Subpopulation of alveolar macrophages inhibits superoxide anion production by macrophages

Abstract

Pig alveolar macrophages are a heterogeneous population of cells. Three subpopulations or bands exist when the whole population is separated according to density. Band 1 cells are the least dense cells and constitute 9% of the total population. Bands 2 and 3 represent 44 and 47% of the total population. The three subpopulations generate superoxide anions, although to varying degrees. Band 3 cells are the most active, while band 1 cells are the least active. The amount of superoxide anions released in a mixed population of bands 1, 2, and 3 cells was less than the sum of that produced from each band assayed separately. Band 1 cells were found to inhibit by 47% the production of superoxide anions by band 3 cells. Conditioned medium from band 1 cells contains a heat-sensitive, nondialyzable, soluble factor responsible for this inhibition.

Human Alveolar Macrophages and Granulocyte-macrophage Colony-stimulating Factor-induced Monocyte-derived Macrophages Are Resistant to H2O2 via Their High Basal and Inducible Levels of Catalase Activity

“…into H 2 O 2 , which is metabolized by catalase and glutathione peroxidase. Previous studies indicated that these enzymes are abundant in A-M⌽ (7)(8)(9). However, the mechanism to maintain high antioxidant activities in A-M⌽ has not been understood because of its heterogeneity and lack of availability to study.…”

Leukocyte‐deactivating factor from macrophages: Partial purification and biochemical characterization. A novel cytokine

“…It inhibits the ability of activated macrophages and other phagocytic cells to release O2 (Camarero et al, 1990). Several other factors produced by some tumor cell lines, microbes, lung macrophages, and fibroblasts have been reported to inhibit the respiratory burst of macrophages (Nathan et al, 1979;Zeidler et al, 1987). Of those factors, none has been shown to inhibit 0,production by neutrophils, as does MDF.…”

Isolation of phenotypically and functionally distinct macrophage subpopulations from human bronchoalveolar lavage

“…Anything from three [11] to 18 [12] bands of cells have been separated from BAL by the use of colloidal silica density gradients alone. However, with the possible exception of the relationship between so-called "dendritic" cells and mature phagocytes in light-density and dense bands, respectively [13], no established correlations exist between cell density and function.…”