EIAV弱毒疫苗免疫马外周血单核细胞IL-2表达水平的研究

目的:通过定量监测马传染性贫血病毒(EIAV)弱毒疫苗免疫马外周血单核细胞(PBMC)IL-2表达水平的变化特征,探讨EIAV弱毒疫苗的免疫保护机制。方法:用实时定量RT-PCR技术建立了马外周血PBMCIL-2表达水平的定量检测方法。在不同的时间点定期对4组(疫苗免疫组、健康对照组、强毒攻毒组和EIAV自然感染组)12匹马的外周血PBMCIL-2表达水平进行了检测,同时观察了临床症状及体温变化等指标。疫苗株免疫动物8个月后用强毒攻毒,观察了攻毒前后IL-2表达水平的变化。结果:(1)疫苗免疫马外周血PBMCIL-2的表达量显著高于健康对照组及自然感染组(P<0.01),且免疫后攻毒IL2继续升高,4匹疫苗免疫马均获得完全保护;(2)强毒攻毒对照组IL2表达量随疾病进展波动,发热期明显下降。结论:首次证明EIAV弱毒疫苗可诱导马外周血PBMC表达高水平的IL-2,提示IL-2在疫苗的免疫保护应答中发挥了重要作用;IL-2表达水平还与EIAV感染后的疾病进展密切相关。

Elevation of IL-2 Expressing Level in PBMC of EIAV Vaccinated Horses

Objective: To evaluate the induction of IL-2 by vaccinated horses with attenuated EIAV vaccine, and elucidate the role of IL-2 in immune protective response, and provide a valuable basis for study on other lentivirus vaccines such as HIV and immune adjuvant. Methods: Specific real-time RT-PCR method was established to measure the production of IL-2 from horses PBMC. All the horses used in this experiment were screened for EIAV-free by AGID, and divided into three groups (vaccinated group,healthy control group, and virulent challenged group), and EIAV natural infectious group was also set up as control. All the animals were monitored for temperature and clinical manifestation at daily bases. Blood samples were collected at regular intervals and at febrific episodes. Results: (1)The induction of IL-2 in vaccinated group was much higher than healthy control, natural infectious as well as virulent challenge groups (p<0 01), and the level continuously increased even after challenged with virulent EIAV strain. All vaccinated animals were protected. (2)In the challenged group without immunization previously, the induction of IL-2 fluctuated with disease progression, descending evidently during febrific episodes. Conclusion: EIAV attenuated vaccine could induce high expression level of IL-2 in vivo, which played an important role in immune protective response to virulent EIAV infection; the expression level of IL-2 was closely correlated with the disease progression and the prognosis after EIAV infection.