Guo Le, Yin Runting, Liu Kunmei, Lv Xiaobo, Li Yonghong, Duan Xiangguo, Chu Yuankui, Xi Tao, Xing Yingying
State Key Laboratory of Natural Medicines, School of Life Science and Technology, China Pharmaceutical University, 24 Tong Jiaxiang Road, Nanjing, 210009, China.
Appl Microbiol Biotechnol. 2014 Apr;98(8):3495-507. doi: 10.1007/s00253-013-5408-6. Epub 2013 Dec 28.
Epitope vaccine is a promising option for prophylactic and therapeutic vaccination against Helicobacter pylori infection. Urease is an essential virulence factor and colonization factor for H. pylori. In this study, we constructed a multi-epitope vaccine named CTB-UE with mucosal adjuvant cholera toxin B subunit (CTB) and tandem copies of Th and B cell epitopes from H. pylori urease A and B subunits. The immunogenicity, specificity, ability to induce neutralizing antibodies against H. pylori urease, and prophylactic and therapeutic efficacy of the CTB-UE vaccine were evaluated in BALB/c mice model after purification. The experimental results indicated that CTB-UE could induce comparatively high levels of specific antibodies against native H. pylori urease, UreA, UreB, or the selected B cell epitopes UreA₁₈₃₋₂₀₃ and UreB₃₂₇₋₃₃₄ involved with the active site of urease and showed an effectively inhibitory effect on the enzymatic activity of urease. Besides, oral prophylactic or therapeutic immunization with CTB-UE significantly decreased H. pylori colonization compared with oral immunization with rUreB or PBS, and the protection was correlated with antigen-specific CD4⁺ T cells and IgG, IgA, and mucosal sIgA antibody responses. This CTB-UE vaccine may be a promising vaccine candidate for the control of H. pylori infection.
表位疫苗是预防和治疗幽门螺杆菌感染的一种有前景的疫苗选择。脲酶是幽门螺杆菌的一种必需毒力因子和定植因子。在本研究中,我们构建了一种名为CTB-UE的多表位疫苗,其含有黏膜佐剂霍乱毒素B亚单位(CTB)以及来自幽门螺杆菌脲酶A和B亚单位的Th和B细胞表位的串联拷贝。纯化后,在BALB/c小鼠模型中评估了CTB-UE疫苗的免疫原性、特异性、诱导抗幽门螺杆菌脲酶中和抗体的能力以及预防和治疗效果。实验结果表明,CTB-UE可诱导产生针对天然幽门螺杆菌脲酶、UreA、UreB或与脲酶活性位点相关的选定B细胞表位UreA₁₈₃₋₂₀₃和UreB₃₂₇₋₃₃₄的较高水平特异性抗体,并对脲酶的酶活性显示出有效抑制作用。此外,与用rUreB或PBS口服免疫相比,用CTB-UE进行口服预防或治疗性免疫显著降低了幽门螺杆菌的定植,且这种保护作用与抗原特异性CD4⁺ T细胞以及IgG、IgA和黏膜sIgA抗体反应相关。这种CTB-UE疫苗可能是控制幽门螺杆菌感染的一种有前景的候选疫苗。