Equine theileriosis, caused by the Theileria equi protozoan, is a disease of worldwide importance. T. equi expresses surface proteins, of which the EMA-2 protein is a promising antigen for vaccine use. The aim of this study was to evaluate the immune response of adult horses, pregnant mares, and foals to an experimental EMA-2 protein of recombinant T. equi vaccine. A total of 46 horses were used in this study for vaccine trials and challenges. Twelve geldings, 14 pregnant mares, and 14 foals were divided into vaccinated and control groups. Total serum specific anti-rEMA-2 IgG, IgG subclasses, and transcription of cytokines related to the immune response were evaluated. For the vaccine challenge, six six-month-old foals were divided into vaccinated and control groups. For the challenge, blood from a horse with theileriosis was transfused to the foals. Geldings and pregnant mares maintained anti-rEMA-2 IgG levels at 130 and 140 days after vaccination, respectively. The most-detected IgG subclasses in vaccinated were IgG3/5, IgG4/7, and IgG1. IL2, IL10, IL12, IL17, IFN-γ, and TNF-α were the most-transcribed cytokines in PBMCs of vaccinated horses stimulated with rEMA-2. Challenge with T. equi demonstrated that vaccinated foals had an increase of 33% in total IgG four days after blood transfusion, while control foals had no significant response, suggesting that vaccine antibodies may have recognized EMA-2 protein of the native T. equi antigen. T. equi recombinant EMA-2 was shown to be a promising vaccine antigen by inducing humoral and cellular immunity similar to that observed in natural parasite infections.

由马泰勒虫原虫引起的马泰勒虫病是一种具有世界重要性的疾病。T. equi表达表面蛋白，其中 EMA-2 蛋白是疫苗使用的有希望的抗原。本研究的目的是评估成年马、怀孕母马和小马驹对重组马铃薯的实验性 EMA-2 蛋白的免疫反应。疫苗。本研究共使用 46 匹马进行疫苗试验和挑战。将 12 匹骟马、14 匹怀孕母马和 14 匹马驹分成接种疫苗组和对照组。评估了总血清特异性抗 rEMA-2 IgG、IgG 亚类和与免疫反应相关的细胞因子的转录。对于疫苗挑战，六只六个月大的小马驹被分为接种疫苗组和对照组。为了挑战，将患有泰勒虫病的马的血液输给小马驹。Geldings 和怀孕的母马分别在接种疫苗后 130 天和 140 天保持抗 rEMA-2 IgG 水平。接种疫苗中检测最多的 IgG 亚类是 IgG3/5、IgG4/7 和 IgG1。IL2、IL10、IL12、IL17、IFN-γ和TNF-α是用 rEMA-2 刺激的接种马的 PBMC 中转录最多的细胞因子。用马铃薯进行攻击表明，输血后四天，接种疫苗的小马驹的总 IgG 增加了 33%，而对照小马驹没有显着反应，这表明疫苗抗体可能识别了天然马铃薯抗原的EMA-2 蛋白. 通过诱导类似于在天然寄生虫感染中观察到的体液和细胞免疫，T. equi重组 EMA-2 被证明是一种有前途的疫苗抗原。