Wang Mingyue, Tian Di, Xu Lixin, Lu Mingmin, Yan Ruofeng, Li Xiangrui, Song Xiaokai
MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China.
Front Vet Sci. 2023 Jan 4;9:1049551. doi: 10.3389/fvets.2022.1049551. eCollection 2022.
Avian coccidiosis, caused by apicomplexan protozoa belonging to the genus, is considered one of the most important diseases in the intensive poultry industry worldwide. Due to the shortcomings of live anticoccidial vaccines and drugs, the development of novel anticoccidial vaccines is increasingly urgent.
rhomboid-like protein 1 (EmROM1), an invasion-related molecule, was selected as a candidate antigen to evaluate its protective efficacy against in chickens. Firstly, the prokaryotic recombinant plasmid pET-32a-EmROM1 was constructed to prepare EmROM1 recombinant protein (rEmROM1), which was used as a subunit vaccine. The eukaryotic recombinant plasmid pVAX1.0-EmROM1 (pEmROM1) was constructed as a DNA vaccine. Subsequently, 2-week-old chicks were separately vaccinated with the rEmROM1 and pEmROM1 twice every 7 days. One week post the booster vaccination, induced cellular immune responses were determined by evaluating the mRNA level of cytokines including IL-2, IFN-γ, IL-4, IL-10, TGF-β, IL-17, and TNFSF15, as well as the percentages of CD4 and CD8 T cells from spleens of vaccinated chickens. Specific serum antibody level in the vaccinated chickens was determined to assess induced humoral immune responses. Finally, the protective efficacy of EmROM1 was evaluated by a vaccination-challenge trial.
EmROM1 vaccination significantly upregulated the cytokine transcription levels and CD4/CD8 T cell percentages in vaccinated chickens compared with control groups, and also significantly increased the levels of serum-specific antibodies in vaccinated chickens. The animal trial showed that EmROM1 vaccination significantly reduced oocyst shedding, enteric lesions, and weight loss of infected birds compared with the controls. The anticoccidial index (ACI) from the rEmROM-vaccination group and pEmROM1-vaccination group were 174.11 and 163.37, respectively, showing moderate protection against infection.
EmROM1 is an effective candidate antigen for developing DNA or subunit vaccines against avian coccidiosis.
由艾美耳属顶复门原生动物引起的禽球虫病，被认为是全球集约化家禽业中最重要的疾病之一。由于活抗球虫疫苗和药物存在的缺点，新型抗球虫疫苗的研发变得越来越紧迫。
选择与侵袭相关的类菱形蛋白1（EmROM1）作为候选抗原，评估其对鸡艾美耳球虫的保护效力。首先，构建原核重组质粒pET-32a-EmROM1以制备EmROM1重组蛋白（rEmROM1），用作亚单位疫苗。构建真核重组质粒pVAX1.0-EmROM1（pEmROM1）作为DNA疫苗。随后，对2周龄雏鸡每隔7天分别用rEmROM1和pEmROM1免疫两次。加强免疫一周后，通过评估包括IL-2、IFN-γ、IL-4、IL-10、TGF-β、IL-17和TNFSF15等细胞因子的mRNA水平，以及接种疫苗鸡脾脏中CD4和CD8 T细胞的百分比，来测定诱导的细胞免疫反应。测定接种疫苗鸡的特异性血清抗体水平，以评估诱导的体液免疫反应。最后，通过接种疫苗-攻毒试验评估EmROM1的保护效力。
与对照组相比，EmROM1免疫显著上调了接种疫苗鸡的细胞因子转录水平和CD4/CD8 T细胞百分比，并且显著提高了接种疫苗鸡的血清特异性抗体水平。动物试验表明，与对照组相比，EmROM1免疫显著减少了感染鸡的卵囊排出、肠道病变和体重减轻。rEmROM免疫组和pEmROM1免疫组的抗球虫指数（ACI）分别为174.11和163.37，显示出对感染的中度保护作用。
EmROM1是开发抗禽球虫病DNA或亚单位疫苗的有效候选抗原。
