, there appears to be interplay between secretion systems, providing unique, synergistic mechanisms to support a successful lifestyle for possibly pathogenesis, symbiosis and/or parasitosis.

scholarly journals Vibrio deploys type 2 secreted lipase to esterify cholesterol with host fatty acids and mediate cell egress

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Suneeta Chimalapati ◽  
Marcela de Souza Santos ◽  
Alexander E Lafrance ◽  
Ann Ray ◽  
Wan-Ru Lee ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Host Cell ◽  
Host Cells ◽  
Host Cytoplasm ◽  
System 2 ◽  
Protective Environment ◽  
Mediate Cell ◽  
Type 3 ◽  
Secreted Lipase ◽  
Esterify Cholesterol

Pathogens find diverse niches for survival including inside a host cell where replication occurs in a relatively protective environment. Vibrio parahaemolyticus is a facultative intracellular pathogen that uses its type 3 secretion system 2 (T3SS2) to invade and replicate inside host cells. Analysis of the T3SS2 pathogenicity island encoding the T3SS2 appeared to lack a mechanism for egress of this bacterium from the invaded host cell. Using a combination of molecular tools, we found that VPA0226, a constitutively secreted lipase, is required for escape of V. parahaemolyticus from the host cells. This lipase must be delivered into the host cytoplasm where it preferentially uses fatty acids associated with innate immune response to esterify cholesterol, weakening the plasma membrane and allowing egress of the bacteria. This study reveals the resourcefulness of microbes and the interplay between virulence systems and host cell resources to evolve an ingenious scheme for survival and escape.

scholarly journals Author response: Vibrio deploys type 2 secreted lipase to esterify cholesterol with host fatty acids and mediate cell egress

2020 ◽  
Author(s):  
Suneeta Chimalapati ◽  
Marcela de Souza Santos ◽  
Alexander E Lafrance ◽  
Ann Ray ◽  
Wan-Ru Lee ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Author Response ◽  
Mediate Cell ◽  
Secreted Lipase ◽  
Esterify Cholesterol

Salmonella in Australia: understanding and controlling infection

2017 ◽  
Vol 38 (3) ◽  
pp. 112
Author(s):  
Joshua PM Newson
Keyword(s):  
Host Cell ◽  
Cell Biology ◽  
Protein Translocation ◽  
Cell Signalling ◽  
Effector Proteins ◽  
Host Cells ◽  
Secretion Systems ◽  
Significant Burden ◽  
Systemic Infections ◽  
Bacterial Effectors

The bacterium Salmonella causes a spectrum of foodborne diseases ranging from acute gastroenteritis to systemic infections, and represents a significant burden of disease globally. In Australia, Salmonella is frequently associated with outbreaks and is a leading cause of foodborne illness, which results in a significant medical and economic burden. Salmonella infection involves colonisation of the small intestine, where the bacteria invades host cells and establishes an intracellular infection. To survive within host cells, Salmonella employs type-three secretion systems to deliver bacterial effector proteins into the cytoplasm of host cells. These bacterial effectors seek out and modify specific host proteins, disrupting host processes such as cell signalling, intracellular trafficking, and programmed cell death. This strategy of impairing host cells allows Salmonella to establish a replicative niche within the cell, where they can replicate to high numbers before escaping to infect neighbouring cells, or be transmitted to new hosts. While the importance of effector protein translocation to infection is well established, our understanding of many effector proteins remains incomplete. Many Salmonella effectors have unknown function and unknown roles during infection. A greater understanding of how Salmonella manipulates host cells during infection will lead to improved strategies to prevent, control, and eliminate disease. Further, studying effector proteins can be a useful means for exploring host cell biology and elucidating the details of host cell signalling.

scholarly journals Intracellular Vibrio parahaemolyticus Escapes the Vacuole and Establishes a Replicative Niche in the Cytosol of Epithelial Cells

mBio ◽  
2014 ◽  
Vol 5 (5) ◽  
Author(s):  
Marcela de Souza Santos ◽  
Kim Orth
Keyword(s):  
Epithelial Cells ◽  
Acute Gastroenteritis ◽  
Vibrio Parahaemolyticus ◽  
Marine Bacterium ◽  
Host Cells ◽  
Secretion Systems ◽  
Content Type ◽  
Early Endosomes ◽  
Extracellular Bacterium

ABSTRACT Vibrio parahaemolyticus is a globally disseminated Gram-negative marine bacterium and the leading cause of seafood-borne acute gastroenteritis. Pathogenic bacterial isolates encode two type III secretion systems (T3SS), with the second system (T3SS2) considered the main virulence factor in mammalian hosts. For many decades, V. parahaemolyticus has been studied as an exclusively extracellular bacterium. However, the recent characterization of the T3SS2 effector protein VopC has suggested that this pathogen has the ability to invade, survive, and replicate within epithelial cells. Herein, we characterize this intracellular lifestyle in detail. We show that following internalization, V. parahaemolyticus is contained in vacuoles that develop into early endosomes, which subsequently mature into late endosomes. V. parahaemolyticus then escapes into the cytoplasm prior to vacuolar fusion with lysosomes. Vacuolar acidification is an important trigger for this escape. The cytoplasm serves as the pathogen’s primary intracellular replicative niche; cytosolic replication is rapid and robust, with cells often containing over 150 bacteria by the time of cell lysis. These results show how V. parahaemolyticus successfully establishes an intracellular lifestyle that could contribute to its survival and dissemination during infection. IMPORTANCE The marine bacterium V. parahaemolyticus is the leading cause worldwide of seafood-borne acute gastroenteritis. For decades, the pathogen has been studied exclusively as an extracellular bacterium. However, recent results have revealed the pathogen’s ability to invade and replicate within host cells. The present study is the first characterization of the V. parahaemolyticus’ intracellular lifestyle. Upon internalization, V. parahaemolyticus is contained in a vacuole that would in the normal course of events ultimately fuse with a lysosome, degrading the vacuole’s contents. The bacterium subverts this pathway, escaping into the cytoplasm prior to lysosomal fusion. Once in the cytoplasm, it replicates prolifically. Our study provides new insights into the strategies used by this globally disseminated pathogen to survive and proliferate within its host.

scholarly journals Manipulation of IRE1-dependent MAPK signaling by a Vibrio agonist-antagonist effector pair

2020 ◽  
Author(s):  
Nicole J. De Nisco ◽  
Amanda K. Casey ◽  
Mohammed Kanchwala ◽  
Alexander E. Lafrance ◽  
Fatma S. Coskun ◽  
...  
Keyword(s):  
Host Cell ◽  
Rho Gtpases ◽  
Vibrio Parahaemolyticus ◽  
Rho Gtpase ◽  
Membrane Integrity ◽  
Mapk Signaling ◽  
Host Cells ◽  
Secretion Systems ◽  
Signaling Systems ◽  
Host Signaling

AbstractDiverse bacterial pathogens employ effector delivery systems to disrupt vital cellular processes in the host (1). The type III secretion system 1 of the marine pathogen, Vibrio parahaemolyticus, utilizes the sequential action of four effectors to induce a rapid, pro-inflammatory cell death uniquely characterized by a pro-survival host transcriptional response (2, 3). Herein, we show that this pro-survival response is caused by the action of the channel-forming effector VopQ that targets the host V-ATPase resulting in lysosomal deacidification and inhibition of lysosome-autophagosome fusion. Recent structural studies have shown how VopQ interacts with the V-ATPase and, while in the ER, a V-ATPase assembly intermediate can interact with VopQ causing a disruption in membrane integrity. Additionally, we observe that VopQ-mediated disruption of the V-ATPase activates the IRE1 branch of the unfolded protein response (UPR) resulting in an IRE1-dependent activation of ERK1/2 MAPK signaling. We also find that this early VopQ-dependent induction of ERK1/2 phosphorylation is terminated by the VopS-mediated inhibitory AMPylation of Rho GTPase signaling. Since VopS dampens VopQ-induced IRE1-dependent ERK1/2 activation, we propose that IRE1 activates ERK1/2 phosphorylation at or above the level of Rho GTPases. This study illustrates how temporally induced effectors can work as in tandem as agonist/antagonist to manipulate host signaling and reveal new connections between V-ATPase function, UPR and MAPK signaling.ImportanceVibrio parahaemolyticus (V. para) is a seafood-borne pathogen that encodes two Type 3 Secretion Systems (T3SS). The first system T3SS1 is thought to be maintained in all strains of V. para to to maintain survival in the environment, whereas the second sytem T3SS2 is linked to clinical isolates and disease in humans. Herein, we find that first system targets evolutionarily conserved signaling systems to manipulate host cells, eventually causing a rapid, orchestrated cells death within three hours. We have found that the T3SS1 injects virulence factors that temporally manipulate host signaling. Within the first hour of infection, the effector VopQ acts first by activating host surval signals while diminishing the host cell apoptotic machinery. Less than an hour later, another effector VopS reverses activation and inhibition of these signaling systems ultimately leading to death of the host cell. This work provides example of how pathogens have evolved to manipulate the interplay between T3SS effectors to regulate host signaling pathways.

scholarly journals Calcium and Iron Regulate Swarming and Type III Secretion in Vibrio parahaemolyticus

2010 ◽  
Vol 192 (22) ◽  
pp. 6025-6038 ◽  
Author(s):  
Cindy J. Gode-Potratz ◽  
Daniel M. Chodur ◽  
Linda L. McCarter
Keyword(s):  
Gene Expression ◽  
Type Iii Secretion ◽  
Vibrio Parahaemolyticus ◽  
Marine Organism ◽  
Ectopic Expression ◽  
Host Cells ◽  
Secretion Systems ◽  
Type Iii ◽  
Calcium Chelation ◽  
Calcium Stimulation

ABSTRACT Here, we probe the response to calcium during growth on a surface and show that calcium influences the transcriptome and stimulates motility and virulence of Vibrio parahaemolyticus. Swarming (but not swimming) gene expression and motility were enhanced by calcium. Calcium also elevated transcription of one of the organism's two type III secretion systems (T3SS1 but not T3SS2) and heightened cytotoxicity toward host cells in coculture. Calcium stimulation of T3SS gene expression has not been reported before, although low calcium is an inducing signal for the T3SS of many organisms. EGTA was also found to increase T3SS1 gene expression and virulence; however, this was demonstrated to be the consequence of iron rather than calcium chelation. Ectopic expression of exsA, encoding the T3SS1 AraC-type regulator, was used to define the extent of the T3SS1 regulon and verify its coincident induction by calcium and EGTA. To begin to understand the regulatory mechanisms modulating the calcium response, a calcium-repressed, LysR-type transcription factor named CalR was identified and shown to repress swarming and T3SS1 gene expression. Swarming and T3SS1 gene expression were also demonstrated to be linked by LafK, a σ54-dependent regulator of swarming, and additionally connected by a negative-feedback loop on the swarming regulon propagated by ExsA. Thus, calcium and iron, two ions pertinent for a marine organism and pathogen, play a signaling role with global consequences on the regulation of gene sets that are relevant for surface colonization and infection.

scholarly journals Manipulation of IRE1-Dependent MAPK Signaling by a Vibrio Agonist-Antagonist Effector Pair

mSystems ◽  
2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Nicole J. De Nisco ◽  
Amanda K. Casey ◽  
Mohammed Kanchwala ◽  
Alexander E. Lafrance ◽  
Fatma S. Coskun ◽  
...  
Keyword(s):  
Host Cell ◽  
Vibrio Parahaemolyticus ◽  
Rho Gtpase ◽  
Mapk Signaling ◽  
Host Cells ◽  
Secretion Systems ◽  
Content Type ◽  
Signaling Systems ◽  
Link Type ◽  
Host Signaling

ABSTRACT Diverse bacterial pathogens employ effector delivery systems to disrupt vital cellular processes in the host (N. M. Alto and K. Orth, Cold Spring Harbor Perspect Biol 4:a006114, 2012, https://doi.org/10.1101/cshperspect.a006114). The type III secretion system 1 of the marine pathogen Vibrio parahaemolyticus utilizes the sequential action of four effectors to induce a rapid, proinflammatory cell death uniquely characterized by a prosurvival host transcriptional response (D. L. Burdette, M. L. Yarbrough, A Orvedahl, C. J. Gilpin, and K. Orth, Proc Natl Acad Sci USA 105:12497–12502, 2008, https://doi.org/10.1073/pnas.0802773105; N. J. De Nisco, M. Kanchwala, P. Li, J. Fernandez, C. Xing, and K. Orth, Sci Signal 10:eaa14501, 2017, https://doi.org/10.1126/scisignal.aal4501). Herein, we show that this prosurvival response is caused by the action of the channel-forming effector VopQ that targets the host V-ATPase, resulting in lysosomal deacidification and inhibition of lysosome-autophagosome fusion. Recent structural studies have shown how VopQ interacts with the V-ATPase and, while in the ER, a V-ATPase assembly intermediate can interact with VopQ, causing a disruption in membrane integrity. Additionally, we observed that VopQ-mediated disruption of the V-ATPase activates the IRE1 branch of the unfolded protein response (UPR), resulting in an IRE1-dependent activation of ERK1/2 MAPK signaling. We also find that this early VopQ-dependent induction of ERK1/2 phosphorylation is terminated by the VopS-mediated inhibitory AMPylation of Rho GTPase signaling. Since VopS dampens VopQ-induced IRE1-dependent ERK1/2 activation, we propose that IRE1 activates ERK1/2 phosphorylation at or above the level of Rho GTPases. This study illustrates how temporally induced effectors can work as in tandem as agonist/antagonist to manipulate host signaling and reveals new connections between V-ATPase function, UPR, and MAPK signaling. IMPORTANCE Vibrio parahaemolyticus is a seafood-borne pathogen that encodes two type 3 secretion systems (T3SS). The first system, T3SS1, is thought to be maintained in all strains of V. parahaemolyticus to maintain survival in the environment, whereas the second system, T3SS2, is linked to clinical isolates and disease in humans. Here, we found that first system targets evolutionarily conserved signaling systems to manipulate host cells, eventually causing a rapid, orchestrated cells death within 3 h. We have found that the T3SS1 injects virulence factors that temporally manipulate host signaling. Within the first hour of infection, the effector VopQ acts first by activating host survival signals while diminishing the host cell apoptotic machinery. Less than an hour later, another effector, VopS, reverses activation and inhibition of these signaling systems, ultimately leading to death of the host cell. This work provides example of how pathogens have evolved to manipulate the interplay between T3SS effectors to regulate host signaling pathways.

scholarly journals Remodeling of the Intestinal Brush Border Underlies Adhesion and Virulence of an Enteric Pathogen

mBio ◽  
2014 ◽  
Vol 5 (4) ◽  
Author(s):  
Xiaohui Zhou ◽  
Ramiro H. Massol ◽  
Fumihiko Nakamura ◽  
Xiang Chen ◽  
Benjamin E. Gewurz ◽  
...  
Keyword(s):  
Brush Border ◽  
Bacterial Adhesion ◽  
Vibrio Parahaemolyticus ◽  
Structural Changes ◽  
Host Cells ◽  
Intestinal Colonization ◽  
Secretion Systems ◽  
Content Type ◽  
Infected Infant ◽  
Bacterial Agent

ABSTRACT Intestinal colonization by Vibrio parahaemolyticus—the most common cause of seafood-borne bacterial enteritis worldwide—induces extensive disruption of intestinal microvilli. In orogastrically infected infant rabbits, reorganization of the apical brush border membrane includes effacement of some microvilli and marked elongation of others. All diarrhea, inflammation, and intestinal pathology associated with V. parahaemolyticus infection are dependent upon one of its type 3 secretion systems (T3SS2); however, translocated effectors that directly mediate brush border restructuring and bacterial adhesion are not known. Here, we demonstrate that the effector VopV is essential for V. parahaemolyticus intestinal colonization and therefore its pathogenicity, that it induces effacement of brush border microvilli, and that this effacement is required for adhesion of V. parahaemolyticus to enterocytes. VopV contains multiple functionally independent and mechanistically distinct domains through which it disrupts microvilli. We show that interaction between VopV and filamin, as well as VopV’s previously noted interaction with actin, mediates enterocyte cytoskeletal reorganization. VopV’s multipronged approach to epithelial restructuring, coupled with its impact on colonization, suggests that remodeling of the epithelial brush border is a critical step in pathogenesis. IMPORTANCE Colonization of the small bowel by Vibrio parahaemolyticus, the most common bacterial agent of seafood-borne enteric disease, induces extensive structural changes in the intestinal epithelium. Here, we show that this diarrheal pathogen’s colonization and virulence depend upon VopV, a bacterial protein that is transferred into host epithelial cells. VopV induces marked rearrangement of the apical epithelial cell membrane, including elimination of microvilli, by two means: through interaction with actin and through a previously unrecognized interaction with the actin-cross-linking protein filamin. VopV-mediated “effacement” of microvilli enables V. parahaemolyticus to adhere to host cells, although VopV may not directly mediate adhesion. VopV’s effects on microvillus structure and bacterial adhesion likely account for its essential role in V. parahaemolyticus intestinal pathogenesis. Our findings suggest a new role for filamin in brush border maintenance and raise the possibility that microvillus effacement is a common strategy among enteric pathogens for enhancing adhesion to host cells.

VopB1 and VopD1 are essential for translocation of type III secretion system 1 effectors of Vibrio parahaemolyticus

2012 ◽  
Vol 58 (8) ◽  
pp. 1002-1007 ◽  
Author(s):  
Takaaki Shimohata ◽  
Kazuaki Mawatari ◽  
Hitomi Iba ◽  
Masakazu Hamano ◽  
Sachie Negoro ◽  
...  
Keyword(s):  
Type Iii Secretion ◽  
Vibrio Parahaemolyticus ◽  
Therapeutic Potential ◽  
Sequence Similarity ◽  
Host Cells ◽  
Secretion Systems ◽  
Reporter System ◽  
Type Iii ◽  
Pathogenic Vibrio ◽  
Essential Components

Vibrio parahaemolyticus is a pathogenic Vibrio species that causes food-borne acute gastroenteritis, often related to the consumption of raw or undercooked seafood. Vibrio parahaemolyticus has 2 type III secretion systems (T3SS1 and T3SS2). Here, we demonstrate that VP1657 (VopB1) and VP1656 (VopD1), which share sequence similarity with Pseudomonas genes popB (38%) and popD (36%), respectively, are essential for translocation of T3SS1 effectors into host cells. A VP1680CyaA fusion reporter system was constructed to observe effector translocation. Using this reporter assay we showed that the VopB1 and VopD1 deletion strains were unable to translocate VP1680 to host cell but that the secretion of VP1680 into the culture medium was not affected. VopB1 or VopD1 deletion strains did not enhance cytotoxicity and failed to activate mitogen-activated protein kinases and secretion of interleukin-8, which depend on VP1680. Thus, we conclude that VopB1 and VopD1 are essential components of the translocon. To target VopB1 and VopD1 may have therapeutic potential for the treatment or prevention in V. parahaemolyticus infection.

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