Decidual and peripheral blood CD4+CD25+ regulatory T cells in early pregnancy subjects and spontaneous abortion cases

• Published in: Molecular human reproduction Vol. 10; no. 5; pp. 347 - 353
• Main Authors: Sasaki, Y., Sakai, M., Miyazaki, S., Higuma, S., Shiozaki, A., Saito, S.
• Format: Journal Article
• Language: English
• Published: Oxford Oxford University Press 01.05.2004; Oxford Publishing Limited (England)
• Subjects: Abortion, Spontaneous - immunology; Biological and medical sciences; CD3 Complex - immunology; CD4-Positive T-Lymphocytes - immunology; Clonal Anergy; Decidua - cytology; Embryology: invertebrates and vertebrates. Teratology; Female; Fundamental and applied biological sciences. Psychology; Humans; Key words: abortion/decidua/pregnancy/regulatory T cells/tolerance; Pregnancy; Receptors, Interleukin-2 - immunology; T-Lymphocyte Subsets; Human; Blood cell; Pregnancy disorders; Uterus; Female genital system; T-Lymphocyte; Tolerance; Early pregnancy; abortion/decidua/pregnancy/regulatory T cells/tolerance; Decidua; Abortion
• ISSN: 1360-9947; 1460-2407; 1460-2407
• DOI: 10.1093/molehr/gah044

Human pregnancy represents a situation of semiallograft to maternal host. Therefore, it has been reported that tolerance to the fetal allograft represents a mechanism for maintaining a pregnancy. CD4+CD25bright regulatory T cells are known to play an important role in the development and maintenance of tolerance in peripheral tissues. However, the potential role of CD4+CD25bright T cells in maintaining human pregnancy has not been reported. In this study, we show that early human pregnancy decidua contains an abundance of CD4+CD25bright T cells, which express CD152(CTLA‐4) at a high level. CD4+CD25bright T cells mediate potent inhibition of autologous T‐cell proliferation by anti‐CD3 stimulation. Furthermore, these cells inhibit the proliferation of autologous CD4+CD25– T cells in a dose‐dependent fashion. This suppressive function of decidual CD4+CD25+ T cells required cell‐to‐cell contact. The proportion of decidual CD4+CD25bright T cells was significantly lower in specimens from spontaneous abortion compared to those from specimens from induced abortions. These results suggest that decidual CD4+CD25bright T cells contribute to the mechanisms mediating maternal immune tolerance of conceptus antigens and therefore might contribute to the maintenance of pregnancy.