scholarly journals Trypanosoma cruzi Differentiates and Multiplies within Chimeric Parasitophorous Vacuoles in Macrophages Coinfected with Leishmania amazonensis

2016 ◽  
Vol 84 (5) ◽  
pp. 1603-1614 ◽  
Author(s):  
Carina Carraro Pessoa ◽  
Éden Ramalho Ferreira ◽  
Ethel Bayer-Santos ◽  
Michel Rabinovitch ◽  
Renato Arruda Mortara ◽  
...  
Keyword(s):  
Trypanosoma Cruzi ◽  
Host Cell ◽  
Cell Biology ◽  
Mammalian Cells ◽  
Leishmania Amazonensis ◽  
Content Type ◽  
Multidimensional Imaging ◽  
Protozoan Infections ◽  
Cell Cytosol ◽  
Host Cell Cytosol

The trypanosomatidsLeishmania amazonensisandTrypanosoma cruziare excellent models for the study of the cell biology of intracellular protozoan infections. After their uptake by mammalian cells, the parasitic protozoan flagellatesL. amazonensisandT. cruzilodge within acidified parasitophorous vacuoles (PVs). However, whereasL. amazonensisdevelops in spacious, phagolysosome-like PVs that may enclose numerous parasites,T. cruziis transiently hosted within smaller vacuoles from which it soon escapes to the host cell cytosol. To investigate if parasite-specific vacuoles are required for the survival and differentiation ofT. cruzi, we constructed chimeric vacuoles by infection ofL. amazonensisamastigote-infected macrophages withT. cruziepimastigotes (EPIs) or metacyclic trypomastigotes (MTs). These chimeric vacuoles, easily observed by microscopy, allowed the entry and fate ofT. cruziinL. amazonensisPVs to be dynamically recorded by multidimensional imaging of coinfected cells. We found that althoughT. cruziEPIs remained motile and conserved their morphology in chimeric vacuoles,T. cruziMTs differentiated into amastigote-like forms capable of multiplying. These results demonstrate that the large adaptive vacuoles ofL. amazonensisare permissive toT. cruzisurvival and differentiation and that noninfective EPIs are spared from destruction within the chimeric PVs. We conclude thatT. cruzidifferentiation can take place inLeishmania-containing vacuoles, suggesting this occurs prior to their escape into the host cell cytosol.

scholarly journals Differential Expression and Characterization of a Member of the Mucin-Associated Surface Protein Family Secreted by Trypanosoma cruzi

2011 ◽  
Vol 79 (10) ◽  
pp. 3993-4001 ◽  
Author(s):  
Luis Miguel De Pablos ◽  
Gloria González González ◽  
Jennifer Solano Parada ◽  
Víctor Seco Hidalgo ◽  
Isabel María Díaz Lozano ◽  
...  
Keyword(s):  
Trypanosoma Cruzi ◽  
Host Cell ◽  
Surface Protein ◽  
Surface Proteins ◽  
Host Cells ◽  
Content Type ◽  
The Family ◽  
Cell Cytosol ◽  
Host Cell Cytosol

ABSTRACTWe describe the characterization, purification, expression, and location of a 52-kDa protein secreted during interaction between the metacyclic form ofTrypanosoma cruziand its target host cell. The protein, which we have named MASP52, belongs to the family of mucin-associated surface proteins (MASPs). The highest levels of expression of both the protein and mRNA occur during the metacyclic and bloodstream trypomastigote stages, the forms that infect the vertebrate host cells. The protein is located in the plasma membrane and in the flagellar pockets of the epimastigote, metacyclic, and trypomastigote forms and is secreted into the medium at the point of contact between the parasite and the cell membrane, as well as into the host-cell cytosol during the amastigote stage. IgG antibodies specific against a synthetic peptide corresponding to the catalytic zone of MASP52 significantly reduce the parasite's capacity to infect the host cells. Furthermore, when the protein is adsorbed onto inert particles of bentonite and incubated with a nonphagocytic cell culture, the particles are able to induce endocytosis in the cells, which seems to demonstrate that MASP52 plays a role in a process whereby the trypomastigote forms of the parasite invade the host cell.

scholarly journals Actin Polymerization Drives Septation ofListeria monocytogenes namAHydrolase Mutants, Demonstrating Host Correction of a Bacterial Defect

2011 ◽  
Vol 79 (4) ◽  
pp. 1458-1470 ◽  
Author(s):  
Francis Alonzo ◽  
P. David McMullen ◽  
Nancy E. Freitag
Keyword(s):  
Cell Wall ◽  
Host Cell ◽  
Exponential Growth ◽  
Bacterial Cell ◽  
Mammalian Cells ◽  
Actin Polymerization ◽  
Broth Culture ◽  
Gram Positive ◽  
Cell Cytosol ◽  
Host Cell Cytosol

ABSTRACTThe Gram-positive bacterial cell wall presents a structural barrier that requires modification for protein secretion and large-molecule transport as well as for bacterial growth and cell division. The Gram-positive bacteriumListeria monocytogenesadjusts cell wall architecture to promote its survival in diverse environments that include soil and the cytosol of mammalian cells. Here we provide evidence for the enzymatic flexibility of the murein hydrolase NamA and demonstrate that bacterial septation defects associated with a loss of NamA are functionally complemented by physical forces associated with actin polymerization within the host cell cytosol.L. monocytogenesΔnamAmutants formed long bacterial chains during exponential growth in broth culture; however, normal septation could be restored if mutant cells were cocultured with wild-typeL. monocytogenesbacteria or by the addition of exogenous NamA. Surprisingly, ΔnamAmutants were not significantly attenuated for virulence in mice despite the pronounced exponential growth septation defect. The physical force ofL. monocytogenes-mediated actin polymerization within the cytosol was sufficient to sever ΔnamAmutant intracellular chains and thereby enable the process of bacterial cell-to-cell spread so critical forL. monocytogenesvirulence. The inhibition of actin polymerization by cytochalasin D resulted in extended intracellular bacterial chains for which septation was restored following drug removal. Thus, despite the requirement for NamA for the normal septation of exponentially growingL. monocytogenescells, the hydrolase is essentially dispensable onceL. monocytogenesgains access to the host cell cytosol. This phenomenon represents a notable example of eukaryotic host cell complementation of a bacterial defect.

scholarly journals A Chlamydia trachomatis OmcB C-Terminal Fragment Is Released into the Host Cell Cytoplasm and Is Immunogenic in Humans

2011 ◽  
Vol 79 (6) ◽  
pp. 2193-2203 ◽  
Author(s):  
Manli Qi ◽  
Siqi Gong ◽  
Lei Lei ◽  
Quanzhong Liu ◽  
Guangming Zhong
Keyword(s):  
Chlamydia Trachomatis ◽  
Host Cell ◽  
Host Cells ◽  
Content Type ◽  
Membrane Complex ◽  
Host Cell Cytoplasm ◽  
Complex Protein ◽  
Infected Cells ◽  
Cell Cytosol ◽  
Host Cell Cytosol

ABSTRACTTheChlamydia trachomatisouter membrane complex protein B (OmcB) is an antigen with diagnostic and vaccine relevance. To further characterize OmcB, we generated antibodies against OmcB C-terminal (OmcBc) and N-terminal (OmcBn) fragments. Surprisingly, the anti-OmcBc antibody detected dominant signals in the host cell cytosol, while the anti-OmcBn antibody exclusively labeled intrainclusion signals inC. trachomatis-infected cells permeabilized with saponin. Western blot analyses revealed that OmcB was partially processed into OmcBc and OmcBn fragments. The processed OmcBc was released into host cell cytosol, while the OmcBn and remaining full-length OmcB were retained within the chlamydial inclusions. The organism-associated OmcB epitopes became detectable only after theC. trachomatis-infected cells were permeabilized with strong detergents such as SDS. However, the harsh permeabilization conditions also led to the leakage of the already secreted OmcBc and chlamydia-secreted protease (CPAF) out of the host cells. The OmcBc processing and release occurred in all biovars ofC. trachomatis. Moreover, the released OmcBc but not the retained OmcBn was highly immunogenic inC. trachomatis-infected women, which is consistent with the concept that exposure of chlamydial proteins to host cell cytosol is accompanied by increased immunogenicity. These observations have provided important information for further exploring/optimizing OmcB as a target for the development of diagnosis methods and vaccines.

scholarly journals Yogi Berra, Forrest Gump, and the discovery ofListeriaactin comet tails

2012 ◽  
Vol 23 (7) ◽  
pp. 1141-1145 ◽  
Author(s):  
Daniel A. Portnoy
Keyword(s):  
Electron Microscope ◽  
Host Cell ◽  
Actin Filaments ◽  
Cell Biology ◽  
Assistant Professor ◽  
Host System ◽  
Cytoskeletal Dynamics ◽  
Cell Cytosol ◽  
Growth Movement ◽  
Host Cell Cytosol

In 1988, eminent cell biologist Lew Tilney and newly appointed Assistant Professor of Microbiology Dan Portnoy met at a picnic and initiated a collaboration that led to a groundbreaking paper published in Journal of Cell Biology entitled “Actin filaments and the growth, movement, and spread of the intracellular bacterial parasite, Listeria monocytogenes.” The paper has been cited more than 800 times, the most of any publication in the careers of both investigators. Using an electron microscope from the Sputnik era, they assembled a stunning collection of micrographs that illustrated how L. monocytogenes enters the host cell and exploits a host system of actin-based motility to move within cells and into neighboring cells without leaving the host cell cytosol. This research captured the imagination of cell biologists and microbiologists alike and led to novel insights into cytoskeletal dynamics. Here, Portnoy provides a retrospective that shares text from the original submission that was deleted at the time of publication, along with reviewers' comments ranging from “It is really just a show and tell paper and doesn';t have any meat” to “the finding will have major impact in cell biology and in medicine. Potentially, the paper will be a classic.”

Cyclophilin 19 secreted in the host cell cytosol by Trypanosoma cruzi promotes ROS production required for parasite growth

2020 ◽  
Author(s):  
Gregory Pedroso Santos ◽  
Fernanda Midori Abukawa ◽  
Normanda Souza‐Melo ◽  
Laura Maria Alcântara ◽  
Paula Bittencourt‐Cunha ◽  
...  
Keyword(s):  
Trypanosoma Cruzi ◽  
Host Cell ◽  
Parasite Growth ◽  
Ros Production ◽  
Cell Cytosol ◽  
Host Cell Cytosol

scholarly journals Neurotrophin Receptor TrkC Is an Entry Receptor for Trypanosoma cruzi in Neural, Glial, and Epithelial Cells

2011 ◽  
Vol 79 (10) ◽  
pp. 4081-4087 ◽  
Author(s):  
Craig Weinkauf ◽  
Ryan Salvador ◽  
Mercio PereiraPerrin
Keyword(s):  
Trypanosoma Cruzi ◽  
Chagas Disease ◽  
Mammalian Cells ◽  
Chinese Hamster ◽  
Neuronal Cell ◽  
Host Cells ◽  
Neurotrophin Receptor ◽  
Content Type

ABSTRACTTrypanosoma cruzi, the agent of Chagas' disease, infects a variety of mammalian cells in a process that includes multiple cycles of intracellular division and differentiation starting with host receptor recognition by a parasite ligand(s). Earlier work in our laboratory showed that the neurotrophin-3 (NT-3) receptor TrkC is activated byT. cruzisurfacetrans-sialidase, also known as parasite-derived neurotrophic factor (PDNF). However, it has remained unclear whether TrkC is used byT. cruzito enter host cells. Here, we show that a neuronal cell line (PC12-NNR5) relatively resistant toT. cruzibecame highly susceptible to infection when overexpressing human TrkC but not human TrkB. Furthermore,trkCtransfection conferred an ∼3.0-fold intracellular growth advantage. Sialylation-deficient Chinese hamster ovarian (CHO) epithelial cell lines Lec1 and Lec2 also became much more permissive toT. cruziafter transfection with thetrkCgene. Additionally, NT-3 specifically blockedT. cruziinfection of the TrkC-NNR5 transfectants and of naturally permissive TrkC-bearing Schwann cells and astrocytes, as did recombinant PDNF. Two specific inhibitors of Trk autophosphorylation (K252a and AG879) and inhibitors of Trk-induced MAPK/Erk (U0126) and Akt kinase (LY294002) signaling, but not an inhibitor of insulin-like growth factor 1 receptor, abrogated TrkC-mediated cell invasion. Antibody to TrkC blockedT. cruziinfection of the TrkC-NNR5 transfectants and of cells that naturally express TrkC. The TrkC antibody also significantly and specifically reduced cutaneous infection in a mouse model of acute Chagas' disease. TrkC is ubiquitously expressed in the peripheral and central nervous systems, and in nonneural cells infected byT. cruzi, including cardiac and gastrointestinal muscle cells. Thus, TrkC is implicated as a functional PDNF receptor in cell entry, independently of sialic acid recognition, mediating broadT. cruziinfection bothin vitroandin vivo.

scholarly journals Mammalian cell invasion and intracellular trafficking by Trypanosoma cruzi infective forms

2005 ◽  
Vol 77 (1) ◽  
pp. 77-94 ◽  
Author(s):  
Renato A. Mortara ◽  
Walter K. Andreoli ◽  
Noemi N. Taniwaki ◽  
Adriana B. Fernandes ◽  
Claudio V. da Silva ◽  
...  
Keyword(s):  
Trypanosoma Cruzi ◽  
Host Cell ◽  
Mammalian Cells ◽  
Parasitophorous Vacuole ◽  
Host Cells ◽  
Mammalian Host ◽  
Target Cells ◽  
Sylvatic Cycle ◽  
Final Destination ◽  
Different Strains

Trypanosoma cruzi, the etiological agent of Chagas’ disease, occurs as different strains or isolates that may be grouped in two major phylogenetic lineages: T. cruzi I, associated with the sylvatic cycle and T. cruzi II, linked to the human disease. In the mammalian host the parasite has to invade cells and many studies implicated the flagellated trypomastigotes in this process. Several parasite surface components and some of host cell receptors with which they interact have been identified. Our work focused on how amastigotes, usually found growing in the cytoplasm, can invade mammalian cells with infectivities comparable to that of trypomastigotes. We found differences in cellular responses induced by amastigotes and trypomastigotes regarding cytoskeletal components and actin-rich projections. Extracellularly generated amastigotes of T. cruzi I strains may display greater infectivity than metacyclic trypomastigotes towards cultured cell lines as well as target cells that have modified expression of different classes of cellular components. Cultured host cells harboring the bacterium Coxiella burnetii allowed us to gain new insights into the trafficking properties of the different infective forms of T. cruzi, disclosing unexpected requirements for the parasite to transit between the parasitophorous vacuole to its final destination in the host cell cytoplasm.

Parasitophorous vacuoles of Leishmania mexicana acquire macromolecules from the host cell cytosol via two independent routes

1999 ◽  
Vol 112 (5) ◽  
pp. 681-693
Author(s):  
U.E. Schaible ◽  
P.H. Schlesinger ◽  
T.H. Steinberg ◽  
W.F. Mangel ◽  
T. Kobayashi ◽  
...  
Keyword(s):  
Host Cell ◽  
Lucifer Yellow ◽  
Cysteine Proteinase ◽  
Organic Anion ◽  
Organic Anion Transporter ◽  
Anion Transporter ◽  
Infected Cells ◽  
Lysobisphosphatidic Acid ◽  
Cell Cytosol ◽  
Host Cell Cytosol

The intracellular parasite Leishmania survives and proliferates in host macrophages. In this study we show that parasitophorous vacuoles of L. mexicana gain access to cytosolic material via two different routes. (1) Small anionic molecules such as Lucifer Yellow are rapidly transported into the vacuoles by an active transport mechanism that is sensitive to inhibitors of the host cell's organic anion transporter. (2) Larger molecules such as fluorescent dextrans introduced into the host cell cytosol are also delivered to parasitophorous vacuoles. This transport is slower and sensitive to modulators of autophagy. Infected macrophages were examined by two novel assays to visualize and quantify this process. Immunoelectron microscopy of cells loaded with digoxigenin-dextran revealed label in multivesicular endosomes, which appeared to fuse with parasitophorous vacuoles. The inner membranes of the multivesicular vesicles label strongly with antibodies against lysobisphosphatidic acid, suggesting that they represent a point of confluence between the endosomal and autophagosomal pathways. Although the rate of autophagous transfer was comparable in infected and uninfected cells, infected cells retained hydrolyzed cysteine proteinase substrate to a greater degree. These data suggest that L. mexicana-containing vacuoles have access to potential nutrients in the host cell cytosol via at least two independent mechanisms.

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