卡介菌多糖核酸对IBDV感染鸡的免疫活性研究

Immune activities induced by BCG-PSN in IBDV infected chickens

为了评价卡介菌多糖核酸(BCG-PSN)在畜禽病毒性疾病中的作用及其诱导机体免疫的能力,建立了人工感染传染性法氏囊病(IBD)动物模型,通过检测免疫器官指数、IBDV抗体、外周淋巴细胞亚群、诱导干扰素和白介素水平等特异性和非特异性免疫指标,评估不同剂量BCG-PSN对IBDV感染鸡免疫功能的影响。结果显示:免疫器官脾脏指数和胸腺指数在注射BCG-PSN的初期出现上升趋势,而在注射BCG-PSN后期(15d)受试鸡外周血液CD4+/CD8+值显著提升;各BCG-PSN注射组的IBDV抗体滴度在试验初期明显提高;从注射开始,BCG-PSN就显示出其对IFN-γ、IFN-α和IL-2的显著提升效果。上述结果说明:BCG-PSN既能调节IBDV感染鸡的细胞免疫功能,又能调节机体的体液免疫功能,激活组织细胞释放包括IFN-γ、IFN-α和IL-2等多种细胞因子,以0.3mg·kg-1的注射剂量可获得良好的免疫效果。

To evaluate the protective effects and immune activities induced by polysaccharide nucleic acid fraction of Bacillus Calmette Guerin （ BCG-PSN） in the livestock,the animal model of IBD （ infectious bursal disease） on chicken was established. The specific and nonspecific immune response parameters such as the titer of IBDV antibody,the periphery lymphocyte subsets,the levels of IFN-α,IFN-β,and IL-2 were used to evaluate the effects of clinicaltherapy and its immune activities in IBDV vacci-nated chickens which were injected with different doses of BCG-PSN. The results showed that immune organ index such as spleen index and thymus index had the induction tendency at the beginning of BCG-PSN injection. During later period （ 15 d） ,the ratio of CD4 ＋ /CD8 ＋ T lymphocytes in peripheral blood of chickens increased significantly. The titers of IBDV antibody from the beginning stage after BCG-PSN injection increased obviously in IBDV vaccinated chickens. The levels of serum IFN-γ,IFN-α and IL-2 increased significantly from the beginning of BCG-PSN injection. The results suggested that BCG-PSN could not only increase and regulate cellular immunity including IFN-γ,IFN-α and IL-2 but also humoral immunity. The middle dosage of BCG-PSN （0.3 mg·kg-1） used in chickens could produce upstanding immune and protective effects.