Investigating the Role of Helicobacter pylori PriA Protein.

Background: In bacteria, PriA protein, a conserved DEXH-type DNA helicase, plays a central role in replication restart at stalled replication forks. Its unique DNA binding property allows it to recognize and stabilize stalled forks and the structures derived from them. PriA plays a very critical role in replication fork stabilization and DNA repair in E.

Stimulation of Toll-Like Receptors profoundly influences the titer of polyreactive antibodies in the circulation.

Polyreactive antibodies are a major component of the natural antibody repertoire and bind to a variety of structurally unrelated molecules. These antibodies are thought to provide a first line of defense against bacterial infections and play a major role in the clearance of apoptotic cells. What triggers the secretion of these antibodies has remained an enigma.

Prevalence of Helicobacter pylori infection and its relation with body mass index in a Chinese population.

Background: Helicobacter pylori infection is highly prevalent worldwide. The association between obesity and H. pylori infection is controversial in the literature.

A reporter mouse reveals lineage-specific and heterogeneous expression of IRF8 during lymphoid and myeloid cell differentiation.

The IFN regulatory factor family member 8 (IRF8) regulates differentiation of lymphoid and myeloid lineage cells by promoting or suppressing lineage-specific genes. How IRF8 promotes hematopoietic progenitors to commit to one lineage while preventing the development of alternative lineages is not known. In this study, we report an IRF8-EGFP fusion protein reporter mouse that revealed previously unrecognized patterns of IRF8 expression.

Olfm4 deletion enhances defense against Staphylococcus aureus in chronic granulomatous disease.

Chronic granulomatous disease (CGD) patients have recurrent life-threatening bacterial and fungal infections. Olfactomedin 4 (OLFM4) is a neutrophil granule protein that negatively regulates host defense against bacterial infection. The goal of this study was to evaluate the impact of Olfm4 deletion on host defense against Staphylococcus aureus and Aspergillus fumigatus in a murine X-linked gp91phox-deficiency CGD model.

Screening Helicobacter pylori genes induced during infection of mouse stomachs.

Aim: To investigate the effect of in vivo environment on gene expression in Helicobacter pylori (H. pylori) as it relates to its survival in the host.

Methods: In vivo expression technology (IVET) systems are used to identify microbial virulence genes.

Olfactomedin 4 inhibits cathepsin C-mediated protease activities, thereby modulating neutrophil killing of Staphylococcus aureus and Escherichia coli in mice.

Neutrophils kill bacteria generally through oxidative and nonoxidative mechanisms. Whereas much research has focused on the enzymes essential for neutrophil killing, little is known about the regulatory molecules responsible for such killing. In this study, we investigated the role of olfactomedin 4 (OLFM4), an olfactomedin-related glycoprotein, in neutrophil bactericidal capability and host innate immunity.

Olfactomedin 4 down-regulates innate immunity against Helicobacter pylori infection.

Olfactomedin 4 (OLFM4) is a glycoprotein that has been found to be up-regulated in inflammatory bowel diseases and Helicobacter pylori infected patients. However, its role in biological processes such as inflammation or other immune response is not known. In this study, we generated OLFM4 KO mice to investigate potential role(s) of OLFM4 in gastric mucosal responses to H.

Regulation of cell growth during serum starvation and bacterial survival in macrophages by the bifunctional enzyme SpoT in Helicobacter pylori.

In Helicobacter pylori the stringent response is mediated solely by spoT. The spoT gene is known to encode (p)ppGpp synthetase activity and is required for H. pylori survival in the stationary phase.

Dismutase activity of ADP-L-glycero-D-manno-heptose 6-epimerase: evidence for a direct oxidation/reduction mechanism.

The first positive evidence for the utilization of a direct C-6' ' oxidation/reduction mechanism by ADP-l-glycero-d-manno-heptose 6-epimerase is reported here. The epimerase (HldD or AGME, formerly RfaD) operates in the biosynthetic pathway of l-glycero-d-manno-heptose, which is a conserved sugar in the core region of lipopolysaccharide (LPS) of Gram-negative bacteria. The stereochemical inversion catalyzed by the epimerase is interesting as it occurs at an "unactivated" stereocenter that lacks an acidic C-H bond, and therefore, a direct deprotonation/reprotonation mechanism cannot be employed.

Development of a noninvasive method for detecting and monitoring the time course of Helicobacter pylori infection.

Helicobacter pylori infection status following experimental inoculation of mice presently requires euthanasia. The purpose of this study was to develop a method for following the time course of H. pylori infection in live experimental animals.

The mechanism of the reaction catalyzed by ADP-beta-L-glycero-D-manno-heptose 6-epimerase.

ADP-l-glycero-d-manno-heptose 6-epimerase (AGME, RfaD) is a bacterial enzyme that is involved in lipopolysaccharide biosynthesis and interconverts ADP-beta-l-glycero-d-manno-heptose (ADP-l,d-Hep) with ADP-beta-d-glycero-d-manno-heptose (ADP-d,d-Hep). AGME is known to require a tightly bound NADP+ cofactor for activity and presumably employs a mechanism involving transient oxidation of the substrate. Four mechanistic possibilities are considered that involve transient oxidation at either C-7' ', C-6' ', or C-4' ' of the heptose nucleotide.