Helicobacter pylori outer membrane proteins and gastroduodenal disease

Abstract

Background and aims: A number of Helicobacter pylori outer membrane proteins (OMPs) undergo phase variations. This study examined the relation between OMP phase variations and clinical outcome. Methods: Expression of H pylori BabA, BabB, SabA, and OipA proteins was determined by immunoblot. Multiple regression analysis was performed to determine the relation among OMP expression, clinical outcome, and mucosal histology.Results: H pylori were cultured from 200 patients (80 with gastritis, 80 with duodenal ulcer (DU), and 40 with gastric cancer). The most reliable results were obtained using cultures from single colonies of low passage number. Stability of expression with passage varied with OipA . BabA . BabB . SabA. OipA positive status was significantly associated with the presence of DU and gastric cancer, high H pylori density, and severe neutrophil infiltration. SabA positive status was associated with gastric cancer, intestinal metaplasia, and corpus atrophy, and negatively associated with DU and neutrophil infiltration. The Sydney system underestimated the prevalence of intestinal metaplasia/atrophy compared with systems using proximal and distal corpus biopsies. SabA expression dramatically decreased following exposure of H pylori to pH 5.0 for two hours. Conclusions: SabA expression frequently switched on or off, suggesting that SabA expression can rapidly respond to changing conditions in the stomach or in different regions of the stomach. SabA positive status was inversely related to the ability of the stomach to secrete acid, suggesting that its expression may be regulated by changes in acid secretion and/or in antigens expressed by the atrophic mucosa.

Roles of Helicobacter pylori BabA in gastroduodenal pathogenesis

“…Nonetheless, approximately half of the studies have suggested a correlation between babA2-positive H pylori in Western countries and increased risk of developing significant clinical outcomes [38,[44][45][46]52] and are in agreement with protein data as described above [31,33,34] . The prevalence of clinical isolates with a non-functional babA2 gene without production of BabA protein may be low and negligible in some studies.…”

“…There currently are only a few studies that correlate the importance of BabA with clinical outcomes using immunoblot analyses [31,33,34] . My group recently performed large scale studies of 520 geographically diverse patients presenting with different clinical symptoms to evaluate BabA status by immunoblot analysis [31] .…”

Functional and Intracellular Signaling Differences Associated with the Helicobacter pylori AlpAB Adhesin from Western and East Asian Strains

“…Immunoblotting-Anti-AlpA (AK214) (8), anti-AlpB (AK262) (9), anti-BabA (AK277) (18), and anti-OipA antisera (AK282) (19) were used as primary antibodies at a 1:5,000 dilution. Anti-CagA and anti-VacA antibodies (Austral Biologicals, San Ramon, CA) were used at a 1:3,000 dilution.…”

Helicobacter pylori BabA Expression, Gastric Mucosal Injury, and Clinical Outcome

“…To minimize the risk of phase variations, all H pylori samples were obtained from a single bacterial colony that was passaged in vitro less than 4 times. 26 The control strain was strain J99, 27 which contains a babA gene and possesses Le b binding ability. 3 We also used strain 26695, 23 which contains a babA gene but does not bind to Le b , 3 and strain TN2GF4, 28 which contains a babA gene and possesses Le b binding ability.…”