Characterization of a clone from an adult worm cDNA library selected with anti-Schistosoma mansoni human antibodies dissociated from immune complexes: a preliminary report Caracterização de um clone selecionado a partir de biblioteca de cDNA de verme adulto com anticorpos anti-Schistosoma mansoni dissociados de imunocomplexos

• Published in: Revista do Instituto de Medicina Tropical de São Paulo
• Main Authors: Luiz Carlos Pedrosa Valli, Herminia Yohko Kanamura, Paulo Cesar Cotrim, Guilherme Correa Oliveira, Edward José de Oliveira
• Format: Article in Journal/Newspaper
• Language: English
• Published: Universidade de São Paulo (USP) 2007
• Subjects: Schistosoma mansoni; cDNA library; Immunoscreening; DNA sequencing; Synthetic peptides; Arctic medicine. Tropical medicine; RC955-962; Infectious and parasitic diseases; RC109-216; Arctic; Larga
• Online Access: https://doi.org/10.1590/S0036-46652007000300009; https://doaj.org/article/ec2871bf05a34e84a6dd69e8807cbeb3

Considering the scarcity of defined antigens, actually useful and reliable for use in the field studies, we propose an alternative method for selection of cDNA clones with potential use in the diagnosis of schistosomiasis. Human antibodies specific to a protein fraction of 31/32 kDa (Sm31/32), dissociated from immune complexes, are used for screening of clones from an adult worm cDNA library. Partial sequencing of five clones, selected through this strategy, showed to be related to Schistosoma mansoni: two were identified as homologous to heat shock protein 70, one to glutathione S-transferase, one to homeodomain protein, and one to a previously described EST (expressed sequence tag) of S. mansoni. This last clone was the most consistently reactive during the screening process with the anti-Sm31/32 antibodies dissociated from the immune complexes. The complete sequence of this clone was obtained and the translation data yielded only one ORF (open reading frame) that code for a protein with 57 amino acids. Based on this amino acid sequence two peptides were chemically synthesized and evaluated separately against a pool of serum samples from schistosomiasis patients and non-schistosomiasis individuals. Both peptides showed strong reactivity only against the positive pool, suggesting that these peptides may be useful as antigens for the diagnosis of schistosomiasis mansoni. Considerando a escassez de antígenos quimicamente definidos, realmente úteis e confiáveis para aplicação na soroepidemiologia da esquistossomose em larga escala, foi proposto, neste trabalho, um método alternativo para a seleção de clones de cDNA que expressam proteínas com putativo potencial diagnóstico na esquistossomose. Empregando anticorpos específicos contra uma fração proteica de 31/32 kDa (Sm31/32), purificados através da dissociação de imunocomplexos, foram selecionados cinco clones de cDNA a partir de genoteca de verme adulto de Schistosoma mansoni. O seqüenciamento parcial destes clones demonstrou que todos eram relacionados ao S. ...