Manz-Keinke H, Plattner H, Schlepper-Schäfer J
Faculty of Biology, University of Konstanz, Konstanz, Germany.
Eur J Cell Biol. 1992 Feb;57(1):95-100.
Surfactant protein A (SP-A) is the main protein component of lung surfactant. We studied the involvement of SP-A in body defense, i.e., effect of SP-A on the phagocytosis of bacteria by alveolar macrophages. We show here that SP-A enhances the phagocytosis of some non-opsonized bacteria: Escherichia coli growing logarithmically (E. coli/log), Pseudomonas aeruginosa/log as well as from stationary phase (P. aeruginosa/stat) and Staphylococcus aureus/log. Furthermore, not only serum-independent phagocytosis was effected by SP-A but also phagocytosis of serum-opsonized S. aureus/stat. No effect of SP-A on phagocytosis was observed with E. coli/stat neither on serum-independent nor on serum-dependent phagocytosis and on phagocytosis of non-opsonized S. aureus/stat. Thus, effect of SP-A on phagocytosis is dependent on bacterial species and on the growth phase of the microorganisms, and this effect is concentration dependent. We studied two different human recombinant SP-As and SP-A isolated from lung lavage material from proteinosis patients. These SP-A molecules contain different isomeric chains, and they differ in complexity of their structure. Qualitatively, we found the same effect with all three substances. Quantitatively, the proteinosis SP-A that forms the most complex structure was the most effective. Taken together, we demonstrated a stimulating effect of SP-A on serum-independent as well as on serum-dependent phagocytosis of bacteria by alveolar macrophages, both depending on species and growth phase of the bacteria.
表面活性蛋白A（SP-A）是肺表面活性剂的主要蛋白质成分。我们研究了SP-A在机体防御中的作用，即SP-A对肺泡巨噬细胞吞噬细菌的影响。我们在此表明，SP-A可增强对某些未调理细菌的吞噬作用：对数生长期的大肠杆菌（E. coli/log）、铜绿假单胞菌/log以及稳定期的铜绿假单胞菌（P. aeruginosa/stat）和对数生长期的金黄色葡萄球菌。此外，SP-A不仅影响非血清依赖性吞噬作用，还影响血清调理的金黄色葡萄球菌/stat的吞噬作用。未观察到SP-A对大肠杆菌/stat的吞噬作用有影响，无论是非血清依赖性还是血清依赖性吞噬作用，以及对未调理的金黄色葡萄球菌/stat的吞噬作用。因此，SP-A对吞噬作用的影响取决于细菌种类和微生物的生长阶段，且这种影响是浓度依赖性的。我们研究了两种不同的人重组SP-A以及从蛋白沉积症患者肺灌洗材料中分离出的SP-A。这些SP-A分子含有不同的异构链，其结构复杂性也不同。定性地说，我们发现这三种物质有相同的作用。定量地说，形成最复杂结构的蛋白沉积症SP-A最有效。综上所述，我们证明了SP-A对肺泡巨噬细胞非血清依赖性以及血清依赖性细菌吞噬作用具有刺激作用，这两种作用均取决于细菌的种类和生长阶段。
