Oviduct epithelium induces interferon-tau in bovine Day-4 embryos, which generates an anti-inflammatory response in immune cells

Anup K. Talukder,Takashi Shimizu,Kazuya Kusama,Masayuki Shimada,Akio Miyamoto,Kazuhiko Imakawa,Mohamed S. Yousef,Susan S. Suarez,Mohammad B. Rashid

doi:10.1038/s41598-018-26224-8

Abstract

Recent studies indicate that communication between the bovine embryo and the mother begins in the oviduct. Here, we aimed to investigate the effect of embryos on bovine oviducts for their immune responses using an in vitro model. First, zygotes were cultured with or without bovine oviduct epithelial cells (BOECs) for 4 days, when embryos had reached the 16-cell stage. At that time, we detected interferon-tau (IFNT) in embryos co-cultured with BOECs, but not in embryos cultured alone. Next, peripheral blood mononuclear cells (PBMCs) were incubated either in media from embryo alone cultures or from co-cultures of embryos with BOECs. The medium from embryo alone cultures did not modulate PBMCs gene expression; whereas the embryo-BOEC co-culture medium increased interferon-stimulated genes (ISGs: ISG15, OAS1, MX2), STAT1, PTGES and TGFB1 but suppressed IL17 expression in PBMCs. Both IFNT-treated BOEC culture medium and IFNT-supplemented fresh medium alone without BOEC, modulated PBMCs gene expressions similar to those by the embryo-BOEC co-culture medium. Further, specific antibody to IFNT neutralized the effect of embryo-BOEC co-culture medium on PBMCs gene expression. Our results indicate that BOECs stimulate embryos to produce IFNT, which then acts on immune cells to promote an anti-inflammatory response in the oviduct.

Highlights

The oviduct is a key organ responsible for final maturation of oocytes, transport of gametes, sperm capacitation, fertilization, and early embryo development[1,2]
IFNT was detected in embryos co-cultured with bovine oviduct epithelial cells (BOECs)
For the first time, that bovine D4 embryos at the 16-cell stage express IFNT when cultured with oviduct epithelial cells

Summary

Introduction

The oviduct is a key organ responsible for final maturation of oocytes, transport of gametes, sperm capacitation, fertilization, and early embryo development[1,2]. The developing embryo spends about 4 days in the bovine oviduct and enters into the uterus at the 16-cell to early morula stage[6]. The same group observed transcriptional differences between ampulla and isthmus regions of the bovine oviduct, when a D3 embryo was present[8] These findings suggest that embryo-maternal communication starts in the oviduct in the cow. It was observed that early cleavage-stage bovine embryos express MHC I transcript[9] and they could be detected as foreign by the oviduct immune system. We demonstrated in vitro that D5-D9 bovine embryos starts to produce IFNT, which acts as one of the major players for generation of an anti-inflammatory response in the uterus[15]. We investigated the effect of pre-blastocyst embryos on immune-related gene profile in bovine oviduct epithelial cells (BOECs) in vitro, and examined the effect of conditioned media from embryo alone cultures and embryo-BOEC co-cultures on gene expression of peripheral blood mononuclear cells (PBMCs)

Objectives

Methods

Results

Conclusion