Comparison of the responsiveness of primary alveolar macrophages (AM's), primary alveolar type II cells (TII), and a rat alveolar type II cell line (RLE-6TN) to lipopolysaccharide (LPS) and silica exposure.
Kanj-R; Kang-J; Castranova-V
FASEB J 2002 Mar; 16(5):A1146
The goal of this study was to compare the responses of AM's and TII cells' to LPS or silica and eventually determine their mutual interactions. AM's were collected by bronchoalveolar lavage, TII cells were isolated by enzymatic digestion and purified by panning (approximately 20 million cells/rat, 95% pure), and RLE-6TN were commercially obtained. Cells were exposed in vitro to LPS or silica for 18 hours, after which nitric oxide (NO) and tumor necrosis factor-alpha (TNF-a) release were measured in the supernate using a modified Greiss reaction and ELISA, respectively. Cytotoxicity was measured by trypan blue exclusion and lactate dehydrogenase (LDH) activity. Upon LPS exposure, AM's released more NO and TNF-a than TII cells, which in turn were more responsive than RLE-6TN. Peak release of NO and TNF-a occurred at LPS doses of 1-5 ug/ml, 5-10 ug/ml, and 50-100 ug/ml for AM's, TII cells and RLE-6TN cells, respectively. Silica doses below 50 ug/ml failed to stimulate NO or TNF-a production in any of these cell types. These data indicate that LPS is a potent inducer of NO and TNF-a release with AM's being the most responsive and RLE-6TN the least responsive alveolar cell type tested.
Silica-dusts; Silicates; Alveolar-cells; In-vitro-studies; Oxides; Tumors; Cytotoxicity; Exposure-levels; Lung-cells
NIOSH, 1095 Willowdale Road, Morgantown, WV 26505
Abstract; Conference/Symposia Proceedings
The FASEB Journal, Experimental Biology 2002, New Orleans, Louisiana, April 20-24, 2002