Identification of strain-specific B-cell epitopes in Trypanosoma cruzi using genome-scale epitope prediction and high-throughput immunoscreening with peptide arrays

Autor: Ana Rita Rocha dos Santos, Daniella Castanheira Bartholomeu, Ricardo Toshio Fujiwara, Lúcia Maria da Cunha Galvão, Robert H. Gilman, João Luís Reis Cunha, Gabriela Flávia Rodrigues Luiz, Rodrigo de Almeida Lourdes, Antônia Cláudia Jácome da Câmara, Lucas De Carvalho Dhom Lemos, Caryn Bern, Ricardo T. Gazzinelli, Tiago Antônio de Oliveira Mendes
Rok vydání: 2013
Předmět:
Male
haplotype
Chagas disease
genotype
Epitope
Mice
Genotype
cross reaction
DNA extraction
serodiagnosis
epitope
lcsh:Public aspects of medicine
Infectious Diseases
real time polymerase chain reaction
antigenicity
Epitopes
B-Lymphocyte
genetic strain
immunoblotting
purl.org/pe-repo/ocde/ford#3.03.06 [https]
Research Article
lcsh:Arctic medicine. Tropical medicine
lcsh:RC955-962
Trypanosoma cruzi
DNA sequence
Protein Array Analysis
Antigens
Protozoan
Enzyme-Linked Immunosorbent Assay
Biology
Sensitivity and Specificity
SPOT synthesis
Antigen
Immunoscreening
peptide synthesis
parasitic diseases
medicine
Animals
Humans
controlled study
Chagas Disease
Serologic Tests
protein expression
Genotyping
mouse
B lymphocyte
animal model
Haplotype
Public Health
Environmental and Occupational Health
Computational Biology
lcsh:RA1-1270
biology.organism_classification
medicine.disease
major clinical study
serotyping
Virology
RNA extraction
enzyme linked immunosorbent assay
amino acid sequence
Mice
Inbred C57BL
epitope mapping
protein microarray
computer model
high throughput screening
Zdroj: PLoS Neglected Tropical Diseases
PLoS Neglected Tropical Diseases, Vol 7, Iss 10, p e2524 (2013)
ISSN: 1935-2735
Popis: Background The factors influencing variation in the clinical forms of Chagas disease have not been elucidated; however, it is likely that the genetics of both the host and the parasite are involved. Several studies have attempted to correlate the T. cruzi strains involved in infection with the clinical forms of the disease by using hemoculture and/or PCR-based genotyping of parasites from infected human tissues. However, both techniques have limitations that hamper the analysis of large numbers of samples. The goal of this work was to identify conserved and polymorphic linear B-cell epitopes of T. cruzi that could be used for serodiagnosis and serotyping of Chagas disease using ELISA. Methodology By performing B-cell epitope prediction on proteins derived from pair of alleles of the hybrid CL Brener genome, we have identified conserved and polymorphic epitopes in the two CL Brener haplotypes. The rationale underlying this strategy is that, because CL Brener is a recent hybrid between the TcII and TcIII DTUs (discrete typing units), it is likely that polymorphic epitopes in pairs of alleles could also be polymorphic in the parental genotypes. We excluded sequences that are also present in the Leishmania major, L. infantum, L. braziliensis and T. brucei genomes to minimize the chance of cross-reactivity. A peptide array containing 150 peptides was covalently linked to a cellulose membrane, and the reactivity of the peptides was tested using sera from C57BL/6 mice chronically infected with the Colombiana (TcI) and CL Brener (TcVI) clones and Y (TcII) strain. Findings and Conclusions A total of 36 peptides were considered reactive, and the cross-reactivity among the strains is in agreement with the evolutionary origin of the different T. cruzi DTUs. Four peptides were tested against a panel of chagasic patients using ELISA. A conserved peptide showed 95.8% sensitivity, 88.5% specificity, and 92.7% accuracy for the identification of T. cruzi in patients infected with different strains of the parasite. Therefore, this peptide, in association with other T. cruzi antigens, may improve Chagas disease serodiagnosis. Together, three polymorphic epitopes were able to discriminate between the three parasite strains used in this study and are thus potential targets for Chagas disease serotyping.
Author Summary Serological tests are preferentially used for the diagnosis of Chagas disease during the chronic phase because of the low parasitemia and high anti-T. cruzi antibody titers. However, contradictory or inconclusive results, mainly related to the characteristics of the antigens used, are often observed. Additionally, the factors influencing variation in the clinical forms of Chagas disease have not been elucidated, although it is likely that host and parasite genetics are involved. Several studies attempting to correlate the parasite strain with the clinical forms have used hemoculture and/or PCR-based genotyping. However, both techniques have limitations. Hemoculture requires the isolation of parasites from patient blood and the growth of these parasites in animals or in vitro culture, thereby possibly selecting certain subpopulations. Moreover, the level of parasitemia in the chronic phase is very low, hindering the detection of parasites. Additionally, direct genotyping of parasites from infected tissues is an invasive procedure that requires medical care and hinders studies with a large number of samples. The goal of this work was to identify conserved and polymorphic linear B-cell epitopes of T. cruzi on a genome-wide scale for use in the serodiagnosis and serotyping of Chagas disease using ELISA. Development of a serotyping method based on the detection of strain-specific antibodies may help to understand the relationship between the infecting strain and disease evolution.
Databáze: OpenAIRE
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