Lipopolysaccharide and a phorbol ester stimulate secretion of tumor necrosis factor-α from alveolar macrophages through action on overlapping subsets of cells

A cell-by-cell analysis of the secretory ability of stimulated, individual alveolar macrophages (AMs) was performed through use of a tumor necrosis factor alpha (TNF-alpha) reverse hemolytic plaque assay. Two functional end points were measured: the percentage of AMs that were TNF-alpha secretors and the cumulative amount of TNF-alpha secreted by AMs (average plaque area, microns 2). Lipopolysacch…