Differential roles of interleukin-1beta and interleukin-8 in neutrophil transendothelial migration in patients with Helicobacter pylori infection

Identification of a neutrophil-specific PIK3R1 mutation facilitates targeted treatment in a patient with Sweet syndrome

BackgroundAcute febrile neutrophilic dermatosis (Sweet syndrome) is a potentially fatal multiorgan inflammatory disease characterized by fever, leukocytosis, and a rash with a neutrophilic infiltrate. The disease pathophysiology remains elusive, and current dogma suggests that Sweet syndrome is a process of reactivity to an unknown antigen. Corticosteroids and steroid-sparing agents remain frontline therapies, but refractory cases pose a clinical challenge.MethodsA 51-year-old woman with multiorgan Sweet syndrome developed serious corticosteroid-related side effects and was refractory to steroid-sparing agents. Blood counts, liver enzymes, and skin histopathology supported the diagnosis. Whole-genome sequencing, transcriptomic profiling, and cellular assays of the patient's skin and neutrophils were performed.ResultsWe identified elevated IL-1 signaling in lesional Sweet syndrome skin caused by a PIK3R1 gain-of-function mutation specifically found in neutrophils. This mutation increased neutrophil migration toward IL-1β and neutrophil respiratory burst. Targeted treatment of the patient with an IL-1 receptor 1 antagonist resulted in a dramatic therapeutic response and enabled a tapering off of corticosteroids.ConclusionDysregulated PI3K/AKT signaling is the first signaling pathway linked to Sweet syndrome and suggests that this syndrome may be caused by acquired mutations that modulate neutrophil function. Moreover, integration of molecular data across multiple levels identified a distinct subtype within a heterogeneous disease that resulted in a rational and successful clinical intervention. Future patients will benefit from efforts to identify potential mutations. The ability to directly interrogate the diseased skin allows this method to be generalizable to other inflammatory diseases and demonstrates a potential personalized medicine approach for patients with clinically challenging disease.Funding SourcesBerstein Foundation, NIH, Veterans Affairs (VA) Administration, Moseley Foundation, and H.T. Leung Foundation.

Helicobacter pylori, liver cirrhosis, and portal hypertension: an updated appraisal

OBJECTIVE

Helicobacter pylori (H. pylori) is the most common cause of gastritis and peptic ulcer. However, H. pylori is even involved in extragastric diseases, and it has been hypothesized that H. pylori could be a risk factor for several hepatic diseases. For instance, a direct involvement of H. pylori in the development of portal hypertension (PH) in cirrhotic patients has been postulated.

METHODS

We performed a literature search in major databases to elucidate the relationship between H. pylori, portal hypertension, and liver cirrhosis.

RESULTS

The effect of H. pylori on PH may be multifactorial. Endothelial dysfunction, alterations in the vasodilating dynamics, and neoangiogenesis are the most appealing theories about this issue, but the proofs come mainly from experimental studies, therefore a solid pathophysiological basis is still to be demonstrated. Congestive gastropathy (CG) and gastric antral vascular ectasia (GAVE) are two common endoscopic entities responsible for acute/chronic upper gastrointestinal bleeding, and a link with H. pylori has been hypothesized: the gastric mucosa, exposed to H. pylori, could develop both inflammatory microcirculatory alterations and thrombi, resembling the histologic pattern of GAVE.

CONCLUSIONS

Despite clues for an association between H. pylori and PH have been shown, these evidences are mostly experimental, therefore, in the absence of a direct proof on human beings, the role of H. pylori in the development of PH is uncertain. However, since this germ may be a cause of peptic ulcer, it should be found and eradicated in cirrhotic patients to reduce the risk of blood loss anemia.

Persisting and Increasing Neutrophil Infiltration Associates with Gastric Carcinogenesis and E-cadherin Downregulation

H. pylori-induced chronic inflammation is considered the most important cause of gastric cancer. The actual process how chronic inflammation triggers gastric carcinogenesis is still not clear. In this study, neutrophils and relative markers in gastric cancer development were examined with immunohistochemistry and fluorescence RNA in situ hybridization methods. On average, 24 times more neutrophils were found in gastric cancer tissues and about 9 times more neutrophils were found in gastric intestinal metaplasia tissues comparing to normal gastric tissue controls. CagA⁺ H. pylori infection in cancer adjacent tissues or EBV infection in cancer tissues did not increase neutrophil infiltration into gastric cancer tissues significantly. Neutrophil density was positively correlated with cell proliferation while negatively correlated with E-cadherin intensity. E-cadherin is also transcriptionally downregulated in gastric cancer tissues comparing to adjacent tissue controls. The increased neutrophils in the gastric cancer tissues appear to be related to increased chemoattractant IL-8 levels. In gastric cancers, neutrophil numbers were higher comparing to cancer adjacent tissues and not associated with patient ages, tumor invasion depth, tumor staging, metastasis or cancer types. The conclusion is that persisting and increasing neutrophil infiltration is associated with E-cadherin downregulation, cell proliferation and gastric carcinogenesis.

TLR9 and NF-κB are partially involved in activation of human neutrophils by Helicobacter pylori and its purified DNA

Helicobacter pylori infection represents one of the most common bacterial infections worldwide. The inflammatory response to this bacterium involves a large influx of neutrophils to the lamina propria of the gastric mucosa. However, little is known about the receptors and molecular mechanisms involved in activation of these neutrophils. In this study, we aimed to determine the role of toll-like receptor 9 (TLR9) in the response of human neutrophils to H. pylori and purified H. pylori DNA (Hp-DNA). Neutrophils were isolated from the blood of adult volunteers and challenged with either H. pylori or Hp-DNA. We found that both, H. pylori and Hp-DNA induced increased expression and release of IL-8. Furthermore, we showed that TLR9 is involved in the induction of IL-8 production by H. pylori and Hp-DNA. IL-8 production induced by H. pylori but not by Hp-DNA was partially mediated by NF-κB. In conclusion, this study showed for first time that both, H. pylori and Hp-DNA activate TLR9 and induce a different inflammatory response that leads to activation of neutrophils.

Helicobacter species methods and protocols. Introduction

Helicobacter infection is a chronic persistent condition which is responsible for the majority of cases of gastric and duodenal ulcers, and gastric cancer. The study of the bacteria, the interaction of the bacteria with the host, and the host immune response has greatly benefited from standardization of culture techniques and animal models. The following chapters will describe the clinical aspects of infection and touch on the important techniques for optimal investigation of this infection.

Phagocytosis and persistence of Helicobacter pylori

Helicobacter pylori is a spiral-shaped, flagellated, microaerophilic Gram-negative bacterium that colonizes the gastric epithelium of humans. All persons infected with H. pylori have gastritis, and some will develop severe disease such as peptic ulcers or gastric cancer. A characteristic feature of this infection is the pronounced accumulation of phagocytes, particularly neutrophils, in the gastric mucosa. H. pylori thrives in a phagocyte-rich environment, and we describe here how this organism uses an array of novel virulence factors to manipulate chemotaxis, phagocytosis, membrane trafficking and the respiratory burst as a means to evade elimination by the innate immune response.

Stem cells and cancer: Evidence for bone marrow stem cells in epithelial cancers

Cancer commonly arises at the sites of chronic inflammation and infection. Although this association has long been recognized, the reason has remained unclear. Within the gastrointestinal tract, there are many examples of inflammatory conditions associated with cancer, and these include reflux disease and Barrett’s adenocarcinoma of the esophagus, Helicobacter infection and gastric cancer, inflammatory bowel disease and colorectal cancer and viral hepatitis leading to hepatocellular carcinoma. There are several mechanisms by which chronic inflammation has been postulated to lead to cancer which includes enhanced proliferation in an endless attempt to heal damage, the presence of a persistent inflammatory environment creating a pro-carcinogenic environment and more recently a role for engraftment of circulating marrow-derived stem cells which may contribute to the stromal components of the tumor as well as the tumor mass itself. Here we review the recent advances in our understanding of the contributions of circulating bone marrow-derived stem cells to the formation of tumors in animal models as well as in human beings.

Bone marrow cells as the origin of stomach cancer

Cells derived from bone marrow are pluripotent, with the ability to differentiate into multiple cell types. Environmental cues dictate differentiation decisions. It should not be surprising then, that abnormal cell environments lead to abnormal differentiation of these cells, and in some cases, malignant transformation. Identifying a role for bone marrow-derived cells in the initiation and progression of cancer allows a dramatic change in the way in which cancer is viewed. Identifying the cell responsible for initiating a tumor offers the exciting possibility of specifically targeting unique aspects of these cells and altering signaling properties for more effective therapeutic approaches.