Identification Of The Th Epitopes From Urease B Subunit Of Helicobactor Pylori And Study On The Immunogenicity Of The Epitope Vaccine

ObjectiveEpitope vaccine is a special type of vaccine to combat the infection disease,cancer and autoimmune disease. Epitope based vaccine design can promote the protective immune responses and exclude the effects of non-protective and inhibitory immune responses. So selecting the protective B cell and T cell epitopes of antigen and designing the epitope vaccine rationally can avoid the side effect of the inhibitory epitopes on natural antigen.When Helicobacter pylori (Hp) infection occurs,the immune responses induced by Hp infection fail to clear Hp. In order to protect the human from chronic Hp infection by immunization, it is maybe necessary to design vaccine antigen different from natrual style to ecilit the effective immune responses. Studies have showed that protection is mediated by CD4~+T cells but not CD8 +T cells. So identification of the Th epitope of Hp antigen is the premise of designing the Hp epitope vaccine. The epitope vaccine containing the Hp protective B cell epitope and Th epitope may ecilit effective immune responses. This study is to identify the H-2d restricted Th epitope from protective antigen Urease B subunit(UreB) of Hp and to design the epitope vaccine containing three Th cell epitopes and one B cell epitope.Methods1. Th epitopes were predicted by the RANKPEP software; The predicted epitopes were identified by the proliferation of lymphocyte in BALB/c mice immunized with rUreB and the phenotype of the proliferated cells was analyzed by FACS; CD4~+T lymphocyte proliferation assays were carried to reconfirm the type of the proliferated cells; The MHC restriction assay was used to study the MHC restriction of Th epitopes;The cytokine production of CD4~+T lymphocyte induced by the peptides was detected by ELISA; The peptides were pooled to stimulate the CD4~+T lymphocyte simultaneously to investigate if...