Table_6_Antigenic epitope targets of rhesus macaques self-curing from Schistosoma mansoni infection.xlsx

The self-cure of rhesus macaques from a schistosome infection and their subsequent strong immunity to a cercarial challenge should provide novel insights into the way these parasites can be eliminated by immunological attack. High-density arrays comprising overlapping 15-mer peptides from target proteins printed on glass slides can be used to screen sera from host species to determine antibody reactivity at the single epitope level. Careful selection of proteins, based on compositional studies, is crucial to encompass only those exposed on or secreted from the intra-mammalian stages and is intended to focus the analysis solely on targets mediating protection. We report the results of this approach using two pools of sera from hi- and lo-responder macaques undergoing self-cure, to screen arrays comprising tegument, esophageal gland, and gastrodermis proteins. We show that, overall, the target epitopes are the same in both groups, but the intensity of response is twice as strong in the high responders. In addition, apart from Sm25, tegument proteins elicit much weaker responses than those originating in the alimentary tract, as was apparent in IFNγR KO mice. We also highlight the most reactive epitopes in key proteins. Armed with this knowledge, we intend to use multi-epitope constructs in vaccination experiments, which seek to emulate the self-cure process in experimental animals and potentially in humans.

恒河猴从血吸虫（schistosome）感染中自愈，以及后续对尾蚴攻毒（cercarial challenge）的强免疫力，可为通过免疫攻击清除这类寄生虫的机制提供全新见解。将靶标蛋白的重叠15肽段（15-mer peptides）制备为高密度点阵并打印于玻片（glass slides）上的微阵列，可用于筛选宿主物种的血清，以在单表位水平（single epitope level）检测抗体反应性。基于组成成分分析精心筛选蛋白至关重要，仅需涵盖血吸虫在哺乳动物体内发育阶段（intra-mammalian stages）中暴露于虫体表面或由虫体分泌的蛋白，旨在将分析范围限定于介导保护性免疫的靶标。我们报道了使用两批来自经历自愈过程的高反应与低反应恒河猴的血清混合样本，筛选包含皮层（tegument）、食管腺（esophageal gland）和肠上皮（gastrodermis）蛋白的微阵列所得到的结果。总体而言，两组恒河猴识别的靶表位完全一致，但高反应组的抗体响应强度是低反应组的两倍。此外，除Sm25外，皮层蛋白引发的抗体响应远弱于源自消化道的蛋白，这一现象在干扰素γ受体敲除小鼠（IFNγR KO mice）中也有体现。我们还明确了关键蛋白中反应性最强的表位。依托本研究所得的认知，我们计划在疫苗试验中使用多表位构建体（multi-epitope constructs），旨在在实验动物乃至人类中模拟血吸虫感染的自愈过程。