Lectin-like Attachment Sites on Murine Pulmonary Alveolar Macrophages Bind Aspergillus Fumigatus Conidia

Murine pulmonary alveolar macrophages bound Aspergillus fumigatus conidia in vitro at 4 C and 37 C in the absence of serum or opsonins. This attachment was dependent on calcium and was sensitive to mild trypsinization and paraformaldehyde pretreatment of the macrophage membrane. Chitotriose, N-acetylglucosamine, D-mannose, alpha-methyl-mannoside, and L-fucose, but not D-galactose, were effective inhibitors of conidial binding. This pattern of reduction of conidial binding was consistent with that for the mannosylfucosyl receptor. In addition, conidial binding may be mediated by another lectin on the macrophage membrane, one that recognizes chitin components, because N-acetylglucosamine and chitotriose exhibited greater inhibition than expected for the mannosyl-fucosyl lectin.