The aim of this study was to evaluate the in vitro immune modulation of two de novo peptides with hypothetical identity to the serine protease family (S28) from Haemonchus spp. Expression of mRNAs encoding these peptides was confirmed by RTqPCR in L₃ and adult stage parasites. Antibodies from serum samples collected from an H. contortus-infected lamb at 60 days post infection detected both peptides, as assessed by indirect ELISA. Lamb peripheral blood mononuclear cells (PBMCs) were exposed to each peptide, as well as to the peptide mixture, and cell proliferation assays were performed at 24, 48 and 72 h. The relative expression of the IL4, IL5, IL6, IL13, CXCL8 and FCεR1A genes was quantified by RTqPCR from lamb PBMCs exposed to the peptide mixture at 24 and 48 h. With respect to immune gene expression, 15- and 3-fold upregulation at 24 h was observed with IL5 and CXCL8, respectively, and 2-fold upregulation of CXCL8 at 48 h. In contrast, downregulation of IL5 was stimulated at 48 h. These data suggest that these peptides (pep-hsp and pep-pcx), which show high identity with intestinal and excretion/secretion serine proteases, can trigger immunogenic activity, and suggest that they may be useful as potential parasite vaccines.

本研究的目的是评估与血矛线虫属的丝氨酸蛋白酶家族 (S28) 具有假设同一性的两种从头肽的体外免疫调节。编码这些肽的 mRNA 的表达通过 RT qPCR 在 L ₃和成虫期寄生虫中得到证实。感染后 60 天，从感染扭曲螺旋杆菌的羔羊身上收集的血清样本中的抗体检测到这两种肽，如通过间接 ELISA 评估的那样。将羔羊外周血单核细胞 (PBMC) 暴露于每种肽以及肽混合物，并在 24、48 和 72 小时进行细胞增殖测定。IL4、IL5、IL6的相对表达、IL13、CXCL8和FCεR1A基因通过 RT qPCR 从在 24 和 48 小时暴露于肽混合物的羔羊 PBMC 中定量。关于免疫基因表达，在 24 小时观察到IL5和CXCL8分别上调 15 倍和 3 倍，在 48 小时观察到CXCL8上调 2 倍。相反，IL5的下调在 48 小时时受到刺激。这些数据表明这些肽（pep-hsp 和 pep-pcx）与肠道和排泄/分泌丝氨酸蛋白酶具有高度同一性，可触发免疫原性活性，并表明它们可用作潜在的寄生虫疫苗。