Cytokine-induced neutrophil chemotaxis assay.

Chemotaxis is directed migration of a cell type to a distant chemoattractant. When this chemoattractant is a cytokine, the term chemokine is often used. Chemotaxis by neutrophils, specifically polymorphonuclear leukocytes (PMNs), plays a critical role in the innate immune response.

Control of pro-inflammatory cytokine release from human monocytes with the use of an interleukin-10 monoclonal antibody.

The monocytes (MONOs) can be considered as "double-edge swords"; they have both important pro-inflammatory and anti-inflammatory functions manifested in part by cytokine production and release. Although MONOs are circulating cells, they are the major precursors of a variety of tissue-specific immune cells such as the alveolar macrophage, dendritic cells, microglial cells, and Kupffer cells. Unlike the polymorphonuclear leukocyte, which produces no or very little interleukin-10 (IL-10), the monocyte can produce this potent anti-inflammatory cytokine to control inflammation.

Differential effect of exogenous interleukin-10 versus glucocorticoids on gene expression and pro-inflammatory cytokine release by polymorphonuclear leukocytes and monocytes of the newly born.

Bronchopulmonary dysplasia (BPD) is one of the most common causes of mortality and morbidity in neonatal intensive care units. Persistent inflammation, with an abnormal influx of polymorphonuclear leukocytes (PMNs) followed by monocytes (MONOs), occurs early in the pathogenesis of BPD. Anti-inflammatory therapy with better efficacy and safety than dexamethasone (DEX) is needed.

Gene expression profile of endotoxin-stimulated leukocytes of the term new born: control of cytokine gene expression by interleukin-10.

Introduction: Increasing evidence now supports the association between the fetal inflammatory response syndrome (FIRS) with the pathogenesis of preterm labor, intraventricular hemorrhage and bronchopulmonary dysplasia. Polymorphonuclear leukocyte (PMNs) and mononuclear cell (MONOs) infiltration of the placenta is associated with these disorders. The aim of this study was to reveal cell-specific differences in gene expression and cytokine release in response to endotoxin that would elucidate inflammatory control mechanisms in the newly born.

Gene-specific repression of proinflammatory cytokines in stimulated human macrophages by nuclear IκBα.

We have previously shown that increased nuclear accumulation of IkappaBalpha inhibits NF-kappaB activity and induces apoptosis in human leukocytes. In this study, we wanted to explore the possibility that the nucleocytoplasmic distribution of IkappaBalpha can be used as a therapeutic target for the regulation of NF-kappaB-dependent cytokine synthesis. Treatment of LPS-stimulated human U937 macrophages with an inhibitor of chromosome region maintenance 1-dependent nuclear export, leptomycin B, resulted in the increased nuclear accumulation of IkappaBalpha and inhibition of NF-kappaB DNA binding activity, caused by the nuclear IkappaBalpha-p65 NF-kappaB interaction.

Transcriptional control of cytokine release from monocytes of the newborn: effects of endogenous and exogenous interleukin-10 versus dexamethasone.

Background: Monocytes play an important role in the fetal and neonatal inflammatory response syndrome. They are also the precursors of alveolar macrophages, microglial and Kupffer cells. Monocytes have pro-inflammatory (PI) and anti-inflammatory (AI) functions.

Interleukin-10 versus dexamethasone: effects on polymorphonuclear leukocyte functions of the newborn.

Interleukin-10 (IL-10), an anti-inflammatory cytokine, may have therapeutic potential in the fetal inflammatory response syndrome and its sequelae such as bronchopulmonary dysplasia (BPD). Our aim was to compare the effects of IL-10 versus dexamethasone (DEX) on important PMN functions of the newborn. PMNs were isolated into culture medium from cord blood after elective cesarean section deliveries.

NFkappaB is persistently activated in continuously stimulated human neutrophils.

Increased activation of the transcription factor NFkappaB in the neutrophils has been associated with the pathogenesis of sepsis, acute lung injury (ALI), bronchopulmonary dysplasia (BPD), and other neutrophil-mediated inflammatory disorders. Despite recent progress in analyzing early NFkappaB activation in human neutrophils, activation of NFkappaB in persistently stimulated neutrophils has not been previously studied. Because it is the persistent NFkappaB activation that is thought to be involved in the host response to sepsis and the pathogenesis of ALI and BPD, we hypothesized that continuously stimulated human neutrophils may exhibit a late phase of NFkappaB activity.

Interleukin-10 production after pro-inflammatory stimulation of neutrophils and monocytic cells of the newborn. Comparison to exogenous interleukin-10 and dexamethasone levels needed to inhibit chemokine release.

Background: Neutrophils followed by monocytic cells are recruited into the lung during the early development of bronchopulmonary dysplasia (BPD).

Objectives: We determined: (1) the capacity of polymorphonuclear leukocytes (PMNs) and peripheral blood monocytic cells (PBMCs) of the newborn to produce and release the anti-inflammatory cytokine, interleukin (IL)-10, after stimulation by lipopolysaccharide (LPS) or tumor necrosis factor (TNF), and (2) the levels of exogenous IL-10 and/or dexamethasone (DEX) needed to inhibit the release of the pro-inflammatory chemokine IL-8 from stimulated cells.

Methods: PMNs and PBMCs were isolated from cord blood of healthy term infants.

TNFalpha release from peripheral blood leukocytes depends on a CRM1-mediated nuclear export.

Tumor necrosis factor-alpha (TNFalpha) is a potent pro-inflammatory cytokine that plays a major role in the pathogenesis of acute and chronic inflammatory disorders such as septic shock and arthritis, respectively. Leukocytes stimulated with inflammatory signals such as lipopolysaccharide (LPS) are the predominant producers of TNFalpha, and thus control of TNFalpha release from stimulated leukocytes represents a potential therapeutic target. Here, we report that leptomycin B (LMB), a specific inhibitor of CRM1-dependent nuclear protein export, inhibits TNFalpha release from LPS-stimulated human peripheral blood neutrophils and mononuclear cells.

Okadaic acid induces sustained activation of NFkappaB and degradation of the nuclear IkappaBalpha in human neutrophils.

Human neutrophils differ from other cells by containing high amount of IkappaBalpha in the nucleus, and this increased nuclear IkappaBalpha accumulation is associated with the inhibition of NFkappaB activity and increased apoptosis. However, the mechanisms regulating NFkappaB activation and IkappaBalpha degradation in human neutrophils are little understood. The objective of this study was to provide a further insight into the mechanisms regulating NFkappaB activity and IkappaBalpha degradation in human neutrophils.

Interleukin-10 inhibits proinflammatory chemokine release by neutrophils of the newborn without suppression of nuclear factor-kappa B.

An increase in polymorphonuclear leukocytes (PMNs) and proinflammatory chemokines, such as IL-8 and macrophage inflammatory protein-1 alpha (MIP), are found in the airways during early stages of bronchopulmonary dysplasia. We determined whether IL-10 produces a dose-related inhibition of proinflammatory chemokine release from stimulated neutrophils of the newborn and whether the mechanism involves the pivotal transcription factor, nuclear factor-kappa B. PMNs isolated from the cord blood of healthy newborns were stimulated submaximally with either lipopolysaccharide (n = 5) or tumor necrosis factor (n = 4), with and without IL-10 (0.

NF-kappa B regulation in human neutrophils by nuclear I kappa B alpha: correlation to apoptosis.

Neutrophils are among the first circulating leukocytes involved in acute inflammatory processes. Transcription factor NF-kappaB plays a key role in the inflammatory response, regulating the expression of proinflammatory and anti-apoptotic genes. Recently we have shown that human neutrophils contain a significant amount of NF-kappaB inhibitor, IkappaBalpha, in the nucleus of unstimulated cells.

Dose-related inhibition of proinflammatory cytokine release from neutrophils of the newborn by dexamethasone, betamethasone, and hydrocortisone.

The objective of this study was to determine the doses of dexamethasone (DEX), betamethasone (BET), and hydrocortisone (HC) that effectively inhibit the release of two potent proinflammatory chemokines, interleukin 8 (IL-8) and macrophage inflammatory protein alpha (MIP), from polymorphonuclear neutrophils (PMNs) of the newborn. Human PMNs were isolated from cord blood (n = 18). Chemokines were measured from PMN cell culture supernatants after 18 h of stimulation using tumor necrosis factor (1 ng/ml), with and without pretreatment by DEX (10(-10) to 10(-6) M) versus HC or BET (10(-10) to 10(-5) M).

Neurodevelopmental and medical outcomes of persistent pulmonary hypertension in term newborns treated with nitric oxide.

Objective: To determine the medical and neurodevelopmental outcome of children with moderately severe persistent pulmonary hypertension of the newborn (PPHN) treated with or without inhaled nitric oxide (I-NO).

Study Design: Term infants with PPHN and a baseline oxygenation index of 24 +/- 9 at study entry were randomly assigned to early treatment with placebo or initial doses of I-NO (5, 20, and 80 ppm). Outcome was measured at approximately 1 year by frequency of hospitalization, growth, and neurodevelopmental and audiologic evaluation.