CCR5-Positive Inflammatory Monocytes are Crucial for Control of Sepsis.

Neutrophils and inflammatory monocytes control sepsis by migration to the site of infection via their chemokine receptors. CCR5 is a chemokine receptor that is not expressed on neutrophils and inflammatory monocytes under homeostatic conditions. However, it has been demonstrated that CCR5 can become expressed on these cells during different models of inflammation.

The host control of a clinical isolate strain of P. aeruginosa infection is independent of Nod-1 but depends on MyD88.

Objective And Design: The objective of this study was to investigate the role of Nod1 in the recruitment of neutrophils into the infection site and in the establishment of the inflammatory response elicited by a clinical isolate strain of P. aeruginosa in vivo, while comparing it to the well-established role of MyD88 in this process.

Subjects: Wild-type, Nod1 and MyD88 mice, all with a C57Bl/6 background.

IL-33 contributes to sepsis-induced long-term immunosuppression by expanding the regulatory T cell population.

Patients who survive sepsis can develop long-term immune dysfunction, with expansion of the regulatory T (Treg) cell population. However, how Treg cells proliferate in these patients is not clear. Here we show that IL-33 has a major function in the induction of this immunosuppression.

Immune modulation of some autoimmune diseases: the critical role of macrophages and neutrophils in the innate and adaptive immunity.

Macrophages and neutrophils are key components involved in the regulation of numerous chronic inflammatory diseases, infectious disorders, and especially certain autoimmune disease. However, little is known regarding the contribution of these cells to the pathogenesis of autoimmune disorders. Recent studies have aimed to clarify certain important factors affecting the immunogenicity of these cells, including the type and dose of antigen, the microenvironment of the cell-antigen encounter, and the number, subset, and phenotype of these cells, which can prevent or induce autoimmune responses.

Neutrophil Extracellular Traps Induce Organ Damage during Experimental and Clinical Sepsis.

Organ dysfunction is a major concern in sepsis pathophysiology and contributes to its high mortality rate. Neutrophil extracellular traps (NETs) have been implicated in endothelial damage and take part in the pathogenesis of organ dysfunction in several conditions. NETs also have an important role in counteracting invading microorganisms during infection.

MyD88-, but not Nod1- and/or Nod2-deficient mice, show increased susceptibility to polymicrobial sepsis due to impaired local inflammatory response.

Pathogen recognition and triggering of the inflammatory response following infection in mammals depend mainly on Toll-like and Nod-like receptors. Here, we evaluated the role of Nod1, Nod2 and MyD88-dependent signaling in the chemokine production and neutrophil recruitment to the infectious site during sepsis induced by cecal ligation and puncture (CLP) in C57Bl/6 mice. We demonstrate that Nod1 and Nod2 are not involved in the release of chemokines and recruitment of neutrophils to the infectious site during CLP-induced septic peritonitis because these events were similar in wild-type, Nod1-, Nod2-, Nod1/Nod2- and Rip2-deficient mice.

Heme oxygenase inhibition enhances neutrophil migration into the bronchoalveolar spaces and improves the outcome of murine pneumonia-induced sepsis.

A reduction of the neutrophil migration into the site of infection during cecal ligation and puncture-induced sepsis increases host mortality. Inhibition of heme oxygenase (HO) prevents this neutrophil paralysis and improves host survival in the cecal ligation and puncture model. Taking into account that almost 50% of all sepsis cases are a consequence of pneumonia, we designed the present study to determine the role of HO in an experimental model of pneumonia-induced sepsis.

Sildenafil improves the beneficial hemodynamic effects exerted by atorvastatin during acute pulmonary thromboembolism.

We investigated whether atorvastatin has beneficial hemodynamic effects during acute pulmonary thromboembolism (APT) and whether sildenafil improves these effects. We studied the involvement of oxidative stress, matrix metalloproteinases (MMPs), and neutrophil activation. APT was induced with autologous blood clots (500 mg/kg) in anesthetized male lambs pretreated with atorvastatin (10 mg/kg/day, subcutaneously; 1 week) or vehicle (dimethyl sulfoxide 10% subcutaneously).

Divergent role of heme oxygenase inhibition in the pathogenesis of sepsis.

The reduction of neutrophil migration to an infectious focus is associated with a high mortality in severe sepsis. Previously, we showed that heme oxygenase (HO) products downregulate neutrophil recruitment in a noninfectious inflammatory model. The present study was designed to determine the role of HO in sepsis induced by cecal ligation and puncture (CLP) model.

Anticoagulant and fibrinogenolytic properties of the venom of Polybia occidentalis social wasp.

Previous studies have shown that venoms of social wasps and bees exhibit strong anticoagulant activity. The present study describes the anticoagulant and fibrinogen-degrading pharmacological properties of the venom of Polybia occidentalis social wasp. The results demonstrated that this venom presented anticoagulant effect, inhibiting the coagulation at different steps of the clotting pathway (intrinsic, extrinsic and common pathway).

Hydrogen sulfide improves neutrophil migration and survival in sepsis via K+ATP channel activation.

Rationale: Recovering the neutrophil migration to the infectious focus improves survival in severe sepsis. Recently, we demonstrated that the cystathionine gamma-lyase (CSE)/hydrogen sulfide (H(2)S) pathway increased neutrophil recruitment to inflammatory focus during sterile inflammation.

Objectives: To evaluate if H(2)S administration increases neutrophil migration to infectious focus and survival of mice.