Cytokine gene expression at the maternal–fetal interface after somatic cell nuclear transfer pregnancies in small ruminants

Abstract

The present retrospective study investigated pregnancy rates, the incidence of pregnancy loss and large offspring syndrome (LOS) and immune-related gene expression of sheep and goat somatic cell nuclear transfer (SCNT) pregnancies. We hypothesised that significantly higher pregnancy losses observed in sheep compared with goat SCNT pregnancies are due to the increased amounts of T-helper 1 cytokines and proinflammatory mediators at the maternal-fetal interface. Sheep and goat SCNT pregnancies were generated using the same procedure. Control pregnancies were established by natural breeding. Although SCNT pregnancy rates at 45 days were similar in both species, pregnancy losses between 45 and 60 days of gestation and the incidence of LOS were significantly greater in sheep than in goats. At term, the expression of proinflammatory genes in sheep SCNT placentas was increased, whereas that in goats was similar to that in control animals. Genes with altered expression in sheep SCNT placentas included cytotoxic T-lymphocyte-associated protein 4 (CTLA4), interleukin 2 receptor alpha (IL2RA), cluster of differentiation 28 (CD28), interferon gamma (IFNG), interleukin 6 (IL6), interleukin 10 (IL10), transforming growth factor beta 1 (TGFB1), tumor necrosis factor alpha (TNF-α), interleukin 1 alpha (IL1A) and chemokine (C-X-C motif) ligand 8 (CXCL8). Major histocompatibility complex-I protein expression was greater in sheep and goat SCNT placentas at term than in control pregnancies. An unfavourable immune environment is present at the maternal-fetal interface in sheep SCNT pregnancies.

Increased expression of pro‐inflammatory cytokines at the fetal–maternal interface in bovine pregnancies produced by cloning

“…In addition, goat SCNT pregnancies had rates of pregnancy loss and immune relatedgene expression profiles similar to what was observed in goat pregnancies established by natural breeding. 22 In this study, however, endometrial CSF2 expression was downregulated in the "healthier" SCNT pregnancies, MHC-I homozygous incompatible pregnancies, and numerically downregulated in the MHC-I homozygous compatible pregnancies. Decreased expression of CSF2, which is a potent proinflammatory factor, is likely due to decreased expression by Th1 lymphocytes and macrophages in the endometrium of healthy MHC-I homozygous pregnancies.…”

“…There is limited information on MHC‐I expression in the placentas of sheep and goats; one study failed to find evidence of trophoblast MHC‐I expression in samples collected between 9 and 125 days of gestation, while another study documented MHC‐I expression by interplacentomal trophoblast cells at term with increased expression in SCNT pregnancies. 10 , 22 In horses, MHC‐I proteins have not been detected on the non‐invasive trophoblast cells of the allantochorion; however, the invasive trophoblast cells that form the chorionic girdle express classical MHC‐I proteins between days 30 and 45 of pregnancy (reviewed by Rutigliano et al. 21 ).…”

Generation of Genetically Engineered Livestock Using Somatic Cell Nuclear Transfer

“…A dozen embryo transfers are usually sufficient to produce a few of GE founder animals for their initial phenotype assessment and GE line expansion by breeding. Intriguingly, we observed significantly greater pregnancy losses and incidence of large offspring syndrome in sheep compared to goats using the same SCNT procedure (Rutigliano et al 2017). This might be a result of abnormal proinflammatory gene expression in sheep SCNT placentas that were significantly higher than in naturally bred control sheep.…”

Controlled Cytoplast Arrest and Morula Aggregation Enhance Development, Cryoresilience, andIn VivoSurvival of Cloned Sheep Embryos

“…The vast majority of sheep cloning publications in the past decade have reported fusing donor cells in the presence of calcium ions (Fan et al, 2018;Fu et al, 2012;Hajian et al, 2011;Heidari et al, 2010;Hua et al, 2013;Khan et al, 2018;Ma et al, 2014Ma et al, , 2015Moulavi et al, 2013;Rutigliano et al, 2017;Tang et al, 2012;Wen et al, 2014;Ye et al, 2010), rather than in the absence (Choi et al, 2010(Choi et al, , 2013Deng et al, 2013;German et al, 2015;Rathbone et al, 2010). Most of the publications that report fusing in the presence of calcium ions treat the reconstructs with ionomycin/6-DMAP within 1 hour, so correct ploidy may have been maintained.…”