Protective effects of surfactant protein D treatment in 1,3-β-glucan-modulated allergic inflammation.

Abstract

Surfactant protein D (SP-D) is a pulmonary collectin important in lung immunity. SP-D-deficient mice (Sftpd(-/-)) are reported to be susceptible to ovalbumin (OVA)- and fungal allergen-induced pulmonary inflammation, while treatment with exogenous SP-D has therapeutic effects in such disease models. β-Glucans are a diverse group of polysaccharides previously suggested to serve as fungal ligands for SP-D. We set out to investigate if SP-D could interact with 1,3-β-glucan and attenuate allergic pulmonary inflammation in the presence of 1,3-β-glucan. Allergic airway disease was induced in Sftpd(-/-) and Sftpd(+/+) mice by OVA sensitization and subsequent challenge with OVA, 1,3-β-glucan, or OVA/1,3-β-glucan together. Mice in the combined treatment group were further treated with a high dose of recombinant fragment of human SP-D (rfhSP-D). We demonstrated direct interaction between SP-D and 1,3-β-glucan. OVA-induced mucous cell metaplasia was increased in Sftpd(-/-) mice, supporting previously reported protective effects of endogenous SP-D in allergy. OVA-induced parenchymal CCL11 levels and eosinophilic infiltration in bronchoalveolar lavage were unaffected by 1,3-β-glucan, but were reversed with rfhSP-D treatment. 1,3-β-Glucan treatment did, however, induce pulmonary neutrophilic infiltration and increased TNF-α levels in bronchoalveolar lavage, independently of OVA-induced allergy. This infiltration was also reversed by treatment with rfhSP-D. 1,3-β-Glucan reduced OVA-induced mucous cell metaplasia, T helper 2 cytokines, and IFN-γ production. rfhSP-D treatment further reduced mucous metaplasia and T helper 2 cytokine secretion to background levels. In summary, rfhSP-D treatment resulted in attenuation of both allergic inflammation and 1,3-β-glucan-mediated neutrophilic inflammation. Our data suggest that treatment with high-dose SP-D protects from mold-induced exacerbations of allergic asthma.

• Authors: Dalia Fakih, Bartosz Pilecki, Anders Schlosser, Christine S Jepsen, Laura K Thomsen, Maria Ormhøj, Alastair Watson, Jens Madsen, Howard W Clark, Kenneth K Barfod, Soren Hansen, Niels Marcussen, Rania Jounblat, Soulaima Chamat, Uffe Holmskov, Grith L Sorensen
• Journal: American journal of physiology. Lung cellular and molecular physiology (Am J Physiol Lung Cell Mol Physiol) Vol. 309 Issue 11 Pg. L1333-43 (Dec 01 2015) ISSN: 1522-1504 [Electronic] United States
• PMID: 26432866 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2015 the American Physiological Society.

Chemical References

• Ccl11 protein, mouse
• Chemokine CCL11
• Cytokines
• Ligands
• Protective Agents
• Proteoglycans
• Pulmonary Surfactant-Associated Protein D
• beta-Glucans
• Immunoglobulin E
• polysaccharide-K
• Ovalbumin

Topics

• Animals
• Chemokine CCL11 (metabolism)
• Cytokines (metabolism)
• Female
• Humans
• Hypersensitivity (complications, drug therapy, pathology)
• Immunoglobulin E (metabolism)
• Inflammation (complications, drug therapy, pathology)
• Ligands
• Metaplasia
• Mice, Inbred C57BL
• Microbiota (drug effects)
• Ovalbumin
• Protective Agents (pharmacology, therapeutic use)
• Proteoglycans
• Pulmonary Alveoli (drug effects, pathology)
• Pulmonary Surfactant-Associated Protein D (pharmacology, therapeutic use)
• Respiratory Hypersensitivity (complications)
• beta-Glucans (metabolism)