title: [In vitro study of the biological activities and immunogenicity of recombinant adhesin of Heliobacter pylori rHpaA].
abstract: OBJECTIVE
  To evaluate the biological activities and immunogenicity of recombinant adhesin of Helicobacter pylori rHpaA in vitro and the feasibility of its application in development of Helicobacter pylori vaccine.
  
  
  METHODS
  The effect of rHpaA and its antibody on the adhesion of H. pylori to human gastric epithelial cell lines was investigated by flow cytometry and light microscopy. ELISA was used to measure the HpaA-specific antibodies in sera of H. pylori-infected patients. The proliferation of peripheral blood lymphocytes (PBL) in response to rHpaA was examined by (3)H-TDR incorporation test. Flow cytometry was adopted to detect the selective proliferation effect of rHpaA on different phenotypes of T helper cells in PBLs.
  
  
  RESULTS
  Both rHpaA and anti-HpaA serum partially inhibited the adhesion of Heliobacter pylori to gastric epithelial cell lines. Anti-HpaA antibodies (coated with rHpaA) were detected in sera from H. Pylori-infected patients with a detection rate similar to that of anti-HpaA antibodies coated with HpSON (50% Vs 53.75%, P > 0.05). The rHpaA was capable of stimulating the proliferation of PBL (P < 0.05), no matter IL-2 was added into the culture medium or not. Both Hp positive and negative PBLs, after incubation with rHpaA, could significantly raise the proportion of IL-4 positive T cell (Th2 cell) (P < 0.05).
  
  
  CONCLUSIONS
  HpaA is an immunogenic surface protein of H. pylori and can selectively increase the proportion of Th2 cells in vitro and is a hopeful new antigen in the development of H. pylori vaccine.
authors.affiliation: PLA Institute of Digestive Medicine, The First Military Medical University, Guangzhou 510515, China.
authors.forename: Y
authors.initials: Y
authors.lastname: Chen
authors.forename: J
authors.initials: J
authors.lastname: Wang
authors.forename: L
authors.initials: L
authors.lastname: Shi
mesh_terms: D018829:Adhesins, Bacterial / Q000235:genetics / Q000276:immunology*; D000906:Antibodies / Q000494:pharmacology; D016480:Helicobacter pylori / Q000235:genetics / Q000276:immunology*; D006388:Hemagglutinins / Q000235:genetics / Q000276:immunology*; D006801:Humans; D011994:Recombinant Proteins / Q000235:genetics / Q000276:immunology; D014407:Tumor Cells, Cultured
chemical_list: D018829:Adhesins, Bacterial; D000906:Antibodies; D006388:Hemagglutinins; D011994:Recombinant Proteins; C095977:adhesin A, Helicobacter