4种多糖对口蹄疫疫苗免疫反应的影响

Effects of Four Polysaccharides on Immune Responses of Vaccination Against FMDV

目的：该研究旨在探讨口服黄芪多糖、白术多糖、黄芩多糖和金银花多糖等4种多糖对小鼠注射口蹄疫疫苗后体液免疫和细胞免疫反应的影响.方法：试验选取4～6周龄ICR小鼠42只,随机分为6组,每组7只.各试验组小鼠分别灌服多糖或生理盐水,连续给药4d后,注射口蹄疫疫苗进行首次免疫,间隔14d后2次免疫.2免后2周采集血清测定抗体质量分数,同时无菌取脾,制备脾细胞悬液,测定淋巴细胞增殖能力、细胞因子的表达水平和CTL杀伤能力.结果：结果显示,与对照组相比在二免后14d,这4种多糖均不同程度促进了淋巴细胞增殖反应,诱导产生了较高水平的IgG抗体,同时能够上调CD4＋T细胞IL-2,IL-4,IFN-γ和CD8＋T细胞IFN-γ的表达,并增强了CTL反应.结论：免疫前口服这4种多糖均可提高Th1,Th2型免疫反应,进而增强小鼠的体液和细胞免疫反应.该研究为增强口蹄疫疫苗的免疫应答提供了新途径,同时也表明受试的3种多糖均具备良好的佐剂潜力.

Objective.. This study was designed to investigate the effects of oral administration of four poly saccharides （APS, RAPS, BSPS and FLPS） on the specific cellular and humoral immune responses in mice injected with foot-and-mouth disease vaccine. Methods： Forty-two ICR mice, 4- to 6-week-old, were ran- domly divided into six groups （n=7） and orally administered at a dose equivalent to 0 or 50 mg of the four polysaccharides continuously for 4 days. After that, the animals were subcutaneously immunized twice with FMDV vaccine at 2-week intervals. Blood samples were taken on day 14 alter boosting for serum anti body level determination and the spleen was collected to determine CTL activity, lymphocyte proliferation, and surface and intracellular molecule expression. Results： Compared to mice immunized with FMDV vac cine alone, the addition of the four polysaccharides increased lymphocyte proliferation and an FMDV-spe- cific antibody response that was marked with a higher titer of IgG. Importantly, FMDV vaccine plus poly saccharide elicited a higher level of IL-2, IFN-γ and IL-4 in CD4＋ T cells and a higher level of IFN-γ in CD8q- T cells. Conclusion.. To sum up, the four polysaccharides used in this study can increase both cetlu- lar and humoral immune responses via up-regulating Thl and Th2 responses. The study has provided a no- vel method for enhancing the immunological effect of FMDV vaccine and demonstrated that the three poly saccharides possess promising potential of being adjuvant and have a good prospect of application.