Binding of human secretory leukocyte protease inhibitor in uterine cervical mucus to immunoglobulins: pathophysiology in immunologic infertility and local immune defense.
OBJECTIVE
To identify an Fc receptor-like molecule in human cervical mucus.


METHODS
Controlled experimental laboratory study.


METHODS
Department of Obstetrics and Gynecology, School of Medicine, University of Tokushima.


METHODS
Women undergoing treatment for infertility.


METHODS
Sodium dodecyl sulfate-polyacrylimide gel electrophoresis and Western blot were used for analysis.


METHODS
A water-insoluble protein with immunoglobulin-binding activity was purified from human cervical mucus by ammonium sulfate fractionation. The initial 21 amino acids of the N-terminus of the immunoglobulin-binding protein were determined and analyzed in a computer search for homology.


RESULTS
The purified fraction contained a 15-kd protein that binds immunoglobulin A, immunoglobulin M, and all subclasses of human immunoglobulin G as determined by Western blot analysis. The amino acid sequence of the N-terminus is identical to that of secretory leukocyte protease inhibitor. The capacity of secretory leukocyte protease inhibitor to bind immunoglobulins was confirmed by Western blot analysis.


CONCLUSIONS
A component in human cervical mucus capable of binding immunoglobulins was identified as secretory leukocyte protease inhibitor. The capacity to bind immunoglobulins is a unique property of the protein, providing additional support for the contention that it plays an important physiologic role in local tissue defense mechanisms. It also is involved in the pathogenesis of immunologic infertility by trapping sperm in the cervical mucus.
Hirano
M
M
Department of Obstetrics and Gynecology, School of Medicine, University of Tokushima, Japan.
Kamada
M
M
Maegawa
M
M
Gima
H
H
Aono
T
T
D000595:Amino Acid Sequence; D015153:Blotting, Western; D002582:Cervix Mucus / Q000276:immunology*; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D006801:Humans; D007070:Immunoglobulin A / Q000378:metabolism; D007074:Immunoglobulin G / Q000378:metabolism; D007075:Immunoglobulin M / Q000378:metabolism; D007136:Immunoglobulins / Q000378:metabolism*; D007247:Infertility, Female / Q000276:immunology*; D008969:Molecular Sequence Data; D053491:Proteinase Inhibitory Proteins, Secretory; D011506:Proteins / Q000737:chemistry / Q000378:metabolism*; D015842:Serine Proteinase Inhibitors / Q000737:chemistry / Q000378:metabolism*
D007070:Immunoglobulin A; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D007136:Immunoglobulins; D053491:Proteinase Inhibitory Proteins, Secretory; D011506:Proteins; D015842:Serine Proteinase Inhibitors