In vivo expression of the 25-kDa laminin-binding protein ofHelicobacter pylori

Abstract

The gastroduodenal pathogen Helicobacter pylori has been shown to inhibit the interaction between the extracellular matrix protein laminin and its receptor on gastric epithelial cells, potentially contributing to a loss of mucosal integrity. As a 25-kDa outer membrane protein of H. pylori in association with the bacterial lipopolysaccharides (LPS) mediates attachment to laminin, the aim of this study was to determine whether the 25-kDa protein is produced by H. pylori in infected hosts. We examined the immune response to the 25-kDa laminin binding protein in 12 paediatric patients; samples from a H. pylori-negative healthy adult were used as controls. In immunoblotting, antibodies to a 25-kDa protein were found in the serum and saliva of H. pylori-positive individuals only, and using the positive sera and saliva, laminin binding to the 25-kDa protein was inhibited. Thus, the 25-kDa laminin-binding protein is produced by H. pylori in infected hosts.

Human pathogens utilize host extracellular matrix proteins laminin and collagen for adhesion and invasion of the host

“…Several H. pylori surface proteins are involved in the interaction with Ln. One such molecule is a 25-kDa protein that functions as a surface antigen and gives rise to antibodies detectable in saliva and sera of H. pylori-positive patients (Trust et al, 1991;Valkonen et al, 1994;Moran et al, 2005). Additionally, it has been predicted that haemagglutinating H. pylori isolates bind Ln two-fold higher (K d = 4.1 picomole) in comparison with nonhaemagglutinating isolates (K d = 8.2 picomole).…”

Sweet-talk: role of host glycosylation in bacterial pathogenesis of the gastrointestinal tract

“…Other known H pylori adhesins include neutrophil-activating protein, which binds to sulfated carbohydrate structures,26 27 a 25 kDa adhesin that binds the glycoprotein laminin in the extracellular matrix,28 29 as well as adherence-associated lipoprotein A and B (AlpA/B)10 30 and HorB,31 whose gastric receptors have not been identified. Moreover, H pylori lectins bind molecules in the oral cavity, such as salivary agglutinin, that may influence re-infection of the gastric mucosa from this secondary infection reservoir 32.…”

Lipopolysaccharide in bacterial chronic infection: Insights from Helicobacter pylori lipopolysaccharide and lipid A

“…For example, in conjunction with a 25-kDa protein adhesin (Valkonen et al, 1997), that has been confirmed to be produced in vivo (Moran et al, 2005a), H. pylori LPS can bind laminin which is an important extracellular matrix glycoprotein found in the basement membrane (Valkonen et al, 1994). Moreover, the LPS-laminin binding may inhibit recognition of the glycoprotein by the laminin receptor (67 kDa integrin) on gastric epithelial cells (Slomiany et al, 1991).…”