Preimplantation factor inhibits circulating natural killer cell cytotoxicity and reduces CD69 expression: implications for recurrent pregnancy loss therapy

Intrauterine perfusion of dexamethasone improves pregnancy outcomes in recurrent reproductive failure patients with elevated uterine natural killer cells. A retrospective cohort study

OBJECTIVE

To determine the effect of intrauterine perfusion of dexamethasone (DXM) on pregnancy outcomes in recurrent reproductive failure (RRF) patients with elevated uNK cells.

METHODS

This retrospective cohort study included 132 RRF patients with elevated uNK cells: 56 patients received DXM treatment and 76 patients refused it in the frozen-thawed embryo transfer cycles. To determine the efficacy of intrauterine perfusion of DXM, multivariate logistic regression models and diagnosis-based subgroup analysis were performed. We also compared the pregnancy outcomes of patients with different responsiveness to DXM treatment.

RESULTS

Intrauterine perfusion of DXM significantly improved clinical pregnancy rate (aOR: 3.188, 95% CI: 1.395-7.282, P = .006) and live birth rate (aOR: 3.176, 95% CI: 1.318-7.656, P = .010) in RRF patients with elevated uNK cells, but there was no significant association with miscarriage rate. Subgroup analysis revealed that intrauterine perfusion of DXM in patients with recurrent implantation failure (RIF) showed significant improvement in clinical pregnancy rate (aOR: 6.110, 95% CI: 1.511-24.713, P = .011) and live birth rate (aOR: 9.904, 95% CI: 1.963-49.968, P = .005), but there was insufficient evidence of benefit in recurrent pregnancy loss (RPL) patients. Additionally, uNK cell levels dropped to normal range was achieved in only 35.90% of RRF patients after DXM treatment, no significant difference was found in pregnancy outcomes among patients with different responsiveness to DXM treatment (all P > .05).

CONCLUSION

Intrauterine perfusion of DXM was a promising and effective treatment to enhance clinical pregnancy rate and live birth rate in RRF women with abnormally elevated uNK cells, and RIF patients are more likely to benefit than RPL patients.

Pharmacological activation of insulin-degrading enzyme improves insulin secretion and glucose tolerance in diet-induced obese mice

AIM

To investigate the use of synthetic preimplantation factor (sPIF) as a potential therapeutic tool for improving glucose-stimulated insulin secretion (GSIS), glucose tolerance and insulin sensitivity in the setting of diabetes.

MATERIALS AND METHODS

We used a preclinical murine model of type 2 diabetes (T2D) induced by high-fat diet (HFD) feeding for 12 weeks. Saline or sPIF (1 mg/kg/day) was administered to mice by subcutaneously implanted osmotic mini-pumps for 25 days. Glucose tolerance, circulating insulin and C-peptide levels, and GSIS were assessed. In addition, β-cells (Min-6) were used to test the effects of sPIF on GSIS and insulin-degrading enzyme (IDE) activity in vitro. The effect of sPIF on GSIS was also tested in human islets.

RESULTS

GSIS was enhanced 2-fold by sPIF in human islets ex vivo. Furthermore, continuous administration of sPIF to HFD mice increased circulating levels of insulin and improved glucose tolerance, independently of hepatic insulin clearance. Of note, islets isolated from mice treated with sPIF exhibited restored β-cell function. Finally, genetic (shRNA-IDE) or pharmacological (6bK) inactivation of IDE in Min-6 abolished sPIF-mediated effects on GSIS, showing that both the protein and its protease activity are required for its action.

CONCLUSIONS

We conclude that sPIF is a promising secretagogue for the treatment of T2D.

Functional prominence of natural killer cells and natural killer T cells in pregnancy and infertility: A comprehensive review and update

During pregnancy, complicated connections are formed between a mother and a fetus. In a successful pregnancy, the maternal-fetal interface is affected by dynamic changes, and the fetus is protected against the mother's immune system. Natural killer (NK) cells are one of the immune system cells in the female reproductive system that play an essential role in the physiology of pregnancy. NK cells not only exist in peripheral blood (PB) but also can exist in the decidua. Studies have suggested multiple roles for these cells, including decidualization, control of trophoblast growth and invasion, embryo acceptance and maintenance by the mother, and facilitation of placental development during pregnancy. Natural killer T (NKT) cells are another group of NK cells that play a crucial role in the maintenance of pregnancy and regulation of the immune system during pregnancy. Studies show that NK and NKT cells are not only effective in maintaining pregnancy but also can be involved in infertility-related diseases. This review focuses on NK and NKT cells biology and provides a detailed description of the functions of these cells in implantation, placentation, and immune tolerance during pregnancy and their role in pregnancy complications.

Preimplantation factor modulates trophoblastic invasion throughout the decidualization of human endometrial stromal cells

BACKGROUND

Successful human embryo implantation requires the differentiation of endometrial stromal cells (ESCs) into decidual cells during a process called decidualization. ESCs express specific markers of decidualization, including prolactin, insulin-like growth factor-binding protein-1 (IGFBP-1), and connexin-43. Decidual cells also control of trophoblast invasion by secreting various factors, such as matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases. Preimplantation factor (PIF) is a recently identified, embryo-derived peptide with activities at the fetal-maternal interface. It creates a favorable pro-inflammatory environment in human endometrium and directly controls placental development by increasing the human trophoblastic cells' ability to invade the endometrium. We hypothesized that PIF's effects on the endometrium counteract its pro-invasive effects.

METHODS

We tested sPIF effect on the expression of three decidualization markers by RT-qPCR and/or immunochemiluminescence assay. We examined sPIF effect on human ESC migration by performing an in vitro wound healing assay. We analyzed sPIF effect on endometrial control of human trophoblast invasion by performing a zymography and an invasion assay.

RESULTS

Firstly, we found that a synthetic analog of PIF (sPIF) significantly upregulates the mRNA expression of IGFBP-1 and connexin-43, and prolactin secretion in ESCs - suggesting a pro-differentiation effect. Secondly, we showed that the HTR-8/SVneo trophoblastic cell line's invasive ability was low in the presence of conditioned media from ESCs cultured with sPIF. Thirdly, this PIF's anti-invasive action was associated with a specifically decrease in MMP-9 activity.

CONCLUSION

Taken as a whole, our results suggest that PIF accentuates the decidualization process and the production of endometrial factors that limit trophoblast invasion. By controlling both trophoblast and endometrial cells, PIF therefore appears to be a pivotal player in the human embryo implantation process.

Limosilactobacillus fermentum CECT5716: Mechanisms and Therapeutic Insights

Probiotics microorganisms exert their health-associated activities through some of the following general actions: competitive exclusion, enhancement of intestinal barrier function, production of bacteriocins, improvement of altered microbiota, and modulation of the immune response. Among them, Limosilactobacillus fermentum CECT5716 has become one of the most promising probiotics and it has been described to possess potential beneficial effects on inflammatory processes and immunological alterations. Different studies, preclinical and clinical trials, have evidenced its anti-inflammatory and immunomodulatory properties and elucidated the precise mechanisms of action involved in its beneficial effects. Therefore, the aim of this review is to provide an updated overview of the effect on host health, mechanisms, and future therapeutic approaches.

Lipid emulsion therapy in women with recurrent pregnancy loss and repeated implantation failure: The role of abnormal natural killer cell activity

Altered immune and/or inflammatory response plays an important role in cases of recurrent pregnancy loss (RPL) and repeated implantation failure (RIF). Exacerbation of the maternal immune response through increased NK cell activity and inflammatory cytokines can cause embryo rejection leading to abortion or embryo implantation failure. Immunosuppressors or immunomodulators can help or prevent this condition. Currently, lipid emulsion therapy (LET) has emerged as a treatment for RPL and RIF in women with abnormal NK cell activity, by decreasing the exacerbated immune response of the maternal uterus and providing a more receptive environment for the embryo. However, the mechanisms by which the intralipid acts to reduce NK cell activity are still unclear. In this review, we focus on the studies that conducted LET to treat patients with RPL and RIF with abnormal NK cell activity. We find that although some authors recommend LET as an effective intervention, more studies are necessary to confirm its effectiveness in restoring NK cell activity to normal levels and to comprehend the underlying mechanisms of the lipids action in ameliorating the maternal environment and improving the pregnancy rate.

Endometrial receptivity and pregnancy outcome

Human implantation is a highly complex and multifactorial process. Successful implantation requires the presence of a healthy embryo, a receptive endometrium, and a synchronized molecular dialogue between the two, as well as immune tolerance/protection from the host. The endometrial receptivity refers to a hormonally limited period in which the endometrial tissue acquires a transient functional status allowing blastocyst implantation and pregnancy initiation. Global knowledge of endometrial receptivity grew up in recent years. Improvements in genetics, new biomarkers, noninvasive methods, new advanced techniques (Endometrial receptivity assay - the ERA system, proteomic analysis) offer the possibility to evaluate the endometrial status and to manage patients with infertility problems, especially women undergoing assisted reproductive treatment. This overview reports the most relevant knowledge and recent advances in the study of implantation processes from the perspective of the endometrium, often considered as being the main barrier for a successful pregnancy initiation. Endometrial receptivity is a topic of great interest and further studies are needed for the early identification of endometrial abnormalities and the discovery of new strategies for increasing the chance for the establishment of pregnancy.

Synthetic PreImplantation Factor (sPIF) reduces inflammation and prevents preterm birth

Preterm birth (PTB) is the leading cause of neonatal morbidity and mortality and spontaneous PTB is a major contributor. The preceding inflammation/infection contributes not only to spontaneous PTB but is associated with neonatal morbidities including impaired brain development. Therefore, control of exaggerated immune response during pregnancy is an attractive strategy. A potential candidate is synthetic PreImplantation Factor (sPIF) as sPIF prevents inflammatory induced fetal loss and has neuroprotective properties. Here, we tested maternal sPIF prophylaxis in pregnant mice subjected to a lipopolysaccharides (LPS) insult, which results in PTB. Additionally, we evaluated sPIF effects in placental and microglial cell lines. Maternal sPIF application reduced the LPS induced PTB rate significantly. Consequently, sPIF reduced microglial activation (Iba-1 positive cells) and preserved neuronal migration (Cux-2 positive cells) in fetal brains. In fetal brain lysates sPIF decreased IL-6 and INFγ concentrations. In-vitro, sPIF reduced Iba1 and TNFα expression in microglial cells and reduced the expression of pro-apoptotic (Bad and Bax) and inflammatory (IL-6 and NLRP4) genes in placental cell lines. Together, maternal sPIF prophylaxis prevents PTB in part by controlling exaggerated immune response. Given the sPIF`FDA Fast Track approval in non-pregnant subjects, we envision sPIF therapy in pregnancy.

PreImplantation Factor immunohistochemical expression correlates with prostate cancer aggressiveness

BACKGROUND

The PreImplantation Factor (PIF)-a peptide secreted by viable embryos-exerts autotrophic protective effects, promotes endometrial receptivity and controls trophoblast invasion. Synthetic PIF (sPIF) has both immune-protective and regenerative properties, and reduces oxidative stress and protein misfolding. PIF is detected by immunohistochemistry (IHC) in hyperplastic endometriotic lesions and advanced uterine cancer. sPIF reduces graft-versus-host disease while maintaining a graft-versus-leukemia effect.

METHODS

PIF detection in prostate cancer was assessed in 50 human prostate samples following radical prostatectomy using tumor-microarray-based IHC correlating PIF immune staining with Gleason score (GS) and cancer aggressiveness.

RESULTS

PIF was detected in moderate-to-high risk prostate cancer (GS 4+3 and beyond, prognostic groups 3 to 5). In prostate cancer (GS (WHO Grade Group (GG)5), PIF was detected in 50% of cases; in prostate cancer (GS 4+4 GG4), PIF was observed in 62.5% of cases; in prostate cancer (GS 4+3 GG3), PIF immunostaining was observed in 57.1% of cases. In prostate cancer, (GS 3+4 GG2) and (GS 3+3 GG1) cases where PIF staining was negative to weak, membranous staining was observed in 20% of cases (staining pattern considered negative). High-grade prostate intraepithelial neoplasia PIF positive stain in 28.57% of cases (6 of 21) was observed. In contrast, PIF was not detected in normal prostate glands. Importantly, sPIF added to the PC3 cell line alone or combined with prostate cancer fibroblast feeder-cells did not affect proliferation. Only when peripheral blood mononuclear cells were added to the culture, a minor increase in cell proliferation was noted, reflecting local proliferation control.

CONCLUSIONS

Collectively, PIF assessment could be a valuable, simple-to-use immunohistochemical biomarker to evaluate aggressiveness/prognosis in specimens from prostate cancer patients.

Preimplantation Factor (PIF): a peptide with various functions

Preimplantation Factor (PIF) is a novel fifteen amino acid linear peptide (MVRIKPGSANKPSDD), which has different biological functions in mammalian species e.g. its role in neuron restoration, pregnancy and related disorders, and also in autoimmune diseases. Since all clinical studies have shown that PIF has both local and systemic effects, it can be considered as an integrated therapy for the treatment of inflammation conditions, along with the prevention of advanced disease. The synthetic PIF (sPIF) analog is a good representative of native PIF action, and it regulates peripheral immune cells to achieve endurance without immune suppression - an effective agent in nonpregnant autoimmune models. This study provides information, from evidence-based studies so far about PIF’s different functional aspects.

The Role of Natural Killer Cells and Mast Cells in Female Infertility and Associated Treatment Outcomes

Introduction:

One of the identified causes of infertility has been related to the inability to regulate immunological tolerance of the maternal immune system against the developing fetus, thereby inhibiting the process of implantation. Various immune cells have been identified to contribute to the concept of un-regulated immunological tolerance, such as mast cells (MCs) and natural killer cells (NK). There are available evidences that MC play a role in the pathogenesis of infertility diseases like endometriosis and NK in specific infertility disease.

Objective:

Presently, there are studies to formulate and develop immunosuppressive drugs in order to suppress or inhibit the process of immune rejection caused by maternal immune cells. In addition, there have been reports regarding the use of steroids for the treatment of miscarriage that can inhibit the activity of most immune cells.

Conclusion:

This review is to give a comprehensive mini-review on the role of immune cells, especially mast cells and NK cells in developing novel infertility treatment.

Synthetic PreImplantation Factor (sPIF) induces posttranslational protein modification and reverses paralysis in EAE mice

An autoimmune response against myelin protein is considered one of the key pathogenic processes that initiates multiple sclerosis (MS). The currently available MS disease modifying therapies have demonstrated to reduce the frequency of inflammatory attacks. However, they appear limited in preventing disease progression and neurodegeneration. Hence, novel therapeutic approaches targeting both inflammation and neuroregeneration are urgently needed. A new pregnancy derived synthetic peptide, synthetic PreImplantation Factor (sPIF), crosses the blood-brain barrier and prevents neuro-inflammation. We report that sPIF reduces paralysis and de-myelination of the brain in a clinically-relevant experimental autoimmune encephalomyelitis mice model. These effects, at least in part, are due to post-translational modifications, which involve cyclic AMP dependent protein kinase (PKA), calcium-dependent protein kinase (PKC), and immune regulation. In terms of potential MS treatment, sPIF was successfully tested in neurodegenerative animal models of perinatal brain injury and experimental autoimmune encephalitis. Importantly, sPIF received a FDA Fast Track Approval for first in human trial in autommuninty (completed).

sPIF promotes myoblast differentiation and utrophin expression while inhibiting fibrosis in Duchenne muscular dystrophy via the H19/miR-675/let-7 and miR-21 pathways

Duchenne muscular dystrophy (DMD) is a progressive, lethal, X-linked disease of skeletal and cardiac muscles caused by mutations in the dystrophin gene. Loss of dystrophin leads to muscle fiber damage and impairment of satellite cell asymmetric division, which are essential for muscle regeneration. These processes ultimately result in muscle wasting and the replacement of the degenerating muscles by fibrogenic cells, a process that leads to the generation of fibrotic tissues. Preimplantation factor (PIF) is an evolutionary conserved 15-amino acid peptide secreted by viable mammalian embryos. Synthetic PIF (sPIF) reproduces the protective/regenerative effects of the endogenous peptide in immune disorders and transplantation models. In this study, we demonstrated that sPIF treatment promoted mouse and human myoblast differentiation and inhibited the expression of collagen 1A1, collagen 1A2, and TGF-β in DMD patient-derived myoblasts. Additionally, sPIF increased the expression of utrophin, a homolog of dystrophin protein. sPIF effects were mediated via the upregulation of lncRNA H19 and miR-675 and downregulation of let-7. sPIF also inhibited the expression of miR-21, a major fibrosis regulator. The administration of sPIF in mdx mice significantly decreased serum creatine kinase and collagen I and collagen IV expression in the diaphragm, whereas it increased utrophin expression in the diaphragm, heart and quadriceps muscles. In conclusion, sPIF promoted the differentiation of DMD myoblasts, increased utrophin expression via the H19/miRNA-675/let-7 pathway, and reduced muscle fibrosis possibly via the upregulation of miR-675 and inhibition of miR-21 expression. These findings strongly support pursuing sPIF as a potential therapeutic agent for DMD. Moreover, the completion of an sPIF phase I safety trial will further promote the use of sPIF for the treatment of muscular dystrophies.

NK and trophoblast cells interaction: cytotoxic activity on recurrent pregnancy loss

The trial objective was to determine the peripheral blood NK cells cytotoxic activity effect on trophoblast cells at recurrent pregnancy loss (RPL). The investigation involved non-pregnant women with PRL in proliferating and secretory menstrual cycle phases (PMCPh and SMCPh, respectively); women of 6-7 weeks pregnancy with RPL in past medical history; healthy fertile non-pregnant women in PMCPh and SMCPh, women of 6-7 weeks physiological pregnancy, nulliparity healthy women with regular menstrual function in PMCPh and SMCPh. NK cells cytotoxic activity was determined using peripheral blood mononuclear cells. The target cells were JEG-3 line trophoblasts. It has been established that NK cells cytotoxic activity effect on trophoblasts is lower in SMCPh than in PMCPh in non-pregnant fertile women. The NK cells cytotoxic activity was higher in SMCPh than in PMCPh in non-pregnant women with PRL and also higher than the same value in SMCPh in non-pregnant fertile women. The increased NK cells cytotoxic activity values in SMCPh in women with RPL may be the reason for miscarriage.

Preimplantation factor modulates acute inflammatory responses of equine endometrium

Persistent mating-induced endometritis (PMIE) is a significant cause of mare infertility hence its treatment would advance the management of susceptible mares. Preimplantation factor (PIF) is secreted by viable embryos, including human, mouse and cattle, and is essential for maternal immune-tolerance without immune-suppression by modulating inflammation. This preliminary study aimed to test whether PIF exerts inflammatory-modulating properties upon equine endometrium challenged with Escherichia coli-derived lipopolysaccharide (LPS) using endometrial explant culture. Follicular (n = 3), luteal (n = 4), anoestrous (n = 4) and transitional (n = 4) stage endometrial explants were established and cultured in triplicate in either serum-free medium alone (control) or medium with; 50 or 100 nmol/L synthetic PIF (sPIF); 3 μg/mL LPS; LPS and 50 or 100 nmol/L sPIF; or scrambled PIF (PIFscr; same amino acid composition arranged in a different order). Media samples were collected at 24 and 72 h, representing acute and chronic inflammatory response. Radioimmunoassay determined Prostaglandin F_2α (PGF_2α ) as an inflammatory marker. The only significant observation was the abrogation of PGF_2α response to LPS challenge by 100 nmol/L PIF for follicular stage tissue, 24 h after treatment. Further studies are therefore, warranted to realise PIF potential in managing PMIE.

Randomized, Double-Blind, Placebo-Controlled, Single Ascending Dose Trial of Synthetic Preimplantation Factor in Autoimmune Hepatitis

Preimplantation factor (PIF) is an evolutionary conserved peptide secreted by viable embryos which promotes maternal tolerance without immune suppression. Synthetic PIF (sPIF) replicates native peptide activity. The aim of this study was to conduct the first‐in‐human trial of the safety, tolerability, and pharmacokinetics of sPIF in patients with autoimmune hepatitis (AIH). We performed a randomized, double‐blind, placebo‐controlled, prospective phase I clinical trial. Patients were adults with documented AIH with compensated chronic liver disease. Diagnosis of AIH was confirmed by either a pretreatment International Criteria for the Diagnosis of AIH score of 15 or more, or a posttreatment score of 17 or more. Patients were divided into three dosing cohorts (0.1, 0.5, or 1.0 mg/kg) of 6 patients in each group. Three patients in each group had normal liver tests and 3 patients had abnormal liver tests. They were randomized to receive a single, subcutaneous dose of either sPIF or a matching placebo. Eighteen patients were enrolled, and all successfully completed the trial. There were no clinically significant adverse events and all doses were well tolerated. Ascending doses of sPIF produced a linear increase in the respective serum levels with a half‐life of 90 minutes. There were no grade 2, 3 or 4 laboratory abnormalities. No patient developed detectable anti‐sPIF antibodies. Conclusion: This first‐in‐human trial of the safety and pharmacokinetics of sPIF (a novel biologic immune modulatory agent) demonstrated both excellent safety and tolerability. The data support further studies of multiple ascending doses of sPIF in autoimmune hepatitis and potentially other autoimmune disorders.

The core sequence of PIF competes for insulin/amyloid β in insulin degrading enzyme: potential treatment for Alzheimer's disease

The central pathological feature of Alzheimer's disease (AD) is the sequential proteolytic processing of amyloid precursor protein (APP) to amyloid-β peptides (Aβ) agglomeration. The clearance of Aβ may be induced by the large zinc-binding protease insulin degrading enzyme (IDE). IDE is the common link between AD and Type II diabetes as insulin is an IDE target as well. Not surprisingly, the search for safe and effective drugs modulating IDE is ongoing. A new pregnancy derived peptide, PreImplantation Factor (PIF), inhibits neuro-inflammation and crosses the blood-brain-barrier. Importantly, we report that the (R3I4K5P6) core sequence of the PIF peptide modulates IDE function and results in decreased Aβ agglomeration in neuronal cells. Using bioinformatics we show that PIF binds to the IDE complex and sterically competes for the same place as insulin or Aβ. The predicted RIKP sequence and especially the specific I4 and P6 amino acids are essential for hydrophobic interactions with the IDE complex. In terms of potential AD treatment, PIF was successfully tested in neurodegenerative animal models of perinatal brain injury and experimental autoimmune encephalitis. Importantly, sPIF received a FDA Fast Track Approval and orphan drug designation for first-in-human trial in autoimmunity.

Recurrent Miscarriage: Diagnostic and Therapeutic Procedures. Guideline of the DGGG, OEGGG and SGGG (S2k-Level, AWMF Registry Number 015/050)

Purpose

Official guideline of the German Society of Gynecology and Obstetrics (DGGG), the Austrian Society of Gynecology and Obstetrics (ÖGGG) and the Swiss Society of Gynecology and Obstetrics (SGGG). The aim of this guideline was to standardize the diagnosis and treatment of couples with recurrent miscarriage (RM). Recommendations were based on the current literature and the views of the involved committee members.

Methods

Based on the current literature, the committee members developed the statements and recommendations of this guideline in a formalized process which included DELPHI rounds and a formal consensus meeting.

Recommendations

Recommendations for the diagnosis and treatment of patients with RM were compiled based on the international literature. Specific established risk factors such as chromosomal, anatomical, endocrine, hemostatic, psychological, infectious and immunological disorders were taken into consideration.

PreImplantation factor (PIF) protects cultured embryos against oxidative stress: relevance for recurrent pregnancy loss (RPL) therapy

Recurrent pregnancy loss (RPL) affects 2-3% of couples. Despite a detailed work-up, the etiology is frequently undefined, leading to non-targeted therapy. Viable embryos and placentae express PreImplantation Factor (PIF). Maternal circulating PIF regulates systemic immunity and reduces circulating natural killer cells cytotoxicity in RPL patients. PIF promotes singly cultured embryos' development while anti-PIF antibody abrogates it. RPL serum induced embryo toxicity is negated by PIF. We report that PIF rescues delayed embryo development caused by <3 kDa RPL serum fraction likely by reducing reactive oxygen species (ROS). We reveal that protein disulfide isomerase/thioredoxin (PDI/TRX) is a prime PIF target in the embryo, rendering it an important ROS scavenger. The 16F16-PDI/TRX inhibitor drastically reduced blastocyst development while exogenous PIF increased >2 fold the number of embryos reaching the blastocyst stage. Mechanistically, PDI-inhibitor preferentially binds covalently to oxidized PDI over its reduced form where PIF avidly binds. PIF by targeting PDI/TRX at a distinct site limits the inhibitor's pro-oxidative effects. The >3kDa RPL serum increased embryo demise by three-fold, an effect negated by PIF. However, embryo toxicity was not associated with the presence of putative anti-PIF antibodies. Collectively, PIF protects cultured embryos both against ROS, and higher molecular weight toxins. Using PIF for optimizing in vitro fertilization embryos development and reducing RPL is warranted.

PreImplantation factor (PIF) therapy provides comprehensive protection against radiation induced pathologies

Acute Radiation Syndrome (ARS) may lead to cancer and death and has few effective countermeasures. Efficacy of synthetic PIF treatment was demonstrated in preclinical autoimmune and transplantation models. PIF protected against inflammation and mortality following lethal irradiation in allogeneic bone marrow transplant (BMT) model. Herein, we demonstrate that PIF imparts comprehensive local and systemic protection against lethal and sub-lethal ARS in murine models. PIF treatment 2 h after lethal irradiation led to 100% survival and global hematopoietic recovery at 2 weeks after therapy. At 24 h after irradiation PIF restored hematopoiesis in a semi-allogeneic BMT model. PIF-preconditioning provided improved long-term engraftment. The direct effect of PIF on bone marrow cells was also demonstrated in vitro: PIF promoted pre-B cell differentiation and increased immunoregulatory properties of BM-derived mesenchymal stromal cells. PIF treatment also improved hematopoietic recovery and reduced systemic inflammatory cytokine production after sub-lethal radiation exposure. Here, PIF also prevented colonic crypt and basal membrane damage coupled with reduced nitric oxide synthetase (iNOS) and increased (B7h1) expression. Global upper GI gene pathway analysis revealed PIF's involvement in protein-RNA interactions, mitochondrial oxidative pathways, and responses to cellular stress. Some effects may be attributed to PIF's influence on macrophage differentiation and function. PIF demonstrated a regulatory effect on irradiated macrophages and on classically activated M1 macrophages, reducing inflammatory gene expression (iNOS, Cox2), promoting protective (Arg1) gene expression and inducing pro-tolerance cytokine secretion. Notably, synthetic PIF is stable for long-term field use. Overall, clinical investigation of PIF for comprehensive ARS protection is warranted.

Allogeneic ovarian transplantation using immunomodulator preimplantation factor (PIF) as monotherapy restored ovarian function in olive baboon

PURPOSE

Allogeneic ovarian transplantation may be an alternative in the future to oocyte donation in women with premature ovarian failure. The objectives of this study were to (a) evaluate allotransplantation feasibility for restoration of ovarian function and (b) assess efficacy of synthetic preimplantation factor (PIF) monotherapy as sole immune-acceptance regimen.

METHODS

This is an experimental animal study using non-human primates (Papio anubis). Allogeneic orthotopic ovarian tissue transplantation was performed in two female olive baboons. PIF was administered as a monotherapy to prevent immune rejection and achieve transplant maintenance and function. Subjects underwent bilateral oophorectomy followed by cross-transplantation of prepared ovarian cortex. Postoperatively, subjects were monitored for clinical and biochemical signs of graft rejection and return of function. Weekly blood samples were obtained to monitor graft acceptance and endocrine function restoration.

RESULTS

Postoperatively, there were no clinical signs of rejection. Laboratory parameters (alanine aminotransferase (ALT), aspartate aminotransferase (AST), blood urea nitrogen (BUN), creatinine) did not indicate organ rejection at any stage of the experiment. Initially, significant loss of follicles was noticed after grafting and serum follicle-stimulating hormone (FSH) and E2 levels were consistent with ovarian failure. Seven months after transplantation, one animal exhibited recurrence of ovarian endocrine function (perineal swelling, E2 rise, FSH decrease, and return of menstruation).

CONCLUSIONS

Organ rejection after allogeneic ovarian transplantation was prevented using PIF as monotherapy for the first time and no side effects were recorded. The study suggests the clinical feasibility of ovarian allotransplantation to obtain ovarian function.

PreImplantation factor prevents atherosclerosis via its immunomodulatory effects without affecting serum lipids

PreImplantation factor (PIF) is a 15-amino acid peptide endogenously secreted by viable embryos, regulating/enabling maternal (host) acceptance/tolerance to the “invading” embryo (allograft) all-while preserving maternal immunity to fight infections. Such attributes make PIF a potential therapeutic agent for chronic inflammatory diseases. We investigated whether PIF’s immunomodulatory properties prevent progression of atherosclerosis in the hyper-cholesterolaemic ApoEdeficient murine model. Male, high-fat diet fed, ApoE-deficient (ApoE-/-) mice were administered either PBS, scrambled PIF (0.3–3 mg/kg) or PIF (0.3–3 mg/kg) for seven weeks. After treatment, PIF (3 mg/kg)-treated ApoE-/- mice displayed significantly reduced atherosclerosis lesion burden in the aortic sinus and aortic arch, without any effect on lipid profile. PIF also caused a significant reduction in infiltration of macrophages, decreased expression of pro-inflammatory adhesion molecules, cytokines and chemokines in the plaque, and reduced circulating IFN-γ levels. PIF preferentially binds to monocytes/neutrophils. In vitro, PIF attenuated monocyte migration (MCP-1-induced chemotaxis assay) and in vivo in LPS peritonitis model. Also PIF prevented leukocyte extravasation (peritonitis thioglycollate-induced model), demonstrating that PIF exerts its effect in part by modulation of monocyte function. Inhibition of the potassium channel KCNAB3 (Kv1.3) and of the insulin degrading enzyme (IDE) was demonstrated as potential mechanism of PIF’s immunomodulatory effects. In conclusion, PIF regulates/lowers inflammation and prevents atherosclerosis development without affecting circulating lipids. Overall our findings establish PIF as a strong immunomodulatory drug candidate for atherosclerosis therapy.

Supplementary Material to this article is available online at www.thrombosis-online.com.

PIF* promotes brain re-myelination locally while regulating systemic inflammation- clinically relevant multiple sclerosis M.smegmatis model

Neurologic disease diagnosis and treatment is challenging. Multiple Sclerosis (MS) is a demyelinating autoimmune disease with few clinical forms and uncertain etiology. Current studies suggest that it is likely caused by infection(s) triggering a systemic immune response resulting in antigen/non-antigen-related autoimmune response in central nervous system (CNS). New therapeutic approaches are needed. Secreted by viable embryos, PreImplantation Factor (PIF) possesses a local and systemic immunity regulatory role. Synthetic PIF (PIF) duplicates endogenous peptide's protective effect in pre-clinical autoimmune and transplantation models. PIF protects against brain hypoxia-ischemia by directly targeting microglia and neurons. In chronic experimental autoimmune encephalitis (EAE) model PIF reverses paralysis while promoting neural repair. Herein we report that PIF directly promotes brain re-myelination and reverses paralysis in relapsing remitting EAE MS model. PIF crosses the blood-brain barrier targeting microglia. Systemically, PIF decreases pro-inflammatory IL23/IL17 cytokines, while preserving CNS-specific T-cell repertoire. Global brain gene analysis revealed that PIF regulates critical Na⁺/K⁺/Ca⁺⁺ ions, amino acid and glucose transport genes expression. Further, PIF modulates oxidative stress, DNA methylation, cell cycle regulation, and protein ubiquitination while regulating multiple genes. In cultured astrocytes, PIF promotes BDNF-myelin synthesis promoter and SLC2A1 (glucose transport) while reducing deleterious E2F5, and HSP90ab1 (oxidative stress) genes expression. In cultured microglia, PIF increases anti-inflammatory IL10 while reducing pro-inflammatory IFNγ expression. Collectively, PIF promotes brain re-myelination and neuroprotection in relapsing remitting EAE MS model. Coupled with ongoing, Fast-Track FDA approved clinical trial, NCT#02239562 (immune disorder), current data supports PIF's translation for neurodegenerative disorders therapy.

Synthetic PreImplantation Factor (PIF) prevents fetal loss by modulating LPS induced inflammatory response

Maternal control of inflammation is essential during pregnancy and an exaggerated response is one of the underlying causes of fetal loss. Inflammatory response is mediated by multiple factors and Toll-like receptors (TLRs) are central. Activation of TLRs results in NALP-3 mediated assembly of apoptosis-associated speck-like protein containing a CARD (ASC) and caspase-1 into the inflammasome and production of pro-inflammatory cytokines IL-1β and IL-18. Given that preventing measures are lacking, we investigated PreImplantation Factor (PIF) as therapeutic option as PIF modulates Inflammation in pregnancy. Additionally, synthetic PIF (PIF analog) protects against multiple immune disorders. We used a LPS induced murine model of fetal loss and synthetic PIF reduced this fetal loss and increased the embryo weight significantly. We detected increased PIF expression in the placentae after LPS insult. The LPS induced serum and placenta cytokines were abolished by synthetic PIF treatment and importantly synthetic PIF modulated key members of inflammasome complex NALP-3, ASC, and caspase-1 as well. In conclusion our results indicate that synthetic PIF protects against LPS induced fetal loss, likely through modulation of inflammatory response especially the inflammasome complex. Given that synthetic PIF is currently tested in autoimmune diseases of non-pregnant subjects (clinicaltrials.gov, NCT02239562), therapeutic approach during pregnancy can be envisioned.

Preimplantation factor is an anti-apoptotic effector in human trophoblasts involving p53 signaling pathway

From the earliest stages of gestation, embryonic-maternal interaction has a key role in a successful pregnancy. Various factors present during gestation may significantly influence this type of juxta/paracrine interaction. PreImplantation Factor (PIF) is a recently identified factor with activity at the fetomaternal interface. PIF is secreted by viable embryos and directly controls placental development by increasing the invasive capacity of human extravillous trophoblasts (EVTs). To further specify PIF's role in the human placenta, we analyzed the genome-wide expression profile of the EVT in the presence of a synthetic PIF analog (sPIF). We found that sPIF exposure altered several pathways related to p53 signaling, survival and the immune response. Functional assays revealed that sPIF acts through the p53 pathway to reduce both early and late trophoblast apoptosis. More precisely, sPIF (i) decreases the phosphorylation of p53 at Ser-15, (ii) enhances the B-cell lymphoma-2 (BCL2) expression and (iii) reduces the BCL2-associated X protein (BAX) and BCL2 homologous antagonist killer (BAK) mRNA expression levels. Furthermore, invalidation experiments of TP53 allowed us to demonstrate that PIF's effects on placental apoptosis seemed to be essentially mediated by this gene. We have clearly shown that p53 and sPIF pathways could interact in human trophoblast and thus promotes cell survival. Furthermore, sPIF was found to regulate a gene network related to immune tolerance in the EVT, which emphasizes the beneficial effect of this peptide on the human placenta. Finally, the PIF protein levels in placentas from pregnancies affected by preeclampsia or intra-uterine growth restriction were significantly lower than in gestational age-matched control placentas. Taken as a whole, our results suggest that sPIF protects the EVT's functional status through a variety of mechanisms. Clinical application of sPIF in the treatment of disorders of early pregnancy can be envisioned.

PreImplantation factor (PIF*) regulates systemic immunity and targets protective regulatory and cytoskeleton proteins

Secreted by viable embryos, PIF is expressed by the placenta and found in maternal circulation. It promotes implantation and trophoblast invasion, achieving systemic immune homeostasis. Synthetic PIF successfully transposes endogenous PIF features to non-pregnant immune and transplant models. PIF affects innate and activated PBMC cytokines and genes expression. We report that PIF targets similar proteins in CD14+, CD4+ and CD8+ cells instigating integrated immune regulation. PIF-affinity chromatography followed by mass-spectrometry, pathway and heatmap analysis reveals that SET-apoptosis inhibitor, vimentin, myosin-9 and calmodulin are pivotal for immune regulation. PIF acts on macrophages down-stream of LPS (lipopolysaccharide-bacterial antigen) CD14/TLR4/MD2 complex, targeting myosin-9, thymosin-α1 and 14-3-3eta. PIF mainly targets platelet aggregation in CD4+, and skeletal proteins in CD8+ cells. Pathway analysis demonstrates that PIF targets and regulates SET, tubulin, actin-b, and S100 genes expression. PIF targets systemic immunity and has a short circulating half-life. Collectively, PIF targets identified; protective, immune regulatory and cytoskeleton proteins reveal mechanisms involved in the observed efficacy against immune disorders.

Add-ons in IVF programme - Hype or Hope?

A series of new technologies and adjuvant therapies have been advocated in order to improve the success of IVF treatment. Dehydro-epiandrostenedione, growth hormones, Coenzyme Q 10, calcium ionosphores, immune therapy, heparin, low-dose aspirin, and vasodilators are among commonly prescribed pharmacological adjuvants. New technologies that are proposed to improve IVF outcomes include advanced sperm selection procedures, time- lapse embryo monitoring, preimplantation genetic screening, assisted hatching endometrial injury or embryo-glue. This review looked into current evidence to justify the use of these co-interventions and whether some of them can still be offered while awaiting more robust evidence to con rm or refute their role.

PreImplantation Factor (PIF*) endogenously prevents preeclampsia: Promotes trophoblast invasion and reduces oxidative stress

Preeclampsia is a unique pregnancy disorder whose patho-physiology is initiated early in gestation, while clinical manifestations typically occur in mid-to-late pregnancy. Thus, prevention should optimally be initiated in early gestation. The intimate interaction between PIF, secreted early by viable embryos, and its host-mother provides insight into putative mechanisms of preeclampsia prevention. PIF is instrumental at the two critical events underlying preeclampsia. At first, shallow implantation leads to impaired placentation, oxidative stress, protein misfolding, and endothelial dysfunction. Later in gestation, hyper-oxygenation due to overflow of maternally derived oxygenated blood compromises the placenta. The first is likely involved in early preeclampsia occurrence due to reduced effectiveness of trophoblast/uterus interaction. The latter is observed with later-onset preeclampsia, caused by a breakdown in placental blood flow regulation. We reported that 1. PIF promotes implantation, endometrium receptivity, trophoblast invasion and increases pro-tolerance trophoblastic HLA-G expression and, 2. PIF protects against oxidative stress and protein misfolding, interacting with specific targets in embryo, 3. PIF regulates systemic immunity to reduce oxidative stress. Using PIF as an early preventative preeclampsia intervention could ameliorate or even prevent the disease, whose current main solution is early delivery.

PreImplantation Factor bolsters neuroprotection via modulating Protein Kinase A and Protein Kinase C signaling

A synthetic peptide (sPIF) analogous to the mammalian embryo-derived PreImplantation Factor (PIF) enables neuroprotection in rodent models of experimental autoimmune encephalomyelitis and perinatal brain injury. The protective effects have been attributed, in part, to sPIF's ability to inhibit the biogenesis of microRNA let-7, which is released from injured cells during central nervous system (CNS) damage and induces neuronal death. Here, we uncover another novel mechanism of sPIF-mediated neuroprotection. Using a clinically relevant rat newborn brain injury model, we demonstrate that sPIF, when subcutaneously administrated, is able to reduce cell death, reverse neuronal loss and restore proper cortical architecture. We show, both in vivo and in vitro, that sPIF activates cyclic AMP dependent protein kinase (PKA) and calcium-dependent protein kinase (PKC) signaling, leading to increased phosphorylation of major neuroprotective substrates GAP-43, BAD and CREB. Phosphorylated CREB in turn facilitates expression of Gap43, Bdnf and Bcl2 known to have important roles in regulating neuronal growth, survival and remodeling. As is the case in sPIF-mediated let-7 repression, we provide evidence that sPIF-mediated PKA/PKC activation is dependent on TLR4 expression. Thus, we propose that sPIF imparts neuroprotection via multiple mechanisms at multiple levels downstream of TLR4. Given the recent FDA fast-track approval of sPIF for clinical trials, its potential clinical application for treating other CNS diseases can be envisioned.

PreImplantation factor (PIF*) promotes embryotrophic and neuroprotective decidual genes: effect negated by epidermal growth factor

Background

Intimate embryo-maternal interaction is paramount for pregnancy success post-implantation. The embryo follows a specific developmental timeline starting with neural system, dependent on endogenous and decidual factors. Beyond altered genetics/epigenetics, post-natal diseases may initiate at prenatal/neonatal, post-natal period, or through a continuum. Preimplantation factor (PIF) secreted by viable embryos promotes implantation and trophoblast invasion. Synthetic PIF reverses neuroinflammation in non-pregnant models. PIF targets embryo proteins that protect against oxidative stress and protein misfolding. We report of PIF’s embryotrophic role and potential to prevent developmental disorders by regulating uterine milieu at implantation and first trimester.

Methods

PIF’s effect on human implantation (human endometrial stromal cells (HESC)) and first-trimester decidua cultures (FTDC) was examined, by global gene expression (Affymetrix), disease-biomarkers ranking (GeneGo), neuro-specific genes (Ingenuity) and proteins (mass-spectrometry). PIF co-cultured epidermal growth factor (EGF) in both HESC and FTDC (Affymetrix) was evaluated.

Results

In HESC, PIF promotes neural differentiation and transmission genes (TLX2, EPHA10) while inhibiting retinoic acid receptor gene, which arrests growth. PIF promotes axon guidance and downregulates EGF-dependent neuroregulin signaling. In FTDC, PIF promotes bone morphogenetic protein pathway (SMAD1, 53-fold) and axonal guidance genes (EPH5) while inhibiting PPP2R2C, negative cell-growth regulator, involved in Alzheimer’s and amyotrophic lateral sclerosis. In HESC, PIF affects angiotensin via beta-arrestin, transforming growth factor-beta (TGF-β), notch, BMP, and wingless-int (WNT) signaling pathways that promote neurogenesis involved in childhood neurodevelopmental diseases—autism and also affected epithelial-mesenchymal transition involved in neuromuscular disorders. In FTDC, PIF upregulates neural development and hormone signaling, while downregulating genes protecting against xenobiotic response leading to connective tissue disorders.

In both HESC and FTDC, PIF affects neural development and transmission pathways. In HESC interactome, PIF promotes FUS gene, which controls genome integrity, while in FTDC, PIF upregulates STAT3 critical transcription signal. EGF abolished PIF’s effect on HESC, decreasing metalloproteinase and prolactin receptor genes, thereby interfering with decidualization, while in FTDC, EGF co-cultured with PIF reduced ZHX2, gene that regulates neural AFP secretion.

Conclusions

PIF promotes decidual trophic genes and proteins to regulate neural development. By regulating the uterine milieu, PIF may decrease embryo vulnerability to post-natal neurodevelopmental disorders. Examination of PIF-based intervention strategies used during embryogenesis to improve pregnancy prognosis and reduce post-natal vulnerability is clearly in order.

PreImplantation factor promotes neuroprotection by targeting microRNA let-7

Dysfunction and loss of neurons are the major characteristics of CNS disorders that include stroke, multiple sclerosis, and Alzheimer's disease. Activation of the Toll-like receptor 7 by extracellular microRNA let-7, a highly expressed microRNA in the CNS, induces neuronal cell death. Let-7 released from injured neurons and immune cells acts on neighboring cells, exacerbating CNS damage. Here we show that a synthetic peptide analogous to the mammalian PreImplantation factor (PIF) secreted by developing embryos and which is present in the maternal circulation during pregnancy inhibits the biogenesis of let-7 in both neuronal and immune cells of the mouse. The synthetic peptide, sPIF, destabilizes KH-type splicing regulatory protein (KSRP), a key microRNA-processing protein, in a Toll-like receptor 4 (TLR4)-dependent manner, leading to decreased production of let-7. Furthermore, s.c. administration of sPIF into neonatal rats following hypoxic-ischemic brain injury robustly rescued cortical volume and number of neurons and decreased the detrimental glial response, as is consistent with diminished levels of KSRP and let-7 in sPIF-treated brains. Our results reveal a previously unexpected mechanism of action of PIF and underscore the potential clinical utility of sPIF in treating hypoxic-ischemic brain damage. The newly identified PIF/TLR4/KSRP/let-7 regulatory axis also may operate during embryo implantation and development.

Insight into PreImplantation Factor (PIF*) mechanism for embryo protection and development: target oxidative stress and protein misfolding (PDI and HSP) through essential RIKP [corrected] binding site

Background

Endogenous PIF, upon which embryo development is dependent, is secreted only by viable mammalian embryos, and absent in non-viable ones. Synthetic PIF (sPIF) administration promotes singly cultured embryos development and protects against their demise caused by embryo-toxic serum. To identify and characterize critical sPIF-embryo protein interactions novel biochemical and bio-analytical methods were specifically devised.

Methods

FITC-PIF uptake/binding by cultured murine and equine embryos was examined and compared with scrambled FITC-PIF (control). Murine embryo (d10) lysates were fractionated by reversed-phase HPLC, fractions printed onto microarray slides and probed with Biotin-PIF, IDE and Kv1.3 antibodies, using fluorescence detection. sPIF-based affinity column was developed to extract and identify PIF-protein interactions from lysates using peptide mass spectrometry (LC/MS/MS). In silico evaluation examined binding of PIF to critical targets, using mutation analysis.

Results

PIF directly targets viable cultured embryos as compared with control peptide, which failed to bind. Multistep Biotin-PIF targets were confirmed by single-step PIF-affinity column based isolation. PIF binds protein disulfide isomerases a prolyl-4-hydroxylase β-subunit, (PDI, PDIA4, PDIA6-like) containing the antioxidant thioredoxin domain. PIF also binds protective heat shock proteins (70&90), co-chaperone, BAG-3. Remarkably, PIF targets a common RIPK site in PDI and HSP proteins. Further, single PIF amino acid mutation significantly reduced peptide-protein target bonding. PIF binds promiscuous tubulins, neuron backbones and ACTA-1,2 visceral proteins. Significant anti-IDE, while limited anti-Kv1.3b antibody-binding to Biotin-PIF positive lysates HPLC fractions were documented.

Conclusion

Collectively, data identifies PIF shared targets on PDI and HSP in the embryo. Such are known to play a critical role in protecting against oxidative stress and protein misfolding. PIF-affinity-column is a novel utilitarian method for small molecule targets direct identification. Data reveals and completes the understanding of mechanisms involved in PIF-induced autotrophic and protective effects on the embryo.

Preimplantation and postimplantation therapy for the treatment of reproductive failure

Treatment of patients with recurrent pregnancy losses and recurrent implantation failure can be instituted only when the underlying etiology is determined. Embryo-secreted preimplantation factor (PIF) is essential for implantation and adequate trophoblastic invasion. Deficiency of PIF affects the outcome of the pregnancy leading to recurrent pregnancy losses. Synthetic PIF modulates the outcome of the pregnancy decreasing the incidence of recurrent implantation failure and recurrent pregnancy losses. In this article a thorough search is done regarding the data published for diagnoses of reproductive failure and its treatment. The effect of immunoglobulin (Ig), intralipid, heparin, aspirin, progesterone, estrogen, and granulocyte colony stimulating factor (G-CSF) is taken into consideration. Heparin, aspirin, and progesterone have successfully shown to decrease the incidence of recurrent pregnancy loses; whereas G-CSF, intralipids, estrogen, and Igs have shown success in the treatment of the recurrent implantation failure and recurrent pregnancy failure. The pregnancies treated with Igs and intralipids showed equal outcome when evaluated and compared. The place of intralipid in reducing natural killer (NK) cells has been discussed.

PreImplantation factor (PIF) detection in maternal circulation in early pregnancy correlates with live birth (bovine model)

BACKGROUND

Early identification of viable pregnancy is paramount for successful reproduction. Detection of specific signals from pre-implantation viable embryos in normal pregnancy circulation would indicate initiation of embryo-maternal interaction and create a continuum to accurately reflect embryo/fetal well-being post-implantation. Viable mammalian embryos secrete PreImplantation Factor (PIF), a biomarker which plays key, multi-targeted roles to promote implantation, trophoblast invasion and modulate maternal innate and adaptive immunity toward acceptance. Anti-PIF monoclonal antibody (mAb-based chemiluminescent ELISA) accurately detects PIF in singly cultured embryos media and its increased levels correlate with embryo development up to the blastocyst stage. Herein reported that PIF levels (ELISA) in early maternal serum correlate with pregnancy outcome.

METHODS

Artificially inseminated (AI) blind-coded Angus cattle (N = 21-23) serum samples (day 10,15 & 20 post-AI) with known calf birth were blindly tested, using both non-pregnant heifers (N = 30) and steer serum as negative controls. Assay properties and anti-PIF monoclonal antibody specificity were determined by examining linearity, spike and recovery experiments and testing the antibody against 234 different circulating proteins by microarray. Endogenous PIF was detected using <3 kDa filter separation followed by anti-PIF mAb-based affinity chromatography and confirmed by ELISA and HPLC. PIF expression was established in placenta using anti-PIF mAb-based IHC.

RESULTS

PIF detects viable pregnancy at day 10 post-AI with 91.3% sensitivity, reaching 100% by day 20 and correlating with live calf birth. All non-pregnant samples were PIF negative. PIF level in pregnant samples was a stringent 3 + SD higher as compared to heifers and steer sera. Assay is linear and spike and recovery data demonstrates lack of serum interference. Anti-PIF mAb is specific and does not interact with circulating proteins. Anti-PIF based affinity purification demonstrates that endogenous PIF is what ELISA detects. The early bovine placenta expresses PIF in the trophoblast layer.

CONCLUSION

Data herein documents that PIF is a specific, reliable embryo-derived biomarker conveniently detectable in early maternal circulation. PIF ELISA emerges as practical tool to detect viable early pregnancy from day 20 post-AI.

Reproduction and autoimmune disease: important translational implications from embryo–maternal interaction

Pregnancy and autoimmune disorders (ADs) coexist in a delicate balance. Whereas women are disproportionately affected by ADs – frequently occurring during reproductive years – the disease often improves during pregnancy, unless severe. However, when ADs are at an advanced stage, both mother and fetus can be severely affected. Maternal AD amelioration reduces fetal morbidity/mortality. AD improvement occurs without compromising immune tolerance for the fetus; however, it is short-lived since postpartum, flare-up frequently occurs. Consequences of pregnancy-related maternal disease can have life-long impact. Pregnancy is not an immune-suppressed state, but rather a controlled inflammatory environment with distinct local and systemic coordination. Pregnancy requires a delicate immune balance; the embryo/allograft does not cause graft-versus-host disease while the mother/host immunity is modulated without suppression. We herein critically examine the synergetic reciprocal relationship between pregnancy and ADs. We review key ADs and their current prognosis and management. Finally, we describe PreImplantation Factor, a peptide secreted by viable embryos that, beyond its essential autotrophic and proimplantation properties, regulates systemic immune response and also proved effective in nonpregnant autoimmune and transplantation models. Hence, PreImplantation Factor may have a key role in improving ADs in pregnancy, and provide a novel drug for treatment of immune disorders in general.