Fonseca Gabriela Rodrigues E, Grossi de Oliveira Ana Laura, Brito Ramayana Morais de Medeiros, Corral Marcelo Andreetta, Ward Richard John, de Lima Pâmela Aparecida, Rihs José Bryan da Rocha, Cardozo Marcelo Eduardo, Sato Paula Keiko, Fujiwara Ricardo Toshio, Santos Sergio Vieira Dos, Gryschek Ronaldo Cesar Borges, Lescano Susana Angelica Zevallos
Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, Laboratório de Investigação Médica em Imunopatologia da Esquistossomose e Outras Parasitoses, São Paulo, SP, Brasil.
Faculdade de Ciências Médicas da Santa Casa de São Paulo, Departamento de Ciências Patológicas, Laboratório de Parasitologia, São Paulo, SP, Brasil.
Mem Inst Oswaldo Cruz. 2025 Mar 14;120:e240111. doi: 10.1590/0074-02760240111. eCollection 2025.
Toxocariasis is a neglected global zoonosis. The immunological diagnosis has setbacks that hinder further knowledge about its pathology, epidemiology, and public control measures, and lack of financial support and attention prevents innovative research. Although studies on synthetic peptides are common for several infectious pathologies, none evaluated chemically synthetic peptides for toxocariasis diagnosis.
This study aimed to identify potential synthetic peptides from C-type lectin 1 (Tc-CTL-1) from Toxocara canis.
In silico analyses were made by five B-cell peptide prediction programs, 3-D modelling, BLASTp homology analysis, and signal-peptide identification. SPOT-synthesis was used for epitope mapping and assessed by dot-blot. Sera from non-infected and T. canis, Strongyloides venezuelensis, Ascaris suum, or Schistosoma mansoni-infected animals were used to assess the peptide's immunogenicity and cross-reactivity. The selection of potential immunogenic epitopes included the most immunogenic peptides with the least cross-reactivity.
Fifty-five peptides were selected by in silico analysis. Dot-blot showed intense recognition by anti-Toxocara IgG and cross-reactivity with A. suum-infected mice. Selection criteria identified four epitopes with diagnostic potential.
The findings demonstrate that synthetic peptides should be explored for innovation of toxocariasis diagnosis, and suggest the adaptation of dot-blot using the SPOT-synthesis technique as a potential immunodiagnostic platform.
弓首蛔虫病是一种被忽视的全球人畜共患病。免疫诊断存在阻碍，妨碍了对其病理学、流行病学和公共控制措施的进一步了解，而缺乏资金支持和关注则阻碍了创新性研究。尽管关于合成肽的研究在几种感染性疾病中很常见，但尚无研究评估化学合成肽用于弓首蛔虫病的诊断。
本研究旨在从犬弓首蛔虫的C型凝集素1（Tc-CTL-1）中鉴定潜在的合成肽。
通过五个B细胞肽预测程序进行计算机分析、三维建模、BLASTp同源性分析和信号肽鉴定。采用SPOT合成法进行表位定位，并通过斑点印迹法进行评估。使用未感染动物以及感染犬弓首蛔虫、委内瑞拉类圆线虫、猪蛔虫或曼氏血吸虫的动物的血清来评估肽的免疫原性和交叉反应性。潜在免疫原性表位的选择包括免疫原性最强且交叉反应性最低的肽。
通过计算机分析选择了55个肽。斑点印迹显示抗弓首蛔虫IgG有强烈识别，且与感染猪蛔虫的小鼠有交叉反应。选择标准确定了四个具有诊断潜力的表位。
研究结果表明，应探索合成肽用于弓首蛔虫病诊断的创新，并建议采用基于SPOT合成技术的斑点印迹法作为潜在的免疫诊断平台。
