scholarly journals Lamellipodin Is Important for Cell-to-Cell Spread and Actin-Based Motility in Listeria monocytogenes

2015 ◽  
Vol 83 (9) ◽  
pp. 3740-3748 ◽  
Author(s):  
Jiahui Wang ◽  
Jane E. King ◽  
Marie Goldrick ◽  
Martin Lowe ◽  
Frank B. Gertler ◽  
...  

Listeria monocytogenesis a foodborne pathogen capable of invading a broad range of cell types and replicating within the host cell cytoplasm. This paper describes the colocalization of host cell lamellipodin (Lpd) with intracellularL. monocytogenesdetectable 6 h postinfection of epithelial cells. The association was mediated via interactions between both the peckstrin homology (PH) domain in Lpd and phosphatidylinositol (3,4)-bisphosphate [PI(3,4)P2] on the bacterial surface and by interactions between the C-terminal EVH1 (Ena/VASP [vasodilator-stimulated phosphoprotein] homology domain 1) binding domains of Lpd and the host VASP (vasodilator-stimulated phosphoprotein) recruited to the bacterial cell surface by the listerial ActA protein. Depletion of Lpd by short interfering RNA (siRNA) resulted in reduced plaque size and number, indicating a role for Lpd in cell-to-cell spread. In contrast, overexpression of Lpd resulted in an increase in the number ofL. monocytogenes-containing protrusions (listeriopods). Manipulation of the levels of Lpd within the cell also affected the intracellular velocity ofL. monocytogenes, with a reduction in Lpd corresponding to an increase in intracellular velocity. These data, together with the observation that Lpd accumulated at the interface between the bacteria and the developing actin tail at the initiation of actin-based movement, indicate a possible role for Lpd in the actin-based movement and the cell-to-cell spread ofL. monocytogenes.

2015 ◽  
Vol 83 (8) ◽  
pp. 3233-3242 ◽  
Author(s):  
Lena Meyer ◽  
Jeanette E. Bröms ◽  
Xijia Liu ◽  
Martin E. Rottenberg ◽  
Anders Sjöstedt

Certain intracellular bacteria use the host cell cytosol as the replicative niche. Although it has been hypothesized that the successful exploitation of this compartment requires a unique metabolic adaptation, supportive evidence is lacking. ForFrancisella tularensis, many genes of theFrancisellapathogenicity island (FPI) are essential for intracellular growth, and therefore, FPI mutants are useful tools for understanding the prerequisites of intracytosolic replication. We compared the growth of bacteria taken up by phagocytic or nonphagocytic cells with that of bacteria microinjected directly into the host cytosol, using the live vaccine strain (LVS) ofF. tularensis; five selected FPI mutants thereof, i.e., ΔiglA, ΔiglÇ ΔiglG, ΔiglI, and ΔpdpEstrains; andListeria monocytogenes. After uptake in bone marrow-derived macrophages (BMDM), ASC−/−BMDM, MyD88−/−BMDM, J774 cells, or HeLa cells, LVS, ΔpdpEand ΔiglGmutants, andL. monocytogenesreplicated efficiently in all five cell types, whereas the ΔiglAand ΔiglCmutants showed no replication. After microinjection, all 7 strains showed effective replication in J774 macrophages, ASC−/−BMDM, and HeLa cells. In contrast to the rapid replication in other cell types,L. monocytogenesshowed no replication in MyD88−/−BMDM and LVS showed no replication in either BMDM or MyD88−/−BMDM after microinjection. Our data suggest that the mechanisms of bacterial uptake as well as the permissiveness of the cytosolic compartmentper seare important factors for the intracytosolic replication. Notably, none of the investigated FPI proteins was found to be essential for intracytosolic replication after microinjection.


2018 ◽  
Vol 7 (13) ◽  
Author(s):  
Yanhong Liu ◽  
Aixia Xu ◽  
Pina M. Fratamico ◽  
Christopher H. Sommers ◽  
Luca Rotundo ◽  
...  

Listeria monocytogenes is an important foodborne pathogen that causes listeriosis. Here, we report the draft genome sequences of seven L. monocytogenes strains isolated from food, environmental, and clinical sources.


mBio ◽  
2021 ◽  
Author(s):  
Courtney M. Klappenbach ◽  
Nicholas M. Negretti ◽  
Jesse Aaron ◽  
Teng-Leong Chew ◽  
Michael E. Konkel

Campylobacter jejuni is a major foodborne pathogen that causes severe gastritis. We investigated the dynamics of focal adhesion structure and function in C. jejuni -infected epithelial cells.


2020 ◽  
Vol 86 (22) ◽  
Author(s):  
Tracey Lee Peters ◽  
Yaxiong Song ◽  
Daniel W. Bryan ◽  
Lauren K. Hudson ◽  
Thomas G. Denes

ABSTRACT Bacteriophages (phages) are currently available for use by the food industry to control the foodborne pathogen Listeria monocytogenes. Although phage biocontrols are effective under specific conditions, their use can select for phage-resistant bacteria that repopulate phage-treated environments. Here, we performed short-term coevolution experiments to investigate the impact of single phages and a two-phage cocktail on the regrowth of phage-resistant L. monocytogenes and the adaptation of the phages to overcome this resistance. We used whole-genome sequencing to identify mutations in the target host that confer phage resistance and in the phages that alter host range. We found that infections with Listeria phages LP-048, LP-125, or a combination of both select for different populations of phage-resistant L. monocytogenes bacteria with different regrowth times. Phages isolated from the end of the coevolution experiments were found to have gained the ability to infect phage-resistant mutants of L. monocytogenes and L. monocytogenes strains previously found to be broadly resistant to phage infection. Phages isolated from coinfected cultures were identified as recombinants of LP-048 and LP-125. Interestingly, recombination events occurred twice independently in a locus encoding two proteins putatively involved in DNA binding. We show that short-term coevolution of phages and their hosts can be utilized to obtain mutant and recombinant phages with adapted host ranges. These laboratory-evolved phages may be useful for limiting the emergence of phage resistance and for targeting strains that show general resistance to wild-type (WT) phages. IMPORTANCE Listeria monocytogenes is a life-threatening bacterial foodborne pathogen that can persist in food processing facilities for years. Phages can be used to control L. monocytogenes in food production, but phage-resistant bacterial subpopulations can regrow in phage-treated environments. Coevolution experiments were conducted on a Listeria phage-host system to provide insight into the genetic variation that emerges in both the phage and bacterial host under reciprocal selective pressure. As expected, mutations were identified in both phage and host, but additionally, recombination events were shown to have repeatedly occurred between closely related phages that coinfected L. monocytogenes. This study demonstrates that in vitro evolution of phages can be utilized to expand the host range and improve the long-term efficacy of phage-based control of L. monocytogenes. This approach may also be applied to other phage-host systems for applications in biocontrol, detection, and phage therapy.


2020 ◽  
Vol 88 (5) ◽  
Author(s):  
Susmita Ghosh ◽  
Elizabeth A. Ruelke ◽  
Joshua C. Ferrell ◽  
Maria D. Bodero ◽  
Kenneth A. Fields ◽  
...  

ABSTRACT The translocated actin recruiting phosphoprotein (Tarp) is a multidomain type III secreted effector used by Chlamydia trachomatis. In aggregate, existing data suggest a role of this effector in initiating new infections. As new genetic tools began to emerge to study chlamydial genes in vivo, we speculated as to what degree Tarp function contributes to Chlamydia’s ability to parasitize mammalian host cells. To address this question, we generated a complete tarP deletion mutant using the fluorescence-reported allelic exchange mutagenesis (FRAEM) technique and complemented the mutant in trans with wild-type tarP or mutant tarP alleles engineered to harbor in-frame domain deletions. We provide evidence for the significant role of Tarp in C. trachomatis invasion of host cells. Complementation studies indicate that the C-terminal filamentous actin (F-actin)-binding domains are responsible for Tarp-mediated invasion efficiency. Wild-type C. trachomatis entry into HeLa cells resulted in host cell shape changes, whereas the tarP mutant did not. Finally, using a novel cis complementation approach, C. trachomatis lacking tarP demonstrated significant attenuation in a murine genital tract infection model. Together, these data provide definitive genetic evidence for the critical role of the Tarp F-actin-binding domains in host cell invasion and for the Tarp effector as a bona fide C. trachomatis virulence factor.


2017 ◽  
Vol 5 (49) ◽  
Author(s):  
Taylor W. Bailey ◽  
Naila C. do Nascimento ◽  
Arun K. Bhunia

ABSTRACT Listeria monocytogenes is an opportunistic invasive foodborne pathogen. Here, we performed whole-genome sequencing of L. monocytogenes strain F4244 (serotype 4b) using Illumina sequencing. The sequence showed 94.5% identity with strain F2365, serotype 4b, and 90.6% with EGD-e, serotype 1/2a.


mBio ◽  
2018 ◽  
Vol 9 (5) ◽  
Author(s):  
Benjamin J. Koestler ◽  
Carolyn R. Fisher ◽  
Shelley M. Payne

ABSTRACTThe intracellular human pathogenShigella flexneriinvades the colon epithelium, replicates to high cell density within the host cell, and then spreads to adjacent epithelial cells. WhenS. flexnerigains access to the host cytosol, the bacteria metabolize host cytosolic carbon using glycolysis and mixed acid fermentation, producing formate as a by-product. We show thatS. flexneriinfection results in the accumulation of formate within the host cell. Loss of pyruvate formate lyase (PFL; ΔpflB), which converts pyruvate to acetyl coenzyme A (CoA) and formate, eliminatesS. flexneriformate production and reduces the ability ofS. flexnerito form plaques in epithelial cell monolayers. This defect in PFL does not decrease the intracellular growth rate ofS. flexneri; rather, it affects cell-to-cell spread. TheS. flexneriΔpflBmutant plaque defect is complemented by supplying exogenous formate; conversely, deletion of theS. flexneriformate dehydrogenase genefdnGincreases host cell formate accumulation andS. flexneriplaque size. Furthermore, exogenous formate increases plaque size of the wild-type (WT)S. flexneristrain and promotesS. flexnericell-to-cell spread. We also demonstrate that formate increases the expression ofS. flexnerivirulence genesicsAandipaJ. IntracellularS. flexneriicsAandipaJexpression is dependent on the presence of formate, andipaJexpression correlates withS. flexneriintracellular density during infection. Finally, consistent with elevatedipaJ, we show that formate altersS. flexneri-infected host interferon- and tumor necrosis factor (TNF)-stimulated gene expression. We propose thatShigella-derived formate is an intracellular signal that modulates virulence in response to bacterial metabolism.IMPORTANCEShigellais an intracellular pathogen that invades the human host cell cytosol and exploits intracellular nutrients for growth, enabling the bacterium to create its own metabolic niche. ForShigellato effectively invade and replicate within the host cytoplasm, it must sense and adapt to changing environmental conditions; however, the mechanisms and signals sensed byS. flexneriare largely unknown. We have found that the secretedShigellametabolism by-product formate regulatesShigellaintracellular virulence gene expression and its ability to spread among epithelial cells. We propose thatShigellasenses formate accumulation in the host cytosol as a way to determine intracellularShigelladensity and regulate secreted virulence factors accordingly, enabling spatiotemporal regulation of effectors important for dampening the host immune response.


2016 ◽  
Vol 84 (6) ◽  
pp. 1806-1814 ◽  
Author(s):  
Diego E. Alvarez ◽  
Hervé Agaisse

Listeria monocytogenesis an intracellular pathogen that disseminates within the intestinal epithelium through acquisition of actin-based motility and formation of plasma membrane protrusions that project into adjacent cells. The resolution of membrane protrusions into vacuoles from which the pathogen escapes results in bacterial spread from cell to cell. This dissemination process relies on themlp-actA-plcBoperon, which encodes ActA, a bacterial nucleation-promoting factor that mediates actin-based motility, and PlcB, a phospholipase that mediates vacuole escape. Here we investigated the role of the metalloprotease Mpl in the dissemination process. In agreement with previous findings showing that Mpl is required for PlcB activation, infection of epithelial cells with the ΔplcBor Δmplstrains resulted in the formation of small infection foci. As expected, the ΔplcBstrain displayed a strong defect in vacuole escape. However, the Δmplstrain showed an unexpected defect in the resolution of protrusions into vacuoles, in addition to the expected but mild defect in vacuole escape. The Δmplstrain displayed increased levels of ActA on the bacterial surface in protrusions. We mapped an Mpl-dependent processing site in ActA between amino acid residues 207 to 238. Similar to the Δmplstrain, the ΔactA207–238strain displayed increased levels of ActA on the bacterial surface in protrusions. Although the ΔactA207–238strain displayed wild-type actin-based motility, it formed small infection foci and failed to resolve protrusions into vacuoles. We propose that, in addition to its role in PlcB processing and vacuole escape, the metalloprotease Mpl is required for ActA processing and protrusion resolution.


2019 ◽  
Vol 8 (41) ◽  
Author(s):  
Lauren K. Hudson ◽  
Tracey L. Peters ◽  
Yaxiong Song ◽  
Thomas G. Denes

Bacteriophages that infect the foodborne pathogen Listeria monocytogenes were previously isolated from New York dairy farms. The complete genome sequences for three of these Listeria phages, with genome sizes of 64.6 to 65.7 kb, are presented here. Listeria phages LP-010, LP-013, and LP-031-2 are siphoviruses that belong to the genus Homburgvirus.


2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Lauren K. Hudson ◽  
Tracey Lee Peters ◽  
Daniel W. Bryan ◽  
Yaxiong Song ◽  
Henk C. den Bakker ◽  
...  

ABSTRACT Bacteriophages can be used as a biocontrol for the foodborne pathogen Listeria monocytogenes. Propagation of phages is a necessary step for their use in experimental studies and biocontrol applications. Here, we present the complete genomes of three Listeria monocytogenes strains commonly used as propagation hosts for Listeria phages.


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