Metaperiodate deglycosylation of Strongyloides venezuelensis larvae: Immunochemical characterization and antigen production for human strongyloidiasis diagnosis

Abstract

Strongyloidiasis is an important helminthiasis affecting million people worldwide. The aim of this study was to use sodium metaperiodate (MP) treatment to immunochemically characterize Strongyloides venezuelensis filariform larvae and use MP-treated heterologous antigen to detect IgG and subclasses in serum. Samples from individuals with definitive diagnosis of strongyloidiasis (n = 50), other parasitic diseases (n = 60) and negative endemic (n = 50) were tested. TG-ROC and two-way ANOVA were applied. MP-treatment resulted on differential localization of carbohydrates at larval structure and no carbohydrate content in saline extract (SE). Electrophoretic profiles were similar before and after treatment. ELISA sensitivity and specificity were: 90%; 88.2% for SE and 92.0%; 94.6% for MP, respectively. When using MP treated antigen we observed reduction in IgG1 and IgG3 detection in strongyloidiasis group and decrease of cross reactions in control groups. Our data demonstrate the role of carbohydrate residues in cross reactions and on the recognition of anti-Strongyloides IgG and its subclasses.

Glycosylation of Trypanosoma cruzi TcI antigen reveals recognition by chagasic sera

“…Contribution of glycosylation to antigenicity was assessed using an assay based on the protocol of Woodward et al 31 , and employed subsequently 32 , 33 , which described the oxidative cleavage of carbohydrate vicinal –OH groups and subsequent reduction of generated aldehyde groups to prevent non-specific antibody binding. After the blocking and washing steps of the ELISA, described above, all wells were rinsed in periodate buffer (50 mM sodium acetate buffer, pH 4.5), and the wells that had been coated with gTSSA-I received 5 mM freshly-made sodium (meta)periodate (71859: Sigma Aldrich) in periodate buffer; the remaining wells received periodate buffer only.…”