Parasitology Lab., Zoology Department, Faculty of Science, Assiut University, Assiut71516, Egypt.
Department of Pathology and Clinical Pathology, Faculty of Veterinary Medicine, Assiut University, Assiut, Egypt.
Microsc Microanal. 2020 Aug;26(4):708-716. doi: 10.1017/S1431927620001695.
Schistosomiasis is a multifactorial disease that includes environmental, behavioral, parasitic, vector, and host factors. This study aimed to assess the protective effect of single and polyvalent antigens from cercarial antigen preparations (CAPs), soluble worm antigen preparations (SWAPs), and soluble egg antigens (SEAs) which were used as candidate vaccines in an experimental model of Schistosoma mansoni-infected mice. The efficiency of the antigens was tested by determining their effects on fecal egg count, egg viability analysis, and tissue egg counts. Histological and morphometric analyses of granulomas in liver and intestine tissues were performed. In the present study, all immunized groups showed a significant reduction in the average fecal egg count and tissue egg load compared with infected mice. The most substantial reduction in fecal egg count was observed in the combined vaccinated group (23.23 ± 3.2). The group vaccinated with CAP before infection showed the highest reduction in tissue egg load (liver and intestine: 85.22 and 91.70%, respectively). Immunized animals showed a highly significant reduction in the numbers of hepatic granulomas compared with the infected non-immunized group. In conclusion, combining these different antigens (CAP, SWAP, and SEA) augments the protective immunity compared with other immunized groups.
血吸虫病是一种多因素疾病，包括环境、行为、寄生虫、媒介和宿主因素。本研究旨在评估单抗原和多价抗原（从尾蚴抗原制剂（CAP）、可溶性虫体抗原制剂（SWAP）和可溶性卵抗原（SEA））在曼氏血吸虫感染小鼠实验模型中的保护作用，这些抗原被用作候选疫苗。通过测定粪便卵计数、卵活力分析和组织卵计数来测试抗原的效率。对肝和肠组织中的肉芽肿进行组织学和形态计量学分析。在本研究中，与感染小鼠相比，所有免疫组的平均粪便卵计数和组织卵负荷均显著降低。联合免疫组的粪便卵计数下降幅度最大（23.23±3.2）。在感染前用 CAP 免疫的组显示出组织卵负荷（肝和肠：分别为 85.22%和 91.70%）的最高降低。与未感染的非免疫组相比，免疫动物的肝肉芽肿数量显著减少。总之，与其他免疫组相比，联合使用这些不同的抗原（CAP、SWAP 和 SEA）增强了保护免疫。
