Immune checkpoint molecules in pregnancy: Focus on regulatory T cells

Surface Immune Checkpoints as Potential Biomarkers in Physiological Pregnancy and Recurrent Pregnancy Loss

Due to the genetic diversity between the mother and the fetus, heightened control over the immune system during pregnancy is crucial. Immunological parameters determined by clinicians in women with idiopathic recurrent spontaneous abortion (RSA) include the quantity and activity of Natural Killer (NK) and Natural Killer T (NKT) cells, the quantity of regulatory T lymphocytes, and the ratio of pro-inflammatory cytokines, which indicate imbalances in Th1 and Th2 cell response. The processes are controlled by immune checkpoint proteins (ICPs) expressed on the surface of immune cells. We aim to investigate differences in the expression of ICPs on T cells, T regulatory lymphocytes, NK cells, and NKT cells in peripheral blood samples collected from RSA women, pregnant women, and healthy multiparous women. We aim to discover new insights into the role of ICPs involved in recurrent pregnancy loss. Peripheral blood mononuclear cells (PBMCs) were isolated by gradient centrifugation from blood samples obtained from 10 multiparous women, 20 pregnant women (11-14th week of pregnancy), and 20 RSA women, at maximum of 72 h after miscarriage. The PBMCs were stained for flow cytometry analysis. Standard flow cytometry immunophenotyping of PBMCs was performed using antibodies against classical lymphocyte markers, including CD3, CD4, CD8, CD56, CD25, and CD127. Additionally, ICPs were investigated using antibodies against Programmed Death Protein-1 (PD-1, CD279), T cell immunoglobulin and mucin domain-containing protein 3 (TIM-3, CD366), V-domain Ig suppressor of T cell activation (VISTA), T cell immunoglobulin and ITIM domain (TIGIT), and Lymphocyte activation gene 3 (LAG-3). We observed differences in the surface expression of ICPs in the analyzed subpopulations of lymphocytes between early pregnancy and RSA, after miscarriage, and in women. We noted diminished expression of PD-1 on T lymphocytes (p = 0.0046), T helper cells (CD3CD4 positive cells, p = 0.0165), T cytotoxic cells (CD3CD8 positive cells, p = 0.0046), T regulatory lymphocytes (CD3CD4CD25CD127 low positive cells, p = 0.0106), and NKT cells (CD3CD56/CD16 positive cells, p = 0.0438), as well as LAG-3 on lymphocytes T (p = 0.0225) T helper, p = 0.0426), T cytotoxic cells (p = 0.0458) and Treg (p = 0.0293), and cells from RSA women. Impaired expression of TIM-3 (p = 0.0226) and VISTA (p = 0.0039) on CD8 cytotoxic T and NK (TIM3 p = 0.0482; VISTA p = 0.0118) cells was shown, with an accompanying increased expression of TIGIT (p = 0.0211) on NKT cells. The changes in the expression of surface immune checkpoints indicate their involvement in the regulation of pregnancy. The data might be utilized to develop specific therapies for RSA women based on the modulation of ICP expression.

Melanoma in Pregnancy-Diagnosis, Treatment, and Consequences for Fetal Development and the Maintenance of Pregnancy

Cutaneous malignant melanoma is one of the most common neoplasms among pregnancy-associated cancers (PACs). Risk factors include excessive exposure to ultraviolet radiation, the presence of benign and dysplastic nevi, and a patient or family history of melanoma. Self-examination and careful inspection of nevi are crucial, especially in the context of their progression over time. Physiological changes that occur during pregnancy, such as the darkening and enlargement of the nevi, delay the diagnosis of CMM. In the fetus, metastases are very rare, and if they do occur, they concern the placenta or fetal tissues. The choice of treatment is influenced by the cancer stage, symptoms, the time of termination of pregnancy, and the patient's decision. Essential procedures which are safe for the fetus are diagnostic biopsy, ultrasound, and the therapeutic excision of the lesion and the affected lymph nodes. Other imaging methods can be used with a safe radiation dose limit of 100 mGy. Immunotherapy and targeted treatments must be carefully considered, because of their possible adverse effects on the fetus. An interdisciplinary approach to the problem of melanoma during pregnancy is necessary, involving doctors of various specialties.

Beyond Immune Balance: The Pivotal Role of Decidual Regulatory T Cells in Unexplained Recurrent Spontaneous Abortion

Recurrent spontaneous abortion (RSA) is defined as two or more consecutive pregnancy failures, which brings tremendous stress to women of childbearing age and seriously affects family well-being. However, the reason in about 50% of cases remains unknown and is defined as unexplained recurrent spontaneous abortion (URSA). The immunological perspective in URSA has attracted widespread attention in recent years. The embryo is regarded as a semi-allogeneic graft to the mother. A successful pregnancy requires transition to an immune environment conducive to embryo survival at the maternal-fetal interface. As an important member of regulatory immunity, regulatory T (Treg) cells play a key role in regulating immune tolerance at the maternal-fetal interface. This review will focus on the phenotypic plasticity and lineage stability of Treg cells to illustrate its relationship with URSA.

Evaluation of changes in exhausted T lymphocytes and miRNAs expression in the different trimesters of pregnancy in pregnant women

BACKGROUND

Throughout the three trimesters of a typical pregnancy, we looked at changes in the expression of miRNAs and exhausted T lymphocytes for this study.

METHODS AND RESULTS

Fifty healthy subjects were included in this study. The frequency of exhausted T lymphocytes was measured in isolated PBMCs using flow cytometry. PD-1, TIM-3, and related miRNAs gene expression were assessed using qRT-PCR. The analyses revealed a significant decline in PD-1 and Tim-3 expression in PBMCs from RPL women (p = 0.0003 and p = 0.001, respectively). In addition, PD-1 and TIM-3 expression increased significantly in the 2nd trimester compared with the 1st trimester of healthy pregnant women (p < 0.0001 and p = 0.0002, respectively). PD-1 and TIM-3 expression was down-regulated in the 3rd trimester compared with the 1st and 2nd trimesters. In the present study, we demonstrated that TIM-3+/CD4+, TIM-3+/CD8+, PD-1+/CD4+, and PD-1+/CD8 + exhausted T lymphocytes increased in the circulation of women in the 2nd trimester compared to the 1st and 3rd trimester. In the 3rd trimester, the expression of miR-16-5p increased significantly (p < 0.0001). miR-125a-3p expression was down and upregulated in 2nd (p < 0.0001) and 3rd (p = 0.0007) trimesters compared to 1st trimester, respectively. This study showed a significant elevation of miR-15a-5p in 3rd trimester compared to 1st trimester of pregnant women (p = 0.0002).

CONCLUSIONS

Expression pattern of PD-1 and TIM3 in exhausted T lymphocytes is different not only between normal pregnant and RPL women but also in different trimesters of pregnancy. So, our results showed the role of these markers in the modulation lymphocytes activity in different stages of pregnancy.

Immunological effects of human decidual mesenchymal stem cells in spontaneous and recurrent abortions

The aim of this study was to evaluate the immunological activities of human decidual mesenchymal stem cells (MSCs) on proliferation, apoptosis and percentage of regulatory T cells (Treg) in abortions and to investigate whether these activities differ in spontaneous abortions (SA) and recurrent abortions (RA). This prospective cohort study included women who had a first-trimester abortion between 2019 and 2022. Women with uterine anomaly, endocrinological disease, known autoimmune or thrombophilic disease, and fetal chromosomal abnormality in abortion material were excluded. Decidual MSCs isolated from abortion materials were classified as spontaneous abortion-MSCs (SA-MSCs) and recurrent abortion-MSCs (RA-MSCs). Peripheral blood mononuclear cells were isolated from venous blood and co-cultured with SA-MSCs and RA-MSCs. The effects of MSCs on proliferation and apoptosis of lymphocytes, and Tregs levels were compared between SA-MSCs and RA-MSCs groups. Thirty cases (15 SA-MSCs and 15 RA-MSCs) were included in the study. The presence of MSC in co-cultures increased percentage of Treg cells while reducing proliferation and apoptosis compared to those without MSCs (p < 0.0001, p < 0.0001 and p < 0.0001). The increase in percentage of Treg cells and the reduction in apoptosis were significantly lower in the RA-MSCs group compared to the SA-MSCs group (p < 0.0001 and p < 0.001, respectively). Although the proliferation reducing effect of the presence of MSCs was lower in the RA-MSCs group compared to the SA-MSCs group, the difference was not significant (p = 0.07). MSCs contribute to maternal immunotolerance to semi-allogeneic fetus by suppressing proliferation and apoptosis, and increasing percentage of Treg cells. However, the immunoregulatory effects of MSCs are lower in RA compared to SA.

Immunologic aspects of preeclampsia

Preeclampsia is a syndrome with multiple etiologies. The diagnosis can be made without proteinuria in the presence of dysfunction of at least 1 organ associated with hypertension. The common pathophysiological pathway includes endothelial cell activation, intravascular inflammation, and syncytiotrophoblast stress. There is evidence to support, among others, immunologic causes of preeclampsia. Unlike defense immunology, reproductive immunology is not based on immunologic recognition systems of self/non-self and missing-self but on immunotolerance and maternal-fetal cellular interactions. The main mechanisms of immune escape from fetal to maternal immunity at the maternal-fetal interface are a reduction in the expression of major histocompatibility complex molecules by trophoblast cells, the presence of complement regulators, increased production of indoleamine 2,3-dioxygenase, activation of regulatory T cells, and an increase in immune checkpoints. These immune protections are more similar to the immune responses observed in tumor biology than in allograft biology. The role of immune and nonimmune decidual cells is critical for the regulation of trophoblast invasion and vascular remodeling of the uterine spiral arteries. Regulatory T cells have been found to play an important role in suppressing the effectiveness of other T cells and contributing to local immunotolerance. Decidual natural killer cells have a cytokine profile that is favored by the presence of HLA-G and HLA-E and contributes to vascular remodeling. Studies on the evolution of mammals show that HLA-E, HLA-G, and HLA-C1/C2, which are expressed by trophoblasts and their cognate receptors on decidual natural killer cells, are necessary for the development of a hemochorial placenta with vascular remodeling. The activation or inhibition of decidual natural killer cells depends on the different possible combinations between killer cell immunoglobulin-like receptors, expressed by uterine natural killer cells, and the HLA-C1/C2 antigens, expressed by trophoblasts. Polarization of decidual macrophages in phenotype 2 and decidualization of stromal cells are also essential for high-quality vascular remodeling. Knowledge of the various immunologic mechanisms required for adequate vascular remodeling and their dysfunction in case of preeclampsia opens new avenues of research to identify novel biological markers or therapeutic targets to predict or prevent the onset of preeclampsia.

Regulatory T-cell phenotypes in prenatal psychological distress

BACKGROUND

Experiencing symptoms of psychological distress during pregnancy is common and has been linked to dysregulated immune functioning. In this context, immunoregulatory function is especially relevant because of its crucial role in establishment and maintenance of healthy pregnancy. However, little research has examined associations between women's prenatal psychological distress and immunoregulatory biomarkers. We investigated how symptoms of depression, anxiety, and stress relate to circulating levels of regulatory T-cells (Tregs).

MATERIALS AND METHODS

Pregnant Latina women were assessed at around 12 weeks of pregnancy (N = 82). These assessments included blood draws and self-report questionnaires assessing symptoms of depression, state anxiety, pregnancy-related anxiety, and perceived stress. Flow cytometry on PBMCs was used to quantify circulating Tregs, defined as CD3+CD4+CD25hiCD127loFoxP3+, and subpopulations positive for one of the following intra- or extracellular markers, CD45RA, CTLA-4, Helios, PD-1, TIM-3, and TIGIT. We collected 82 samples at 12 weeks. Multivariable linear regressions tested for associations between symptoms of psychological distress and Treg concentrations, adjusted for gestational age.

RESULTS

State anxiety symptoms at 12 weeks were negatively associated with parent Treg cell levels (b = -4.02, p = 0.023) and subpopulations Helios+ (b = -3.29, p = 0.019) and TIM3+ (b = -3.17, p = 0.008). Perceived stress was negatively associated with the PD-1+ subpopulation at 12 weeks (b = -4.02, p = 0.023). Depression was not related to Tregs or the subpopulations.

CONCLUSION

Our observation that symptoms of anxiety and stress are related to tolerogenic immunology suggests a possible biomechanism explaining correlations of maternal mood disorders with adverse outcomes for mothers and offspring.

Chronic non-bacterial osteomyelitis and immune checkpoint molecules

OBJECTIVE

We aimed to investigate the plasma levels and cell surface expression of two checkpoint molecules, TIM-3 (T cell immunoglobulin and mucin domain-containing protein 3) and PD-1 (programmed cell death protein 1), in pediatric patients with chronic non-bacterial osteomyelitis (CNO).

METHODS

Plasma samples of CNO patients were collected at diagnosis or during biologic agent treatment. Plasma levels of TIM-3 and PD-1 were measured using the sandwich enzyme-linked immunosorbent assay method, and the expression of the two immune checkpoint molecules on the cell surface was analyzed by isolating peripheral blood mononuclear cells by density gradient centrifugation technique.

RESULTS

Twenty-seven patients with CNO (14 boys, 51.9%) and six healthy controls (3 boys, 50%) were enrolled in the study. There were no age differences between CNO patients and healthy controls (median age 14.5 vs. 13.5 years, respectively, p=0.762). Of the CNO patients, 18 were included at the time of diagnosis while 9 were receiving biologic treatment at enrollment. The median plasma PD-1 levels were significantly lower in the CNO group than in the healthy controls (p=0.011). However, no significant difference was found in the cellular expression of PD-1 and TIM-3 on CD3+CD4+ T cells in patients and healthy controls (p=0.083 and p=0.245, respectively). There was also no statistically significant difference in plasma TIM-3 levels of the patient and control groups (p=0.981).

CONCLUSION

CNO is an autoinflammatory disease, and overall, our results suggest that T cell exhaustion may not be significant in CNO. Further research is needed to find out whether the immune checkpoints are mainly associated with autoimmunity but not autoinflammation. Key Points • The median plasma PD-1 levels were significantly lower in the CNO group than in the healthy controls. • No significant difference was found in the cellular expression of PD-1 and TIM-3 on CD3+CD4+ T cells in patients and healthy controls. • Our results suggest that T cell exhaustion may not be significant in CNO pathogenesis.

Emerging Therapeutic Targets and Drug Resistance Mechanisms in Immunotherapy of Hematological Malignancies

CAR-T cell therapy has revolutionized the treatment of hematological malignancies with high remission rates in the case of ALL and NHL. This therapy has some limitations such as long manufacturing periods, persistent restricted cell sources and high costs. Moreover, combination regimens increase the risk of immune-related adverse events, so the identification new therapeutic targets is important to minimize the risk of toxicities and to guide more effective approaches. Cancer cells employ several mechanisms to evade immunosurveillance, which causes resistance to immunotherapy; therefore, a very important therapeutic approach is to focus on the development of rational combinations of targeted therapies with non-overlapping toxicities. Recent progress in the development of new inhibitory clusters of differentiation (CDs), signaling pathway molecules, checkpoint inhibitors, and immunosuppressive cell subsets and factors in the tumor microenvironment (TME) has significantly improved anticancer responses. Novel strategies regarding combination immunotherapies with CAR-T cells are the most promising approach to cure cancer.

A Review on Inflammasomes and Immune Checkpoints in Pre-Eclampsia Complicated with Tuberculosis and Human Immune Deficiency Virus

The current review evaluates how inflammasomes and immune checkpoints are regulated in pre-eclampsia (PE) associated with tuberculosis (TB) and Human Immune Deficiency Virus (HIV). Studies indicate that inflammasomes such as (NRLP3, NEK7, and AIM2) and immune checkpoints such as (CLT4, PD-1, TIM3, and LAG-3) are dysregulated in TB- and HIV-infected individuals, and also in pre-eclamptic pregnancies, which explains why pregnant women who are either infected with TB or HIV have an increased risk of developing PE. Evidence suggests that inhibition of inflammasomes and immune checkpoints may assist in the development of novel anti-inflammatory drugs for the prevention and management of PE in patients with or without TB and HIV infection.

Immune-checkpoint proteins, cytokines, and microbiome impact on patients with cervical insufficiency and preterm birth

Background

Microenvironmental factors, including microbe-induced inflammation and immune-checkpoint proteins that modulate immune cells have been associated with both cervical insufficiency and preterm delivery. These factors are incompletely understood. This study aimed to explore and compare interactions among microbiome and inflammatory factors, such as cytokines and immune-checkpoint proteins, in patients with cervical insufficiency and preterm birth. In particular, factors related to predicting preterm birth were identified and the performance of the combination of these factors was evaluated.

Methods

A total of 220 swab samples from 110 pregnant women, prospectively recruited at the High-Risk Maternal Neonatal Intensive Care Center, were collected between February 2020 and March 2021. This study included 63 patients with cervical insufficiency receiving cerclage and 47 control participants. Endo- and exocervical swabs and fluids were collected simultaneously. Shotgun metagenomic sequencing for the microbiome and the measurement of 34 immune-checkpoint proteins and inflammatory cytokines were performed.

Results

First, we demonstrated that immune-checkpoint proteins, the key immune-regulatory molecules, could be measured in endocervical and exocervical samples. Secondly, we identified significantly different microenvironments in cervical insufficiency and preterm birth, with precise cervical locations, to provide information about practically useful cervical locations in clinical settings. Finally, the presence of Moraxella osloensis (odds ratio = 14.785; P = 0.037) and chemokine CC motif ligand 2 levels higher than 73 pg/mL (odds ratio = 40.049; P = 0.005) in endocervical samples were associated with preterm birth. Combining M. osloensis and chemokine CC motif ligand 2 yielded excellent performance for predicting preterm birth (area under the receiver operating characteristic curve = 0.846, 95% confidence interval = 0.733-0.925).

Conclusion

Multiple relationships between microbiomes, immune-checkpoint proteins, and inflammatory cytokines in the cervical microenvironment were identified. We focus on these factors to aid in the comprehensive understanding and therapeutic modulation of local microbial and immunologic compositions for the management of cervical insufficiency and preterm birth.

Chinese expert consensus recommendations for the administration of immune checkpoint inhibitors to special cancer patient populations

Immune checkpoint inhibitors (ICIs) targeting programmed cell death 1, programmed cell death ligand 1, and cytotoxic T lymphocyte-associated antigen-4 have shown significantly durable clinical benefits and tolerable toxicities and have improved the survival of patients with various types of cancer. Since 2018, the National Medical Products Administration of China has approved 17 ICIs as the standard treatment for certain advanced or metastatic solid tumors. As ICIs represent a broad-spectrum antitumor strategy, the populations eligible for cancer immunotherapy are rapidly expanding. However, the clinical applications of ICIs in cancer patient populations with special issues, a term that refers to complex subgroups of patients with comorbidities, special clinical conditions, or concomitant medications who are routinely excluded from prospective clinical trials of ICIs or are underrepresented in these trials, represent a great real-world challenge. Although the Chinese Society of Clinical Oncology (CSCO) has provided recommendations for screening before the use of ICIs in special populations, the recommendations for full-course management remain insufficient. The CSCO Expert Committee on Immunotherapy organized leading medical oncology and multidisciplinary experts to develop a consensus that will serve as an important reference for clinicians to guide the proper application of ICIs in special patient populations. This article is a translation of a study first published in Chinese in The Chinese Clinical Oncology (ISSN 1009-0460, CN 32-1577/R) in May 2022 (27(5):442-454). The publisher of the original paper has provided written confirmation of permission to publish this translation in Therapeutic Advances in Medical Oncology.

Melanoma in pregnancy

Melanoma is one of the most common types of cancer diagnosed during pregnancy. Patients with advanced disease require frequent staging examinations (e.g., CT, PET, MRI, ultrasound), which, during pregnancy must be modified from routine protocol to minimize risk to the fetus. We will review the diagnostic and treatment approach to pregnant patients with melanoma, with a discussion and pictorial examples of imaging protocol modifications, and the appearance of metastatic melanoma on radiology exams using modified protocols due to pregnancy.

Soluble TIM-3 as a biomarker of progression and therapeutic response in cancers and other of human diseases

Immune checkpoints inhibition is a privileged approach to combat cancers and other human diseases. The TIM-3 (T cell immunoglobulin and mucin-domain containing-3) inhibitory checkpoint expressed on different types of immune cells is actively investigated as an anticancer target, with a dozen of monoclonal antibodies in (pre)clinical development. A soluble form sTIM-3 can be found in the plasma of patients with cancer and other diseases. This active circulating protein originates from the proteolytic cleavage by two ADAM metalloproteases of the membrane receptor shared by tumor and non-tumor cells, and extracellular vesicles. In most cancers but not all, overexpression of mTIM-3 at the cell surface leads to high level of sTIM-3. Similarly, elevated levels of sTIM-3 have been reported in chronic autoimmune diseases, inflammatory gastro-intestinal diseases, certain viral and parasitic diseases, but also in cases of organ transplantation and in pregnancy-related pathologies. We have analyzed the origin of sTIM-3, its methods of dosage in blood or plasma, its presence in multiple diseases and its potential role as a biomarker to follow disease progression and/or the treatment response. In contrast to sPD-L1 generated by different classes of proteases and by alternative splicing, sTIM-3 is uniquely produced upon ADAM-dependent shedding, providing a more homogenous molecular entity and a possibly more reliable molecular marker. However, the biological functionality of sTIM-3 remains insufficiently characterized. The review shed light on pathologies associated with an altered expression of sTIM-3 in human plasma and the possibility to use sTIM-3 as a diagnostic or therapeutic marker.

Immunology of Pregnancy and Systemic Consequences

Pregnancy is an immunological paradox, with renowned Nobel Prize winning transplantation biologist Sir Peter Brian Medawar being the first to introduce this concept back in 1953. This concept considers how the maternal immune system can tolerate the developing fetus, which is 50% antigenically foreign to the uterus. There have been significant advances in our understanding of the immune system in regulating fertility, pregnancy and in complications of these, and what was once considered a paradox can be seen as a highly evolved system. Indeed, the complexity of the maternal-fetal interface along with our ever-advancing knowledge of immune cells and mediators means that we have a better understanding of these interactions, with gaps still present.  This chapter will summarise the key aspects of the role of the immune system at each stage of pregnancy and highlight the recent advances in our knowledge.

Adrenal metastatic melanoma first identified during pregnancy: a diagnostic challenge

Adrenal nonadenomatous tumors (NAT) first identified during pregnancy are very rare and pose a diagnostic and therapeutic dilemma with significant risks for the mother and fetus. The aim of this study is to report a case of a large adrenal NAT identified in pregnancy and literature review. A literature search was conducted, and data were summarized. A 37-year-old primigravida woman, with a history of melanoma, excised 12 years before presentation without recurrence, presented at 35 weeks gestation due to intractable right flank pain. MRI demonstrated an eight cm, heterogeneous, septate, right adrenal mass suspected to be either pheochromocytoma/paraganglioma (PPGL), adrenocortical carcinoma or metastasis. Blood metanephrines were sent urgently to enable a safe delivery and were within normal range, as were cortisol and androgen levels. A biopsy was taken from a palpable breast mass as well as from an ovarian mass during the operation. At 36 weeks gestation, she was delivered by cesarean section. PET computed tomography performed after delivery revealed the extensive metastatic spread of recurring melanoma including the right adrenal gland. Timely diagnosis and management by a multidisciplinary team are important to avoid a catastrophic outcome. There is no consensus on optimal management and timing of delivery. PPGL should be ruled out before delivery.

Early pregnancy regulates the expression of prolactin and its receptor in the thymus, the liver, the spleen and lymph nodes in sheep

As a pituitary hormone, prolactin (PRL) is also synthesized by immune system cells, and exerts its effects on the immune system by binding to its receptor (PRLR) via endocrine and paracrine/autocrine pathways. The immune organs adapt to the presence of fetal alloantigens during pregnancy, and the immune system is composed of primary organs and secondary organs. The objective of this study is to analyze the effects of early pregnancy on expression of PRL and PRLR in maternal immune organs in sheep. In this study, the thymus, lymph node, the spleen and the liver were sampled at day 16 of the estrous cycle, and at days 13, 16, and 25 of pregnancy in ewes. Expression of PRL and PRLR was analyzed through quantitative real-time PCR, Western blot and immunohistochemistry. Our data showed that there were an upregulation of PRL and PRLR in the thymus, lymph node and the spleen, and a downregulation in the liver during early pregnancy in ewes. In conclusion, it is reported for the first time that early pregnancy has tissue specific effects on expression of PRL isoform and PRLR isoform in the thymus, lymph node, the spleen and the liver, which may be owing to these organs exerting different functions during early pregnancy, and necessary for the successful pregnancy in sheep.

Maternal leucocyte trajectory across pregnancy associated with offspring's growth

BACKGROUND

Leucocytes for individuals during pregnancy may form into different trajectory patterns. Since no studies have been conducted, we aim to examine the associations between leucocyte trajectory across pregnancy and offspring's birth outcomes and growth during the first 2 years.

METHODS

We conducted a retrospective study enrolled 1070 singleton pregnancies aged 21-46 years old between 2014 and 2018 in Huazhong University of Science and Technology Union Shenzhen Hospital, China. Leucocyte trajectories were modelled using growth mixture modelling and four trajectories were identified: moderate-increasing (n = 41), low-stable (n = 828), high-decreasing (n = 145) and low-increasing (n = 56).

RESULTS

Relative to the low-stable group, logistic regression analysis after adjusting for covariates indicated that the odds ratios of preterm were 3.06 (95% confidence interval (CI): 1.43-6.23) for moderate-increasing, 0.78 (95% CI: 0.38-1.47) for high-decreasing and 0.68 (95% CI: 0.23-1.61) for the low-increasing group, respectively. By using generalized estimating equation analysis, we observed that infants in the moderate-increasing and low-increasing group had -0.35 and -0.21 (P &lt; 0.01) lower head circumference z-score compared with the low-stable group, respectively. No significant association of leucocyte trajectory with other birth weight measures or anthropometric measure z-scores was found.

CONCLUSIONS

Changes in leucocytes across pregnancy affected the occurrence of preterm and offspring's head circumference during the first 2 years of life.

IMPACT

Previous researches on the association of leucocytes with pregnancy outcomes mainly focused on leucocytes in a specific trimester. No studies until now have been conducted to assess the influences of the leucocyte trajectories on the growth and development of infants. Changes in leucocytes across pregnancy affected the occurrence of preterm and offspring's head circumference during the first 2 years of life. Our study will positively contribute to the dialogue regarding the treatment of pregnancies with different levels of inflammation in each trimester to minimize adverse pregnancy outcomes and optimize brain growth.

Expression level of immune checkpoint inhibitory factors in preeclampsia

Preeclampsia (PE) is a severe complication in pregnancy, and its symptoms (proteinuria and hypertension) manifest after 20 weeks of gestation, affecting up to 8 % of pregnancies. The pregnant women's immune system uses different tolerance mechanisms to deal with a semi-allogeneic fetus. The T-cell subsets including CD8+, CD4+, and Treg play a critical role in maintaining pregnancies. The expression of immune checkpoint molecules in T-cells can ensure pregnancy at the feto-maternal interface by controlling immune responses. This research aims to evaluate the expression level of immune checkpoint factors, including PD-1, LAG-3, CTLA-4, and TIM-3 in normal pregnant women and PE patients. Decidual tissue was collected from 50 participants (25 PE and 25 control). For evaluating the genes expression, real-time PCR was employed. The western blot was used to assess the proteins level. The results of real-time PCR indicated significantly decreased expression level of these immune checkpoints in PE patients. In parallel to gene expression results, the protein level of PD-1, LAG-3, CTLA-4, and TIM-3 in the PE group was also reduced. We revealed that the profile of proteins and genes expression of immune checkpoints in the decidua of PE mothers are different from normal pregnancy and these results indicate aberrant expression of immune checkpoints such as PD-1, LAG-3, CTLA-4, and TIM-3 may cause maladaptation immune response which results in PE manifestation.

Breast Cancer during Pregnancy as a Special Type of Early-Onset Breast Cancer: Analysis of the Tumor Immune Microenvironment and Risk Profiles

Breast cancer during pregnancy (PrBC) is a rare tumor with only a little information on its immune landscape. Here, we sought to characterize the cellular composition of the tumor microenvironment (TME) of PrBC and identify its differences from early-onset breast cancer (EOBC) in non-pregnant women. A total of 83 PrBC and 89 EOBC were selected from our Institutional registry and subjected to tumor-infiltrating lymphocytes (TILs) profiling and immunohistochemistry for CD4, CD8, forkhead box P3 (FOXP3), and programmed death-ligand 1 (PD-L1) (clone 22C3). A significantly lower frequency of hormone receptor (HR)-positive tumors was observed in PrBC. The prevalence of low/null PD-L1 and CD8+TILs was higher in PrBC than in the controls, specifically in HR+/HER2– breast cancers. PrBC had a significantly higher risk of relapse and disease-related death, compared to EOBC. The presence of TILs and each TIL subpopulation were significantly associated with disease relapse. Moreover, the death rate was higher in PrBC with CD8+ TILs. The TME of PrBC is characterized by specific patterns of TIL subpopulations with significant biological and prognostic roles. Routine assessment of TILs and TILs subtyping in these patients would be a valid addition to the pathology report that might help identify clinically relevant subsets of women with PrBC.

Mechanisms of carcinogenic activity triggered by lysine-specific demethylase 1A

Epigenetics has emerged as a prime focus area in the field of cancer research. Lysine-specific demethylase 1A (LSD1), the first discovered histone demethylase, is mainly responsible for catalysing demethylation of histone 3 lysine 4 (H3K4) and H3K9 to activate or inhibit gene transcription. LSD1 is abnormally expressed in various cancers and participates in cancer proliferation, apoptosis, metastasis, invasion, drug resistance and other processes by interacting with regulatory factors. Therefore, it may serve as a potential therapeutic target for cancer. This review summarises the major oncogenic mechanisms mediated by LSD1 and provides a reference for developing novel and efficient anticancer strategies targeting LSD1.

Isolation of cfDNA from spent culture media and its association with implantation rate and maternal immunomodulation

OBJECTIVES

This investigation aims to evaluate the association between the concentration of cell-free DNA (cfDNA) in the spent culture medium (SCM) with implantation rate and the maternal immune system in the invitro fertilization (IVF). In this study, 30 embryos were cultured and scored according to Gardner's criteria. SCM was gathered on day five from every embryo to analyze the quantity of cfDNA. The real-time PCR technique evaluated the expression level of transcription factors, including Foxp3, RORγt, GATA3, and T-bet. The percentage of Th1, Th2, Th17, Treg, NK cells, and NK cells cytotoxicity was evaluated by flow cytometry.

RESULTS

The concentration of cfDNA in the β-HCG (-), β-HCG ( +), and ongoing pregnancy groups were 20.70 ± 9.224 ng/µL, 27.97 ± 7.990 ng/µL, and 28.91 ± 8.566 ng/µL, respectively. The ratio of Th1/Th2 and Th17/Treg reduced significantly in pregnant women, as well as the level of NK cells and NK cytotoxicity cells fell dramatically in the ongoing pregnancy group. The expression level of RORγt and T-bet declined while the expression level of Foxp3 and GATA3 increased considerably in pregnant mothers. Our investigation revealed that the concentration level of cfDNA in SCM could not be associated with implantation rate, prediction of ongoing pregnancy, and maternal immune system.

Immunological Changes in Pregnancy and Prospects of Therapeutic Pla-Xosomes in Adverse Pregnancy Outcomes

Stringent balance of the immune system is a key regulatory factor in defining successful implantation, fetal development, and timely parturition. Interference in these primary regulatory mechanisms, either at adolescence or prenatal state led to adverse pregnancy outcomes. Fertility restoration with the help of injectable gonadotrophins/progesterone, ovulation-inducing drugs, immunomodulatory drugs (corticosteroids), and reproductive surgeries provides inadequate responses, which manifest its own side effects. The development of a potential diagnostic biomarker and an effectual treatment for adverse pregnancy outcomes is a prerequisite to maternal and child health. Parent cell originated bi-layered-intraluminal nano-vesicles (30-150 nm) also known as exosomes are detected in all types of bodily fluids like blood, saliva, breast milk, urine, etc. Exosomes being the most biological residual structures with the least cytotoxicity are loaded with cargo in the form of RNAs (miRNAs), proteins (cytokines), hormones (estrogen, progesterone, etc.), cDNAs, and metabolites making them chief molecules of cell-cell communication. Their keen involvement in the regulation of biological processes has portrayed them as the power shots of cues to understand the disease's pathophysiology and progression. Recent studies have demonstrated the role of immunexosomes (immunomodulating exosomes) in maintaining unwavering immune homeostasis between the mother and developing fetus for a healthy pregnancy. Moreover, the concentration and size of the exosomes are extensively studied in adverse pregnancies like preeclampsia, gestational diabetes mellitus (GDM), and preterm premature rupture of membrane (pPROMs) as an early diagnostic marker, thus giving in-depth information about their pathophysiology. Exosomes have also been engineered physically as well as genetically to enhance their encapsulation efficiency and specificity in therapy for cancer and adverse pregnancies. Successful bench to bedside discoveries and interventions in cancer has motivated developmental biologists to investigate the role of immunexosomes and their active components. Our review summarizes the pre-clinical studies for the use of these power-shots as therapeutic agents. We envisage that these studies will pave the path for the use of immunexosomes in clinical settings for reproductive problems that arise due to immune perturbance in homeostasis either at adolescence or prenatal state.

Toward an understanding of allogeneic conflict in pregnancy and transplantation

Pregnancy is recognized as a spontaneously acquired state of immunological tolerance by the mother to her semi-allogeneic fetus, but it is a major cause of allosensitization in candidates for organ transplantation. This sensitization, assessed by the presence of anti-HLA IgG, contributes to sex disparity in access to transplantation and increases the risk for rejection and graft loss. Understanding this dual tolerance/sensitization conundrum may lead to new strategies for equalizing access to transplantation among sexes and improving transplant outcomes in parous women. Here, we review the clinical evidence that pregnancy results in humoral sensitization and query whether T cell responses are sensitized. Furthermore, we summarize preclinical evidence on the effects of pregnancy on fetus-specific CD4⁺ conventional, regulatory, and CD8⁺ T cells, and humoral responses. We end with a discussion on the impact of the divergent effects that pregnancy has upon alloantigen re-encounter in the context of solid organ transplantation, and how these insights point to a therapeutic roadmap for controlling pregnancy-dependent allosensitization.

Pregnancy and Tumour: The Parallels and Differences in Regulatory T Cells

Immunological tolerance plays a critical role during pregnancy as semi-allogeneic fetus must be protected from immune responses during the gestational period. Regulatory T cells (Tregs), a subpopulation of CD4+ T cells that express transcription factor Foxp3, are central to the maintenance of immunological tolerance and prevention of autoimmunity. Tregs are also known to accumulate at placenta in uterus during pregnancy, and they confer immunological tolerance at maternal-fetal interface by controlling the immune responses against alloantigens. Thus, uterine Tregs help in maintaining an environment conducive for survival of the fetus during gestation, and low frequency or dysfunction of Tregs is associated with recurrent spontaneous abortions and other pregnancy-related complications such as preeclampsia. Interestingly, there are many parallels in the development of placenta and solid tumours, and the tumour microenvironment is considered to be somewhat similar to that at maternal-fetal interface. Moreover, Tregs play a largely similar role in tumour immunity as they do at placenta- they create a tolerogenic system and suppress the immune responses against the cells within tumour and at maternal-fetal interface. In this review, we discuss the role of Tregs in supporting the proper growth of the embryo during pregnancy. We also highlight the similarities and differences between Tregs at maternal-fetal interface and tumour Tregs, in an attempt to draw a comparison between their roles in these two physiologic and pathologic states.

Melanoma in pregnancy: Diagnosis and management in early-stage and advanced disease

Approximately one-third of women diagnosed with melanoma are of child-bearing age. The annual incidence of melanoma has risen steadily over the last 40 years, resulting in increasing numbers of women diagnosed with melanoma both during pregnancy, and post-partum. To date, there are no formal guidelines on the management of pregnancy associated melanoma (PAM), both early stage and metastatic. This article reviews the existing literature and provides a framework for the investigation and multidisciplinary management of PAM.

Characterisation of peri-implantation endometrial Treg and identification of an altered phenotype in recurrent pregnancy loss

Recurrent Pregnancy Loss (RPL) affects 2-4% of couples, and with increasing numbers of pregnancy losses the risk of miscarrying a euploid pregnancy is increased, suggesting RPL is a pathology distinct from sporadic miscarriage that is due largely to lethal embryonic aneuploidy. There are a number of conditions associated with RPL including unspecified "immune" pathologies; one of the strongest candidates for dysregulation remains T regulatory cells as depletion in the very early stages of pregnancy in mice leads to pregnancy loss. Human endometrial Treg and conventional CD4T cells were isolated during the peri-implantation period of the menstrual cycle in normal women. We identified an endometrial Treg transcriptomic signature and validated an enhanced regulatory phenotype compared to peripheral blood Treg. Parous women had an altered endometrial Treg transcriptome compared to nulliparity, indicating acquired immune memory of pregnancy within the Treg population, by comparison endometrial conventional CD4T cells were not altered. We compared primary and secondary RPL to nulliparous or parous controls respectively. Both RPL subgroups displayed differentially expressed Treg gene transcriptomes compared to controls. We found increased cell surface S1PR1 and decreased TIGIT protein expression by Treg in primary RPL, confirming the presence of altered Treg in the peri-implantation RPL endometrium.

Immunotherapy for cancer treatment during pregnancy

Immunotherapy has greatly improved outcomes for subgroups of patients with cancer. As indications keep expanding, there is an unmet need to gain a better understanding of the effect of these therapies on pregnancy and fertility. During pregnancy, substantial adaptations occur in the maternal immune system to maintain protection against pathogens while avoiding detrimental reactions to the semi-allogeneic fetus. The pathways involved in the establishment of this fetomaternal tolerance can be hijacked by cancers. Immunotherapies that target these inhibitory pathways, or that directly interact with the regulatory immune cells involved in tolerance mechanisms, might therefore result in complications during pregnancy. Similarly, by activating the patient's immune system with immunotherapy, a broad range of immune-related adverse events can occur that could negatively affect the fetus or impede a future desired pregnancy. This Review summarises preclinical and clinical data related to the use of immunotherapy during pregnancy, including all approved immune checkpoint inhibitors, recombinant cytokines, cell therapies, vaccines, and immunomodulatory drugs.

The Coevolution of Placentation and Cancer

Analogies between placentation, in particular the behavior of trophoblast cells, and cancer have been noted since the beginning of the twentieth century. To what degree these can be explained as a consequence of the evolution of placentation has been unclear. In this review, we conclude that many similarities between trophoblast and cancer cells are shared with other, phylogenetically older processes than placentation. The best candidates for cancer hallmarks that can be explained by the evolution of eutherian placenta are mechanisms of immune evasion. Another dimension of the maternal accommodation of the placenta with an impact on cancer malignancy is the evolution of endometrial invasibility. Species with lower degrees of placental invasion tend to have lower vulnerability to cancer malignancy. We finally identify several areas in which one could expect to see coevolutionary changes in placental and cancer biology but that, to our knowledge, have not been explored. Expected final online publication date for the Annual Review of Animal Biosciences, Volume 10 is February 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Malignant melanoma treated with pembrolizumab during pregnancy: A case report and review of the literature

There have been very few reports on the use of immune checkpoint inhibitors for malignant tumors during pregnancy. Herein, the current study reports a case of a patient diagnosed with advanced malignant melanoma who was treated with pembrolizumab during pregnancy. A 40-year-old primigravida underwent noninvasive prenatal testing at 10 weeks of gestation, and the result was inconclusive, suggesting the possibility of maternal malignancy. A biopsy of the gluteal mass led to a diagnosis of malignant melanoma, and computed tomography revealed extensive metastases in her lungs and lymph nodes. She had a strong desire to proceed with pregnancy. In consideration of fetal growth and maturation, monotherapy was administered with pembrolizumab from 21 weeks of gestation, aiming for 28 weeks of gestation. The fetus grew well without maternal complications. At 28 weeks of pregnancy, the patient gave birth to a healthy boy by cesarean section. There was no evidence of metastasis in the placenta. The patient received nivolumab-ipilimumab combination therapy from postpartum day 13, followed by nivolumab monotherapy, and has been alive with controlled disease for 20 months.

Differences in Immune Checkpoints Expression (TIM-3 and PD-1) on T Cells in Women with Recurrent Miscarriages-Preliminary Studies

Background: Immune checkpoints are molecules that regulate the function of immune cells and control inflammation processes. An important role in this regard is played by TIM-3/Gal-9 and PD-1/PDL-1 interactions. Previous research performed in a mouse model of pregnancy loss confirmed that blocking TIM-3 could induce fetal loss. Similarly, the PD-1 molecule maintains protective interactions between the mother’s immune cells and the fetus. The purpose of this study was to assess the expression of these molecules on a range of T lymphocyte subpopulations from non-pregnant women with recurrent spontaneous abortion (RSA) versus healthy fertile women. Methods: PBMCs were isolated by gradient centrifugation of blood obtained from 12 healthy women and 24 women with RSA and immediately stained for flow cytometry analysis. Standard immunophenotyping of PBMC was performed with the antibodies against classical lymphocyte markers: CD3, CD4, CD8, and CD56. Immune checkpoints were investigated using antibodies against PD-1(CD279) and TIM-3(CD366). Results: We found that expression of TIM-3 was significantly decreased on CD8+ T lymphocytes in the RSA group, and expression of PD-1 was upregulated on CD4+ T lymphocytes in the RSA group in comparison to the healthy controls. Conclusions: Considering our findings, therapeutic intervention towards immune checkpoints may be a promising treatment option for recurrent spontaneous abortion.

Characterization of T cell immunity in chronic hepatitis B virus-infected mothers with postpartum alanine transaminase flare

BACKGROUND

Postpartum alanine transaminase (ALT) flares occur frequently in chronic hepatitis B virus (HBV)-infected mothers with antepartum antiviral therapy (AVT). We aimed to characterize the T cell immunity in HBV-infected mothers experiencing postpartum ALT flares.

METHODS

Twenty HBV-infected pregnant women who received AVT at 26-28 weeks of gestation were enrolled and followed up until 15-18 weeks postpartum. Among the 20 HBV-infected pregnant women, 6 experienced postpartum ALT flare (AF mothers), while 14 did not (NAF mothers). T lymphocyte phenotypes and functions were analyzed using flow cytometry.

RESULTS

Compared to NAF mothers, the quantitative HBsAg levels in AF mothers decreased significantly at 6-8 or 15-18 weeks postpartum. Significant differences in HBeAg levels between these groups were only found at delivery. Regulatory T cell (Treg) numbers in AF mothers were lower than those of NAF mothers before AVT; however, there were no significant differences in Treg numbers at other follow-up points. Expression of other T cell phenotypes were similar between the two groups. T cells in AF mothers produced more pro-inflammatory cytokines (IFN-γ, IL-21, TNF-α, IL-2) or less anti-inflammatory cytokine (IL-10) than those in NAF mothers before, during, or after antiviral treatment. The ratio of IFN-γ to IL-10 producing by CD4⁺ T cells or CD8⁺ T cells was higher in AF mothers than that in NAF mothers during pregnancy or after delivery.

CONCLUSIONS

The characteristics of T cell immunity was distinct between mothers with postpartum ALT flare and those without ALT flare from pregnancy to postpartum, which indicated that T cell immunity might get involved in postpartum ALT flare.

Immune Checkpoint Inhibitors in Special Populations

Cancer is the second leading cause of death in the worldwide. With the growing burden of cancer, the studies on early diagnosis, treatment and prevention of cancer are rapidly increasing. Recently, many new therapeutic strategies have been discovered, among which immunotherapy has dramatically changed the outlook for cancer treatment. Several clinical trials are underway around the world to produce potential treatments. However, these trials set certain strict joining conditions, so that the clinical data cannot be fully applied in the real world. To help clinical oncologists with treatment decision-making, this review collected recent studies on special populations receiving immunotherapy, including organ transplant patients, pregnant women, pediatric patients, patients with pulmonary tuberculosis, patients with human immunodeficiency virus, and patients with autoimmune diseases and mental illness.

Can Immune Suppression and Epigenome Regulation in Placenta Offer Novel Insights into Cancer Immune Evasion and Immunotherapy Resistance?

Cancer is the second leading cause of mortality and morbidity in the developed world. Cancer progression involves genetic and epigenetic alterations, accompanied by aggressive changes, such as increased immune evasion, onset of metastasis, and drug resistance. Similar to cancer, DNA hypomethylation, immune suppression, and invasive cell behaviours are also observed in the human placenta. Mechanisms that lead to the acquisition of invasive behaviour, immune evasion, and drug and immunotherapy resistance are presently under intense investigations to improve patient outcomes. Here, we review current knowledge regarding the similarities between immune suppression and epigenome regulation, including the expression of repetitive elements (REs), endogenous retroviruses (ERVs) and transposable elements (TEs) in cells of the placenta and in cancer, which are associated with changes in immune regulation and invasiveness. We explore whether immune suppression and epigenome regulation in placenta offers novel insights into immunotherapy resistance in cancer, and we also discuss the implications and the knowledge gaps relevant to these findings, which are rapidly being accrued in these quite disparate research fields. Finally, we discuss potential linkages between TE, ERV and RE activation and expression, regarding mechanisms of immune regulation in placenta and cancer. A greater understanding of the role of immune suppression and associated epigenome regulation in placenta could help to elucidate some comparable mechanisms operating in cancer, and identify potential new therapeutic targets for treating cancer.

Immune checkpoints and reproductive immunology: Pioneers in the future therapy of infertility related Disorders?

As co-stimulatory receptors, immune checkpoint molecules are found on the surface of various immune cells and transduce inhibitory signals following ligand binding. The most studied members in this regard include PD-1, TIM-3, and CTLA-4. The physiological part immune checkpoints possess is the prevention of dangerous immune attacks towards self-antigens throughout an immune response, which takes place through the negative regulation of the effector immune cells, through the induction of T-cell exhaustion, for instance. It has recently been suggested that each checkpoint reduces immunoactivation via distinct intracellular mechanisms of signaling. Regulators of immune checkpoints are supposed to participate actively in immune defense mechanisms against infections, preventing autoimmunity, transplantation, and tumor immune evasion. In pregnancy, as an active immunotolerance mechanism which is also natural, the maternal immune system encounters two simultaneous challenges; in addition to accepting the semi-allogeneic fetus, the maternal immune system should also prevent infections. In this regard, the part immune checkpoint molecules possess is particularly interesting. Herein, the current understanding of such part in reproductive immunology is described.

Immunotherapy use outside clinical trial populations: never say never?

BACKGROUND

Based on favourable outcomes in clinical trials, immune checkpoint inhibitors (ICIs), most notably programmed cell death protein 1 (PD-1) and cytotoxic T-lymphocyte antigen-4 (CTLA-4) inhibitors, are now widely used across multiple cancer types. However, due to their strict inclusion and exclusion criteria, clinical studies often do not address challenges presented by non-trial populations.

DESIGN

This review summarises available data on the efficacy and safety of ICIs in trial-ineligible patients, including those with autoimmune disease, chronic viral infections, organ transplants, organ dysfunction, poor performance status, and brain metastases, as well as the elderly, children, and those who are pregnant. In addition, we review data concerning other real-world challenges with ICIs, including timing of therapy switch, relationships to radiotherapy or surgery, re-treatment after an immune-related toxicity, vaccinations in patients on ICIs, and current experience around ICI and coronavirus disease-19. Where possible, we provide recommendations to aid the often-difficult decision-making process in those settings.

CONCLUSIONS

Data suggest that ICIs are often active and have an acceptable safety profile in the populations described above, with the exception of PD-1 inhibitors in solid organ transplant recipients. Decisions about whether to treat with ICIs should be personalised and require multidisciplinary input and careful counselling of patients with respect to potential risks and benefits. Clinical judgements need to be carefully weighed, considering factors such as underlying cancer type, feasibility of alternative treatment options, or activity in trial-eligible patients.

Canonical Secretomes, Innate Immune Caspase-1-, 4/11-Gasdermin D Non-Canonical Secretomes and Exosomes May Contribute to Maintain Treg-Ness for Treg Immunosuppression, Tissue Repair and Modulate Anti-Tumor Immunity via ROS Pathways

We performed a transcriptomic analyses using the strategies we pioneered and made the following findings: 1) Normal lymphoid Tregs, diseased kidney Tregs, splenic Tregs from mice with injured muscle have 3, 17 and 3 specific (S-) pathways, respectively; 2) Tumor splenic Tregs share 12 pathways with tumor Tregs; tumor splenic Tregs and tumor Tregs have 11 and 8 S-pathways, respectively; 3) Normal and non-tumor disease Tregs upregulate some of novel 2641 canonical secretomic genes (SGs) with 24 pathways, and tumor Tregs upregulate canonical secretomes with 17 pathways; 4) Normal and non-tumor disease tissue Tregs upregulate some of novel 6560 exosome SGs with 56 exosome SG pathways (ESP), tumor Treg ESP are more focused than other Tregs; 5) Normal, non-tumor diseased Treg and tumor Tregs upregulate some of novel 961 innate immune caspase-1 SGs and 1223 innate immune caspase-4 SGs to fulfill their tissue/SG-specific and shared functions; 6) Most tissue Treg transcriptomes are controlled by Foxp3; and Tumor Tregs had increased Foxp3 non-collaboration genes with ROS and 17 other pathways; 7) Immune checkpoint receptor PD-1 does, but CTLA-4 does not, play significant roles in promoting Treg upregulated genes in normal and non-tumor disease tissue Tregs; and tumor splenic and tumor Tregs have certain CTLA-4-, and PD-1-, non-collaboration transcriptomic changes with innate immune dominant pathways; 8) Tumor Tregs downregulate more immunometabolic and innate immune memory (trained immunity) genes than Tregs from other groups; and 11) ROS significantly regulate Treg transcriptomes; and ROS-suppressed genes are downregulated more in tumor Tregs than Tregs from other groups. Our results have provided novel insights on the roles of Tregs in normal, injuries, regeneration, tumor conditions and some of canonical and innate immune non-canonical secretomes via ROS-regulatory mechanisms and new therapeutic targets for immunosuppression, tissue repair, cardiovascular diseases, chronic kidney disease, autoimmune diseases, transplantation, and cancers.

Imbalance of uterine innate lymphoid cells is involved in the abnormal pregnancy induced by Toxoplasma gondii infection

Toxoplasma gondii (T. gondii) is a ubiquitous intracellular protozoan parasite that causes adverse pregnancy outcomes. Innate lymphoid cells (ILCs) are critical mediators of mucosal immunity, and have been reported to play an important role in uterine vascular adaptation for successful pregnancy. However, the specific role of ILCs in T. gondii-infection-induced adverse pregnancy outcomes remains elusive. In the present study, we found that T. gondii infection caused the imbalance of uterine ILC cells (uILCs). It was characterized by substantially lower expression of the transcription factor GATA-3 and RORγt and higher expression of T-bet in uILCs. Consistent with the transcription factor changes, uILCs from T. gondii-infected mice produced much less IL-5 and IL-17 and substantially more IFN-γ and TNF-α than did uILCs from uninfected mice. Notably, IL-12, IL-18, and their receptors were increased in the uterus of T. gondii-infected mice. In vitro experiments showed that IL-12 and IL-18 treatment reduced the percentages of uILC2 and uILC3 and increased the percentages of uILC1. Conclusion, our data suggest that alterations in uILC composition may disrupt the balance of immune microenvironment after T. gondii infection and contribute to the adverse pregnancy outcomes caused by T. gondii infection.

A crossroad between placental and tumor biology: What have we learnt?

Placenta in certain species including the human has evolved as a highly invasive tumor-like organ invading the uterus aned its vasculature to derive oxygen and nutrients for the fetus and exchange waste products. While several excellent reviews have been written comparing hemochorial placentation with tumors, no comprehensive review is available dealing with mechanistic insights into what makes them different, and what tumor biologists can learn from placental biologists, and vice versa. In this review, we analyze the structure-function relationship of the human placenta, emphasizing the functional need of the spatio-temporally orchestrated trophoblast invasiveness for fetal development and growth, and pathological consequences of aberrant invasiveness for fetal and maternal health. We then analyze similarities and differences between the placenta and invasive tumors in terms of hallmarks of cancer, some key molecules regulating their invasive functions, and how placental cancers (choriocarcinomas) or other cancers become refractory or even addicted to these invasion-restraining molecules. We cite in vitro models of human trophoblast and choriocarcinoma cell lines utilized to study mechanisms in normal placental development as well as those responsible for tumor progression. We discuss the pathobiology of hyper-invasive placentas and show thattrophoblastic neoplasias are a unique and heterogeneous class of tumors. We delve into the questions as to why metastasis from other organs rarely occurs at the placental site and whether pregnancy makes the mother more or less vulnerable to cancer-related morbidity/mortality. We attempt to compare trophoblast stem cells and cancer stem cells. Finally, we leave the readers with some thoughts as foods of future investigations.

The Protective Role of Maternal Immunization in Early Life

With birth, the newborn is transferred from a quasi-sterile environment to the outside world. At this time, the neonatal immune system is inexperienced and continuously subject to a process of development as it encounters different antigenic stimuli after birth. It is initially characterized by a bias toward T helper 2 phenotype, reduced T helper 1, and cytotoxic responses to microbial stimuli, low levels of memory, and effector T and B cells and a high production of suppressive T regulatory cells. The aim of this setting, during fetal life, is to maintain an anti-inflammatory state and immune-tolerance. Maternal antibodies are transferred during pregnancy through the placenta and, in the first weeks of life of the newborn, they represent a powerful tool for protection. Thus, optimization of vaccination in pregnancy represents an important strategy to reduce the burden of neonatal infections and sepsis. Beneficial effects of maternal immunization are universally recognized, although the optimal timing of vaccination in pregnancy remains to be defined. Interestingly, the dynamic exchange that takes place at the fetal-maternal interface allows the transfer not only of antibodies, but also of maternal antigen presenting cells, probably in order to stimulate the developing fetal immune system in a harmless way. There are still controversial effects related to maternal immunization including the so called "immunology blunting," i.e., a dampened antibody production following infant's vaccination in those infants who received placentally transferred maternal immunity. However, clinical relevance of this phenomenon is still not clear. This review will provide an overview of the evolution of the immune system in early life and discuss the benefits of maternal vaccination. Current maternal vaccination policies and their rationale will be summarized on the road to promising approaches to enhance immunity in the neonate.

Dynamics of TIGIT and PD-1 expression on NK cells during the course of normal pregnancy

PROBLEM

Immune checkpoint molecules are receptors that can transmit inhibitory signals into cells to negatively modulate the immune response. However, their roles in NK cells during normal pregnancy remain poorly understood.

METHOD OF STUDY

Peripheral blood samples were collected from women during the first, second and third trimesters of pregnancy. Peripheral blood NK (pNK) cells and T cells were analyzed for the expression of the immune checkpoint molecules TIGIT and PD-1 by flow cytometry. In addition, the ability of pNK cells to secret functional molecules was also evaluated.

RESULTS

The expression of TIGIT on pNK cells increased gradually throughout pregnancy, whereas that of PD-1 showed the opposite pattern. However, on T cells, the expression of both TIGIT and PD-1 peaked during early pregnancy, and then declined gradually thereafter. Moreover, the expressions of granzyme B, IFN-γ and CD107a by pNK cells also decreased over the course of pregnancy. Compared with TIGIT- NK cells, TIGIT + NK cells possessed reduced expression of functional molecules.

CONCLUSIONS

As pregnancy progressed, the levels of immune checkpoint molecules expressed on pNK cells and T cells changed and the two molecules showed different trends. Furthermore, the secretion of functional molecules from pNK cells was negatively correlated with the trend of TIGIT expression, indicating TIGIT may play an important role in modulating the functions of pNK cells during pregnancy. Further study of TIGIT expression on pNK cells may enhance our understanding of its role in maintaining maternal-fetal tolerance and provide a useful marker for predicting instability during pregnancy.

Prednisone improves pregnancy outcome in repeated implantation failure by enhance regulatory T cells bias

OBJECTIVE

Repeated implantation failure (RIF) has been shown related to maternal immune imbalance. Many studies suggested that prednisone promoted the Th17/Treg balance shift to the direction of immune tolerance. Our study aimed to evaluate the role of prednisone in Th17/Treg balance and pregnancy outcome in RIF patients.

STUDY DESIGN AND MAIN OUTCOME MEASURES

Peripheral blood of healthy fertile controls and RIF patients were collected at the late proliferation phase. The population of Treg and Th17 cells, the expression of Foxp3 and RORC mRNA and the concentration of IL-17A, IL-23 and IL-10 were detected by flow cytometry, qRT-PCR and enzyme-linked immunosorbent assay. RIF patients were given oral prednisone 10 mg daily from the late proliferation phase of the cycle before FET. After one month of treatment, the above immune indicators were tested, and natural cycle frozen embryo transfer was performed.

RESULTS

The Treg cells proportion and IL-10 concentration in peripheral blood of RIF patients was lower than that of NF group, while the proportion of Th17 cells and concentration of proinflammatory cytokine were significantly higher. After prednisone treatment, the indicators related to immune tolerance increased significantly. Five out of 19 RIF patients were successful pregnancy after FET, in which, one had an early miscarriage and four live births. No pregnancy complications and fetal abnormalities were observed.

CONCLUSIONS

We report the beneficial effect of prednisone on RIF patients. The underlying mechanism may attribute to shift the Treg/Th17 immune balance to a Treg bias, and enhance embryo implantation, ultimately improve pregnancy outcomes.

Intrahepatic TH17/TReg Cells in Homeostasis and Disease-It's All About the Balance

Both acute and chronic hepatic inflammation likely result from an imbalance in the T_H1/T_H2 cell response and can lead to liver fibrosis and end-stage liver disease. More recently, a novel CD4+ T helper cell subset was described, characterized by the production of IL-17 and IL-22. These T_H17 cells 50were predominantly implicated in host defense against infections and in autoimmune diseases. Interestingly, studies over the last 10 years revealed that the development of T_H17 cells favors pro-inflammatory responses in almost all tissues and there is a reciprocal relationship between T_H17 and T_Reg cells. The balance between T_H17and T_Reg cells is critical for immune reactions, especially in injured liver tissue and the return to immune homeostasis. The pathogenic contribution of T_H17 and T_Reg cells in autoimmunity, acute infection, and chronic liver injury is diverse and varies among disease etiologies. Understanding the mechanisms underlying T_H17 cell development, recruitment, and maintenance, along with the suppression of T_Reg cells, will inform the development of new therapeutic strategies in liver diseases. Active manipulation of the balance between pathogenic and regulatory processes in the liver may assist in the restoration of homeostasis, especially in hepatic inflammation.

Regulatory T Cells in Pregnancy: It Is Not All About FoxP3

In pregnancy, the semi-allogeneic fetus needs to be tolerated by the mother's immune system. Regulatory T cells (Tregs) play a prominent role in this process. Novel technologies allow for in-depth phenotyping of previously unidentified immune cell subsets, which has resulted in the appreciation of a vast heterogeneity of Treg subsets. Similar to other immunological events, there appears to be great diversity within the Treg population during pregnancy, both at the maternal-fetal interface as in the peripheral blood. Different Treg subsets have distinct phenotypes and various ways of functioning. Furthermore, the frequency of individual Treg subsets varies throughout gestation and is altered in aberrant pregnancies. This suggests that distinct Treg subsets play a role at different time points of gestation and that their role in maintaining healthy pregnancy is crucial, as reflected for instance by their reduced frequency in women with recurrent pregnancy loss. Since pregnancy is essential for the existence of mankind, multiple immune regulatory mechanisms and cell types are likely at play to assure successful pregnancy. Therefore, it is important to understand the complete microenvironment of the decidua, preferably in the context of the whole immune cell repertoire of the pregnant woman. So far, most studies have focused on a single mechanism or cell type, which often is the FoxP3 positive regulatory T cell when studying immune regulation. In this review, we instead focus on the contribution of FoxP3 negative Treg subsets to the decidual microenvironment and their possible role in pregnancy complications. Their phenotype, function, and effect in pregnancy are discussed.