Major antigen and paramyosin proteins as candidate biomarkers for serodiagnosis of canine infection by zoonotic Onchocerca lupi

Author(s)

Latrofa, Maria Stefania ^[1] ; Palmisano, Giuseppe ^[2] ; Annoscia, Giada ^[1] ; Pierri, Ciro Leonardo ^[3] ; Chandrashekar, Ramaswamy ^[4] ; Otranto, Domenico ^{[1, 5]}

Affiliation

^[1] Univ Bari, Dept Vet Med, Bari - Italy

^[2] Univ Sao Paulo, Dept Parasitol, GlycoProte Lab, ICB, Sao Paulo - Brazil

^[3] Univ Bari, Dept Biosci Biotechnol & Biopharmaceut, Lab Biochem & Mol Biol, Bari - Italy

^[4] IDEXX Labs Inc, 1 IDEXX Dr, Westbrook, ME - USA

^[5] Bu Ali Sina Univ, Fac Vet Sci, Dept Pathobiol, Felestin Sq, Hamadan, Hamadan - Iran

• Document type: Journal article
• Source: PLoS Neglected Tropical Diseases; v. 15, n. 2 FEB 2021.
• Web of Science Citations: 1

Abstract

Onchocerca lupi (Spirurida: Onchocercidae) is a filarial worm parasitizing domestic carnivores and humans. Adult nematodes usually localize beneath in the sclera or in the ocular retrobulbar of infected animals, whilst microfilariae are found in the skin. Therefore, diagnosis of O. lupi is achieved by microscopic and/or molecular detection of microfilariae from skin biopsy and/or surgical removal of adults from ocular tissues of infected hosts. An urgent non-invasive diagnostic tool for the diagnosis of O. lupi in dog is mandatory. In this study, an immunoproteomic analyses was performed using a combination of immunoblotting and mass spectrometry techniques. Onchocerca lupi major antigen (Ol-MJA) and paramyosin (Ol-PARA) proteins were identified as potential biomarkers for serodiagnosis. Linear epitopes were herein scanned for both proteins using high-density peptide microarray. Sera collected from dog infected with O. lupi and healthy animal controls led to the identification of 11 immunodominant antigenic peptides (n = 7 for Ol-MJA; n = 4 for Ol-PARA). These peptides were validated using sera of dogs uniquely infected with the most important filarioids infesting dogs either zoonotic (Dirofilaria repens, Dirofilaria immitis) or not (Acanthocheilonema reconditum and Cercopithifilaria bainae). Overall, six antigenic peptides, three for Ol-MJA and for Ol-PARA, respectively, were selected as potential antigens for the serological detection of canine O. lupi infection. The molecular and proteomic dataset herein reported should provide a useful resource for studies on O. lupi toward supporting the development of new interventions (drugs, vaccines and diagnostics) against canine onchocercosis. Author summary The diagnosis of Onchocerca lupi (Spirurida: Onchocercidae), a zoonotic nematode of domestic animals, is currently based on microscopic examination of skin snip sediments and on the identification of adults embedded in ocular nodules or by molecular assays. An urgent non-invasive diagnostic tool for the diagnosis of O. lupi in dogs is mandatory. In this context, combined immunoblotting and mass spectrometry-based analyses have been performed to identify two proteins, major antigen and paramyosin, of O. lupi. Peptides herein identified represent suitable candidate biomarker for the development of a specific diagnostic test for canine onchocercosis. An accurate, minimally invasive diagnostic method could prove useful for the control of the canine diseases, for establishing large sero-surveys, for mapping the distribution of the infection in endemic areas as well as in areas where information on the disease is not available and for the reduction of risks for human infection. (AU)

• FAPESP's process: 18/18257-1 - Multi-user equipment approved in grant 14/06863-3: HPLC system configured for analysis of carbohydrates, amino acidis, peptides and glycoproteins
• Grantee: Giuseppe Palmisano
• Support type: Multi-user Equipment Program
• FAPESP's process: 17/04032-5 - Dissecting the pathogenesis of Chagas Disease by deep glycomics and glycoproteomics approaches
• Grantee: Simon Ngao Mule
• Support type: Scholarships in Brazil - Doctorate
• FAPESP's process: 18/15549-1 - Post-translational modifications in Chagas Disease biological processes and diagnostics: novel methodological approaches and biological applications
• Grantee: Giuseppe Palmisano
• Support type: Research Grants - Young Investigators Grants - Phase 2
• FAPESP's process: 14/06863-3 - Post-translational modifications in cancer and parasite infection diagnosis: methodological approaches and biological implications
• Grantee: Giuseppe Palmisano
• Support type: Research Grants - Young Investigators Grants