Augmentation of Helicobacter pylori urease activity by its specific IgG antibody: implications for bacterial colonization enhancement

Abstract

Gastric colonization of Helicobacter pylori (H. pylori) occurs in a very early age via infected mothers having H. pylori-specifi c IgG antibodies that would be transplacentally transferred to infants. In addition, H. pylori urease-specifi c IgG was associated with chronic gastric atrophy and post-immunization gastritis is usually correlated with a strong local IgG response. These fi ndings indicate that H. pylori-specifi c IgG antibodies, in particular its urease-specifi c IgG, may induce unfavorable infl uence on host resistance against H. pylori. Here, we show that we have found a unique H. pylori urease-specifi c IgG monoclonal antibody (MAb), termed S3, recognizing the conformational structure of the small subunit Ure-A, which enhanced the urease enzymatic activity.

Implications for Induction of Autoimmunity via Activation of B-1 Cells byHelicobacter pyloriUrease

“…The bacterium used in the present study was wild-type H. pylori strain, Sydney strain 1 (SS-1), which is a mousevirulent isolate originally isolated from a human patient (27). To obtain a large amount of bacterial cells, we used the following methods as described previously (21). SS-1 was cultured on brain heart infusion (BHI) agar (Oxoid, Hampshire, United Kingdom) containing 7% defibrinated horse blood (Nisseizai) at 37°C under microaerophilic conditions (5% O 2 , 15% CO 2 , and 80% N 2 ) with AnaeroPack Campylo (Mitsubishi Gas Chemical Co., Inc., Tokyo, Japan).…”

“…pylori infection. The mice were infected with H. pylori was done according to the following recently established procedure (21). Three hundred microliters of the bacterial solution containing about 10 8 CFU of H. pylori (SS-1) was orally administered to each mouse on three successive days.…”

Cross-reaction of antibody against Helicobacter pylori urease B with platelet glycoprotein IIIa and its significance in the pathogenesis of immune thrombocytopenic purpura

“…Bacteria H. pylori were isolated from an antral biopsy sample of a patient with peptic ulcer presenting for gastroscopy, and then cultured on H. pylori selective agar plates with 5% defibrinated sheep blood and antibiotics at 37°C under microaerophilic conditions with 5% O 2 , 15% CO 2 and 80% N 2 following methods as described previously [18]. After being cultured for 5 days, the colonies were scraped and stained to confirm that the cultured bacilli were Gram-negative, flagellate or curved H. pylori (Fig.…”

Production of Autoantibodies by Murine B-1a Cells Stimulated with Helicobacter pylori Urease through Toll-Like Receptor 2 Signaling

“…The blots were blocked overnight at 4°C with Block Ace (Dainihon Seiyaku, Osaka, Japan). The membrane was incubated with anti-whole H. pylori ureasespecific antibody from immune rabbit serum and two murine H. pylori ureasespecific MAbs, termed L2 for the large subunit (UreB) (22) and S2 for the small subunit (UreA) (15). The blots were washed five times with PBS containing 0.05% Tween 20 (T-PBS) and incubated with biotinylated goat anti-rabbit immunoglobulin (Ig) and anti-mouse Ig (Vector Laboratories, Burlingame, CA) at 1:200 in PBS for 2 h at room temperature (RT).…”