Characterization of a Helicobacter pylori neutrophil-activating protein

Infect Immun. 1995 Jun;63(6):2213-20. doi: 10.1128/IAI.63.6.2213-2220.1995.


Helicobacter pylori-associated gastritis is mainly an inflammatory cell response. In earlier work we showed that activation of human neutrophils by a cell-free water extract of H. pylori is characterized by increased expression of neutrophil CD11b/CD18 and increased adhesiveness to endothelial cells. The work reported here indicates that the neutrophil-activating factor is a 150,000-molecular-weight protein (150K protein). Neutrophil proadhesive activity copurified with this protein, which is a polymer of identical 15K subunits. Specific antibody, prepared against the purified 15K subunit, neutralized the proadhesive activity of the pure protein and of water extracts obtained from different strains of H. pylori. The gene (napA) for this protein (termed HP-NAP, for H. pylori neutrophil-activating protein) was detected, by PCR amplification, in all of the H. pylori isolates tested; however, there was considerable strain variation in the level of expression of HP-NAP activity in vitro. HP-NAP could play an important role in the gastric inflammatory response to H. pylori infection.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Bacterial Adhesion
  • Bacterial Proteins / immunology
  • Bacterial Proteins / isolation & purification*
  • Bacterial Proteins / pharmacology
  • Base Sequence
  • CD11 Antigens / analysis
  • CD18 Antigens / analysis
  • Free Radicals
  • Genes, Bacterial
  • Helicobacter pylori / chemistry*
  • Humans
  • Molecular Sequence Data
  • Molecular Weight
  • Neutrophil Activation / drug effects*
  • Oxygen / metabolism


  • Bacterial Proteins
  • CD11 Antigens
  • CD18 Antigens
  • Free Radicals
  • Oxygen