Expression of Surfactant Protein D in the Human Gastric Mucosa and during Helicobacter pylori Infection

AUTOR(ES)
FONTE

American Society for Microbiology

RESUMO

Helicobacter pylori establishes persistent infection of gastric mucosa with diverse clinical outcomes. The innate immune molecule surfactant protein D (SP-D) binds selectively to microorganisms, inducing aggregation and phagocytosis. In this study, we demonstrated the expression of SP-D in gastric mucosa by reverse transcription-PCR and immuohistochemical analysis. SP-D is present at the luminal surface and within the gastric pits, with maximal expression at the surface. Levels of expression are significantly increased in H. pylori-associated gastritis compared to those in the normal mucosa. Immunofluorescence microscopy was used to demonstrate binding and agglutination of H. pylori by SP-D in a lectin-specific manner. These activities resulted in a 50% reduction in the motility of H. pylori, as judged on the basis of curvilinear velocity measured by using a Hobson BacTracker. Lipopolysaccharides extracted from three H. pylori strains were shown to bind SP-D in a concentration-dependent manner, and there was marked variation in the avidity of binding among the strains. SP-D may therefore play a significant role in the innate immune response to H. pylori infection.

Documentos Relacionados