Wang Feiyan, Cao Liqin, Wang Lele, Xu Jinjun, Tao Jianping, Liu Dandan
College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, China.
Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China.
Animals (Basel). 2025 Jun 13;15(12):1750. doi: 10.3390/ani15121750.
Coccidiosis, caused by spp., significantly reduces poultry productivity and causes major economic losses. Traditional control methods are limited by drug resistance and high production costs. Recent genomic and bioinformatic advances have enabled the identification of novel antigens, making recombinant subunit vaccines a promising next-generation strategy by eliciting robust cellular and humoral immune responses. This study investigates the gametocyte protein 56 (EnGAM56) as a potential candidate for recombinant subunit vaccines. The full-length gametocyte gene (En-F) was amplified, expressed in vitro, and characterized via SDS-PAGE and Western blot. Immunofluorescence assays revealed that EnGAM56-F is specifically localized in gametocytes and unsporulated oocysts. Chickens immunized with recombinant proteins (rEnGAM56-F and rEnGAM56-T) were evaluated for immunoprotection against infection through lesion scores, weight gain, oocyst production, anticoccidial index (ACI), and antibody and cytokine levels. The synergistic effects were evaluated by employing various combinations of recombinant proteins, including rEtGAM22, rEtGAM56-T, and rEtGAM59. Results showed that EnGAM56-F encodes a 468-amino acid protein with distinct tyrosine-serine-rich and proline-methionine-rich regions. rEnGAM56-F was specifically recognized by both anti-6 × His tag antibodies and convalescent serum from chickens infected with . Both rEnGAM56-F and rEnGAM56-T provided immune protection, with rEnGAM56-T showing superior efficacy. The combination of rEnGAM (22 + 59 + 56-T) yielded the strongest immune response, followed by rEnGAM (22 + 56-T). These findings highlight the potential of EnGAM56 as a candidate for recombinant subunit anticoccidial vaccines.
球虫病由球虫属物种引起，会显著降低家禽生产力并造成重大经济损失。传统控制方法受到耐药性和高生产成本的限制。近期基因组学和生物信息学的进展使得新型抗原得以鉴定，通过引发强大的细胞免疫和体液免疫反应，使重组亚单位疫苗成为一种有前景的下一代策略。本研究调查配子体蛋白56（EnGAM56）作为重组亚单位疫苗的潜在候选物。全长配子体基因（En-F）被扩增、体外表达，并通过SDS-PAGE和蛋白质印迹进行表征。免疫荧光分析显示EnGAM56-F特异性定位于配子体和未孢子化的卵囊。通过病变评分、体重增加、卵囊产生、抗球虫指数（ACI）以及抗体和细胞因子水平，评估用重组蛋白（rEnGAM56-F和rEnGAM56-T）免疫的鸡对球虫感染的免疫保护作用。通过采用重组蛋白的各种组合，包括rEtGAM22、rEtGAM56-T和rEtGAM59，评估协同效应。结果表明，EnGAM56-F编码一种468个氨基酸的蛋白质，具有明显的富含酪氨酸-丝氨酸和富含脯氨酸-甲硫氨酸的区域。rEnGAM56-F被抗6×His标签抗体和感染球虫的鸡的恢复期血清特异性识别。rEnGAM56-F和rEnGAM56-T均提供免疫保护，rEnGAM56-T显示出更高的效力。rEnGAM（22 + 59 + 56-T）组合产生最强的免疫反应，其次是rEnGAM（22 + 56-T）。这些发现突出了EnGAM56作为重组亚单位抗球虫疫苗候选物的潜力。
