以 Balb／c 小鼠为动物模型的 PCV-2疫苗效力检验方法的建立

摘要

The animal model of Balb/c mice was established for PCV-2 vaccine immune efficacy in the study. The SPF female Balb/c mice of 4 week old were selected and randomly divided into 4 groups.The mice in-group Ⅰ were immunized with PCV-2 vaccine (0.1 mL/rat)by subcutaneous 1 point.The mice in groupⅡ were immunized with PCV-2 vaccine (0.2 mL/rat)by subcutaneous 2 points.The mice in group Ⅲ were immunized with PCV-2 vaccine (0.2 mL/rat)by subcutaneous 2 points and leg muscles.The mice in groupⅣ were not immunized with PCV-2 vaccine as the blank control group.The mice in immunized groups were immunized secondly in 7,14 and 21 d after first immunity.The blood in mice were took and the sera were separated after 7,10,14,21,28,35,42 days.The PCV-2 specific antibody was detected by ELISA in order to determine the best immune way and immune dose.The 4 week old female SPF Balb/c mice were selected and randomly divided into immune group,challenge control group and healthy control group.The mice in immunized and challenge control groups were attacked challenged by PCV-2 virulent strain after immunization 14 days.The differences of the mice in test groups were compared in clinical symptoms, pathological lesions,relative daily weight gain,PCV-2 DNA load and other aspects in order to determine the detection indexes of the animal model of mice.Mouse ELISA antibody test showed that the best im-mune procedure was subcutaneous and leg muscleinjection (0.2 mL/rat).The peak antibody value ap-peared 35 d after immunization,and was significantly higher than that of group I and II.The control mice showed weight loss,hair messy,mental tension and clinical symptoms,lymph node swelling,bleeding, pulmonary hemorrhage and other pathological lesion after challenge and the relative daily weight gain de-creased significantly.The PCV-2 DNA load difference was more than 103 .This study established the test method for PCV-2 vaccine potency in Balb/c mice as animal model.The dose and route of immunization were optimized,and the detection index and the corresponding technical parameters were determined, which laid a technical support for PCV-2 vaccine potency test.%为建立以Balb／c小鼠为动物模型的 PCV-2疫苗免疫效力检验方法，选取4周龄 SPF级雌性Balb／c 小鼠20只，随机分成4组（Ⅰ、Ⅱ、Ⅲ、Ⅳ组），每组5只，Ⅰ、Ⅱ和Ⅲ组分别背部皮下1点，背部皮下2点和背部皮下、腿部肌肉2点接种 PCV-2疫苗0．1、0．2、0．2 mL／只，Ⅳ组空白对照组不接种；各免疫组分别于首免疫后7、14、21 d 加强免疫一次，免疫后7、10、14、21、28、35、42 d 采血分离血清，用 ELISA 方法测定PCV-2特异性抗体，确定最佳免疫途径和免疫剂量。另选取4周龄 SPF 级雌性 Balb／c 小鼠，随机分成免疫组、攻毒对照组和健康对照组，免疫组和攻毒对照组于二免后14 d 用 PCV-2强毒株进行攻毒，比较各试验组小鼠在临床症状、病理变化、相对日增重、PCV-2核酸载量等方面差异性，确定小鼠动物模型检测指标。抗体测定表明，一免背部皮下、腿部肌肉2点免疫0．2 mL／只，间隔21 d 加强免疫为最佳免疫程序，免疫后35 d 抗体水平达到峰值，显著高于Ⅰ和Ⅱ组。对照组小鼠免疫攻毒后出现消瘦、被毛凌乱、精神紧张等临床症状，淋巴结肿胀、出血、肺脏出血等病理变化，相对日增重显著降低，PCV-2核酸载量差异在103以上等临床变化。本研究以 Balb／c 小鼠为动物模型建立了 PCV-2疫苗免疫效力检验方法，优化了小鼠免疫途径及剂量，确定了相应的检测指标及技术参数，为 PCV-2疫苗免疫效力检验奠定了基础。