scholarly journals Immunization with cDNA Expressed by Amastigotes of Trypanosoma cruzi Elicits Protective Immune Response against Experimental Infection

2003 ◽  
Vol 71 (5) ◽  
pp. 2744-2757 ◽  
Author(s):  
Silvia B. Boscardin ◽  
Sheila S. Kinoshita ◽  
Adriana E. Fujimura ◽  
Mauricio M. Rodrigues
Keyword(s):  
Trypanosoma Cruzi ◽  
Vaccine Development ◽  
Surface Protein ◽  
Dna Vaccination ◽  
Eukaryotic Expression ◽  
Host Cells ◽  
Specific Antibodies ◽  
C Terminus ◽  
Lethal Infection ◽  
Genes Encoding

ABSTRACT Immunization of mice with plasmids containing Trypanosoma cruzi genes induced specific antibodies, CD4+ Th1 and CD8+ Tc1 cells, and protective immunity against infection. In most cases, plasmids used for DNA vaccination contained genes encoding antigens expressed by trypomastigotes, the nonreplicative forms of the parasite. In this study, we explored the possibility of using genes expressed by amastigotes, the form of the parasite which replicates inside host cells, for experimental DNA vaccination. For that purpose, we selected a gene related to the amastigote surface protein 2 (ASP-2), an antigen recognized by antibodies and T cells from infected mice and humans, for our study. Using primers specific for the asp-2 gene, four distinct groups of genes were amplified from cDNA from amastigotes of the Y strain of T. cruzi. At the nucleotide level, they shared 82.3 to 89.9% identity with the previously described asp-2 gene. A gene named clone 9 presented the highest degree of identity with the asp-2 gene and was selected for immunological studies. Polyclonal antisera raised against the C terminus of the recombinant protein expressed by the clone 9 gene reacted with an antigen of approximately 83 kDa expressed in amastigotes of T. cruzi. Immunization of BALB/c mice with eukaryotic expression plasmids containing the clone 9 gene elicited specific antibodies and CD4+ T-cell-dependent gamma interferon secretion. Upon challenge with trypomastigotes, mice immunized with plasmids harboring the clone 9 gene displayed reduced parasitemia and survived lethal infection. We concluded that amastigote cDNA is an interesting source of antigens that can be used for immunological studies, as well as for vaccine development.

Protective Immunity Against Trypanosoma cruzi Infection in a Highly Susceptible Mouse Strain After Vaccination with Genes Encoding the Amastigote Surface Protein-2 and Trans-Sialidase

2004 ◽  
Vol 15 (9) ◽  
pp. 878-886 ◽  
Author(s):  
José Ronnie Vasconcelos ◽  
Meire I. Hiyane ◽  
Cláudio R.F. Marinho ◽  
Carla Claser ◽  
Alexandre M.V. Machado ◽  
...  
Keyword(s):  
Trypanosoma Cruzi ◽  
Mouse Strain ◽  
Protective Immunity ◽  
Surface Protein ◽  
Susceptible Mouse ◽  
Genes Encoding ◽  
Cruzi Infection

scholarly journals Effect of the Plasmid-DNA Vaccination on Macroscopic and Microscopic Damage Caused by the Experimental ChronicTrypanosoma cruziInfection in the Canine Model

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Olivia Rodríguez-Morales ◽  
Silvia C. Carrillo-Sánchez ◽  
Humberto García-Mendoza ◽  
Alberto Aranda-Fraustro ◽  
Martha A. Ballinas-Verdugo ◽  
...  
Keyword(s):  
Plasmid Dna ◽  
Vaccine Development ◽  
Canine Model ◽  
Dna Vaccination ◽  
Heart Tissue ◽  
Pathological Changes ◽  
Cardiac Tissues ◽  
Genes Encoding ◽  
Microscopic Damage ◽  
Prevention Methods

The dog is considered the main domestic reservoir forTrypanosoma cruziinfection and a suitable experimental animal model to study the pathological changes during the course of Chagas disease (CD). Vaccine development is one of CD prevention methods to protect people at risk. Two plasmids containing genes encoding atrans-sialidase protein (TcSP) and an amastigote-specific glycoprotein (TcSSP4) were used as DNA vaccines in a canine model. Splenomegaly was not found in either of the recombinant plasmid-immunized groups; however, cardiomegaly was absent in animals immunized only with the plasmid containing theTcSSP4gene. The inflammation of subendocardial and myocardial tissues was prevented only with the immunization withTcSSP4gene. In conclusion, the vaccination with these genes has a partial protective effect on the enlargement of splenic and cardiac tissues during the chronic CD and on microscopic hearth damage, since both plasmids prevented splenomegaly but only one avoided cardiomegaly, and the lesions in heart tissue of dog immunized with plasmid containing theTcSSP4gene covered only subepicardial tissue.

scholarly journals Analysis of Functional Domains of theEnterococcus faecalis Pheromone-Induced Surface Protein Aggregation Substance

2001 ◽  
Vol 183 (19) ◽  
pp. 5659-5667 ◽  
Author(s):  
C. M. Waters ◽  
G. M. Dunny
Keyword(s):  
Cell Surface ◽  
High Efficiency ◽  
Cell Surface Hydrophobicity ◽  
Surface Protein ◽  
Cell Aggregation ◽  
Surface Hydrophobicity ◽  
Host Cells ◽  
Functional Domains ◽  
Aggregation Substance ◽  
C Terminus

ABSTRACT Pheromone-inducible aggregation substance (AS) proteins ofEnterococcus faecalis are essential for high-efficiency conjugation of the sex pheromone plasmids and also serve as virulence factors during host infection. A number of different functions have been attributed to AS in addition to bacterial cell aggregation, including adhesion to host cells, adhesion to fibrin, increased cell surface hydrophobicity, resistance to killing by polymorphonuclear leukocytes and macrophages, and increased vegetation size in an experimental endocarditis model. Relatively little information is available regarding the structure-activity relationship of AS. To identify functional domains, a library of 23 nonpolar 31-amino-acid insertions was constructed in Asc10, the AS encoded by the plasmid pCF10, using the transposons TnlacZ/in and TnphoA/in. Analysis of these insertions revealed a domain necessary for donor-recipient aggregation that extends further into the amino terminus of the protein than previously reported. In addition, insertions in the C terminus of the protein also reduced aggregation. As expected, the ability to aggregate correlates with efficient plasmid transfer. The results also indicated that an increase in cell surface hydrophobicity resulting from AS expression is not sufficient to mediate bacterial aggregation.

scholarly journals The Helicobacter pylori cag Pathogenicity Island Protein CagN Is a Bacterial Membrane-Associated Protein That Is Processed at Its C Terminus

2006 ◽  
Vol 74 (5) ◽  
pp. 2537-2543 ◽  
Author(s):  
Kevin M. Bourzac ◽  
Laura A. Satkamp ◽  
Karen Guillemin
Keyword(s):  
Helicobacter Pylori ◽  
Pathogenicity Island ◽  
Type Iv Secretion ◽  
Host Cells ◽  
Bacterial Membrane ◽  
Gastric Epithelial Cells ◽  
Type Iv ◽  
C Terminus ◽  
Increased Risk ◽  
Genes Encoding

ABSTRACT Helicobacter pylori infects nearly half the world's population and is associated with a spectrum of gastric maladies. Infections with cytotoxin-associated gene pathogenicity island (cag PAI)-containing strains are associated with an increased risk for gastric cancer. The cag PAI contains genes encoding a type IV secretion system (T4SS) and a delivered effector, CagA, that becomes tyrosine phosphorylated upon delivery into host cells and initiates changes in cell signaling. Although some cag PAI genes have been shown to be required for CagA delivery, a subset of which are homologues of T4SS genes from Agrobacterium tumefaciens, the majority have no known function or homologues. We have performed a detailed investigation of one such cag PAI protein, CagN, which is encoded by the gene HP0538. Our results show that CagN is not delivered into host cells and instead is associated with the bacterial membrane. We demonstrate that CagN is cleaved at its C terminus by a mechanism that is independent of other cag PAI proteins. Finally, we show that a ΔcagN mutant is not impaired in its ability to deliver CagA to gastric epithelial cells and initiate cell elongation.

scholarly journals Glycosylation of HIV Env Impacts IgG Subtype Responses to Vaccination

Viruses ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 153 ◽  
Author(s):  
Rebecca Heß ◽  
Michael Storcksdieck genannt Bonsmann ◽  
Dennis Lapuente ◽  
Andre Maaske ◽  
Carsten Kirschning ◽  
...  
Keyword(s):  
Vaccine Development ◽  
Surface Protein ◽  
T Cell Response ◽  
Specific Antibodies ◽  
Lectin Receptor ◽  
Hiv Antigen ◽  
Syncytial Virus ◽  
Antibody Class ◽  
Antigen Presenting ◽  
The Impact

The envelope protein (Env) is the only surface protein of the human immunodeficiency virus (HIV) and as such the exclusive target for protective antibody responses. Experimental evidences from mouse models suggest a modulating property of Env to steer antibody class switching towards the less effective antibody subclass IgG1 accompanied with strong TH2 helper responses. By simple physical linkage we were able to imprint this bias, exemplified by a low IgG2a/IgG1 ratio of antigen-specific antibodies, onto an unrelated antigen, namely the HIV capsid protein p24. Here, our results indicate the glycan moiety of Env as the responsible immune modulating activity. Firstly, in Card9−/− mice lacking specific C-Type lectin responsiveness, DNA immunization significantly increased the IgG2a/IgG1 ratio for the Env-specific antibodies while the antibody response against the F-protein of the respiratory syncytial virus (RSV) serving as control antigen remained unchanged. Secondly, sequential shortening of the Env encoding sequence revealed the C2V3 domain as responsible for the strong IgG1 responses and TH2 cytokine production. Removing all potential N-glycosylation sites from the C2V3 domain by site-specific mutagenesis reversed the vaccine-induced immune response towards a Th1-dominated T-cell response and a balanced IgG2a/IgG1 ratio. Accordingly, the stretch of oligomannose glycans in the C2V3 domain of Env might mediate a specific uptake and/or signaling modus in antigen presenting cells by involving interaction with an as yet unknown C-type lectin receptor. Our results contribute to a deeper understanding of the impact of Env glycosylation on HIV antigen-specific immune responses, which will further support HIV vaccine development.

scholarly journals Modulation of Cardiocyte Functional Activity by Antibodies against Trypanosoma cruzi Ribosomal P2 Protein C Terminus

2000 ◽  
Vol 68 (9) ◽  
pp. 5114-5119 ◽  
Author(s):  
P. Sepulveda ◽  
P. Liegeard ◽  
G. Wallukat ◽  
M. J. Levin ◽  
M. Hontebeyrie
Keyword(s):  
Trypanosoma Cruzi ◽  
Functional Activity ◽  
Molecular Mimicry ◽  
Host Cells ◽  
Cardiac Pathology ◽  
Epitope Recognition ◽  
C Terminus ◽  
P Proteins ◽  
Ribosomal P

ABSTRACT Antibodies against the Trypanosoma cruzi ribosomal P2β protein (TcP2β) have been associated with the chronic cardiac pathology of Chagas' disease in humans. Using synthetic peptides spanning the entire TcP2β molecule, we investigated their epitope recognition by antibodies from mice chronically infected with T. cruzi and from mice immunized with two recombinant TcP2βs. We found clear differences in epitope recognition between antibodies from T. cruzi-infected mice and mice immunized with two different recombinant TcP2βs associated with different schedules of immunization. Major epitopes recognized by antibodies from mice immunized with recombinant glutathioneS-transferase (GST) or histidine (Hist) fusion TcP2β (GST-TcP2β or Hist-TcP2β) are located in the central and hinge regions of the molecule. Nevertheless, mice immunized with Hist-TcP2β were also able to elicit antibodies against the TcP2β C terminus, a region which is highly conserved in both T. cruzi and mammal ribosomal P proteins. Strikingly, antibodies from infected animals recognized only the TcP2β C terminus. By using these antisera with distinct profiles of epitope recognition, it could be shown that only C terminus-specific antibodies were able to increase the beating frequency of cardiomyocytes from neonatal rats in vitro by selective stimulation of the β1-adrenergic receptor. Thus, antibodies against the TcP2β C terminus elicited in the absence of infection are able to modulate a functional activity of host cells through a molecular mimicry mechanism.

scholarly journals Cysteine Protease Inhibitors Cure an Experimental Trypanosoma cruzi Infection

1998 ◽  
Vol 188 (4) ◽  
pp. 725-734 ◽  
Author(s):  
Juan C. Engel ◽  
Patricia S. Doyle ◽  
Ivy Hsieh ◽  
James H. McKerrow
Keyword(s):  
Trypanosoma Cruzi ◽  
Protease Inhibitors ◽  
Chagas Disease ◽  
Golgi Complex ◽  
Cysteine Protease ◽  
Parasitic Infection ◽  
Host Cells ◽  
Vinyl Sulfone ◽  
Cysteine Protease Inhibitors ◽  
Lethal Infection

Trypanosoma cruzi is the causative agent of Chagas' disease. The major protease, cruzain, is a target for the development of new chemotherapy. We report the first successful treatment of an animal model of Chagas' disease with inhibitors designed to inactivate cruzain. Treatment with fluoromethyl ketone–derivatized pseudopeptides rescued mice from lethal infection. The optimal pseudopeptide scaffold was phenylalanine-homophenylalanine. To achieve cure of infection, this pseudopeptide scaffold was incorporated in a less toxic vinyl sulfone derivative. N-methyl piperazine-Phe-homoPhe-vinyl sulfone phenyl also rescued mice from a lethal infection. Six of the treated mice survived over nine months, three without further treatment. Three mice that had entered the chronic stage of infection were retreated with a 20-d regimen. At the conclusion of the experiments, five of the six mice had repeated negative hemacultures, indicative of parasitological cure. Studies of the effect of inhibitors on the intracellular amastigote form suggest that the life cycle is interrupted because of inhibitor arrest of normal autoproteolytic cruzain processing at the level of the Golgi complex. Parasites recovered from the hearts of treated mice showed the same abnormalities as those treated in vitro. No abnormalities were noted in the Golgi complex of host cells. This study provides proof of concept that cysteine protease inhibitors can be given at therapeutic doses to animals to selectively arrest a parasitic infection.

scholarly journals Plasmodium falciparum 19-Kilodalton Merozoite Surface Protein 1 (MSP1)-Specific Antibodies That Interfere with Parasite GrowthIn VitroCan Inhibit MSP1 Processing, Merozoite Invasion, and Intracellular Parasite Development

2011 ◽  
Vol 80 (3) ◽  
pp. 1280-1287 ◽  
Author(s):  
David K. Moss ◽  
Edmond J. Remarque ◽  
Bart W. Faber ◽  
David R. Cavanagh ◽  
David E. Arnot ◽  
...  
Keyword(s):  
Vaccine Development ◽  
Surface Protein ◽  
Merozoite Surface Protein ◽  
Significant Inhibition ◽  
Parasite Growth ◽  
Proteolytic Processing ◽  
Parasite Development ◽  
Intracellular Parasite ◽  
Specific Antibodies ◽  
Merozoite Surface Protein 1

Merozoite surface protein 1 (MSP1) is a target for malaria vaccine development. Antibodies to the 19-kDa carboxy-terminal region referred to as MSP119inhibit erythrocyte invasion and parasite growth, with some MSP1-specific antibodies shown to inhibit the proteolytic processing of MSP1 that occurs at invasion. We investigated a series of antibodies purified from rabbits immunized with MSP119and AMA1 recombinant proteins for their ability to inhibit parasite growth, initially looking at MSP1 processing. Although significant inhibition of processing was mediated by several of the antibody samples, there was no clear relationship with overall growth inhibition by the same antibodies. However, no antibody samples inhibited processing but not invasion, suggesting that inhibition of MSP1 processing contributes to but is not the only mechanism of antibody-mediated inhibition of invasion and growth. Examining other mechanisms by which MSP1-specific antibodies inhibit parasite growth, we show that MSP119-specific antibodies are taken up into invaded erythrocytes, where they persist for significant periods and result in delayed intracellular parasite development. This delay may result from antibody interference with coalescence of MSP119-containing vesicles with the food vacuole. Antibodies raised against a modified recombinant MSP119sequence were more efficient at delaying intracellular growth than those to the wild-type protein. We propose that antibodies specific for MSP119can mediate inhibition of parasite growth by at least three mechanisms: inhibition of MSP1 processing, direct inhibition of invasion, and inhibition of parasite development following invasion. The balance between mechanisms may be modulated by modifying the immunogen used to induce the antibodies.

Protective Immunity Against Trypanosoma cruzi Infection in a Highly Susceptible Mouse Strain After Vaccination with Genes Encoding the Amastigote Surface Protein-2 and Trans-Sialidase

2004 ◽  
Vol 15 (9) ◽  
pp. 878-886 ◽  
Author(s):  
José Ronnie Vasconcelos ◽  
Meire I. Hiyane ◽  
Cláudio R.F. Marinho ◽  
Carla Claser ◽  
Alexandre M.V. Machado ◽  
...  
Keyword(s):  
Trypanosoma Cruzi ◽  
Mouse Strain ◽  
Protective Immunity ◽  
Surface Protein ◽  
Susceptible Mouse ◽  
Genes Encoding

scholarly journals Novel Protective Antigens Expressed by Trypanosoma cruzi Amastigotes Provide Immunity to Mice Highly Susceptible to Chagas' Disease

2008 ◽  
Vol 15 (8) ◽  
pp. 1292-1300 ◽  
Author(s):  
Eduardo L. V. Silveira ◽  
Carla Claser ◽  
Filipe A. B. Haolla ◽  
Luiz G. Zanella ◽  
Mauricio M. Rodrigues
Keyword(s):  
Trypanosoma Cruzi ◽  
Chagas Disease ◽  
Protective Immunity ◽  
Protective Antigen ◽  
Surface Protein ◽  
Cross Reactivity ◽  
Eukaryotic Expression ◽  
Lethal Challenge ◽  
Reading Frame ◽  
Antibody Recognition

ABSTRACT Earlier studies have demonstrated in A/Sn mice highly susceptible to Chagas' disease protective immunity against lethal Trypanosoma cruzi infection elicited by vaccination with an open reading frame (ORF) expressed by amastigotes. In our experiments, we used this mouse model to search for other amastigote-expressed ORFs with a similar property. Fourteen ORFs previously determined to be expressed in this developmental stage were individually inserted into a eukaryotic expression vector containing a nucleotide sequence that encoded a mammalian secretory signal peptide. Immunization with 13 of the 14 ORFs induced specific antibodies which recognized the amastigotes. Three of those immune sera also reacted with trypomastigotes and epimastigotes. After a lethal challenge with Y strain trypomastigotes, the vast majority of plasmid-injected mice succumbed to infection. In some cases, a significant delay in mortality was observed. Only two of these ORFs provided protective immunity against the otherwise lethal infection caused by trypomastigotes of the Y or Colombia strain. These ORFs encode members of the trans-sialidase family of surface antigens related to the previously described protective antigen amastigote surface protein 2 (ASP-2). Nevertheless, at the level of antibody recognition, no cross-reactivity was observed between the ORFs and the previously described ASP-2 from the Y strain. In immunofluorescence analyses, we observed the presence of epitopes related to both proteins expressed by amastigotes of seven different strains. In conclusion, our approach allowed us to successfully identify two novel protective ORFs which we consider interesting for future studies on the immune response to Chagas' disease.

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