栽培一枝蒿粗多糖佐剂增强口蹄疫疫苗的皮下免疫效果

Immuno-enhancement Effects of Cultivated Artemisia rupestris L.Crude Polysaccharide on Foot-and-mouth Disease Vaccine via Subcutaneous Route

旨在评价新疆栽培一枝蒿粗多糖(cultivated Artemisia rupestris L.crude polysaccharides,CARCP)对口蹄疫灭活疫苗(foot and mouth disease vaccine,FMDV)的免疫佐剂活性,确定多糖佐剂的有效性。选用不同剂量的CARCP与FMDV配伍,通过皮下途径免疫ICR小鼠。采用间接ELISA检测FMDV特异性抗体水平,流式细胞仪检测免疫后小鼠脾和淋巴结中T细胞亚群,以及脾中树突状细胞表面分子和调节性T细胞的表达情况。每周称量小鼠体重,观察免疫后小鼠的生长状况。结果表明,与FMDV单独免疫对照组相比,中剂量和高剂量的CARCP可以诱导产生更高水平的FMDV特异性IgG、IgG1和IgG2a(P<0.01)。中剂量的CARCP显著增加小鼠脾和淋巴结中CD4、CD8、CD44 T细胞百分比(P<0.05)。同时,中剂量的CARCP可以显著促进脾树突状细胞CD86和MHC-II分子的表达(P<0.05),并显著下调CD4^(+)CD25^(+)Foxp3^(+)T细胞水平(P<0.05)。CARCP对免疫后小鼠生长和体重无显著影响(P>0.05)。综上表明,CARCP作为FMDV佐剂可以促进DC成熟,抑制调节性T细胞(regulatory T cells,Tregs)表达,增强FMDV特异性的体液和细胞免疫应答,具有良好的佐剂效果,为口蹄疫灭活疫苗多糖佐剂的开发提供一定的研究基础。

The purpose of this study was to evaluate the adjuvant effects of cultivated Artemisia rupestris L.crude polysaccharides(CARCP)on inactivated foot-and-mouth disease vaccine(FMDV).ICR mice were subcutaneously administrated with different doses of CARCP combined with FMDV.ELISA was used for the detection of FMDV-specific antibodies.T cell subsets in spleen and lymph nodes,and the expression of dendritic cell surface molecules as well as regulatory T cells(Tregs)in spleen were detected by flow cytometry.Mice were weighed every week,and observed the growth condition of mice after immunization.Compared with FMDV alone,higher levels of FMDV-specific IgG,IgG1 and IgG2a were induced by both medium-dose and high-dose of CARCP(P<0.01).Medium-dose of CARCP not only significantly increased the percentage of CD4,CD8,and CD44 T cells in the spleen and lymph nodes of mice(P<0.05),but also promoted the expression of CD86 and MHC-II in DC(P<0.05),whereas the CD4^(+)CD25^(+)Foxp3^(+)T cells were significantly down-regulated(P<0.05).There was no noticeable influence on the growth and body weight of immunized mice(P>0.05).The results suggested that CARCP as an adjuvant for FMDV could augment the specific humoral and cellular immune responses via inducing DC maturation,inhibiting Tregs-level,which provided a basis for the development of polysaccharide adjuvant of FMDV.