Oxidative burst in lipopolysaccharide-activated human alveolar macrophages is inhibited by interleukin-9.

Abstract

Interleukin (IL)-9 is known to regulate many cell types involved in T-helper type 2 responses classically associated with asthma, including B- and T-lymphocytes, mast cells, eosinophils and epithelial cells. In contrast, target cells mediating the effects of IL-9 in the lower respiratory tract remain to be identified. Therefore, the authors evaluated the activity of IL-9 on human alveolar macrophages (AM) from healthy volunteers. AM preincubated with IL-9 before lipopolysaccharide (LPS) stimulation exhibited a decreased oxidative burst, as previously shown with IL-4. The inhibitory effect of IL-9 was abolished by anti-hIL-9R alpha monoclonal antibody, and presence of IL-9 receptors on AM was demonstrated by immunofluorescence. Both IL-4 and IL-9 failed to modulate tumour necrosis factor-alpha, IL-8 and IL-10 release by LPS-stimulated AM. However, several observations suggested that IL-9 and IL-4 act through different mechanisms: 1) interferon-gamma antagonised the IL4- but not the IL-9-mediated inhibition of AM oxidative burst; 2) expression of CD14 was downregulated by IL-4 but not by IL-9 and 3) production of tumour growth factor-beta by activated AM was potentiated by IL-9 and not by IL4, and was required for the IL-9-mediated inhibition of AM oxidative burst. These observations provide additional information concerning the activity of interleukin-9 in the lung, related to inflammatory or fibrosing lung processes.

• Authors: C Pilette, Y Ouadrhiri, J Van Snick, J C Renauld, P Staquet, J P Vaerman, Y Sibille
• Journal: The European respiratory journal (Eur Respir J) Vol. 20 Issue 5 Pg. 1198-205 (Nov 2002) ISSN: 0903-1936 [Print] England
• PMID: 12449174 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Antibodies, Monoclonal
• Cytokines
• IL9R protein, human
• Interleukin-9
• Lipopolysaccharides
• Receptors, Interleukin
• Receptors, Interleukin-9
• Interleukin-4
• Interferon-gamma

Topics

• Antibodies, Monoclonal (pharmacology)
• Cytokines (metabolism)
• Dose-Response Relationship, Drug
• Fluorescent Antibody Technique
• Humans
• In Vitro Techniques
• Interferon-gamma (pharmacology)
• Interleukin-4 (pharmacology)
• Interleukin-9 (pharmacology)
• Lipopolysaccharides (pharmacology)
• Macrophage Activation (drug effects)
• Macrophages, Alveolar (metabolism)
• Receptors, Interleukin (immunology)
• Receptors, Interleukin-9
• Respiratory Burst (drug effects)