Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2011-2-21
pubmed:abstractText
Repetitive proteins (RP) of Trypanosoma cruzi are highly present in the parasite and are strongly recognized by sera from Chagas' disease patients. Flagelar Repetitive Antigen (FRA), which is expressed in all steps of the parasite life cycle, is the RP that displays the greatest number of aminoacids per repeat and has been indicated as one of the most suitable candidate for diagnostic test because of its high performance in immunoassays. Here we analyzed the influence of the number of repeats on the immunogenic and antigenic properties of the antigen. Recombinant proteins containing one, two, and four tandem repeats of FRA (FRA1, FRA2, and FRA4, respectively) were obtained and the immune response induced by an equal amount of repeats was evaluated in a mouse model. The reactivity of specific antibodies present in sera from patients naturally infected with T. cruzi was also assessed against FRA1, FRA2, and FRA4 proteins, and the relative avidity was analyzed. We determined that the number of repeats did not increase the humoral response against the antigen and this result was reproduced when the repeated motifs were alone or fused to a non-repetitive protein. By contrast, the binding affinity of specific human antibodies increases with the number of repeated motifs in FRA antigen. We then concluded that the high ability of FRA to be recognized by specific antibodies from infected individuals is mainly due to a favorable polyvalent interaction between the antigen and the antibodies. In accordance with experimental results, a 3D model was proposed and B epitope in FRA1, FRA2, and FRA4 were predicted.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
1090-2449
pubmed:author
pubmed:copyrightInfo
Copyright © 2010 Elsevier Inc. All rights reserved.
pubmed:issnType
Electronic
pubmed:volume
127
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
672-9
pubmed:meshHeading
pubmed-meshheading:21118687-Animals, pubmed-meshheading:21118687-Antibodies, Protozoan, pubmed-meshheading:21118687-Antibody Affinity, pubmed-meshheading:21118687-Antigens, Protozoan, pubmed-meshheading:21118687-Chagas Disease, pubmed-meshheading:21118687-Disease Models, Animal, pubmed-meshheading:21118687-Enzyme-Linked Immunosorbent Assay, pubmed-meshheading:21118687-Female, pubmed-meshheading:21118687-Humans, pubmed-meshheading:21118687-Immune Sera, pubmed-meshheading:21118687-Mice, pubmed-meshheading:21118687-Molecular Conformation, pubmed-meshheading:21118687-Plasmids, pubmed-meshheading:21118687-Protozoan Proteins, pubmed-meshheading:21118687-Recombinant Proteins, pubmed-meshheading:21118687-Repetitive Sequences, Amino Acid, pubmed-meshheading:21118687-Tandem Repeat Sequences, pubmed-meshheading:21118687-Trypanosoma cruzi
pubmed:year
2011
pubmed:articleTitle
Effect of repetitiveness on the immunogenicity and antigenicity of Trypanosoma cruzi FRA protein.
pubmed:affiliation
Laboratorio de Tecnología Inmunológica, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, Santa Fe, Argentina.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't