Wei Hanbing, Chen Sixuan, Liu Chen, Huang Huoqing, Su Xiaoyun, Bai Yingguo, Liang Lin, Ding Jiabo, Tang Xinming, Luo Huiying, Yao Bin, Wang Yuan, Zhang Honglian
State Key Laboratory of Animal Nutrition and Feeding, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China.
Key Laboratory of Animal Biosafety Risk Prevention and Control (North) & Key Laboratory of Veterinary Biological Products and Chemical Drugs of MARA, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China.
Poult Sci. 2025 May 15;104(8):105296. doi: 10.1016/j.psj.2025.105296.
Coccidiosis is a parasitic disease caused by Eimeria species in chickens, leading to substantial threats to the poultry industry worldwide. Vaccination has emerged as a pivotal preventive strategy, with subunit vaccines gaining significant attention due to their safety. Microneme protein 2 (MIC2) of Eimeria tenella (E. tenella) is a promising candidate antigen for coccidiosis vaccination. However, its immune protection efficiency still needs to be further improved. Here, we report that MIC2, cholera toxin B subunit (CTB) and their fusion protein CTB-MIC2 are successfully recombinant expressed and produced in Pichia pastoris (P. pastoris). Notably, CTB and CTB-MIC2 exhibit high affinity for GM1 ganglioside, whereas MIC2 does not. Furthermore, upon administration to mice, the fusion protein CTB-MIC2 triggered a more robust cellular and humoral immune response than MIC2 alone, as evidenced by inducing significantly higher levels of cytokines IFN-γ and IL-4, along with an elevated production of antigen-specific IgG antibodies. More importantly, CTB-MIC2 provided higher immune protection against E. tenella infections in chickens than MIC2. Taken together, these findings reveal that CTB fusion enhances the immunogenicity of MIC2, highlighting a promising strategy for developing effective anti-coccidial subunit vaccines.
球虫病是由艾美耳属物种引起的鸡的一种寄生虫病，对全球家禽业构成重大威胁。疫苗接种已成为一种关键的预防策略，亚单位疫苗因其安全性而备受关注。柔嫩艾美耳球虫（E. tenella）的微线体蛋白2（MIC2）是球虫病疫苗接种的一个有前景的候选抗原。然而，其免疫保护效率仍需进一步提高。在此，我们报告MIC2、霍乱毒素B亚基（CTB）及其融合蛋白CTB-MIC2在毕赤酵母（P. pastoris）中成功重组表达并产生。值得注意的是，CTB和CTB-MIC2对GM1神经节苷脂表现出高亲和力，而MIC2则没有。此外，给小鼠接种后，融合蛋白CTB-MIC2比单独的MIC2引发了更强的细胞和体液免疫反应，这通过诱导显著更高水平的细胞因子IFN-γ和IL-4以及抗原特异性IgG抗体产量的提高得到证明。更重要的是，CTB-MIC2比MIC2为鸡提供了更高的针对柔嫩艾美耳球虫感染的免疫保护。综上所述，这些发现表明CTB融合增强了MIC2的免疫原性，突出了一种开发有效的抗球虫亚单位疫苗的有前景的策略。
