摘要目的 评价环鸟-腺二核苷酸(cGAMP)在非口服幽门螺杆菌蛋白类疫苗研发中作为佐剂的免疫增强效果.方法 以cGAMP为佐剂,与幽门螺杆菌蛋白抗原,包括UreA、UreB和NapA混合,通过皮下途径注射免疫BLAB/c小鼠,同时设置单独抗原组和佐剂组对照,以间接ELISA法测定免疫前后血清中抗原特异性IgG抗体和盲肠灌洗液中IgA抗体;流式细胞术分析脾及腹腔淋巴结(MLN)中T淋巴细胞IFN-γ分泌水平;酶联免疫斑点(ELISpot)分析脾淋巴细胞中抗原特异性IFN-γ的分泌水平.结果 cGAMP可促进小鼠抗幽门螺杆菌蛋白抗原的特异性IgG抗体应答;流式细胞术及ELISpot技术检测结果显示cGAMP可促进淋巴细胞抗原特异性IFN-γ的分泌.结论 cGAMP作为一种稳定的小分子化合物佐剂,通过皮下免疫途径,虽然不能诱导较强的黏膜sIgA抗体反应,但是可诱导较强的特异性T淋巴细胞反应和血清特异性IgG抗体应答,显著减少疫苗中抗原用量,为非口服幽门螺杆菌疫苗研发提供了一种新思路.

abstractsObjective To evaluate the adjuvant activities of cyclic guanosine monophosphate-adenosine monophosphate ( cGAMP) in enhancing humoral and cellular responses against Helicobacter pylori ( H. pylori) . Methods BALB/c mice were immunized with the protein antigens including UreA, UreB and NapA of H. pylori in combination with cGAMP as the adjuvant on 0 d and 14 d by subcutaneous administra-tion. Then, the serum-specific antibody responses were evaluated by ELISA. Flow cytometry ( FCM) and enzyme-linked immunospot assay ( ELISpot) were used to detect the cellular immune responses occurred in spleen and mesenteric lymph nodes (MLN). Results Subcutaneous administration of protein antigens of H. pylori together with cGAMP induced strong humoral and cellular immune responses in BALB/c mice. The levels of serum-specific IgG antibodies induced by adding cGAMP as the adjuvant were significantly higher than those by immunizing with antigens alone. The levels of splenic IFN-γ-producing lymphocytes in re-sponse to H. pylori antigens and cGAMP immunization were significantly higher than those in the correspond-ing groups without using cGAMP. Conclusion By using cGAMP as an adjuvant, H. pylori antigens could elicit significantly stronger humoral and cellular immune responses in mice than those induced by the anti-gens only. As a stable small molecular compound with strong adjuvant activity, cGAMP has the potential to be used for the development of H. pylori vaccine.