Ministry of Education (MOE) Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China.
Front Immunol. 2022 May 20;13:872015. doi: 10.3389/fimmu.2022.872015. eCollection 2022.
A consensus is that the Th1 immune response plays a predominant role against avian coccidiosis. Therefore, an antigen with the ability to induce Th1 cytokine responses is an ideal candidate for the development of coccidiosis vaccines. In our previous study, EmARM-β, a Th1 cytokines-stimulating antigen, was screened from the cDNA expression library of (). Herein, we verified its stimulative effects on Th1 cytokine productions and evaluated its protective efficacy against infection. Recombinant EmARM-β protein was expressed, and eukaryotic expression plasmid pVAX1-EmARM-β was also constructed for the immunization of birds. An immunofluorescence assay was performed to detect the native form of EmARM-β protein in the stage of sporozoites. Expressions of specific transcription factors and cytokines in immunized chickens were measured using qPCR and ELISA to verify its stimulating function on Th1 cytokines. Specific IgG antibody levels and T lymphocyte subpopulation in the immunized chickens were detected using ELISA and indirect flow cytometry to determine induced immune responses. The results showed that EmARM-β native protein is massively expressed in the sporozoites stage of . Effective stimulation from the EmARM-β antigen to T-bet and Th1 cytokines (IL-2 and IFN-γ) was observed . After being immunized with rEmARM-β or pVAX1-EmARM-β, significant promotion to the proportion of CD4 and CD8 T cells and the level of antigen-specific IgG antibodies in immunized chickens was also observed. Furthermore, vaccination with rEmARM-β antigen or pVAX1-EmARM-β resulted in alleviated weight loss and enteric lesion, reduced oocyst output, and higher anticoccidial index (ACI) in challenged birds. These results indicate that EmARM-β antigen can effectively stimulate the expression of Th1 cytokines and initiate host immune responses, providing moderate protective efficacy against . Notably, EmARM-β protein is a promising candidate for developing a novel anticoccidial vaccine.
有一种共识认为，Th1 免疫反应在对抗禽球虫病中起着主导作用。因此，能够诱导 Th1 细胞因子反应的抗原是开发球虫病疫苗的理想候选物。在我们之前的研究中，从（）的 cDNA 表达文库中筛选出了 EmARM-β，一种刺激 Th1 细胞因子的抗原。在这里，我们验证了它对 Th1 细胞因子产生的刺激作用，并评估了它对感染的保护效果。重组 EmARM-β 蛋白被表达，并且还构建了真核表达质粒 pVAX1-EmARM-β 用于鸟类免疫。通过免疫荧光检测来检测在子孢子阶段的 EmARM-β 天然蛋白。使用 qPCR 和 ELISA 来测量免疫鸡中的特异性转录因子和细胞因子的表达，以验证其对 Th1 细胞因子的刺激功能。使用 ELISA 和间接流式细胞术来检测免疫鸡中的特异性 IgG 抗体水平和 T 淋巴细胞亚群，以确定诱导的免疫反应。结果表明，EmARM-β 天然蛋白在的子孢子阶段大量表达。观察到 EmARM-β 抗原对 T-bet 和 Th1 细胞因子（IL-2 和 IFN-γ）的有效刺激。用 rEmARM-β 或 pVAX1-EmARM-β 免疫后，还观察到免疫鸡中 CD4 和 CD8 T 细胞的比例以及抗原特异性 IgG 抗体水平显著提高。此外，rEmARM-β 抗原或 pVAX1-EmARM-β 的接种导致受感染鸟类的体重减轻和肠道病变减轻，卵囊排出量减少，抗球虫指数（ACI）提高。这些结果表明，EmARM-β 抗原可以有效地刺激 Th1 细胞因子的表达并引发宿主免疫反应，对提供中度保护效果。值得注意的是，EmARM-β 蛋白是开发新型抗球虫疫苗的有前途的候选物。
