犬热应激过程中HSP70和免疫相关细胞因子的变化

Variation of HSP70 and Some Related Cytokines during Heat Stress in Dogs

为研究热应激造成犬免疫机能损伤的机制及损伤过程中免疫相关细胞因子的变化规律,分别在夏季持续高热天气中每隔7d、分5次采集了拉布拉多犬的血清和外周血单个核细胞(PBMC),检测血清中皮质醇(COR)、热休克蛋白70(HSP70)、白细胞介素2((IL-2)和白细胞介素(IL-10)、Toll样受体2(TLR-2)和Toll样受体4(TLR-4)的含量及PBMC中HSP70、IL-2、IL-10、TLR-2、TLR-4的mRNA的表达,并与春季非应激温度下检测的同类指标进行比较。结果显示,夏季持续高热天气中犬长期处于应激状态,其PBMC中HSP70mRNA表达上调,IL-2、IL-10、TLR-2、TLR-4mRNA表达下调;血清中COR浓度持续高于正常值,HSP70浓度升高,IL-2、TLR-2浓度未发生显著变化,IL-10、TLR-4浓度显著低于正常水平。热应激条件下PBMC中白介素和Toll样受体mRNA表达下调,可能是导致犬的免疫功能抑制、抗感染免疫机能下降的原因。

To study the mechanism of the canine immune function damage under heat stress and changes of some related cytokines in this damage process,samples from twelve Labrado dogs were collected by five times at seven-day intervals in a continuous high temperature summer.Concentrations of COR,HSP70,IL-2,IL-10,TLR-2,TLR-4in sera and their mRNA expression levels in PBMC were detected by ELISA and real time RT-PCR.Each index under heat stress state was compared with the normal level under non heat stress in spring.Results of COR concentration showed that all dogs were under heat stress in the summer high temperatures.Concentrations of COR and HSP70 increased in blood serum.IL-2and TLR-2unchanged,while IL-10 and TLR-4levels decreased significantly.In PBMC,only the mRNA expression of HSP70 was up-regulated.IL-2,IL-10,TLR-2,TLR-4 mRNA were all down-regulated.These results proved that the increased expression of HSP70 was neccessary for immune cells maintaining their normal structure and functions.Down-regulations of mRNA expressions of IL-2,IL-10,TLR-2and TLR-4in PBMC may be an important reason for immune suppression and anti-infection immune decline under chronic heat stress in dogs.