Surfactant proteins A (SP-A) and D (SP-D): levels in human amniotic fluid and localization in the fetal membranes.
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.
Miyamura
K
K
Department of Biochemistry, University of Oxford, UK.
Malhotra
R
R
Hoppe
H J
HJ
Reid
K B
KB
Phizackerley
P J
PJ
Macpherson
P
P
López Bernal
A
A
D000653:Amniotic Fluid / Q000378:metabolism*; D004797:Enzyme-Linked Immunosorbent Assay; D005321:Extraembryonic Membranes / Q000378:metabolism*; D005260:Female; D006023:Glycoproteins / Q000032:analysis*; D006801:Humans; D015151:Immunoblotting; D007150:Immunohistochemistry; D037102:Lectins / Q000032:analysis; D011247:Pregnancy; D011263:Pregnancy Trimester, Third; D011510:Proteolipids / Q000032:analysis*; D037662:Pulmonary Surfactant-Associated Protein A; D037663:Pulmonary Surfactant-Associated Protein D; D037661:Pulmonary Surfactant-Associated Proteins; D011663:Pulmonary Surfactants / Q000032:analysis*
D006023:Glycoproteins; D037102:Lectins; D011510:Proteolipids; D037662:Pulmonary Surfactant-Associated Protein A; D037663:Pulmonary Surfactant-Associated Protein D; D037661:Pulmonary Surfactant-Associated Proteins; D011663:Pulmonary Surfactants