Expression of the antiviral protein Mx in peripheral blood mononuclear cells of pregnant and bred, non-pregnant ewes

Abstract

Interferon-tau (IFN ) acts locally on the endometrium to suppress estrogen and oxytocin receptor expression and block luteolysis in ruminants. Systemic administration of conceptus homogenates or recombinant ovine IFN does not block luteolysis or enhance pregnancy rates in sheep or cattle, respectively. However, IFN up-regulates expression of the antiviral protein Mx throughout the entire uterine wall during early pregnancy. These studies determined if conceptus-derived IFN also up-regulates Mx expression in components of the circulating immune system that migrate through the endometrial wall. In experiment one, peripheral blood mononuclear cells (PBMC) were isolated from ewes at D26 post-artificial insemination (AI) and Mx mRNA levels examined by Northern and slot-blot hybridization. Pregnancy resulted in a two-fold increase in Mx mRNA levels compared to bred, non-pregnant ewes at D26. In experiment two, PBMC were isolated from ewes at AI, and every three days from D9 to D30. Results showed a four-fold increase in Mx mRNA levels in PBMC from pregnant versus bred, non-pregnant ewes at D15. Increased Mx mRNA, which remained elevated through D30, was accompanied by increased levels of Mx protein. These results show that pregnancy recognition signaling rapidly induces Mx gene expression in PBMC, and are the first to suggest that IFN activates gene expression in components of the circulating immune system.

Pregnancy and interferon tau regulate RSAD2 and IFIH1 expression in the ovine uterus

“…The IFNT stimulated resident immune cells in the endometrium may migrate from the uterus, because IFNT-stimulated genes are higher in the peripheral blood leukocytes isolated from pregnant as compared with non-pregnant ewes and cows (Yankey et al 2001). Eosinophils are also present in the endometrium of early pregnant ewes, and their numbers increase between days 11 and 19 of early pregnancy, perhaps due to actions of both P4 and perhaps IFNT (Asselin et al 2001).…”

Temporal and spatial associations of oestrogen receptor alpha and progesterone receptor in the endometrium of cyclic and early pregnant mares

“…Twomicrogram samples of poly(A) RNA were separated on a 1% agarose formaldehyde gel and transferred to a nylon membrane (Nytran; Schleicher & Schuell, Keene, NH, USA). The nylon membranes were baked and the RNA cross-linked using ultraviolet illumination before hybridising overnight in 15 ml ULTRAhyb Reagent (Ambion) with 75 ng biotinylated ER or PR antisense probe (Yankey et al 2001). Oestrogen receptor and progesterone receptor probes were prepared from oERa8 (pGEM4Z) and oPR7-7A (pCRII) (Spencer & Bazer 1995) plasmids using an in vitro transcription kit (Ambion).…”

Upregulation of Interferon-stimulated Genes and Interleukin-10 in Peripheral Blood Immune Cells During Early Pregnancy in Dairy Cows

“…IFNT acts in the uterus around day 16 after insemination and prevents luteolysis by inhibiting prostaglandin F 2α release, resulting in the maintenance of corpus luteum function; therefore, this period is termed the maternal recognition period (MRP) [5]. IFNT induces the synthesis and secretion of IFN-stimulated genes (ISGs) such as ISG15, 2′,5′-oligoadenylate synthetase (OAS-1), IFN regulatory factor 1, Mx1 and Mx2 not only in the uterus but also in blood cells in ewes and cows [6][7][8][9][10]. In fact, in bovine peripheral blood leukocytes, ISG15 mRNA levels were higher in pregnant cows than in nonpregnant cows on days 18 and 20 after artificial insemination (AI) [7][8][9].…”