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 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 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 A Novel Trichomonas vaginalis Surface Protein Modulates Parasite Attachment via Protein:Host Cell Proteoglycan Interaction

mBio ◽  
2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Brenda M. Molgora ◽  
Anand Kumar Rai ◽  
Michael J. Sweredoski ◽  
Annie Moradian ◽  
Sonja Hess ◽  
...  
Keyword(s):  
Host Cell ◽  
Trichomonas Vaginalis ◽  
Surface Protein ◽  
Host Cells ◽  
Parasite Line ◽  
Cell Adherence ◽  
Common Component ◽  
Content Type ◽  
Sexually Transmitted ◽  
Significant Difference

ABSTRACT Trichomonas vaginalis is a highly prevalent, sexually transmitted parasite which adheres to mucosal epithelial cells to colonize the human urogenital tract. Despite adherence being crucial for this extracellular parasite to thrive within the host, relatively little is known about the mechanisms or key molecules involved in this process. Here, we have identified and characterized a T. vaginalis hypothetical protein, TVAG_157210 (TvAD1), as a surface protein that plays an integral role in parasite adherence to the host. Quantitative proteomics revealed TvAD1 to be ∼4-fold more abundant in parasites selected for increased adherence (MA parasites) than the isogenic parental (P) parasite line. De novo modeling suggested that TvAD1 binds N-acetylglucosamine (GlcNAc), a sugar comprising host glycosaminoglycans (GAGs). Adherence assays utilizing GAG-deficient cell lines determined that host GAGs, primarily heparan sulfate (HS), mediate adherence of MA parasites to host cells. TvAD1 knockout (KO) parasites, generated using CRISPR-Cas9, were found to be significantly reduced in host cell adherence, a phenotype that is rescued by overexpression of TvAD1 in KO parasites. In contrast, there was no significant difference in parasite adherence to GAG-deficient lines by KO parasites compared with wild-type, which is contrary to that observed for KO parasites overexpressing TvAD1. Isothermal titration calorimetric (ITC) analysis showed that TvAD1 binds to HS, indicating that TvAD1 mediates host cell adherence via HS interaction. In addition to characterizing the role of TvAD1 in parasite adherence, these studies reveal a role for host GAG molecules in T. vaginalis adherence. IMPORTANCE The ability of the sexually transmitted parasite Trichomonas vaginalis to adhere to its human host is critical for establishing and maintaining an infection. Yet how parasites adhere to host cells is poorly understood. In this study, we employed a novel adherence selection method to identify proteins involved in parasite adherence to the host. This method led to the identification of a protein, with no previously known function, that is more abundant in parasites with increased capacity to bind host cells. Bioinformatic modeling and biochemical analyses revealed that this protein binds a common component on the host cell surface proteoglycans. Subsequent creation of parasites that lack this protein directly demonstrated that the protein mediates parasite adherence via an interaction with host cell proteoglycans. These findings both demonstrate a role for this protein in T. vaginalis adherence to the host and shed light on host cell molecules that participate in parasite colonization.

scholarly journals Localization of the Hypothetical Protein Cpn0797 in the Cytoplasm of Chlamydia pneumoniae-Infected Host Cells

2006 ◽  
Vol 74 (11) ◽  
pp. 6479-6486 ◽  
Author(s):  
Feng Dong ◽  
Rhonda Flores ◽  
Ding Chen ◽  
Jianhua Luo ◽  
Youmin Zhong ◽  
...  
Keyword(s):  
Host Cell ◽  
Fusion Proteins ◽  
Chlamydia Pneumoniae ◽  
Hypothetical Protein ◽  
Host Cells ◽  
Infected Host ◽  
Reading Frame ◽  
The Third ◽  
Cell Cytosol ◽  
Host Cell Cytosol

ABSTRACT Using antibodies raised with chlamydial fusion proteins, we have localized a protein encoded by the hypothetical open reading frame Cpn0797 in the cytoplasm of Chlamydia pneumoniae-infected host cells. The anti-Cpn0797 antibodies specifically recognized Cpn0797 protein without cross-reacting with either CPAFcp or Cpn0796, the only two proteins known to be secreted into the host cell cytosol by C. pneumoniae organisms. Thus, Cpn0797 represents the third C. pneumoniae protein secreted into the host cell cytosol experimentally identified so far.

scholarly journals Candida albicans Als3, a Multifunctional Adhesin and Invasin

2010 ◽  
Vol 10 (2) ◽  
pp. 168-173 ◽  
Author(s):  
Yaoping Liu ◽  
Scott G. Filler
Keyword(s):  
Candida Albicans ◽  
Host Cell ◽  
Surface Protein ◽  
Host Cells ◽  
Content Type ◽  
Multifunctional Protein ◽  
Multiple Functions ◽  
Abiotic Surfaces ◽  
Disseminated Disease

ABSTRACTCandida albicansis part of the normal human flora, and it grows on mucosal surfaces in healthy individuals. In susceptible hosts, this organism can cause both mucosal and hematogenously disseminated disease. ForC. albicansto persist in the host and induce disease, it must be able to adhere to biotic and abiotic surfaces, invade host cells, and obtain iron. TheC. albicanshypha-specific surface protein Als3 is a member of the agglutinin-like sequence (Als) family of proteins and is important in all of these processes. Functioning as an adhesin, Als3 mediates attachment to epithelial cells, endothelial cells, and extracellular matrix proteins. It also plays an important role in biofilm formation on prosthetic surfaces, both alone and in mixed infection withStreptococcus gordonii. Als3 is one of two knownC. albicansinvasins. It binds to host cell receptors such as E-cadherin and N-cadherin and thereby induces host cells to endocytose the organism. Als3 also binds to host cell ferritin and enablesC. albicansto utilize this protein as a source of iron. Because of its multiple functions and its high expression levelin vivo, Als3 is a promising target for vaccines that induce protective cell-mediated and antibody responses. This review will summarize the multiple functions of this interesting and multifunctional protein.

scholarly journals Identification of Novel Host Interactors of Effectors Secreted by Salmonella and Citrobacter

mSystems ◽  
2016 ◽  
Vol 1 (4) ◽  
Author(s):  
Ryan L. Sontag ◽  
Ernesto S. Nakayasu ◽  
Roslyn N. Brown ◽  
George S. Niemann ◽  
Michael A. Sydor ◽  
...  
Keyword(s):  
Host Cell ◽  
Type Iii Secretion ◽  
Defense Mechanisms ◽  
Pathogenic Bacteria ◽  
Effector Proteins ◽  
Host Cells ◽  
Secretion Systems ◽  
Type Iii ◽  
Cell Cytosol ◽  
Host Cell Cytosol

ABSTRACT During infection, pathogenic bacteria face an adverse environment of factors driven by both cellular and humoral defense mechanisms. To help evade the immune response and ultimately proliferate inside the host, many bacteria evolved specialized secretion systems to deliver effector proteins directly into host cells. Translocated effector proteins function to subvert host defense mechanisms. Numerous pathogenic bacteria use a specialized secretion system called type III secretion to deliver effectors into the host cell cytosol. Here, we identified 75 new host targets of Salmonella and Citrobacter effectors, which will help elucidate their mechanisms of action. Many pathogenic bacteria of the family Enterobacteriaceae use type III secretion systems to inject virulence proteins, termed “effectors,” into the host cell cytosol. Although host-cellular activities of several effectors have been demonstrated, the function and host-targeted pathways of most of the effectors identified to date are largely undetermined. To gain insight into host proteins targeted by bacterial effectors, we performed coaffinity purification of host proteins from cell lysates using recombinant effectors from the Enterobacteriaceae intracellular pathogens Salmonella enterica serovar Typhimurium and Citrobacter rodentium. We identified 54 high-confidence host interactors for the Salmonella effectors GogA, GtgA, GtgE, SpvC, SrfH, SseL, SspH1, and SssB collectively and 21 interactors for the Citrobacter effectors EspT, NleA, NleG1, and NleK. We biochemically validated the interaction between the SrfH Salmonella protein and the extracellular signal-regulated kinase 2 (ERK2) host protein kinase, which revealed a role for this effector in regulating phosphorylation levels of this enzyme, which plays a central role in signal transduction. IMPORTANCE During infection, pathogenic bacteria face an adverse environment of factors driven by both cellular and humoral defense mechanisms. To help evade the immune response and ultimately proliferate inside the host, many bacteria evolved specialized secretion systems to deliver effector proteins directly into host cells. Translocated effector proteins function to subvert host defense mechanisms. Numerous pathogenic bacteria use a specialized secretion system called type III secretion to deliver effectors into the host cell cytosol. Here, we identified 75 new host targets of Salmonella and Citrobacter effectors, which will help elucidate their mechanisms of action.

scholarly journals Microsporidia Interact with Host Cell Mitochondria via Voltage-Dependent Anion Channels Using Sporoplasm Surface Protein 1

mBio ◽  
2019 ◽  
Vol 10 (4) ◽  
Author(s):  
Bing Han ◽  
Yanfen Ma ◽  
Vincent Tu ◽  
Tadakimi Tomita ◽  
Joshua Mayoral ◽  
...  
Keyword(s):  
Host Cell ◽  
Parasitophorous Vacuole ◽  
Surface Protein ◽  
Host Cells ◽  
Anion Channels ◽  
Polar Tube ◽  
Content Type ◽  
Proteomic Approach ◽  
Voltage Dependent ◽  
Microsporidian Infection

ABSTRACT Microsporidia are opportunistic intracellular pathogens that can infect a wide variety of hosts ranging from invertebrates to vertebrates. During invasion, the microsporidian polar tube pushes into the host cell, creating a protective microenvironment, the invasion synapse, into which the sporoplasm extrudes. Within the synapse, the sporoplasm then invades the host cell, forming a parasitophorous vacuole (PV). Using a proteomic approach, we identified Encephalitozoon hellem sporoplasm surface protein 1 (EhSSP1), which localized to the surface of extruded sporoplasms. EhSSP1 was also found to interact with polar tube protein 4 (PTP4). Recombinant EhSSP1 (rEhSSP1) bound to human foreskin fibroblasts, and both anti-EhSSP1 and rEhSSP1 caused decreased levels of host cell invasion, suggesting that interaction of SSP1 with the host cell was involved in invasion. Coimmunoprecipitation (Co-IP) followed by proteomic analysis identified host cell voltage-dependent anion channels (VDACs) as EhSSP1 interacting proteins. Yeast two-hybrid assays demonstrated that EhSSP1 was able to interact with VDAC1, VDAC2, and VDAC3. rEhSSP1 colocalized with the host mitochondria which were associated with microsporidian PVs in infected cells. Transmission electron microscopy revealed that the outer mitochondrial membrane interacted with meronts and the PV membrane, mitochondria clustered around meronts, and the VDACs were concentrated at the interface of mitochondria and parasite. Knockdown of VDAC1, VDAC2, and VDAC3 in host cells resulted in significant decreases in the number and size of the PVs and a decrease in mitochondrial PV association. The interaction of EhSSP1 with VDAC probably plays an important part in energy acquisition by microsporidia via its role in the association of mitochondria with the PV. IMPORTANCE Microsporidia are important opportunistic human pathogens in immune-suppressed individuals, such as those with HIV/AIDS and recipients of organ transplants. The sporoplasm is critical for establishing microsporidian infection. Despite the biological importance of this structure for transmission, there is limited information about its structure and composition that could be targeted for therapeutic intervention. Here, we identified a novel E. hellem sporoplasm surface protein, EhSSP1, and demonstrated that it can bind to host cell mitochondria via host VDAC. Our data strongly suggest that the interaction between SSP1 and VDAC is important for the association of mitochondria with the parasitophorous vacuole during microsporidian infection. In addition, binding of SSP1 to the host cell is associated with the final steps of invasion in the invasion synapse.

scholarly journals Parasite-Mediated Remodeling of the Host Microfilament Cytoskeleton Enables Rapid Egress of Trypanosoma cruzi following Membrane Rupture

mBio ◽  
2021 ◽  
Author(s):  
Eden R. Ferreira ◽  
Alexis Bonfim-Melo ◽  
Barbara A. Burleigh ◽  
Jaime A. Costales ◽  
Kevin M. Tyler ◽  
...  
Keyword(s):  
Trypanosoma Cruzi ◽  
Host Cell ◽  
Cell Invasion ◽  
Lytic Cycle ◽  
Host Cells ◽  
Host Cell Invasion ◽  
High Quality ◽  
Content Type ◽  
Membrane Rupture

Understanding how Trypanosoma cruzi interacts with host cells has been transformed by high-quality studies that have examined in detail the mechanisms of T. cruzi host cell invasion. In contrast, little is known about the latter stages of the parasite’s lytic cycle: how parasites egress and thereby sustain round after round of infection.

scholarly journals Conserved Regions as Markers of Different Patterns of Expression and Distribution of the Mucin-Associated Surface Proteins of Trypanosoma cruzi

2011 ◽  
Vol 80 (1) ◽  
pp. 169-174 ◽  
Author(s):  
Luis M. De Pablos ◽  
Antonio Osuna
Keyword(s):  
Life Cycle ◽  
Trypanosoma Cruzi ◽  
Gene Family ◽  
Signal Peptide ◽  
Fluorescence Intensity ◽  
Surface Proteins ◽  
Content Type ◽  
Conserved Regions ◽  
The Family ◽  
Different Levels

ABSTRACTThe MASP gene family is the second most widely represented gene family in the genome ofTrypanosoma cruzi. One of its main characteristics is that its 5′ and 3′ regions are highly conserved. We assessed the expression of these conserved regions as a marker forT. cruziand also analyzed the expression of themaspgenes and MASP proteins. In parasite strains CL-Brener (DTUVI lineage) and PAN4 (DTUI lineage),maspgenes were expressed at different levels both with regard to the two strains and between stages in the parasite's life cycle. We also studied the expression of the family during the intracellular cycle ofT. cruzi, using antibodies against the conserved MASP signal peptide (SP). Fluorescence intensity showed an increase in expression from 24 h onwards, with a peak in intensity at 72 h postinfection. After 24 and 48 h, the MASP proteins were expressed in 33.33% and 57.14% of the amastigotes, respectively. Our data show that not only the extracellular forms ofT. cruzibut also the intracellular phases express this type of protein, though to different extents in the various forms of the parasite.

scholarly journals Anaplasma phagocytophilum Asp14 Is an Invasin That Interacts with Mammalian Host Cells via Its C Terminus To Facilitate Infection

2012 ◽  
Vol 81 (1) ◽  
pp. 65-79 ◽  
Author(s):  
Amandeep Kahlon ◽  
Nore Ojogun ◽  
Stephanie A. Ragland ◽  
David Seidman ◽  
Matthew J. Troese ◽  
...  
Keyword(s):  
Membrane Protein ◽  
Outer Membrane ◽  
Outer Membrane Protein ◽  
Anaplasma Phagocytophilum ◽  
Affinity Purification ◽  
Surface Protein ◽  
Surface Proteins ◽  
Host Cells ◽  
Mammalian Host ◽  
Content Type

Anaplasma phagocytophilum, a member of the familyAnaplasmataceae, is the tick-transmitted obligate intracellular bacterium that causes human granulocytic anaplasmosis. The life cycle ofA. phagocytophilumis biphasic, transitioning between the noninfectious reticulate cell (RC) and infectious dense-cored (DC) forms. We analyzed the bacterium's DC surface proteome by selective biotinylation of surface proteins, NeutrAvidin affinity purification, and mass spectrometry. Transcriptional profiling of selected outer membrane protein candidates over the course of infection revealed thataph_0248(designatedasp14[14-kDaA. phagocytophilumsurface protein]) expression was upregulated the most duringA. phagocytophilumcellular invasion.asp14transcription was induced during transmission feeding ofA. phagocytophilum-infected ticks on mice and was upregulated when the bacterium engaged its receptor, P-selectin glycoprotein ligand 1. Asp14 localized to theA. phagocytophilumsurface and was expressed duringin vivoinfection. Treating DC organisms with Asp14 antiserum or preincubating mammalian host cells with glutathioneS-transferase (GST)–Asp14 significantly inhibited infection of host cells. Moreover, preincubating host cells with GST-tagged forms of both Asp14 and outer membrane protein A, anotherA. phagocytophiluminvasin, pronouncedly reduced infection relative to treatment with either protein alone. The Asp14 domain that is sufficient for cellular adherence and invasion lies within the C-terminal 12 to 24 amino acids and is conserved among otherAnaplasmaandEhrlichiaspecies. These results identify Asp14 as anA. phagocytophilumsurface protein that is critical for infection, delineate its invasion domain, and demonstrate the potential of targeting Asp14 in concert with OmpA for protecting against infection byA. phagocytophilumand otherAnaplasmataceaepathogens.

Sign in / Sign up

Export Citation Format

Share Document