BINDING OF SURFACTANT PROTEIN-A TO C1Q RECEPTORS MEDIATES PHAGOCYTOSIS OF STAPHYLOCOCCUS-AUREUS BY MONOCYTES
BINDING OF SURFACTANT PROTEIN-A TO C1Q RECEPTORS MEDIATES PHAGOCYTOSIS OF STAPHYLOCOCCUS-AUREUS BY MONOCYTES
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DOI：
10.1152/ajplung.1994.267.5.l578
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发表时间：
1994-11-01
影响因子：
4.9
通讯作者：
VANFURTH, R
中科院分区：
文献类型：
--
作者：
GEERTSMA, MF;NIBBERING, PH;VANFURTH, R
在稳态条件和下气道的炎症反应中，单核细胞迁移到肺泡，在那里它们与表面活性剂接触。表面活性剂由磷脂、中性脂和特异性蛋白组成，其主要作用是降低肺泡内的表面张力。最丰富的糖蛋白表面活性剂蛋白A （SP-A）影响肺表面活性剂的结构、功能和代谢。本研究的目的是确定SP-A是否在人类单核细胞的抗菌活性中起作用，以及这是否由这些细胞上的SP-A受体介导。结果表明，SP-A能与金黄色葡萄球菌和单核细胞结合，并介导单核细胞对金黄色葡萄球菌的吞噬作用。SP-A不会刺激单核细胞在细胞内杀死细菌，SP-A活化的金黄色葡萄球菌不会诱导活性氧中间体的产生。SP-A与单核细胞上的C1q受体（C1qR）结合，因为它的结合被C1q抑制，当单核细胞粘附在包被C1q或抗C1qR单克隆抗体的表面时，SP-A增强的金黄色葡萄球菌与这些细胞的结合被完全消除。此外，SP-A与单核细胞的结合导致细胞内腺苷3',5'-环单磷酸的浓度增加。综上所述，这些结果表明C1qR介导单核细胞对sp - a活化的金黄色葡萄球菌的吞噬作用。
During both steady-state conditions and inflammatory reactions in the lower airways, monocytes migrate to the alveoli where they come into contact with surfactant. Surfactant is composed of phospholipids, neutral lipids, and specific proteins, and its main function is to reduce surface tension in the alveoli. The most abundant glycoprotein surfactant protein A (SP-A) affects the structure, function, and metabolism of pulmonary surfactant. The aim of the present study was to determine whether SP-A plays a role in the antibacterial activities of human monocytes and whether this is mediated by a receptor for SP-A on these cells. The results showed that SP-A binds to both Staphylococcus aureus and monocytes and mediates the phagocytosis of the bacteria by these cells. SP-A does not stimulate the intracellular killing of bacteria by monocytes, and SP-A-opsonized S. aureus do not induce the production of reactive oxygen intermediates. SP-A binds to the C1q receptor (C1qR) on monocytes, since its binding was inhibited by C1q and the SP-A-enhanced association of S. aureus with these cells was completely abolished when monocytes were adherent to surfaces coated with C1q or anti-C1qR monoclonal antibody. Furthermore, the binding of SP-A to monocytes results in an increased intracellular concentration of adenosine 3',5'-cyclic monophosphate. Together, these results demonstrate that C1qR mediates the phagocytosis of SP-A-opsonized S. aureus by monocytes.