MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, Jiangsu, P. R. China.
State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, 730046, Gansu, P. R. China.
Vet Res. 2021 Jan 6;52(1):3. doi: 10.1186/s13567-020-00871-0.
Unlike the successful immunization of native H. contortus antigens that contributed to the realization of the first commercial vaccine Barbervax, not many studies revealed the encouraging protective efficacies of recombinant H. contortus antigens in laboratory trials or under field conditions. In our preliminary study, H. contortus α/β-hydrolase domain protein (HcABHD) was demonstrated to be an immunomodulatory excretory-secretory (ES) protein that interacts with goat T cells. We herein evaluated the protective capacities of two HcABHD preparations, recombinant HcABHD (rHcABHD) antigen and anti-rHcABHD IgG, against H. contortus challenge via active and passive immunization trials, respectively. Parasitological parameter, antibody responses, hematological pathology and cytokine profiling in unchallenged and challenged goats were monitored and determined throughout both trials. Subcutaneous administration of rHcABHD with Freund adjuvants elicited protective immune responses in challenged goats, diminishing cumulative fecal egg counts (FEC) and total worm burden by 54.0% and 74.2%, respectively, whereas passive immunization with anti-rHcABHD IgG conferred substantial protection to challenged goats by generating a 51.5% reduction of cumulative FEC and a 73.8% reduction of total worm burden. Additionally, comparable changes of mucosal IgA levels, circulating IgG levels, hemoglobin levels, and serum interleukin (IL)-4 and IL-17A levels were observed in rHcABHD protein/anti-rHcABHD IgG immunized goats in both trials. Taken together, the recombinant version of HcABHD might have further application under field conditions in protecting goats against H. contortus infection, and the integrated immunological pipeline of ES antigen identification, screening and characterization may provide new clues for further development of recombinant subunit vaccines to control H. contortus.
与成功免疫天然旋毛虫抗原从而实现首个商业化疫苗 Barbervax 不同，在实验室试验或田间条件下，很少有研究揭示重组旋毛虫抗原令人鼓舞的保护效果。在我们的初步研究中，旋毛虫 α/β-水解酶结构域蛋白（HcABHD）被证明是一种具有免疫调节作用的排泄分泌（ES）蛋白，可与山羊 T 细胞相互作用。我们在此分别通过主动和被动免疫试验评估了两种 HcABHD 制剂，即重组 HcABHD（rHcABHD）抗原和抗 rHcABHD IgG，对旋毛虫挑战的保护能力。在这两项试验中，均监测和确定了未挑战和挑战的山羊的寄生虫学参数、抗体反应、血液病理学和细胞因子谱。用弗氏佐剂皮下注射 rHcABHD 在挑战的山羊中引发了保护性免疫反应，使累积粪便卵数（FEC）和总蠕虫负荷分别减少了 54.0%和 74.2%，而用抗 rHcABHD IgG 进行被动免疫则通过产生 51.5%的累积 FEC 减少和 73.8%的总蠕虫负荷减少，为挑战的山羊提供了实质性的保护。此外，在这两项试验中，rHcABHD 蛋白/抗 rHcABHD IgG 免疫的山羊的黏膜 IgA 水平、循环 IgG 水平、血红蛋白水平以及血清白细胞介素（IL）-4 和 IL-17A 水平均发生了类似的变化。综上所述，rHcABHD 的重组版本可能在田间条件下进一步应用于保护山羊免受旋毛虫感染，ES 抗原鉴定、筛选和表征的综合免疫途径可能为进一步开发重组亚单位疫苗控制旋毛虫提供新线索。
