Lin Chun-Xin, Wu Ting, Wu Xiao-Lu, Xie Ming-Hui, Cheng Tong, Li Shao-Wei, Zhang Jun, Xia Ning-Shao
National Institute of Diagnostics and Vaccine Development in Infectious Disease, Xiamen University, Xiamen 361005, China.
Sheng Wu Gong Cheng Xue Bao. 2007 Mar;23(2):310-4.
A dominant H-2d restricted Th epitope P34 was found to be contained in recombinant particulate hepatitis E virus (HEV) vaccine HEV 239. In this paper, the cellular immune response induced in P34 immunized BALB/c mice were studied and the priming effect of P34 was characterized. Groups of BALB/c mice were subcutaneously (s. c.) immunized with P34, splenocytes were then stimulated with P34 and HEV 239 protein, cellular immune response was assayed by IFN-gamma-ELISPOT, flow cytometry and T cell proliferation experiments. Results showed that P34 immunized BALB/c splenocytes responsed to P34 and HEV 239 protein stimulation in IFN-gamma-ELISPOT, flow cytometry and T cell proliferation experiments. After depletion of the CD4+ T cells from the immunized splenocytes by magnetic separation, the response decreased to the background level while almost no influence was observed after CD8 + T cells depletion which showed that the cells responsible for IFN-gamma secretion were mainly CD4+ T cells. Then mice were primed with P34 and boosted with its vector protein, E2, the E2 specific antibody titer were assayed. Results showed that after P34 priming, some of the 10 microg, 20 microg E2 boosted mice could develop anti-E2 antibody 1 week later and all the mice had detectable antibody 3 weeks after boosting. In the control peptide P18 priming group, even after boosting with 20 microg E2, anti-E2 antibody couldn't be detected until the end of this experiment. The results showed that priming with P34 epitope could increase the immunogenicity of its vector protein, E2, in BALB/c mice.
研究发现，重组戊型肝炎病毒（HEV）疫苗HEV 239中含有一个主要的H-2d限制性Th表位P34。本文研究了P34免疫的BALB/c小鼠诱导的细胞免疫反应，并对P34的启动效应进行了表征。将BALB/c小鼠分组皮下免疫P34，然后用P34和HEV 239蛋白刺激脾细胞，通过IFN-γ-ELISPOT、流式细胞术和T细胞增殖实验检测细胞免疫反应。结果显示，在IFN-γ-ELISPOT、流式细胞术和T细胞增殖实验中，P34免疫的BALB/c脾细胞对P34和HEV 239蛋白刺激有反应。通过磁性分离从免疫的脾细胞中去除CD4+ T细胞后，反应降至背景水平，而去除CD8 + T细胞后几乎没有观察到影响，这表明负责IFN-γ分泌的细胞主要是CD4+ T细胞。然后用P34对小鼠进行启动免疫，并用其载体蛋白E2进行加强免疫，检测E2特异性抗体滴度。结果显示，在P34启动免疫后，一些10微克、20微克E2加强免疫的小鼠在1周后可产生抗E2抗体，所有小鼠在加强免疫3周后均可检测到抗体。在对照肽P18启动免疫组中，即使在20微克E2加强免疫后，直到本实验结束也未检测到抗E2抗体。结果表明，用P34表位启动免疫可提高其载体蛋白E2在BALB/c小鼠中的免疫原性。
