The effect of granulocyte-macrophage colony-stimulating factor (GM-CSF), a pluripotent cytokine, on tumoricidal activity of alveolar macrophages and monocytes from nonsmoking normal volunteers was compared using [3H]thymidine-labeled human tumor cells (SK-MEL-28, melanoma) as targets. A dose-response study (500-5000 units/ml) of recombinant GM-CSF indicated dramatic differences between cytotoxi...

Human bronchoalveolar lavage cells from several different disease states were examined by the technique of zymosan-stimulated, luminol-dependent chemiluminescence. Light production correlated well with polymorphonuclear leucocyte contamination of the alveolar macrophage suspension but not with lymphocyte contamination. Regression analysis indicated that human alveolar macrophages produce little...

Alveolar macrophages are essential for the maintenance of surfactant homeostasis. We asked whether surfactant treatment would change alveolar macrophage number and whether the alveolar macrophage phenotype would become activated or apoptotic when challenged in vivo with exogenous surfactant. Surfactant pool size in mice was increased by repetitive surfactant treatments containing 120 mg/kg (110...

BACKGROUND There is a need for novel anti-inflammatory therapies to treat COPD. The liver X receptor (LXR) is a nuclear hormone receptor with anti-inflammatory properties. METHODS We investigated LXR gene and protein expression levels in alveolar macrophages and whole lung tissue from COPD patients and controls, the effect of LXR activation on the suppression of inflammatory mediators from LP...

A patient's recovery from lung inflammatory injury or development of multi-system organ failure is determined by the host's ability to resolve inflammation and repair tissue damage, both of which require the clearance of apoptotic neutrophils by macrophages (efferocytosis). Here, we investigated the effects of isoflurane on macrophage efferocytosis and resolution of lung inflammatory injury. Tr...

Mononuclear phagocytic leukocytes, as well as polymorphonuclear leukocytes, produce and release superoxide at rest, and this is stimulated by phagocytosis. Of the mouse monocytic cells studied, alveolar macrophages released the largest amounts of superoxide during phagocytosis, followed by normal peritoneal macrophages. Casein-elicited and "activated" macrophages released smaller quantities. In...

Influenza viruses (IV) cause pneumonia in humans with progression to lung failure and fatal outcome. Dysregulated release of cytokines including type I interferons (IFNs) has been attributed a crucial role in immune-mediated pulmonary injury during severe IV infection. Using ex vivo and in vivo IV infection models, we demonstrate that alveolar macrophage (AM)-expressed IFN-β significantly contr...

BACKGROUND Dysfunctional immune responses characterize sarcoidosis, but the status of cathelicidin, a potent immunoregulatory and antimicrobial molecule, has not been established in clinical disease activity. METHODS Alveolar macrophage cathelicidin expression was determined in biopsy-proven sarcoidosis patients classified clinically as 'severe' (requiring systemic treatment) or 'non-severe' ...

Molecular mechanisms of the inflammatory reaction in hypoxia-induced lung injury are not well defined. Therefore, effects of alveolar hypoxia were studied in rat lungs, exposing rats to 10% oxygen over periods of 1, 2, 4, 6, and 8 h. An increase in the number of macrophages in bronchoalveolar lavage fluid of hypoxic animals was shown between 1 and 8 h. Extravasation of albumin was enhanced afte...

Background: The pathophysiology of chronic obstructive pulmonary disease (COPD) features pulmonary inflammation with a predominant alveolar macrophage involvement. Bronchoalveolar macrophages from patients with COPD release increased amounts of inflammatory cytokines in vitro, an effect that is not inhibited by the glucocorticosteroid dexamethasone. Resveratrol (3,5,49-trihydroxystilbene) is a ...