Early pregnancy affects expression of Toll-like receptor signaling members in ovine spleen

Abstract

Toll-like receptors (TLRs) are involved to the maternal immune tolerance. The spleen is essential for adaptive immune reactions. However, it is unclear that early pregnancy regulates TLR-mediated signalings in the maternal spleen. The purpose of this study was to investigate the effects of early pregnancy on expression of TLR signaling members in the ovine spleen. Ovine spleens were collected at day 16 of the estrous cycle, and at days 13, 16 and 25 of pregnancy (n = 6 for each group). Real-time quantitative PCR, western blot and immunohistochemistry analysis were used to detect TLR signaling members, including TLR2, TLR3, TLR4, TLR5, TLR7, TLR9, myeloid differentiation primary-response protein 88 (MyD88), tumor necrosis factor receptor associated factor 6 (TRAF6) and interleukin-1-receptor-associated kinase 1 (IRAK1). The results showed that expression levels of TLR2, TLR4 and IRAK1 were downregulated, but expression levels of TLR3, TLR5, TLR7, TLR9, TRAF6 and MyD88 were increased during early pregnancy. In addition, MyD88 protein was located in the capsule, trabeculae and splenic cords of the maternal spleen. This paper reports for the first time that early pregnancy has effects on TLR signaling pathways in the ovine spleen, which is beneficial for understanding the maternal immune tolerance during early pregnancy.

Rumen‐protected l‐carnitine supplementation during mating period altered metabolic status and reproductive performance of ewes

“…Others have stated that inflammation in animals would interfere with maternal recognition of pregnancy and subsequently, in case of maintained pregnancy, decreases placental weight from day 42 of gestation (Ribeiro et al, 2016). Zhang et al (2021) observed TLR4 downregulation in ewes' immune tissues at early pregnancy. The authors postulated a potential correlation with TLR4 downregulation during early pregnancy and higher progesterone levels in the animals.…”

Early Pregnancy Regulates Expression of IkappaB Family in Ovine Spleen and Lymph Nodes

“…Previous studies report that interferon-stimulated genes (ISGs), progesterone receptor, progesterone-induced blocking factor, tumor necrosis factor (TNF)-β, IL-2, IL-5, IL-6, IL-10, cyclooxygenase 2, aldo-keto reductase family 1, member B1, melatonin receptor 1 (MT1), gonadotropin-releasing hormone and its receptor are upregulated, but MT2 is downregulated in the maternal spleen of ewes during early pregnancy [ 21 , 22 , 23 , 24 , 25 , 26 ]. In addition, early pregnancy modulates the expression of Toll-like receptor signaling members and NF-κB components in the ovine maternal spleen [ 7 , 27 ]. Furthermore, the expression of ISGs, progesterone receptor, prostaglandin synthases, Th cytokines, MT1, gonadotropin-releasing hormone and its receptor, and prolactin and its receptor are changed in lymph nodes during early pregnancy in sheep [ 24 , 25 , 28 , 29 , 30 , 31 , 32 ].…”

Changes in expression levels of Nod-like receptors in the spleen of ewes

“…During early pregnancy in sheep, expression levels of gonadotropin releasing hormone, prolactin and its receptor, T help cytokines, melatonin receptors and CD4 are modulated in the maternal spleen ( Cao et al, 2021 ; Li et al, 2019b ; Bai et al, 2020 ; Feng et al, 2022 ). In addition, nuclear factor kappa B signaling pathway, complement signaling pathway and Toll-like receptor signaling pathway are regulated by early pregnancy in the spleen of ewes ( Hao et al, 2022 ; Yang et al, 2021 ; Zhang et al, 2021 ). Therefore, early pregnancy modulates splenic immune related signaling pathways.…”