Specific interaction of lung surfactant protein A (SP-A) with rat alveolar macrophages |
| |
Authors: | Heiderose Manz-Keinke Christine Egenhofer Helmut Plattner Jutta Schlepper-Schfer |
| |
Institution: | Faculty of Biology, University of Konstanz, Federal Republic of Germany. |
| |
Abstract: | We have analyzed interaction of recombinant human surfactant protein A (SP-A) with isolated rat alveolar macrophages in the electron microscope. SP-A coated onto gold particles of different diameter is bound and internalized by macrophages. Binding and uptake occurs via coated membrane structures. SP-A gold particles are transported to secondary lysosomes. Binding and uptake is specific; i.e., excess of SP-A inhibits SP-A gold particle binding and uptake by 67% and depends on the presence of divalent cations. In experiments with ManBSA (5 x 10(-6) M) inhibition is 60%, but no inhibition occurs with GalBSA. The mannose-dependent interaction of SP-A particles with macrophages is not due to the mannose-specific receptor on the cell surface of macrophages as shown in experiments with macrophages exhibiting reduced mannose receptor activity. These cells show reduced binding and uptake of mannan gold particles (42% inhibition) but no reduction of SP-A gold particle binding and uptake. Furthermore, mannan gold particles do not compete with binding of SP-A gold particles. |
| |
Keywords: | |
本文献已被 ScienceDirect 等数据库收录! |