Objective    To construct a fusion vaccine of Helicobacter pylori (Hp) urease subunit B (UreB)

outer membrane protein18 (OMP18) and E.coli heat-labile enterotoxin B subunit

summarized as UOL and study its antigenicity so as to lay a foundation to produce an H.pylori vaccine.     Methods    The UreB414

OMP18 and LTB genes were amplified by PCR

and cloned into pMD 18-T vector

and the products were identified and fused to abtain UOL. UOL was then subcloned into a procaryon expression vector pET-28a and transformed into E. coli cells BL21. Immunogenicity of the recombinant fusion protein was analyzed by Western blotting.     Results    The PCR fragments of ureb414

omp18 and ltb genes were about 414

537 and 320 bp

which had high homology with those related sequences in GenBank. Recombinant protein amounted to 15% of the total bacterial protein. Western blot showed that the protein had a specific reaction with UreB

OMP18 and LTB antiserum.     Conclusion    Expression of the fusion protein of UOL in E. coli cells provides a basis to produce engineered vaccine against Hp.