Expression of surfactant protein D in the human gastric mucosa and during Helicobacter pylori infection.
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 immunohistochemical 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.
Murray
Emma
E
MRC Immunochemistry Unit, Oxford, United Kingdom.
Khamri
Wafa
W
Walker
Marjorie M
MM
Eggleton
Paul
P
Moran
Anthony P
AP
Ferris
John A
JA
Knapp
Susanne
S
Karim
Q Najma
QN
Worku
Mulegata
M
Strong
Peter
P
Reid
Kenneth B M
KB
Thursz
Mark R
MR
D001422:Bacterial Adhesion; D004415:Dyspepsia / Q000276:immunology / Q000378:metabolism* / Q000382:microbiology; D005753:Gastric Mucosa / Q000276:immunology / Q000378:metabolism*; D006023:Glycoproteins / Q000096:biosynthesis* / Q000235:genetics / Q000302:isolation & purification; D016481:Helicobacter Infections / Q000276:immunology / Q000378:metabolism*; D016480:Helicobacter pylori / Q000276:immunology* / Q000472:pathogenicity; D006801:Humans; D007113:Immunity, Innate; D037102:Lectins / Q000378:metabolism; D008070:Lipopolysaccharides / Q000378:metabolism; D011485:Protein Binding; D037663:Pulmonary Surfactant-Associated Protein D; D011663:Pulmonary Surfactants / Q000096:biosynthesis* / Q000235:genetics / Q000302:isolation & purification; D012333:RNA, Messenger / Q000096:biosynthesis; D013045:Species Specificity
D006023:Glycoproteins; D037102:Lectins; D008070:Lipopolysaccharides; D037663:Pulmonary Surfactant-Associated Protein D; D011663:Pulmonary Surfactants; D012333:RNA, Messenger