鼠伤寒结合疫苗研制的初步探讨

通过对鼠伤寒沙门菌LH株的发酵培养,热酚水法提取脂多糖LPS,1%乙酸沸水浴水解90m in脱毒,Super-dex 200柱层析,收集第一峰为鼠伤寒O-SP抗原;然后用CDAP对O-SP活化、ADH衍生后,在EDAC的缩合作用下,结合到破伤风类毒素TT上,制备出鼠伤寒结合疫苗;用含2.5μg多糖鼠伤寒结合疫苗免疫小鼠,以2.5μgO-SP多糖生理盐水溶液以及生理盐水溶液为对照组,间隔14天,免疫三针;以LPS为包被抗原,用间接ELISA法测定血清中抗鼠伤寒LPS IgG抗体。鼠伤寒结合疫苗三针免疫后,小鼠血清抗鼠伤寒LPS IgG抗体效价达到1:80以上的比例为84.2%,而总的几何平均滴度(GMT)达到796;说明制备的鼠伤寒结合疫苗有良好的免疫原性,而且鼠伤寒结合疫苗在小鼠和豚鼠体内有良好的安全性。

Investigation of conjugate vaccine of Salmonella typhimurium O-SP bound to Tetanus toxoid (TT)

To develop polysaccharide-protein conjugate vaccine for protecting Salmonella typhimurium infection,Salmonella typhimurium LH strain was fermented,then LPS was extracted with hot-phenyl method and detoxificated with 1% acetic acid at 100℃ for 90min.The O-SP mixture passed through the Superdex 200 column,first elution peak was collected as effective polysaccharide antigen.O-SP was activated with CDAP,bound to TT with ADH as a spacer,EDAC as condensation reagent.Solutions of 2.5ug of saccharide,alone or as conjugate,were injected subcutaneous three times into young mice,with a interval each 14days.Anti-LPS IgG antibodies were measured with indirected ELISA,LPS used as coating antigen.After third injection mouse anti-LPS IgG antibody titer more than 1:80 reached to 84.2%,the GMT of anti-LPS IgG antibody was 796.The results show that the immunogenicity of this conjugate vaccine was well and the TI(T cell independent) antigen related to O-SP was effectively converted into TD(T cell dependent) antigen.In addition,conjugate vaccine was also safe in mouse and gunia pigs.