Wuchang Hospital affiliated to Wuhan University of Science and Technology, Wuhan, 430063, China.
Department of Clinical Laboratory, Wuhan Fourth Hospital; Pu'ai hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430033, China.
Parasitol Res. 2019 Feb;118(2):559-566. doi: 10.1007/s00436-018-6186-y. Epub 2019 Jan 4.
Schistosomiasis is one of the most devastating parasitic diseases, making it imperative to develop efficient vaccines to control the causative flatworms called schistosomes. Regulatory T cells (Tregs) and the Th1 immune response have been implicated in the effectiveness of vaccines to control schistosomiasis, but the mechanisms underlying their effects are unclear. In this study, we evaluated the role of Tregs on the efficacy of the 14 kDa FABP (fatty acid-binding protein) vaccine against Schistosoma japonicum. BALB/c female mice were randomly divided into five groups: an uninfected group, infected control group, anti-CD25 monoclonal antibody (anti-CD25 mAb) group, FABP group, and combined anti-CD25 mAb and FABP group. Compared with FABP alone, a combined treatment with FABP and anti-CD25 mAb increased the rate of S. japonicum inhibition in mice from 30.3 to 56.08% and decreased the number of eggs per gram of liver. Compared with that of the infected control group, the percentage of Tregs in the spleen decreased significantly after single or combined treatment with FABP and anti-CD25 mAb, while it increased gradually in the anti-CD25 mAb group. Further, the secretion of Th1 cytokines, IFN-γ, and IL-2 increased in splenocytes in the anti-CD25 mAb group. Our results indicate that anti-CD25 mAb partially blocks Tregs and concomitantly enhances the Th1 type immune response, thereby enhancing the protective effect of the FABP vaccine.
血吸虫病是最具破坏性的寄生虫病之一，因此必须开发有效的疫苗来控制引起这种疾病的扁形动物血吸虫。调节性 T 细胞（Tregs）和 Th1 免疫反应已被证明与控制血吸虫病的疫苗的有效性有关，但它们的作用机制尚不清楚。在这项研究中，我们评估了 Tregs 在 14 kDa FABP（脂肪酸结合蛋白）疫苗对日本血吸虫的疗效中的作用。BALB/c 雌性小鼠被随机分为五组：未感染组、感染对照组、抗 CD25 单克隆抗体（抗 CD25 mAb）组、FABP 组和抗 CD25 mAb 和 FABP 联合组。与单独使用 FABP 相比，FABP 与抗 CD25 mAb 联合使用将小鼠对日本血吸虫的抑制率从 30.3%提高到 56.08%，并降低了每克肝中虫卵的数量。与感染对照组相比，单独或联合使用 FABP 和抗 CD25 mAb 后，脾脏中 Tregs 的百分比显著降低，而在抗 CD25 mAb 组中则逐渐增加。此外，抗 CD25 mAb 组脾细胞中 Th1 细胞因子 IFN-γ和 IL-2 的分泌增加。我们的结果表明，抗 CD25 mAb 部分阻断 Tregs，同时增强 Th1 型免疫反应，从而增强 FABP 疫苗的保护作用。
