Article: Fc gamma-receptor activity of isolated human placental syncytiotrophoblast plasma membrane

Fc gamma-receptor activity of isolated human placental syncytiotrophoblast microvillous plasma membrane (StMPM) vesicle preparations has been determined in an immunoradiometric assay using Sepharose-immobilized protein A to separate free 125I-labelled human IgG from membrane-bound 125I-IgG. This receptor assay has been optimalized in terms of buffer pH and molarity, and used to demonstrate that prior 60 min washing of isolated membranes in 3 M KCl to remove extrinsic membrane-bound protein substantially increases the membrane-binding capacity for IgG. Inhibition studies have determined the syncytiotrophoblast Fc gamma-receptor equilibrium constant for association (Ka) as 4.0 x 10(7) M-1 at 37 degrees and the number of available Fc gamma-receptor sites as 1.5 x 10(14) per mg membrane protein.

Citing Articles

Expression of placental alkaline phosphatase does not correlate with IgG binding, internalization and transcytosis.

Stefaner I, Stefanescu A, Hunziker W, Fuchs R Biochem J. 1997; 327 ( Pt 2):585-92.

PMID: 9359433 PMC: 1218833. DOI: 10.1042/bj3270585.

Rabbit peroxidase-antiperoxidase complex (PAP) as a model for the uptake of immunoglobulin G by the human placenta.

Griffiths G, Kershaw D, Booth A Histochem J. 1985; 17(8):867-81.

PMID: 3905720 DOI: 10.1007/BF01004182.

Isolation and characterization of human fetal macrophages from placenta.

Sutton L, Mason D, Redman C Clin Exp Immunol. 1989; 78(3):437-43.

PMID: 2532993 PMC: 1534807.

References

1.

Matre R, Johnson P . Multiple FC receptors in the human placenta. Acta Pathol Microbiol Scand C. 1977; 85C(4):314-6. DOI: 10.1111/j.1699-0463.1977.tb03648.x. View

2.

Van der Meulen J, McNabb T, Haeffner-Cavaillon N, Klein M, DORRINGTON K . The Fc gamma receptor on human placental plasma membrane. I. Studies on the binding of homologous and heterologous immunoglobulin G1. J Immunol. 1980; 124(2):500-7. View

3.

Deisenhofer J, Jones T, Huber R, Sjodahl J, Sjoquist J . Crystallization, crystal structure analysis and atomic model of the complex formed by a human Fc fragment and fragment B of protein A from Staphylococcus aureus. Hoppe Seylers Z Physiol Chem. 1978; 359(8):975-85. DOI: 10.1515/bchm2.1978.359.2.975. View

4.

Hunter W, GREENWOOD F . Preparation of iodine-131 labelled human growth hormone of high specific activity. Nature. 1962; 194:495-6. DOI: 10.1038/194495a0. View

5.

Balfour A, Jones E . Properties of receptors for IgG on human placental cell membranes. Int Arch Allergy Appl Immunol. 1978; 56(5):435-42. DOI: 10.1159/000232053. View

6.

Smith N, BRUSH M, Luckett S . Preparation of human placental villous surface membrane. Nature. 1974; 252(5481):302-3. DOI: 10.1038/252302b0. View

7.

WALKER W . The Scatchard plot in immunometric assay. Clin Chem. 1977; 23(3):588-90. View

8.

McNabb T, KOH T, DORRINGTON K, Painter R . Structure and function of immunoglobulin domains. V. Binding, University of immunoglobulin G and fragments to placental membrane preparations. J Immunol. 1976; 117(3):882-8. View

9.

Ogbimi A, Johnson P, Brown P, Fox H . Characterisation of the soluble fraction of human syncytiotrophoblast microvillous plasma membrane-associated proteins. J Reprod Immunol. 1979; 1(2):127-40. DOI: 10.1016/0165-0378(79)90013-5. View

10.

Johnson P, Faulk W, Wang A . Immunological studies of human placentae: subclass and fragment specificity of binding of aggregated IgG by placental endothelial cells. Immunology. 1976; 31(4):659-64. PMC: 1445366. View

11.

GITLIN D, Kumate J, URRUSTI J, Morales C . THE SELECTIVITY OF THE HUMAN PLACENTA IN THE TRANSFER OF PLASMA PROTEINS FROM MOTHER TO FETUS. J Clin Invest. 1964; 43:1938-51. PMC: 289639. DOI: 10.1172/JCI105068. View

12.

WILD A . Role of the cell surface in selection during transport of proteins from mother to foetus and newly born. Philos Trans R Soc Lond B Biol Sci. 1975; 271(912):395-410. DOI: 10.1098/rstb.1975.0060. View

Fc Gamma-receptor Activity of Isolated Human Placental Syncytiotrophoblast Plasma Membrane