title: Differences in lymphocyte-regulatory activity among variants of ovine IFN-tau.
abstract: Interferon-tau (IFN-tau) is secreted from trophectoderm of the ruminant preimplantation conceptus and functions during pregnancy to prevent luteolysis. In addition, IFN-tau can inhibit proliferation of peripheral blood lymphocytes (PBL) and other cells. Several distinct ovine IFN-tau (OvIFN-tau) gene variants exist; three of these (IFN-tau4, IFN-tau6d, IFN-tau11) differ in their ability to prevent luteolysis (IFN-tau4 > IFN-tau6d > IFN-tau11), inhibit growth of Daudi cells (IFN-tau4 > IFN-tau6d > IFN-tau11), and induce an antiviral state (IFN-tau4 > IFN-tau6d = IFN-tau11). The present objective was to compare variants for differences in ability to inhibit proliferation of phytohemagglutinin-stimulated PBL. At equal concentrations, IFN-tau4 was more inhibitory than IFN-tau6d, IFN-tau11, or an IFN-omega control. Similar differences in potency were seen when IFN-tau variants were tested at equal antiviral concentrations. Thus, the sheep trophectoderm secretes variants of IFN-tau that differ in ability to regulate lymphocyte function. The nature of the effect of the trophectoderm on endometrial lymphocytes may depend on the relative amount of each variant produced.
authors.affiliation: Department of Animal Sciences, University of Florida, Gainesville, FL 32611-0920, USA.
authors.forename: S
authors.initials: S
authors.lastname: Tekin
authors.forename: A D
authors.initials: AD
authors.lastname: Ealy
authors.forename: S Z
authors.initials: SZ
authors.lastname: Wang
authors.forename: P J
authors.initials: PJ
authors.lastname: Hansen
mesh_terms: D000818:Animals; D007370:Interferon Type I / Q000502:physiology*; D008213:Lymphocyte Activation; D008214:Lymphocytes / Q000187:drug effects / Q000276:immunology*; D010835:Phytohemagglutinins / Q000494:pharmacology; D011257:Pregnancy Proteins / Q000502:physiology*; D020033:Protein Isoforms / Q000502:physiology; D012756:Sheep / Q000276:immunology*
chemical_list: D007370:Interferon Type I; D010835:Phytohemagglutinins; D011257:Pregnancy Proteins; D020033:Protein Isoforms; C020947:interferon tau