幽门螺杆菌重组粘附素的安全性、免疫原性和生物学活性的体外评价

目的 通过体外实验确定重组粘附素(rBabA)的安全性、免疫原性及粘附作用，探讨rBabA在幽门螺杆菌(Hp)疫苗应用中的可行性。方法 二苯胺法测定rBabA致T细胞凋亡率．ELISA法测定Hp感染者血清中抗rBabA抗体．MTT法测定T细胞对rBabA的增殖反应．光镜计数法研究rBabA对Hp与胃癌细胞粘附的影响。结果 体外安全性实验表明rBabA无明显致BabA抗体阴性者T细胞凋亡的作用．而且可刺激rBabA抗体阳性者T细胞的增殖；ELISA法共检测了38份Hp感染患者血清，rBabA抗体阳性率为18．4％。rBabA能部分阻断Hp与胃癌细胞系的粘附。结论 研究表明rBabA是安全的、具有免疫原性的。Hp菌体成分.既可以刺激体液免疫，又能够提高细胞免疫,有望成为针对BabA2基因阳性。Hp菌株疫苗研制中一种有效的新抗原。

In vitro evaluation of the safety and biological activity of recombinant Helicobacter pylori blood group antigen-binding adhesin]

OBJECTIVE: To evaluate the safety and biological activity of recombinant Helicobacter pylori (Hp) blood group antigen- binding adhesin (rBabA ) in vitro so as to investigate the feasibility of using rBabA as a Hp vaccine. METHODS: ELISA was used to measure rBabA-specific antibody in the serum of Hp-infected patients, and the proliferation of T lymphocytes in response to rBabA was examined by MTT assay. T cell apoptosis induced by rBabA was detected by diphenylamine assay. The effect of rBabA on Hp binding into human gastric carcinoma cell line(MGC-803) was determined by light microscopy. RESULTS: rBabA did not induce T cell apoptosis in BabA antibody- negative patients and was capable of stimulating T cell proliferation in rBabA antibody-positive patients. In the serum samples from 38 Hp-infected patients, the rBabA antibody positivity rate was 18.4%. rBabA could partially inhibit the binding of Hp to gastric epithelial cells. Under light microscope, the adhesion of Hp to MGC-803 was significantly inhibited by rBabA in comparison with negative control with PBS pretreatment. CONCLUSION: rBabA proves to be a safe and immunogenic bacterial component of Hp, which stimulates humoral and cellular immunity and can be a hopeful antigen targeting at BabA2 gene-positive Hp strain for the development of Hp vaccine.