To further examine the half-life of alveolar macrophages, chimeric CD 45.2 mice were generated through bone marrow transplantation of donorCD45.1 cells. Beforeadministration of donorcells, recipient mice were divided into two cohorts: the first cohort received total body irradiation; the second cohort also received irradiation— however, the thorax, head, and upper extremities were shielded with...

Innate immune mechanisms against Pneumocystis carinii, a frequent cause of pneumonia in immunocompromised individuals, are not well understood. Using both real time polymerase chain reaction as a measure of organism viability and fluorescent deconvolution microscopy, we show that nonopsonic phagocytosis of P. carinii by alveolar macrophages is mediated by the Dectin-1 beta-glucan receptor and t...

Elevated soluble tumor necrosis factor-α receptor (sTNFR) levels in bronchoalveolar lavage fluid (BALF) are associated with poor patient outcome in acute lung injury (ALI). The mechanisms underlying these increases are unknown, but it is possible that pulmonary inflammation and increased alveolar epithelial permeability may individually contribute. We investigated mechanisms of elevated BALF sT...

Ozone is known to produce an acute influx of neutrophils and alveolar epithelial cells secrete chemokines and can modulate inflammatory processes. However, direct exposure of alveolar epithelial cells and macrophages to ozone (O3) produces little chemokine response. To determine if cell-cell interactions might be responsible, we investigated the effect of alveolar macrophage conditioned media a...

INTRODUCTION We have previously established a link between impaired phagocytic capacity and deregulated S1P signaling in alveolar macrophages from COPD subjects. We hypothesize that this defect may include a disruption of epithelial-macrophage crosstalk via Spns2-mediated intercellular S1P signaling. METHODS Primary alveolar macrophages and bronchial epithelial cells from COPD subjects and co...

The lysosomes of several varieties of cells such as the tubular proximal cell of the kidney and the alveolar macrophage have the ability to concentrate and precipitate several elements inhaled in water-soluble form, usually as phosphate. The mechanism involved is attributed to the high acid phosphatase activity of lysosomes and can be considered as an in vivo Gomori reaction. Among the elements...

BACKGROUND Dysfunctional innate responses of alveolar macrophages to nontypeable Haemophilus influenzae, Moraxella catarrhalis and Streptococcus pneumoniae contribute to morbidity in chronic obstructive pulmonary disease (COPD). Our earlier studies discovered impaired COPD alveolar macrophage responses to Toll-like receptor (TLR) ligands of nontypeable H. influenzae and provide rationale for fu...

BACKGROUND The proliferative response of type II cells is an important event following silica-induced lung injury. Alveolar macrophages, when activated by fibrogenic agents, secrete various biological mediators which affect cell growth. METHODS Human alveolar macrophages from normal volunteers were incubated in serum-free medium or in the presence of increasing concentrations of silica. Alveo...