ABSTRACT
Crude human decidual extracts containing up to 26.6 mg/l of placental protein 14 (PP14) and purified PP14 were assessed for their effects on the in vitro lymphocyte reactivity to phytohemagglutinin (PHA). Both decidual extract and purified PP14 suppressed the mitogenic response to PHA with the suppression being dose-dependent over the range of PP14 concentrations investigated (0-26.6 mg/l). On the specific reduction of the PP14 content by a monoclonal anti-PP14 immunoadsorbant the suppression was reduced. The suppressive activity of PP14 was related to the degree of proliferation of the stimulated lymphocytes. These results suggest that PP14, which is present at peak levels in the first trimester of pregnancy and constitutes up to 10% of the soluble protein content of decidual tissue, may be an immunomodulator important for the survival of the implanting embryo and maintenance of early pregnancy.
Subject(s)
Glycoproteins , Lymphocyte Activation , Pregnancy Proteins/pharmacology , Decidua/immunology , Female , Glycodelin , Humans , In Vitro Techniques , Phytohemagglutinins/pharmacology , Pregnancy , Pregnancy Proteins/immunology , Pregnancy Proteins/isolation & purification , Suppressor Factors, ImmunologicABSTRACT
Extracts of human decidual tissue obtained in the first trimester of pregnancy showed potent suppressive activity in mixed lymphocyte cultures. These extracts contained substantial amounts of the decidual protein PP14. Purified PP14 also exhibited in vitro immunosuppressive activity, and such activity in decidual extract and purified PP14 preparations was removed by treatment with a monoclonal anti-PP14 antibody-based immunoadsorbent. PP14 was present in seminal plasma, which also exhibited immunosuppressive activity that could be reduced, but not removed, by the immunoadsorbent. PP14 may be an important immunomodulator in the human reproductive system.
Subject(s)
Glycoproteins , Immunosuppression Therapy , Pregnancy Proteins/immunology , Pregnancy/immunology , Animals , Antibodies, Monoclonal/analysis , Endometrium/immunology , Female , Glycodelin , Humans , Immunosorbents/pharmacology , Lymphocyte Culture Test, Mixed , Male , Mice , Mice, Inbred BALB C , Pregnancy Proteins/analysis , Thymidine , TritiumABSTRACT
Levels of placental protein 14 (PP14), human placental lactogen (hPL) and unconjugated oestriol (E3) were measured in maternal peripheral and umbilical arterial and venous blood obtained from 65 normal pregnancies at term delivery. PP14 levels were one order of magnitude higher in the mother than in the fetus. Neither maternal nor fetal levels of PP14 were related to the birthweight of the fetus. There was a relationship between maternal and umbilical venous levels of PP14, which suggests that fetal PP14 is derived by transfer from the mother, or that there is an independent fetal source with a control mechanism similar to that of the mother. The findings are compatible with earlier observations to the effect that PP14, in contrast to products such as hPL and E3, is not specific to the trophoblast.
Subject(s)
Fetal Blood/analysis , Glycoproteins , Pregnancy Proteins/blood , Birth Weight , Estriol/blood , Female , Glycodelin , Humans , Infant, Newborn , Placental Lactogen/blood , PregnancyABSTRACT
The development and validation of a radioimmunoassay for the measurement of human placental protein 14 in maternal serum is described. The mean concentration of this protein in serum from 22 normal pregnant women showed a decline during the third trimester from 120 micrograms/l at 27 weeks gestation to 65 micrograms/l at term. Serum samples from 16 patients with intra-uterine growth retardation tended to contain lower concentrations of placental protein 14, these results reaching significance at weeks 36-38 of gestation. Of seven patients with pre-eclampsia from whom two or more blood samples were taken, four showed increases in concentration of this protein as pregnancy proceeded, compared with the normal pattern of decreasing values.
