Isolation and Purification of an Early Pregnancy Factor–Like Molecule from Culture Supernatants Obtained from Lymphocytes of Pregnant Women

摘要

>Purpose:Our purpose was to determine whether lymphocytes synthesize proteins during pregnancy, to observe whether one of the proteins synthesized has early pregnancy factor (EPF)–like activity and to isolate and purify this molecule from culture supernatants obtained from stimulated lymphocytes of pregnant women.>Methods:Lymphocyte proliferation assay and³⁵S-methionine labeling were done to study de novo synthesis of proteins followed by autoradiography to confirm synthesis of proteins. The rosette inhibition assay was used for detection of the EPF-like molecule. Gel filtration on Sephadex G-100 and RPHPLC were used for purification of the EPF-like molecule.>Results:The rate of incorporation of³⁵S-methionine was significantly higher in the lymphocytes of pregnant women compared to those of the control, and autoradiography confirmed the synthesis of proteins during pregnancy. There is a total protein enhancement trend observed during the first trimester that declines toward term. The EPF-like molecule is observed to be synthesized during all the trimesters of pregnancy. This molecule, when purified, showed a single homogeneous biologically active peak.>Conclusions:The results indicated that there is an enhancement of existing protein or synthesis of new proteins during pregnancy. The EPF-like molecule is one of the many proteins synthesized and secreted by lymphocytes during pregnancy that, when purified, is biologically active.