Trophoblast interferon and pregnancy

The maternal recognition of pregnancy in ruminants requires the production of interferons by the preimplantation blastocyst. These proteins, the troph oblast interferons (IFN-tau), are the products of a number of similar genes , the expression of which is controlled by characteristic promoter regions. They are expressed for a short period in high concentrations, and have ant iluteolytic, antiviral, antiproliferative and immunomodulatory effects, thr ough receptors on the endometrial epithelium. The antiluteolytic effects of IFN-tau result from inhibition of endometrial expression of the oxytocin r eceptor, through which circulating oxytocin stimulates episodic prostagland in F-2 alpha production. Some of the properties of IFN-tau differ from thos e of other type I interferons, and they may have novel therapeutic effects. Because of their central role in early gestation, these proteins have exci ted the interest of reproductive physiologists. However, their other proper ties, and the fact that their expression is controlled so precisely have ma de them of interest to a wide range of biologists.