幽门螺杆菌尿素酶B亚单位Th表位的免疫学特性研究

采用MHC限制性分析、ELISA方法、淋巴细胞增殖实验等方法研究幽门螺杆菌(Hp)尿素酶B亚单位(UreB)的H- 2~d限制性Th表位U_(546-561)、U_(229-244)、U_(237-251)的免疫学特性。发现抗I-E~d抗体能够抑制U_(546-561)对CD4~+T淋巴细胞的刺激,抗I-A~d抗体能够抑制U_(229-244)、U_(237-251)对CD4~+T淋巴细胞的刺激作用。U_(229-244)、U_(229-244)能刺激CD4~+T淋巴细胞分泌IL-4和IL-10,U_(237-251)刺激CD4~+T淋巴细胞分泌IFN-γ、IL-2,且U_(546-561)、U_(229-244)、U_(237-251)三个表位肽免疫BALB/c小鼠能够引起针对各自免疫多肽和rUreB的CD4~+T细胞应答。结果表明U_(546-561)为I-E~d限制性Th2表位,U_(229-244)为I-A~d限制性Th2表位、U_(237-251)为I-A~d限制性Th1表位。三个表位之间具有协同刺激效应,可以用于Hp表位疫苗的研究。

Characterization of the Th epitopes in the urease B subunit of Helicobacter pylori

The immulogical characteristcs of the H-2~d restricted Th epitopes in the urease B subunit of Helicobacter pylori was clarified by means of MHC-restriction,ELISA and lymphocyte proliferation assay.It was demonstrated that the stimula- tory effects of epitope U_(546-561) and epitopes U_(229-244) and U_(237-251) to CD4~+ T lymphocytes could be inhibited by anti-I-E~d antibody and I-A~d antibody respectively.The epitopes U_(546-561) and U_(229-244) could enhance the production of IL-4 and IL-10 by CD4~+ T lymphocytes,while epitope U_(237-251) could stimulate the secretion of IFN-γand IL-2 by CD4~+ T lymphocytes.In addition,im- munization of BALB/c mice with epitopes U_(546-561),U_(229-244) and U_(237-251) could induce the CD4~+ T cell responses against the cor- responding peptides used for immunization and recombinant urease B subunit(rUreB).These results indicate that U_(546-561) repre- sents the I-E~d restricted Th2 type epitope,U_(229-244) represents the I-A~d restricted Th2 type epitope,and U_(237-251) was the I-A~d restricted Th1 type epitope.There was synergistic interaction among these 3 epitopes and they can be used for vaccine design.