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Azcárate IG, Marín-García P, Abad P, Pérez-Benavente S, Paz-Artal E, Reche PA, Fobil JN, Rubio JM, Diez A, Puyet A, Bautista JM. Plasmodium falciparum immunodominant IgG epitopes in subclinical malaria. Sci Rep 2020; 10:9398. [PMID: 32523082 PMCID: PMC7287129 DOI: 10.1038/s41598-020-66384-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Accepted: 05/18/2020] [Indexed: 01/30/2023] Open
Abstract
Incomplete non-sterile immunity to malaria is attained in endemic regions after recurrent infections by a large percentage of the adult population, who carry the malaria parasite asymptomatically. Although blood-stage Plasmodium falciparum rapidly elicits IgG responses, the target antigens of partially protective and non-protective IgG antibodies as well as the basis for the acquisition of these antibodies remain largely unknown. We performed IgG-immunomics to screen for P. falciparum antigens and to identify epitopes associated with exposure and clinical disease. Sera from malaria cases identified five prevalent antigens recognized by all analyzed patients' IgGs. Epitope mapping of them, using adult and children sera samples from an endemic malaria region in Ghana segregated into patients with positive or negative subclinical detection of P. falciparum, revealed binding specificity for two 20-mer immunodominant antigenic regions within the START-related lipid transfer protein and the protein disulfide isomerase PDI8. These 20-mer epitopes challenged with sera samples from children under 5 years old displayed specific IgG binding in those with detectable parasitemia, even at subclinical level. These results suggest that humoral response against START and PDI8 antigens may be triggered at submicroscopic parasitemia levels in children and may eventually be used to differentially diagnose subclinical malaria in children.
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Affiliation(s)
- Isabel G Azcárate
- Department of Biochemistry and Molecular Biology and Research Institute Hospital 12 de Octubre (Imas12), Universidad Complutense de Madrid, 28040, Madrid, Spain.,Isabel G. Azcárate, Faculty of Health Sciences, Rey Juan Carlos University, Alcorcón, 28922, Madrid, Spain
| | | | - Paloma Abad
- Department of Biochemistry and Molecular Biology and Research Institute Hospital 12 de Octubre (Imas12), Universidad Complutense de Madrid, 28040, Madrid, Spain
| | - Susana Pérez-Benavente
- Department of Biochemistry and Molecular Biology and Research Institute Hospital 12 de Octubre (Imas12), Universidad Complutense de Madrid, 28040, Madrid, Spain
| | - Estela Paz-Artal
- Immunodeficiency and Transplant Immunology Unit, Research Institute Hospital 12 de Octubre (Imas12), 28041, Madrid, Spain
| | - Pedro A Reche
- Faculty of Medicine, Department of Immunology, Ophthalmology and ORL, Universidad Complutense de Madrid, 28040, Madrid, Spain
| | - Julius N Fobil
- Department of Biological, Environmental & Occupational Health Sciences, School of Public Health, College of Health Sciences, University of Ghana, P.O. Box LG 13, Legon, Ghana
| | - José M Rubio
- Malaria & Emerging Parasitic Diseases Laboratory, National Centre of Microbiology. Instituto de Salud Carlos III, 28220, Majadahonda, Spain
| | - Amalia Diez
- Department of Biochemistry and Molecular Biology and Research Institute Hospital 12 de Octubre (Imas12), Universidad Complutense de Madrid, 28040, Madrid, Spain
| | - Antonio Puyet
- Department of Biochemistry and Molecular Biology and Research Institute Hospital 12 de Octubre (Imas12), Universidad Complutense de Madrid, 28040, Madrid, Spain.
| | - José M Bautista
- Department of Biochemistry and Molecular Biology and Research Institute Hospital 12 de Octubre (Imas12), Universidad Complutense de Madrid, 28040, Madrid, Spain.
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