小鼠口服重组LTB和HpUreB免疫活性的研究

Study on immunological activities of adjuvant rLTB and rUreB of Hp after oral administration in mice

目的 观察重组大肠杆菌不耐热肠毒素B亚单位 (rLTB)的粘膜佐剂活性以及重组Hp尿素酶B亚单位 (rUreB)的免疫学活性 ,为制备安全有效的Hp疫苗奠定基础。方法 ELISA检测rLTB的GM1(神经节苷脂 )结合活性 ,利用本室基因工程重组表达的rLTB和rUreB口服免疫BALB/c小鼠后 ,在第 4和 /或 5周ELISA方法检测血清IgG ,以及唾液、粪便抽提物、肠粘液sIgA水平。采用3 H掺入实验 ,检测小鼠脾脏淋巴细胞对特异性抗原的增殖反应。结果 ①rLTB具有GM1结合活性。②与不加佐剂的对照比较 ,加rLTB的实验组 ,能够有效地诱发唾液及肠道sIgA的产生。③口服HprUreB抗原能够刺激小鼠产生特异性的IgG和sIgA。④3 HT dR掺入实验提示加佐剂组较不加佐剂组 ,脾脏淋巴细胞对特异性抗原的增殖反应更强。⑤不加佐剂组血清IgG ,免疫第 5周较第 4周高 ;加佐剂则是第 4周比第 5周高。结论 重组LTB具有良好的粘膜佐剂功能 ;HprUreB具备良好的免疫原性 ;小鼠口服rLTB和rUreB后可以产生保护性sIgA ;

Objective To investigate the abilities of recombinant LTB as the mucosal adjuvant and recombinant UreB as immunogen in BALB/c mice after oral administration, which provide a good base for safe and effective vaccine of Hp. Methods The adhesive ability of rLTB to GM1 was determined through ELISA. The levels of IgG in serum and sIgA in saliva, fecal extract and intestine mucus respectively at the 4th and/or 5th week after immunization were detected, and the proliferative rate of the T cell in the spleen after stimulated by the antigen was studied through 3H-TdR cooperation test. Results ①rLTB had the ability to adhere GM1.② Higher levels of sIgA were observed in saliva and gastrointestinal tract in the group with rLTB than the group without rLTB. ③The specific IgG and sIgA were produced after oral immunization with rUreB. ④The proliferation of T cell in the spleen from the group with rLTB was stronger than the group without rLTB.⑤ Serum level of IgG at the 5th week was higher than at 4th week in the group without rLTB, and the contrary result was found in the group with rLTB. Conclusion rLTB has effective ability as mucosal adjuvant, and rUreB processes good immunogenicity. Different levels of IgG in the 2 groupsmight be caused by the change of balance of Th1/Th2 regulated by rLTB.