PRODUCTION AND CHARACTERIZATION OF MONOCLONAL-ANTIBODIES TO HEAT-SHOCK-PROTEIN-60 OF HELICOBACTER-PYLORI

Two monoclonal antibodies (MAbs), designated as H9 (IgG2a) and H20 (Ig M), directed against heat-shock protein 60 (HSP60) of Helicobacter pyl ori strain TK1029 were established, Affinity-purified antigens cross-r eacted in immunoblots with MAb H9 and MAb H20 respectively, These anti gens also reacted with the 3C8 MAb previously established in this labo ratory, which recognised Yersinia enterocolitica HSP60, By aminoacid s equence analysis, the N-terminal amino-acid sequence of the protein re cognised by both H9 and H20 MAbs was confirmed as the amino-acid seque nce of H, pylori HSP60 reported previously, Both MAbs reacted with nin e strains of H, pylori in enzyme-linked immunosorbent assay (ELISA) an d immunoblot analysis, In addition, MAb H9 reacted with extracts of ot her bacteria including H, mustelae, Pseudomonas aeruginosa, Vibrio cho lerae, Serratia marcescens, Proteus mirabilis, Escherichia coli and Sh igella sonnei, In contrast, MAb H20 reacted only with strains H, pylor i. These results suggest that both the species-specific epitope recogn ised by MAb H20 and the common epitope recognised by MAb H9 exist on H SP60 of the bacterial cell, Both MAbs also reacted with the 60-kDa pro tein in the lysate of human gastric carcinoma (MKN45) cells, It was sh own by immunohistochemical staining that gastric epithelial cells of f our out of six biopsy specimens examined stained positively with MAb H 20, These results suggest that there is a common epitope in H, pylori HSP60 and human gastric epithelial cells.