Title: Conceptus Interferons and Maternal Recognition of Pregnancy1
Abstract: Ovine trophoblast protein-1 (oTP-1) and bovine trophoblast protein-1 (bTP-1) are secreted by ovine and bovine conceptuses for a restricted period when the conceptus acts to block regression of the corpus luteum. Both are considered to be antiluteolytic, acting locally on the endometrium to prevent the production of the uterine luteolysin prostaglandin F2α. Molecular cloning of cDNAs for oTP-1 and bTP-1 has shown that both are structurally related to alpha interferons (IFN-αs). In particular, they resemble members of the 172- residue long IFN-α11 (or IFN-omega) subfamily. Both proteins possess the antiviral and antiproliferative properties of IFN-αs and appear to bind IFN-α receptors. A novel and previously unsuspected role for IFNs in early pregnancy is apparent