In Silico Design and Validation of OvMANE1, a Chimeric Antigen for Human Onchocerciasis Diagnosis
Cabirou Mounchili Shintouo,
Robert Adamu Shey,
Derrick Neba Nebangwa,
Kevin K. Esoh,
Nkemngo Francis Nongley,
Joel Ebai Nguve,
Philippe Giron,
Léon Mutesa,
Luc Vanhamme,
Jacob Souopgui,
Stephen Mbigha Ghogomu,
Rose Njemini
Affiliations
Cabirou Mounchili Shintouo
Department of Gerontology, Faculty of Medicine and Pharmacy, Vrije Universiteit Brussel, Laarbeeklaan 103, B-1090 Brussels, Belgium
Robert Adamu Shey
Department of Biochemistry and Molecular Biology, Faculty of Science, University of Buea, P.O. Box 63 Buea, Cameroon
Derrick Neba Nebangwa
Department of Biochemistry and Molecular Biology, Faculty of Science, University of Buea, P.O. Box 63 Buea, Cameroon
Kevin K. Esoh
Division of Human Genetics, Department of Pathology, University of Cape Town, Health Sciences Campus, Anzio Rd, Observatory 7925, South Africa
Nkemngo Francis Nongley
Department of Microbiology and Parasitology, Faculty of Science, University of Buea, P.O. Box 63 Buea, Cameroon
Joel Ebai Nguve
Department of Biochemistry and Molecular Biology, Faculty of Science, University of Buea, P.O. Box 63 Buea, Cameroon
Philippe Giron
Laboratory of Medical and Molecular Oncology, Oncology Research Center, Faculty of Medicine and Pharmacy, Vrije Universiteit Brussel, Laarbeeklaan 103, B-1090 Brussels, Belgium
Léon Mutesa
Centre for Human Genetics, College of Medicine and Health Sciences, University of Rwanda, KG11 Ave, Kigali 4285, Rwanda
Luc Vanhamme
Department of Molecular Biology, Institute of Biology and Molecular Medicine, IBMM, Université Libre de Bruxelles, Gosselies Campus, 126040 Gosselies, Belgium
Jacob Souopgui
Department of Molecular Biology, Institute of Biology and Molecular Medicine, IBMM, Université Libre de Bruxelles, Gosselies Campus, 126040 Gosselies, Belgium
Stephen Mbigha Ghogomu
Department of Biochemistry and Molecular Biology, Faculty of Science, University of Buea, P.O. Box 63 Buea, Cameroon
Rose Njemini
Department of Gerontology, Faculty of Medicine and Pharmacy, Vrije Universiteit Brussel, Laarbeeklaan 103, B-1090 Brussels, Belgium
The public health goal of onchocerciasis in Africa has advanced from control to elimination. In this light, accurate diagnosis is necessary to determine treatment endpoints and confirm elimination, as well as to conduct surveillance for the identification of any possible recrudescence of the disease. Currently, the monitoring of onchocerciasis elimination relies on the Ov-16 test. However, this test is unable to discriminate between past and active infections. Furthermore, about 15–25% of infected persons are reported to be negative for the Ov-16 test, giving a misleading sense of security to false-negative individuals who might continue to serve as reservoirs for infections. Therefore, we opted to design and validate a more sensitive and specific chimeric antigen (OvMANE1) for onchocerciasis diagnosis, using previously reported immunodominant peptides of O. volvulus, the parasite responsible for the disease. In silico analysis of OvMANE1 predicted it to be more antigenic than its individual peptides. We observed that OvMANE1 reacts specifically and differentially with sera from O. volvulus infected and non-infected individuals, as well as with sera from communities of different levels of endemicity. Moreover, we found that total IgG, unlike IgG4 subclass, positively responded to OvMANE1, strongly suggesting its complementarity to the Ov-16 diagnostic tool, which detects Ov-16 IgG4 antibodies. Overall, OvMANE1 exhibited the potential to be utilized in the development of specific diagnostic tools—based on both antibody capture and antigen capture reactions—which are indispensable to monitor the progress of onchocerciasis elimination programs.
