基于黏附素HpaA B细胞表位的多抗原肽疫苗的免疫原性鉴定OACSTPCD

Objective To prepare a multiple antigenic polypetide(MAP)vaccine based on the B-cell epitope of Helicobacter pylori(Hp)adhesin HpaA and to determine its immunogenicity.Methods Amino acid and nucleotide sequences of HpaA were obtained from GenBank.Epitope analysis softwares were utilized for HpaA B-cell epitope prediction.An 8-branch MAP was synthesized and used to immunize white-haired black eye(WHBE)rabbits.The affinity of MAP and rabbit anti-Hp polyclonal antibodies in vitro was determined,and the serum antibody titer and antibody specificity in vivo were detected.Results The dominant B cell epitopes of HpaA were located in the 130-142 and 212-219 amino acid segments,the 8-branched MAP1 and MAP2 were synthesized according to above B cell epitopes.Both MAP1 and MAP2 showed binding ability to rabbit anti-Hp polyclonal antibodies in vitro,while MAP1 exhibited higher affinity.Only MAP1 induced immune response and produced high-titer specific antibody in vivo.Conclusion The dominant B-cell epitope is located in 130-142 amino acid segment of HpaA,the corresponding MAP was synthesized and the vaccine was prepared in the study,which demonstrates strong immunogenicity.