山药多糖作为猪圆环病毒2型疫苗佐剂的活性研究

Study on the Adjuvant Activity of Chinese Yam Polysaccharides as Porcine Circovirus Type 2 Vaccine

山药多糖(Chinese Yam polysaccharide,CYP)是中药山药的主要活性成分之一,具有良好的免疫刺激作用。为了探究山药多糖作为猪圆环病毒2型(Porcine circovirus type 2,PCV2)疫苗的佐剂活性,从中药山药中提取分离得到山药多糖,与PCV2灭活抗原液混合后对小鼠进行免疫接种。通过测定血清中特异性抗体及亚型的水平,脾脏淋巴细胞中CD4+和CD8+T细胞的活化水平,记忆T细胞活化水平,细胞因子水平以及淋巴结中生发中心(germinal center,GC)B细胞活化水平,从而评估CYP作为PCV2疫苗的佐剂活性。结果显示,CYP作为佐剂能够诱导特异性抗体IgG及亚型IgG1和IgG2a的表达,促进CD4+T细胞的活化,促进CD8+T细胞的中央记忆T细胞活化,增强IFN-γ和IL-6细胞因子的表达,促进淋巴结GC B细胞的活化。以上结果表明,CYP作为PCV2疫苗的佐剂能够同时诱导体液免疫和细胞免疫应答,具有开发成畜禽疫苗佐剂的潜力。

Chinese Yam polysaccharide(CYP),as one of the main active ingredients of the traditional Chinese medicine yam,have good immune stimulation effect.In this experiment,to explore the activity of CYP as an adjuvant for porcine circovirus type 2(PCV2)vaccine,CYP was extracted and isolated from Chinese Yam,and mixed with PCV2 inactivated antigen solution to immunize mice.The adjuvant activity of CYP as an adjuvant for PCV2 vaccine was evaluated by measuring the levels of specific antibodies and subtypes in serum,the activation levels of CD4+and CD8+T cells in spleen lymphocytes,the activation levels of memory T cells,the levels of cytokines,and the activation levels of germinal centre(GC)B cells in lymph nodes.The results demonstrated that CYP as an adjuvant promoted the expression of specific antibody IgG and subtypes IgG1 and IgG2a,improved the activation of CD4+T lymphocytes,facilitated the activation of central memory T cells of CD8+T lymphocytes,increased the expressions of IFN-γand IL-6 cytokines,and enhanced the activation of GC B cells in lymph nodes.The above results indicated that CYP as an adjuvant for PCV2 vaccine could induce both humoral and cellular immune responses,and have the potential to be developed into an adjuvant for livestock and poultry vaccines.