Surfactant protein D regulates chemotaxis and degranulation of human eosinophils.
The collectin surfactant protein D (SP-D) is an important component of the pulmonary innate host defence. Up to now, little is known about the regulation of eosinophil function by SP-D. Various murine models of pulmonary hypersensitivity suggest that SP-D may be a potent anti-allergic protein. We investigated the modulation of eosinophil chemotaxis and degranulation by human SP-D. SP-D markedly inhibited the chemotaxis of eosinophils triggered by eotaxin, a major tissue-derived CC-chemokine, as shown in a modified Boyden chamber assay. In addition, degranulation of ECP in response to Ca2+ ionophore, immobilized IgG and serum from allergic patients was inhibited by SP-D. In a fixed-cell enzyme linked immunosorbent assay and in flow cytometry, SP-D bound to eosinophils. This binding was saturable and was inhibited by the addition of maltose and ethylenediaminetetraacetic acid, suggesting the involvement of the carbohydrate recognition domain of SP-D. In addition, flow cytometry showed significant interaction of SP-D with CD32 (FcgammaII receptor) on eosinophils, which might explain the inhibitory effect of SP-D on the IgG and serum-triggered eosinophil cationic protein degranulation of eosinophils. Our data further support the concept of an anti-inflammatory function of SP-D in the lung of patients with allergic diseases.
von Bredow
Christina
C
Lung Research Group, Children's Hospital of Ludwig-Maximilians-University, Munich, Germany.
Hartl
Dominik
D
Schmid
Kristina
K
Schabaz
Farhad
F
Brack
Eva
E
Reinhardt
Dietrich
D
Griese
Matthias
M
D000328:Adult; D000704:Analysis of Variance; D001249:Asthma / Q000378:metabolism; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry; D015550:Cell Degranulation / Q000187:drug effects; D002478:Cells, Cultured; D054413:Chemokine CCL11; D019742:Chemokines, CC; D002633:Chemotaxis / Q000187:drug effects; D004591:Electrophoresis, Polyacrylamide Gel; D047150:Eosinophil Cationic Protein / Q000378:metabolism; D004804:Eosinophils / Q000187:drug effects / Q000378:metabolism*; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D008297:Male; D011485:Protein Binding / Q000187:drug effects; D011649:Pulmonary Alveolar Proteinosis / Q000378:metabolism; D037663:Pulmonary Surfactant-Associated Protein D / Q000302:isolation & purification / Q000378:metabolism / Q000494:pharmacology*; D017452:Receptors, IgG / Q000378:metabolism
C515456:CCL11 protein, human; D054413:Chemokine CCL11; D019742:Chemokines, CC; D037663:Pulmonary Surfactant-Associated Protein D; D017452:Receptors, IgG; D047150:Eosinophil Cationic Protein