Miyamura K, Malhotra R, Hoppe H J, Reid K B, Phizackerley P J, Macpherson P, López Bernal A
Department of Biochemistry, University of Oxford, UK.
Biochim Biophys Acta. 1994 Jan 20;1210(3):303-7. doi: 10.1016/0005-2760(94)90233-x.
Surfactant proteins A (SP-A) and D (SP-D) are major proteins, in the lung, which are composed of collagenous and globular domains. They show an overall similarity to the serum complement protein Clq, which is involved in the initiation of antibody-dependent defence mechanisms. Both SP-A and SP-D were detected, immunochemically, in amniotic fluid as early as 26 weeks gestation and, as expected, SP-A levels rose sharply from 32 weeks towards term. By contrast, SP-D levels in the same samples rose only moderately. Immunochemistry of paraffin sections of fetal membranes, revealed the presence of both SP-A and SP-D in the amniotic epithelium and chorio-decidual layers. SP-A and SP-D are both lectins and therefore they may play a role in the antibody-independent recognition and clearance of pathogens in the amniotic fluid.
表面活性蛋白A（SP-A）和表面活性蛋白D（SP-D）是肺中的主要蛋白质，由胶原结构域和球状结构域组成。它们与血清补体蛋白C1q总体相似，C1q参与抗体依赖性防御机制的启动。早在妊娠26周时，就通过免疫化学方法在羊水中检测到了SP-A和SP-D，正如预期的那样，SP-A水平从32周开始直至足月急剧上升。相比之下，相同样本中的SP-D水平仅适度上升。胎膜石蜡切片的免疫化学显示，羊膜上皮和绒毛膜蜕膜层中均存在SP-A和SP-D。SP-A和SP-D都是凝集素，因此它们可能在羊水病原体的非抗体依赖性识别和清除中发挥作用。
