Regulatory T cells in bovine fertility: Current understanding and future prospects

Regulatory T cells (Tregs) have emerged as crucial players in maintaining maternal-fetal tolerance and promoting successful pregnancy outcomes. This review examines the importance of these cells in pregnancy, drawing on human and animal-based studies, with a focus on their role in bovine fertility. Tregs employ various mechanisms to mediate maternal-fetal tolerance, including regulation of effector T-cell responses, interactions with innate immune cells in the uterine microenvironment, and modulation of trophoblast function. In humans, Treg dynamics during normal pregnancy and alterations in pregnancy complications provide compelling evidence for their involvement in maintaining fetal-maternal harmony. Animal models, particularly mouse studies, have further elucidated the importance of Tregs in preventing fetal rejection and promoting successful pregnancy outcomes. The review also explores the characterization of bovine Tregs, highlighting their similarities and unique features compared to human and rodent counterparts. Recent studies have indicated the presence and potential significance of Tregs in the bovine uterine environment during early pregnancy. Translational applications of Treg research in livestock fertility are discussed, with a focus on immunomodulatory strategies for enhancing Treg function, such as antigen-specific tolerance induction, pharmacological targeting of Treg pathways, and cell-based therapies using autologous or allogeneic Tregs. The review concludes by emphasizing the potential impact of Treg-based strategies on the livestock industry and the broader implications for human reproductive health. Future research directions are outlined, underscoring the need for further investigations into the role of Tregs in bovine reproductive tissues and their relationship with fertility outcomes.

Changes in vaginal cytokines concentrations during artificial insemination and natural service in beef heifers

OBJECTIVE

Heifer development is crucial for the optimization of reproductive efficiency in beef production. Heifer development is largely influenced by nutrition. Nutritional status of these heifers can influence immunological responses that are crucial for reproduction. Commercial Angus heifers (n = 9) were utilized, in a pilot study, to elucidate the effects of sampling time (days 0, 7, 14, 21, 28, and 35), pregnancy status, and type of mating on individual cytokine concentrations and cytokine profiles in the vagina following breeding.

RESULTS

Cytokine profiles were analyzed using MetaboAnalyst 5.0 and one-way ANOVAs were performed in R Studio to identify differences in individual cytokines based on sampling time, pregnancy status, and type of mating. Cytokine profiles were different (P = 0.05) 7 days after either mating type. Cytokines, IL-1β, IL-17a, MCP-1, and TNFα were different based on the mating type and pregnancy status. Multiple cytokines, IL-1α, IL-1β, IL-6, IL-8, IL-10, IL-17a, VEGFa, and MIP1α, were different between days regardless of pregnancy status. In conclusion, vaginal cytokines differ based on pregnancy status, type of mating, and time which may be indicative of vital pathways that need to be activated for pregnancy.

Association between endometrial protein expression of IFN-γ and delayed conception after parturition in dairy cows

The cytokine context present in the reproductive tract of cows is closely involved in normal uterine functions, including the estrous cycle and the establishment and maintenance of pregnancy. However, the roles of some cytokines in the uterus, and their relation with reproductive performance remain to be elucidated. Thus, this study aimed to examine the protein expression of several cytokines such as TNFα, IL-6, IL-8, IFNγ, IL-4, and TGF-β3 in endometrial biopsies previous to conception, to evaluate the possible association with delayed conception in dairy cows. Protein expression levels were evaluated by immunohistochemistry. Results showed that the protein expression levels of TNFα, IL-6, IL-4 and TGF-β3 were not associated with the parturition-conception interval, whereas the high protein expression levels of IFNγ were associated with the parturition-conception interval. Finally, the low protein expression of IL-8 showed a statistical tendency to be associated with delayed conception. This is the first report about the protein expression of IFN-γ in the endometrium of dairy cows and also, this cytokine could enhance the favorable conditions to achieve an early pregnancy.

Effects of early pregnancy on NOD-like receptor expression in the ovine endometrium

Introduction

Nucleotide-binding domain (NOD)-like receptors (NLRs) are expressed in the endometrium, and involved in modulating the female innate immune responses. There are conceptus-endometrial interactions during pregnancy, which ensure immune homeostasis of the maternal-fetal interface. The purpose of this study was to explore the effects of early pregnancy on NLR expression in the ovine endometrium.

Methods

Endometrial tissues were collected at day 16 of the estrous cycle, and at days 13, 16 and 25 of pregnancy (n = 6 for each group), and RT-qPCR, western blot and immunohistochemistry analysis were used to analyze the expression of NLRs, including NOD1, NOD2, major histocompatibility complex class II transactivator (CIITA), neuronal apoptosis inhibitor protein (NAIP), NLR family, pyrin domain-containing 1 (NLRP1), NLRP3 and NLRP7.

Results

Expression levels of NOD1, NOD2, NAIP, CIITA, NLRP1 and NLRP3 declined, but expression level of NLRP7 increased in the endometria during early pregnancy compared with nonpregnant ewes. In addition, NOD2 and CIITA proteins were located in the endometrium in a protein type-, cell type- and pregnancy status-specific manner.

Discussion

Early pregnancy modulated expression of NLR family in the ovine endometrium, which may be essential for conceptus-endometrial interactions and maternal-fetal interface immune homeostasis.

Antimicrobial peptides β-defensin family: Expression and regulation in the endometrium during the estrous cycle and pregnancy in pigs

Members of the β-defensin (DEFB) family, which are antimicrobial peptides and humoral components of the innate immune system, protect the surfaces of various host tissues by killing a broad range of microorganisms and are involved in immunomodulatory actions. The expression of these DEFB members changed during the estrous cycle and pregnancy in a stage-specific manner. The expression of DEFBs was also detected in conceptus and chorioallantoic tissues during pregnancy. DEFB1 and DEFB3 proteins and DEFB2 mRNA were localized primarily to endometrial epithelial cells during early pregnancy. Increasing doses of progesterone upregulated DEFB2 and EP2C expression in endometrial explant tissues. These results showed that members of the DEFB family were expressed stage-specifically at the maternal-conceptus interface in pigs, suggesting that the DEFB family plays important roles at the maternal-conceptus interface in regulation of innate immunity by protection of the maternal endometrial and conceptus tissues from pathogens to preserve fertility in pigs.

Progesterone-dependent and progesterone-independent modulation of luminal epithelial transcription to support pregnancy in cattle

In cattle, starting 4-5 days after estrus, preimplantation embryonic development occurs in the confinement of the uterine lumen. Cells in the endometrial epithelial layer control the molecular traffic to and from the lumen and, thereby determine luminal composition. Starting early postestrus, endometrial function is regulated by sex steroids, but the effects of progesterone on luminal cells transcription have not been measured in vivo. The first objective was to determine the extent to which progesterone controls transcription in luminal epithelial cells 4 days (D4) after estrus. The second objective was to discover luminal transcripts that predict pregnancy outcomes when the effect of progesterone is controlled. Endometrial luminal epithelial cells were collected from embryo transfer recipients on D4 using a cytological brush and their transcriptome was determined by RNASeq. Pregnancy by embryo transfer was measured on D30 (25 pregnant and 18 nonpregnant). Progesterone concentration on D4 was associated positively (n = 182) and negatively (n = 58) with gene expression. Progesterone-modulated transcription indicated an increase in oxidative phosphorylation, biosynthetic activity, and proliferation of epithelial cells. When these effects of progesterone were controlled, different genes affected positively (n = 22) and negatively (n = 292) odds of pregnancy. These set of genes indicated that a receptive uterine environment was characterized by the inhibition of phosphoinositide signaling and innate immune system responses. A panel of 25 genes predicted the pregnancy outcome with sensitivity and specificity ranging from 64%-96% and 44%-83%, respectively. In conclusion, in the early diestrus, both progesterone-dependent and progesterone-independent mechanisms regulate luminal epithelial transcription associated with pregnancy outcomes in cattle.

Proteomic determinants of uterine receptivity for pregnancy in early and mid-postpartum dairy cows†

Dairy cow subfertility is a worldwide issue arising from multiple factors. It manifests in >30% early pregnancy losses in seasonal pasture-grazed herds, especially when cows are inseminated in the early post-partum period. Most losses occur before implantation, when embryo growth depends on factors present in maternal tract fluids. Here we examined the proteomic composition of early and mid-postpartum uterine luminal fluid in crossbred lactating dairy cows to identify molecular determinants of fertility. We also explored changes in uterine luminal fluid from first to third estrus cycles postpartum in individual cows, linking those changes with divergent embryo development. For this, we flushed uteri of 87 cows at day 7 of pregnancy at first and third estrus postpartum, recovering and grading their embryos. Out of 1563 proteins detected, 472 had not been previously reported in this fluid, and 408 were predicted to be actively secreted by bioinformatic analysis. The abundance of 18 proteins with roles in immune regulation and metabolic function (e.g. cystatin B, pyruvate kinase M2) was associated with contrasting embryo quality. Matched-paired pathway analysis indicated that, from first to third estrus postpartum, upregulation of metabolic (e.g. creatine and carbohydrate) and immune (e.g. complement regulation, antiviral defense) processes were related to poorer quality embryos in the third estrus cycle postpartum. Conversely, upregulated signal transduction and protein trafficking appeared related to improved embryo quality in third estrus. These results advance the characterization of the molecular environment of bovine uterine luminal fluid and may aid understanding fertility issues in other mammals, including humans.

The effects of protein level on cytokines and chemokines in the uterine environment of beef heifers during development

The development of replacement heifers is crucial for breeding success and herd efficiency. Nutritional management can affect not only reproductive development but also the inflammatory status of the uterine environment, which may impact reproductive functions such as pregnancy establishment and development. The study herein evaluated the concentration of cytokines and chemokines in the uterus of heifers supplemented with different levels of protein. Angus heifers (n = 60) were blocked by body weight (BW) and randomly assigned to 1 of 3 treatments based on protein supplementation level: control of 10% crude protein (CON), 20% crude protein (P20), or 40% crude protein (P40). BW, body condition score, and blood samples were taken every 2 wk for 140 d to monitor development. Uterine flushes were performed monthly and concentrations of cytokines (IL-1α, IL-1β, TNF-α, IFN-γ, IL-10, VEGF-α, IL-17A, and IL-36RA) and chemokines (IL-8, MCP-1, MIP-1α, and MIP-1β) were quantified via ELISA multiplex. To test if there were mean differences in cytokines between the treatment groups or over time, PROC GLIMMIX (SAS v 9.4) was utilized. Concentrations of all cytokines and chemokines, except IL-1α, changed throughout heifer development (P < 0.05). Heifers in the P40 treatment group displayed reduced concentrations of MCP-1 (P = 0.007) and tended to have decreased concentrations of IFN-γ (P = 0.06). Cytokine IL-36RA tended (P = 0.06) to be affected by protein level, with the lowest concentrations observed in CON heifers. Most cytokines and chemokines increased following the initial month of supplementation (P < 0.05). The increase in concentrations after 1 mo may indicate an adaptive response in the uterus to diet change. Cytokines and chemokines fluctuated due to physiological changes occurring during development. Further research is needed to determine the influence of nutrition on uterine inflammation and long-term impacts on reproductive function.

Association of gastrointestinal parasite burden, serum cytokines and hormones concentrations, and pregnancy in Angus-cross beef cows

The objective was to elucidate the relationships among gastrointestinal (GI) parasite load, serum cytokines (Th 1 - Interleukin (IL) 2, Interferon (IFN) γ and Tumor necrosis factor (TNF) α; Th 2- IL4, IL6, and IL10) levels, hormones (progesterone, cortisol, 8-epi-prostaglandin F2 alpha (isoprostane), prolactin, substance-p, and prostaglandin F metabolites) concentrations, and pregnancy in beef cattle. Angus-cross beef cows (n = 700; age, 3-8 y) were blocked by age and body condition score (BCS, 1-9), and were randomly assigned to treatment (n = 350, TRT, 50 mg of eprinomectin/50 kg BW, im) or control (n = 350, CON, no treatment) on Day -30. Cows were synchronized using Controlled Internal Drug Release insert (CIDR) + CO-Synch protocol and artificially inseminated at a fixed time on Day 0 (66 h after CIDR removal). Fecal samples were collected to determine fecal egg count per gram (FEG, McMaster method) on Days -30, -23, -16, -7, 7, 0, 16 and 23, and blood samples were collected on Days -7, 0, 7, 16 and 23. Serum cytokines were determined on Days -7, 0, 7, 16 and 23, and circulating hormones were measured on Day 16. BCS were recorded on Day 16 following artificial insemination (AI), and pregnancy status was diagnosed on Day 30 and 60. Pregnancy/AI varied among treatment groups on Day 30 [TRT, 62.0% (217/350); CON, 54.9% (192/350) (P = 0.05)] and Day 60 [TRT, 60.9% (213/350); CON, 51.7% (181/350) (P < 0.05)]. Pregnancy loss between 30 and 60 days for TRT and CON groups were 1.8% (4/217) and 5.7% (11/192), respectively (P < 0.05). The BCS on Day 16 did not differ among treatment groups (P> 0.1). Four groups of 40 cows were selected based on their pregnancy status and treatment: pregnant, TRT; non-pregnant, TRT; pregnant, CON; and non-pregnant, CON to compare the mean FEG, cytokines, and hormones levels. The FEG and cytokine concentrations were significantly (P < 0.05) influenced by treatment, pregnancy status, day, treatment by pregnancy status, and treatment by day. Day 16 hormone concentrations were considerably influenced by treatment, pregnancy status, and treatment by pregnancy. Although FEG on Day -30 did not differ among the groups (P> 0.1), it was lower in treated, pregnant cows compared with cows in other three groups from Day -23 onwards (P < 0.05). Overall and pairwise comparisons showed that serum concentrations of Type 1 cytokines, IL2, IFNγ, and TNFα were lower (P < 0.05) from gestational Day 7 onwards in treated, pregnant cows compared with cows in other three groups. In contrast, serum concentrations of Type 2 cytokines, IL4, IL6 and IL10 were greater (P < 0.05) from gestational Day 7 onwards in treated, pregnant cows compared with cows in other groups. Serum concentrations of progesterone was greater and other hormones were lower for pregnant cows in TRT group compared to cows in other groups on gestational Day 16. In conclusion, GI parasite load was reduced; Th 1 cytokines levels were decreased; Th 2 cytokines concentrations were increased; progesterone level was increased; and cortisol, substance-P, prolactin, isoprostane, and PGFM were decreased in pregnant, TRT cows. These changes also resulted in an increase in P/AI. It is plausible that direct and bidirectional host-parasite interactions mediated by cytokines and hormones may have promoted maternal tolerance of an immunologically diverse conceptus and the establishment of pregnancy.

Immune cell infiltration landscape and immune marker molecular typing in preeclampsia

Preeclampsia (PE) is an important topic in obstetrics. In this study, we used weighted gene co-expression network analysis (WGCNA) to screen the key modules related to immune cell infiltration and to identify the hub genes for the molecular subtyping of PE. We first downloaded a set of PE transcriptional data (GSE75010; 157 samples: 80 PE and 77 non-PE) from the GEO database. We then analyzed the PE samples and non-PE samples for immune cell infiltration and screened cells with differences in such infiltration. Next, we downloaded the immune-related genes from an immune-related database to screen the expression profile of the immune-related genes. Then, we obtained a candidate gene set by screening the immune-related genes differentially expressed between the two groups. We used WGCNA to construct a weighted co-expression network for these candidate genes, mined co-expression modules, and then calculated the correlation between each module and immune cells with differential infiltration. We screened the modules related to infiltrating immune cells, identified the key modules' hub genes, and determined the key module genes that interacted with each other. Finally, we obtained the hub genes related to the infiltrating immune cells. We classified the preeclampsia patients by unsupervised cluster molecular typing, determined the difference of immune cell infiltration among the different PE subtypes, and calculated the expression of hub genes in these different subtypes. In conclusion, we found 41 hub genes that may be closely related to the molecular typing of PE.

Transcriptome profiling of buffalo endometrium reveals molecular signature distinct to early pregnancy

Buffalo reproduction struggles with a high incidence of early embryonic mortality. Effective treatment and prevention strategies for this condition are not available due to lack of understanding of molecular pathways in early pregnancy of this species. In the present study, we have attempted to understand these molecular pathways by characterizing the endometrial transcriptomic profiles of pregnant buffalos during early pregnancy. For the transcriptome profiling, buffalo endometrial tissues of 29-36 days of pregnancy and of nonpregnant luteal phase were collected from the local slaughterhouse. We confirmed the status of pregnancy based on the crown vertebral length of the foetus. Total RNA was isolated and sequencing was performed using the Illumina nextseq platform. The raw reads were filtered and mapped to the Bos taurus UMD 3.1 reference genome assembly. An average of 24,597 genes was investigated for differential expression between the two groups. Transcriptome data identified a total of 450 differentially expressed genes (using a cut off value of log₂ fold changes >2 and <-2) in early pregnancy in comparison to the nonpregnant group (P_adj < 0.05). Among these, 270 genes were significantly upregulated and 180 genes were downregulated. The most impacted pathways were related to secretion, transport, ionic homeostasis, mitosis and negative regulation of viral processes. In conclusion, our study characterized a unique set of DEGs, during the early pregnancy of buffalo, which potentially modulate the endometrial environment to establish and maintain a successful pregnancy.

Differential expression of T helper cytokines in the liver during early pregnancy in sheep

Liver plays important roles in the innate and adaptive immunity, and contributes to the maternal immune adjustments during pregnancy in mice and rats. T helper 1 (Th1) and Th2 cytokines are related to immune response. However, expression of Th1 and Th2 cytokines in maternal livers is unclear during early pregnancy in sheep. In this study, livers were collected on day 16 of the estrous cycle and on days 13, 16 and 25 of pregnancy (n = 6 for each group) in ewes, and qRT-PCR, western blot and immunohistochemistry were used to analyze the expression of Th1 and Th2 cytokines in the livers. Our results showed that interferon-gamma (IFN-γ), interleukin (IL)-2, IL-4, IL-6 and IL-10 were downregulated, and IL-5 was upregulated in the livers during early pregnancy. Furthermore, there was no effect for early pregnancy on expression of TNF-β in the livers, and the IFN-γ protein was limited to the endothelial cells of the proper hepatic arteries and portal veins. In conclusion, early pregnancy exerted its effect on the liver to regulate the Th cytokines expression, but there was no evident shift from Th1 to Th2 cytokines, which may be necessary for the maternal hepatic immune adjustments during early pregnancy in sheep.

Alteration of the mare's immune system by the synthetic progestin, altrenogest

PROBLEM

Progestins are immunomodulatory in a variety of species. In the horse, the most commonly administered synthetic progestin is altrenogest (ALT), but its effect on the immune system of the non-pregnant mare is unknown.

METHODS

Peripheral blood mononuclear cells (PBMCs) from diestrous mares were incubated with varying concentrations of progesterone (P4) or ALT to assess intracellular production of IFNγ and the expression of select cytokines. Additionally, ten mares received either ALT or VEH daily utilizing a switchback design beginning on the day of ovulation and continuing for 7 days. Circulating PBMCs and endometrial biopsies were obtained to assess the production and expression of the same cytokines.

RESULTS

In vitro, both P4 and ALT caused a dose-dependent decrease in intracellular IFNγ in PBMCs. P4 caused a dose-dependent decrease in the expression of IFNγ, IL-10 and IL-4, while ALT caused an increase in the expression of IL-6 and IL-1β in PBMCs. In vivo, ALT suppressed the intracellular levels of IFNγ in PBMCs on d6. While control mares experienced a decrease in IL-1β expression from d0 to d6, ALT-treated mares did not. In the endometrium, ALT increased the expression of IL-1RN and IFNγ in comparison with VEH-treated mares.

CONCLUSION

P4 and ALT appear to alter the immune system of the non-pregnant mare both systemically in addition to locally within the endometrium. Further research is necessary to determine the pathways through which this synthetic progestin functions on the immune system of the horse, and the consequences it may have.

Genome-wide association study for stayability measures in Nellore-Angus crossbred cows

Beef cow stayability is a complex, economically important trait often used as an indicator of a cow's potential lifetime productivity. Stayability is defined as capability of a cow to maintain a perfect record up to 6 yr of age. This age is commonly cited as a financial break-even point, where initial costs of cow development and maintenance are recovered by her cumulative net income from yearly calf receipts. Later-maturing Bos indicus-Bos taurus crossbred cows may experience reproductive difficulty early in life but have a high potential for a long reproductive life span. It was the objective of this study to identify genetic variants associated with measures of beef cow stayability. A population of B. indicus-B. taurus crossbred cows (n = 305) from central Texas was used. Phenotypes for various measures of stayability to 6 yr of age were produced by artificially imposing five different culling criteria on data from the population. Cows were scored either as a 1 (indicating a perfect record through 6 yr) or a 0 (indicating failure at or before 6 yr), under each criterion. Genome-wide association studies (GWAS) were conducted for each criterion using univariate procedures and prefitting the fixed effect of cow contemporary group. SNP associations for two criteria surpassed the false discovery threshold of 0.15, when a cow was scored as 0 upon her first failure to wean a calf, regardless of reason, through 6 yr (criterion 2), and when a cow was scored as 0 upon her first failure to give birth to a calf, through 6 yr (criterion 3). Associated SNP were found on bovine chromosomes (BTA) 1, 2, 5, 9, 18, and 21 for criterion 2 and on BTA 1, 5, 11, 15, and 24 for criterion 3. A critical region on BTA 5: 43-50 Mb was identified for each criterion. Due to the similarities to prior work, the tendency for B. indicus cattle to experience reproductive difficulties early in life, and due to the large proportion of cows that left the herd at an early age under these criteria, these results suggest that the associations are likely driven by an early life trait such as age at puberty or rate of heifer development.

Plasma metabolomic profiles differ at the time of artificial insemination based on pregnancy outcome, in Bos taurus beef heifers

Infertility remains the most prevalent reason for cattle being removed from production environments. We utilized metabolomic profiling to identify metabolites in the blood plasma that may be useful in identifying infertile heifers at the time of artificial insemination (AI). Prior to AI, phenotypic parameters including body condition, weight, and reproductive organ measurements were collected. These were determined not effective at differentiating between fertile and infertile heifers. Analysis of the resulting metabolomic profiles revealed 15 metabolites at significantly different levels (T-test P ≤ 0.05), with seven metabolites having a greater than 2-fold difference (T-test P ≤ 0.05, fold change ≥2, ROC-AUC ≥ 0.80) between infertile and fertile heifers. We further characterized the utility of using the levels of these metabolites in the blood plasma to discriminate between fertile and infertile heifers. Finally, we investigated the potential role inflammation may play by comparing the expression of inflammatory cytokines in the white blood cells of infertile heifers to that of fertile heifers. We found significantly higher expression in infertile heifers of the proinflammatory markers tumor necrosis factor alpha (TNFα), interleukin 6 (IL6), and the C-X-C motif chemokine 5 (CXCL5). Our work offers potentially valuable information regarding the diagnosis of fertility problems in heifers undergoing AI.

Runs of homozygosity in a selected cattle population with extremely inbred bulls: Descriptive and functional analyses revealed highly variable patterns

The analysis of runs of homozygosity (ROH), using high throughput genomic data, has become a valuable and frequently used methodology to characterize the genomic and inbreeding variation of livestock and wildlife animal populations. However, this methodology has been scarcely used in highly inbred domestic animals. Here, we analyzed and characterized the occurrence of ROH fragments in highly inbred (HI; average pedigree-based inbreeding coefficient F_PED = 0.164; 0.103 to 0.306) and outbred Retinta bulls (LI; average F_PED = 0.008; 0 to 0.025). We studied the length of the fragments, their abundance, and genome distribution using high-density microarray data. The number of ROH was significantly higher in the HI group, especially for long fragments (>8Mb). In the LI group, the number of ROH continuously decreased with fragment length. Genome-wide distribution of ROH was highly variable between samples. Some chromosomes presented a larger number of fragments (BTA1, BTA19, BTA29), others had longer fragments (BTA4, BTA12, BTA17), while other ones showed an increased ROH accumulation over specific loci (BTA2, BTA7, BTA23, BTA29). Similar differences were observed in the analysis of 12 individuals produced by a similar inbred event (F_PED3 = 0.125). The correlation between the fraction of the genome covered by ROH (F_ROH) and F_PED was high (0.79), suggesting that ROH-based estimations are indicative of inbreeding levels. On the other hand, the correlation between F_PED and the microsatellite-based inbreeding coefficient (F_MIC) was only moderate (r = 0.44), suggesting that STR-based inbreeding estimations should be avoided. Similarly, we found a very low correlation (r = -0.0132) between recombination rate and ROH abundance across the genome. Finally, we performed functional annotation analyses of genome regions with significantly enriched ROH abundance. Results revealed gene clusters related to pregnancy-associated proteins and immune reaction. The same analysis performed for regions enriched with recently formed ROH (> 8 Mb) showed gene clusters related to flagellum assembly. In both cases, the processes were related to male and female reproductive functions, which may partially explain the reduced fertility associated with inbred populations.

Differential expression of interferon-gamma, IL-4 and IL-10 in peripheral blood mononuclear cells during early pregnancy of the bovine

Maternal systemic immune response is regulated by conceptus-derived signals through peripheral blood mononuclear cells (PBMCs) via blood circulation during early pregnancy in cattle. In this study, the PBMCs from day 18 in non-pregnant cows and days 14, 18 and 30 in pregnant cows were used to explore the expression of interferon-gamma (IFN-γ), interleukin 4 (IL-4) and IL-10, and the plasma progesterone (P4) concentration was also determined. The results showed that the expression levels of mRNA and the protein of IFN-γ were lower and that IL-4 and IL-10 were higher in the PBMCs from the pregnant cows than in those of non-pregnant cows. From this study, early pregnancy induced a lower Th1 immunity (IFN-γ) and a higher Th2 immunity (IL-4 and IL-10) in the PBMCs, which may be related to interferon-tau and P4, thereby contributing to successful pregnancy in cattle.

Effects of preimplantation factor on interleukin-6 and prostaglandin F2α and E2 in the bovine endometrium

Preimplantation factor (PIF) is a pregnancy specific peptide with immune modulatory properties exerted on the human endometrium. Viable bovine embryos secrete PIF, but its effect on the bovine endometrial immune response is unknown, both in native and inflammatory stimulated endometrial tissue. An ex vivo bovine endometrial tissue culture model was used with lipopolysaccharide (LPS) as an inflammatory stimulant. The effect of synthetic PIF (sPIF) was assessed, in three separate experiments, on the secretion or mRNA expression of essential prostaglandins and cytokines. Radioimmunoassays were used to assess prostaglandin secretion and ELISA for IL-6 secretion from endometrial explants. mRNA expression of IL6 and IL8 was analysed from endometrial explants with real-time PCR. Synthetic PIF reduced native IL-6 secretion from explants when pre-treated for 24 h. There was no effect of sPIF on IL-6 secretion from LPS challenged explants; however, sPIF increased IL6 mRNA expression when challenged with 500 ng/mL LPS. There was no effect of sPIF on prostaglandin secretion or mRNA expression of IL8. Therefore, sPIF is able to modulate the native IL-6 production pathway in the bovine endometrium, yet demonstrates no effect on prostaglandin secretion or IL8 expression. Unlike in human studies, effects of sPIF were minimal, thus sPIF is not an effective modulator of the immune targets investigated in the bovine endometrium.

Up-regulation of Interferon-inducible protein 16 contributes to psoriasis by modulating chemokine production in keratinocytes

Psoriasis is a common chronic inflammatory skin disease characterized by epidermal hyperplasia and dermal inflammation. Keratinocyte activation is known to play a critical role in psoriasis, but the underlying mechanism remains unclear. Interferon-inducible protein 16 (IFI16), an innate immune system sensor, is reported to affect keratinocyte function. We therefore hypothesized that IFI16 promotes psoriasis by modulating keratinocyte activation. In the present study, we cinfirmed that IFI16 was overexpressed in epidermal keratinocytes of psoriasis patients. In addition, psoriasis-related cytokines, including IFN-γ, TNF-α, IL-17 and IL-22, induced IFI16 up-regulation in keratinocytes via activation of STAT3 signaling. We also observed that IFI16 activated the TBK1-NF-κB signaling, leading to the production of CXCL10 and CCL20. Importantly, knocking down p204, which is reported as the mouse orthologous of human IFI16, inhibited epidermal hyperplasia in mice with imiquimod-induced psoriasiform dermatitis. These findings indicate that IFI16 plays a critical role in the pathogenesis of psoriasis and may be a potential therapeutic target.

The transcriptome signature of the receptive bovine uterus determined at early gestation

Pregnancy success is critical to the profitability of cattle operations. However, the molecular events driving the uterine tissue towards embryo receptivity are poorly understood. This study aimed to characterize the uterine transcriptome profiles of pregnant (P) versus non-pregnant (NP) cows during early pregnancy and attempted to define a potential set of marker genes that can be valuable for predicting pregnancy outcome. Therefore, beef cows were synchronized (n=51) and artificially inseminated (n=36) at detected estrus. Six days after AI (D6), jugular blood samples and a biopsy from the uterine horn contralateral to the ovary containing the corpus luteum were collected. Based on pregnancy outcome on D30, samples were retrospectively allocated to the following groups: P (n=6) and NP (n=5). Both groups had similar plasma progesterone concentrations on D6. Uterine biopsies were submitted to RNA-Seq analysis in a Illumina platform. The 272,685,768 million filtered reads were mapped to the Bos Taurus reference genome and 14,654 genes were analyzed for differential expression between groups. Transcriptome data showed that 216 genes are differently expressed when comparing NP versus P uterine tissue (Padj ≤ 0.1). More specifically, 36 genes were up-regulated in P cows and 180 are up-regulated in NP cows. Functional enrichment and pathway analyses revealed enriched expression of genes associated with extracellular matrix remodeling in the NP cows and nucleotide binding, microsome and vesicular fraction in the P cows. From the 40 top-ranked genes, the transcript levels of nine genes were re-evaluated using qRT-PCR. In conclusion, this study characterized a unique set of genes, expressed in the uterus 6 days after insemination, that indicate a receptive state leading to pregnancy success. Furthermore, expression of such genes can be used as potential markers to efficiently predict pregnancy success.

Global proteomic characterization of uterine histotroph recovered from beef heifers yielding good quality and degenerate day 7 embryos

The objective was to analyze the proteomic composition of uterine flushes collected from beef heifers on day 7 after insemination. Estrus was synchronized in crossbred beef heifers by using a protocol with a controlled intravaginal drug releasing device. Heifers detected in standing estrus (within 24-48 h after removal of controlled intravaginal drug releasing device) were inseminated (estrus = day 0) with frozen-thawed semen from a single ejaculate of a bull with proven fertility. Heifers from which an embryo was recovered (after slaughter on day 7) were classified as either having a viable embryo (morula/blastocyst stage) or a degenerate embryo (arrested at the 2- to 16-cell stage). The overall recovery rate (viable and degenerate combined) was 64%. Global liquid chromatography coupled to tandem mass spectrometry proteomic analysis of the histotroph collected identified 40 high-confidence proteins present on day 7; 26 proteins in the viable group, 10 in the degenerate group, and 4 shared between both groups. Five proteins (platelet-activating factor acetylhydrolase IB subunit γ [PAFAH1B3], tubulin α-1D chain, tubulin β-4A chain, cytochrome C, and dihydropyrimidinase-related protein-2) were unique or more abundant in the histotroph collected from animals with a viable embryo, and 1 protein (S100-A4) was more abundant in the histotroph collected from animals with a degenerate embryo. Of interest, PAFAH1B3, detected only in histotroph from the group yielding viable embryos, belongs to the group of platelet-activating factors that are known to be important for the development of the pre-implantation embryo in other species. To our knowledge this is the first report of PAFAH1B3 in relation to bovine early embryonic development.