EIAV减毒疫苗诱导马外周血单个核细胞Th1型细胞因子的转录

Induction of transcription for Th1 cytokines in peripheral blood mononuclear cells of EIAV vaccinated horses

目的:探讨马传染性贫血病毒驴白细胞减毒疫苗免疫马后,外周血单个核细胞中Th1型细胞因子转录水平与免疫保护应答的关系,揭示DLV的免疫保护机制。方法:应用分子克隆及实时定量RT-PCR技术,建立了马PBMC中IFNγ-、IL-2、IL-12 mRNA转录水平的定量检测方法,定期观察4组(疫苗免疫组、阴性对照组、强毒株阳性对照组、自然感染组)12匹马外周血PBMC中细胞因子的转录水平及分布特征,同时监测体温变化等指标。疫苗株免疫动物8个月后,用EIAV强毒株攻击,观察攻击前后细胞因子转录水平的变化。结果:DLV免疫马,在免疫后3周外周血PBMC中IFN-γ、IL-2转录量显著高于阴性对照组及自然感染组(P<0.01);免疫后用EIAV强毒株攻击,IFNγ-、IL-2和IL-12转录的量明显升高,免疫马获得完全保护;强毒株攻击阳性对照马IFN-γ、IL-2转录量随疾病进展波动,发热期下降。结论:本研究首次证明EIAV减毒疫苗可诱导马外周血PBMC中IFN-γ、IL-2、IL-12基因高效转录,其转录水平与DLV的免疫保护密切相关,此结果在分子水平为阐明DLV的免疫保护机制提供了新的实验依据。

To evaluate the relationship between the transcriptional level of Thl cytokines in peripheral blood mononuclear cells（PBMCs） and immune protective response driven by inoculated horses with donkey leukocyte-attenuated vaccine of EIAV （ DLV）, and to elucidate the immune mechanism of DLV. nethods：A real-time PCR was established for quantitative detection of IFN-γ, IL-2 ,IL-12 mRNA from horse PBMCs. Twelve horses used in this study were divided in to vaccinated group, healthy control group, challenging control group and EIAV naturally infected group. The transcriptional level and distributionof Thl cytokines in PBMCs were analyzed. Body temperature and other parameters of the inoculated horses were monitored daily. Horses inoculated with DLV vaccines were challenged eight months after inoculation, and transcriptional level of Thl cytokines was evaluated pre/post-challenge. Results： The transcriptional level of IFN-γ, IL-2 mRNA was much higher in vaccinated group than healthy control and naturally infected group （P 〈 0. 01 ）, and continuously increasing after challenging with virulent EIAV strains. Four vaccinated horses were completely protec- ted. In the positive control group, transcriptional level of IFN-γ, IL-2 mRNA fluctuated as disease progression, and descended evidently during febrific episodes. Conclusion：This study for the first time reveals that EIAV attenuated vaccine could induce high level transcription of IFN-γ, IL-2, IL-12 mRNA. The transcriptional level is associated closely with immune protective responses induced by DLV. This finding, at molecular levels, could help elucidate the mechanism of immunity protection of DLV.