Surfactant apoprotein A modulates interleukin-8 and monocyte chemotactic peptide-1 production.
Previous studies have shown that surfactant apoprotein A (SP-A) and natural or synthetic surfactant can modulate the release of pro-inflammatory cytokines from alveolar mononuclear phagocytes. The aim of this study was to assess whether SP-A or Surfactant (Surf) from patients with pulmonary alveolar proteinosis (PAP) can affect the release of two chemokines (interleukin (IL)-8 and monocyte chemtactic peptide (MCP)-1) from human monocytes and rat lung type-II cells. In addition IL-8 and MCP-1 levels were assessed in the brochoalveolar lavage fluid (BALF) of seven patients with PAP and compared with those in a group of control subjects (n=5). SP-A, tested over a wide range of concentrations, significantly increased IL-8 and MCP-1 release from monocytes. SP-A retained its activity after collagenase digestion, but was not active after heat treatment. The release of IL-8 by monocytes was also stimulated by Surf. Finally, median BALF IL-8 and MCP-1 levels in PAP patients were significantly higher than in controls (9.50 and 9.51 pg x mL(-1) in controls versus 151.95 and 563.70 pg x mL(-1) in PAP, respectively) and significantly correlated with SP-A concentrations in BALF. Overall the results of this study support the view that the high content of alveolar surfactant apoprotein A may contribute to the upregulation of chemokine release in pulmonary alveolar proteinosis, thus contributing to airway inflammation.
Dept of Haematological, Pneumological and Cardiovascular Sciences, University of of Pavia and Instituto di Ricovero e Cura a Carattere Scientifico Policlinico San Matteo, Italy. federica-meloni@libero.it
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Meloni
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Alberti
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Bulgheroni
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Lupi
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Paschetto
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Marone Bianco
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Rodi
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Fietta
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Luisetti
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Baritussio
D000328:Adult; D000818:Animals; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry; D002478:Cells, Cultured; D018932:Chemokine CCL2 / Q000032:analysis / Q000096:biosynthesis*; D005260:Female; D006801:Humans; D016209:Interleukin-8 / Q000032:analysis / Q000096:biosynthesis*; D008297:Male; D008875:Middle Aged; D009000:Monocytes / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D011649:Pulmonary Alveolar Proteinosis / Q000276:immunology / Q000378:metabolism*; D037662:Pulmonary Surfactant-Associated Protein A / Q000494:pharmacology*; D051381:Rats; D020545:Respiratory Mucosa / Q000166:cytology / Q000187:drug effects / Q000378:metabolism
D018932:Chemokine CCL2; D016209:Interleukin-8; D037662:Pulmonary Surfactant-Associated Protein A