ARS | Publication request: Regulation of Interferon-Tau Gene Expression, the Maternal Recognition of Pregnancy and Implantation

Submitted to: Recent Research Developments In Biophysics & Biochemistry, Vol. 2
Publication Acceptance Date: May 31, 2004
Publication Date: July 31, 2004
Citation: Imakawa, K., Christenson, R.K. 2004. Regulation Of Interferon-Tau Gene Expression, The Maternal Recognition Of Pregnancy And Implantation. Recent Research Developments In Biophysics & Biochemistry, Vol. 4, Part 1. P. 49-68.

Technical Abstract: The maternal recognition of pregnancy has been defined as the uterine recognition of conceptus(es) signal and extension of the ovarian corpus luteum (CL) life-span. These events must occur in a coordinated manner if pregnancy is established. Involvement of interferon-tau (IFN-tau) in the processes of maternal recognition of pregnancy has been realized, but a role for IFN-tau other than CL extension has not been elucidated. In ruminant ungulates, conceptus IFN-tau binds in a paracrine manner to its receptor located in the maternal uterine endometrium. IFN-tau binding decreases endometrial estrogen receptor alpha (ER-alpha) and thereby oxytocin receptors, which subsequently reduces pulsatile secretion of a luteolysin, prostaglandin F2-alpha, resulting in the extension of CL function. Production of IFN-tau appears to parallel the degree of trophoblast elongation and as the conceptus begins its attachment to the endometrium, IFN-tau production declines rapidly. Several transcription factors that may regulate the expression of IFN-tau have been found, but none could explain regulation of IFN-tau's temporal and spatial expression. The action of IFN-tau on the endometrium is mediated through the induction of signal transducer and activator of transcription 1 (STAT-1), STAT-2 and interferon regulatory factor 1 (IRF-1). In addition, several IFN-tau-induced chemokines, which may regulate immune cell distribution and/or re-distribution, are expressed within the endometrium, suggesting that conceptus IFN-tau may also condition the immune-environment to increase its suitability for pregnancy establishment. Recent findings related to maternal recognition of pregnancy are presented herein, including a new insight into the potential regulation of IFN-tau and its involvement in conceptus implantation.