Phenotypic features of alveolar monocytes/macrophages and IL-8 gene activation by IL-1 and TNF-alpha in asthmatic patients

The alveolar macrophage (AM), a major defense cell in the lung, participate s in immune and inflammatory reactions through the release of several regul atory and chemotactic cytokines. In particular, macrophages are considered to play a pivotal proinflammatory role in the production and maintenance of airway inflammation and bronchial hyperreactivity. To assess the phenotypi c pattern of AM from asthmatic subjects, we performed the following experim ents: 1) cytofluorometric analysis of specific phenotypic features (Cr) 1 Ib, CD 14, CD16, CD45, HLA-DR, CD71, CD95, and CD44) 2) assessment of the production of tumor necrosis factor (TNF)-alpha, inter leukin (IL)-1, and the chemotactic regulatory cytokine IL-8 by unstimulated and lipopolysaccharide-stimulated AM. In these patients, we phenotypically characterized the AM, showing their st rong proinflammatory activity also in patients with mild asthma. Their acti vity has been clarified by our biomolecular data that showed a constitutive basal IL-8 production by AM, and also indicated that IL-l and TNF-alpha we re able to upregulate the ability of activated human AM to produce IL-8 at the protein and messenger ribonucleic acid (mRNA) levels.