Antigen discovery by bioinformatics analysis and peptide microarray for the diagnosis of cystic echinococcosis

Abstract

Background Cystic echinococcosis (CE), caused by Echinococcus granulosus sensu lato, is a neglected zoonosis. Its diagnosis relies on imaging, supported by serology, while only imaging is useful for staging and follow-up. Since diagnostic tools and expertise are not widely available, new accurate and easily implementable assays for the diagnosis and follow-up of CE are highly needed. Methodology/Principal Findings We aimed to identify new E. granulosus antigens through a bioinformatics selection applied to the parasite genome, followed by peptide microarray screening and validation in ELISA, using independent panels of sera from patients with hepatic CE and clinically relevant controls. From 950 proteins selected in silico, 2,379 peptides were evaluated by microarray for IgG reactivity and eight candidates selected for validation. Reactivity to one peptide was significantly higher in the CE group (p = 0.044), but had suboptimal diagnostic accuracy. Conclusions/Significance Here we performed bioinformatics analysis and peptide microarray for antigen discovery, useful for the diagnosis of CE. Eight candidates were selected and validated. Reactivity to one peptide associated to CE but had suboptimal diagnostic accuracy. Importantly, the database developed in this study may be used to identify other antigenic candidates for CE diagnosis and follow-up.

Limited value of current and new in silico predicted oocyst-specific proteins of Toxoplasma gondii for source-attributing serology

“…In conclusion, we probably would have made the same (possibly false) decisions in case we had included Discotope 3, Bepipred 3 or EpiDope for our prioritization. Our results and those from other studies (Galanis et al, 2021;Batisti Biffignandi et al, 2023;Cia et al, 2023) indicate that despite recent improvements in the algorithms, making antigenicity predictions the basis for a priori selection of candidates for serological assays is of limited use. Their utility lies more in the verification of epitopes of known antigenic proteins.…”

Evaluation of the Local and Peripheral Immune Responses in Patients with Cystic Echinococcosis

“…Sera/plasma from surgically treated patients were also tested for immune/growth factors [IL-1β, IL-1RA, IL-2, IL-4, IL-5, IL-6, IL-7, IL-8, IL-9, IL-10, IL-12p70, IL-13, IL-15, IL-17A, eotaxin, basic fibroblast growth factor (FGF), granulocyte colony-stimulating factor (G-CSF), granulocyte-macrophage colony-stimulating factor (GM-CSF), IFN-γ, IFN-γ induced protein 10 (IP-10), monocyte chemoattractant protein 1 (MCP-1), macrophage inflammatory protein (MIP)-1α, MIP-1β, platelet-derived growth factor (PDGF), RANTES (regulated on activation, normal T cell expressed and secreted), tumor necrosis factor-α (TNF-α), and vascular endothelial growth factor (VEGF)] using Bio-Plex Pro Human Cytokine 27-plex Assay panel and the Bioplex200 system (all from Bio-Rad, Hercules, CA, USA) following the manufacturer’s instructions. The data were analyzed as previously described [ 31 , 32 , 33 ]. All the stimulated samples were subtracted from the unstimulated control.…”