Evaluation from a B-cell epitope-based chimeric protein for the serodiagnosis of tegumentary and visceral leishmaniasis. (June 2022)

• Record Type: Journal Article
• Authors: Vale, Danniele L.; Machado, Amanda S.; Ramos, Fernanda F.; Lage, Daniela P.; Freitas, Camila S.; de Oliveira, Daysiane; Galvani, Nathalia C.; Luiz, Gabriel P.; Fagundes, Mirian I.; Fernandes, Bruna B.; Oliveira-da-Silva, João A.; Ludolf, Fernanda; Tavares, Grasiele S.V.; Guimarães, Nathalia S.; Chaves, Ana T.; Chávez-Fumagalli, Miguel A.; Tupinambás, Unaí; Rocha, Manoel O.C.; Gonçalves, Denise U.; Martins, Vívian T.; Machado-de-Ávila, Ricardo A.; Coelho, Eduardo A.F.
• Is Part Of: Microbial pathogenesis. Volume 167(2022)
• Publication Date: 2022-06
• Subjects: Leishmaniasis -- Diagnosis -- Chimeric protein -- B-Cell epitopes -- Sensitivity -- Specificity; Pathogenic microorganisms -- Periodicals; Pathology, Molecular -- Periodicals; Communicable Diseases -- microbiology -- Periodicals; Communicable Diseases -- parasitology -- Periodicals; Micro-organismes pathogènes -- Périodiques; Pathologie moléculaire -- Périodiques; Electronic journals; 616.9041
• DOI: 10.1016/j.micpath.2022.105562
• Languages: English
• ISSNs: 0882-4010

Abstract

Abstract: The diagnosis of leishmaniasis presents problems due to the variable sensitivity and/or specificity of tests. In addition, high levels of anti-parasite antibodies can remain after treatment, making it difficult to conduct a prognostic follow-up of patients. In this context, it is necessary to identify new candidates to be examined for the sensitive and specific diagnosis of the disease. In the present study, four Leishmania proteins, previously shown as antigenic for tegumentary leishmaniasis (TL), were evaluated, and their linear specific B-cell epitopes were predicted and used to generate a new gene codifying chimeric protein called ChimB, which was cloned, and the recombinant version was expressed, purified, and evaluated in ELISA (Enzyme-Linked Immunosorbent Assay) to diagnose TL and visceral leishmaniasis (VL). A total of 220 human serum samples were used, and, when ChimB was used, results showed sensitivity, specificity, and positive and negative predictive values of 100% for the diagnosis of both diseases; however, when using peptides, the sensitivity values reached from 28.0% to 57.3% and specificity varied from 16.3% to 83.7%. A soluble Leishmania extract (SLA) showed sensitivity and specificity values of 30.7% and 45.9%, respectively. The area under the curve (AUC) value for ChimB was 1.0, while for synthetic peptides, this value reached between 0.502 and 0.635, whereas for SLA, the value was of 0.589. Serological assays using sera samples collected before and after treatment showed significant reductions in the anti-ChimB antibody levels after therapy, suggesting a prognostic role of this recombinant antigen. In conclusion, preliminary data suggest the use from ChimB as a potential candidate for the diagnosis and prognosis of leishmaniasis. Graphical abstract: Image 1 Highlights: Seven conserved B cell epitopes were predicted in Leishmania protein sequences. A chimeric antigen was designed using such epitopes and tested in ELISA. The protein showed high sensitivity and specificity for the diagnosis of leishmaniasis. Results were better than those obtained using synthetic peptides and SLA. A prognostic role was suggested for protein in treated leishmaniasis patients.