Serum concentrations of soluble B7-H4 in early pregnancy are elevated in women with preterm premature rupture of fetal membranes

An analysis of placental chorionic villous and decidual basalis tissue immunoreactivity in patients after cesarean section due to a placenta accreta spectrum disorder and elective cesarean section followed by the depressed mood

An analysis of placental chorionic villous and decidual basalis tissue immunoreactivity in patients after cesarean section due to a placenta accreta spectrum disorder and elective cesarean section followed by a depressed mood.

RESEARCH BACKGROUND

Over the past few years, interest in investigating immune dysfunction in patients with psychiatric disorders has increased. B7-H4 is a molecule with immunosuppressive properties that seems to play a key role in establishing maternal tolerance against fetal antigens. The aim of this study was to compare the B7-H4 immunoreactivity levels in patients after cesarean section.

METHODS

Placental and decidual tissue samples were obtained from 49 women who delivered at Bielański Hospital in Warsaw between 2009 and 2015. Fifteen of the patients developed postpartum depression and 14 had a diagnosis of placenta accreta spectrum. The control group consisted of 20 healthy patients on whom cesarean section was performed due to breech presentation at term.

RESULTS

The highest levels of B7-H4 immunoreactivity were found in the placental chorionic villous and decidual basalis tissue samples of the patients who later developed postpartum depression, while the lowest levels were found in the samples of those patients with a placenta accreta spectrum disorder. The difference between the B7-H4 immunoreactivity levels of these two groups was statistically significant. The B7-H4 expression levels were statistically significantly higher in the women in the postpartum depression group than in the control group.

CONCLUSION

Postpartum depression follows a disturbance of the suppressive milieu responsible for rebalancing the maternal immune system after the initial cytotoxic activation during labor.

The immunological role of b7-h4 in pregnant women with sars-cov2 infection

Problem

T‐cells are key players in fighting the coronavirus disease 2019 (COVID‐19). The checkpoint molecule B7‐H4, a member of the B7 family, can inhibit T‐cell activation and proliferation by inhibiting NF‐kb expression. We aimed to elucidate the immunological role of soluble B7‐H4 (sB7‐H4) and B7‐H4 in pregnant women suffered from an acute Sars‐Cov2 infection.

Methods

Expression levels of sB7‐H4 and cytokines were detected by enzyme linked immunosorbent assay. B7‐H4 and cytokines mRNA expression was analyzed by qPCR, and B7‐H4 and NF‐κb (p65) protein levels were investigated by western blot and immunofluorescence staining in placenta chorionic villous and decidual basalis tissues of COVID‐19 affected women and healthy controls.

Results

Fibrinoid necrosis in the periphery of placental villi was increased in the COVID‐19‐affected patients. sB7‐H4 protein in maternal and cord blood serum and IL‐6/IL‐10 were increased while leukocytes were decreased during SARS‐CoV‐2 infection. Serum sB7‐H4 level was increased according to the severity of SARS‐Cov‐2 infection. Cytokines (IL‐6, IL‐18, IL‐1β, TNF‐α), B7‐H4 mRNA and protein in the decidual basalis tissues of COVID‐19‐infected pregnant women were significantly increased compared to healthy controls. IL‐18 and IL‐1β were significantly increased in the placenta chorionic villous samples of COVID‐19 affected patients, while NF‐κb (p65) expression was decreased.

Conclusions

The expression of the immunological marker sB7‐H4 correlated with the severity of COVID‐19 disease in pregnant women. sB7‐H4 and B7‐H4 can be used to monitor the progression of COVID‐19 infection during pregnancy, and for evaluating of the maternal immune status.

Expression of the Costimulatory Molecule B7-H4 in the Decidua and Placental Tissues in Patients with Placental Abruption

B7 homolog 4 protein (B7-H4), a member of the B7 family, is a immunomodulatory membrane protein. The aim of the study was to evaluate the expression of this protein in the decidua and placental tissues in case of placental abruption (PA) compared to cases of retained placental tissue (RPT) and controls. Tissue samples were obtained from 47 patients with PA, 60 patients with RPT, and 41 healthy controls. The samples were stained for B7-H4 expression, analyzed by an expert pathologist, and a semi-quantitative scale was applied. A statistical analysis revealed that the expression of B7-H4 was significantly higher in the decidua in PA samples compared to samples from patients with RPT (p-value < 0.001) and healthy controls (p-value < 0.001). The expression of B7-H4 in the placental chorionic villus was significantly higher in PA samples in relation to samples from healthy controls (p-value < 0.001) but not in relation to RPT samples (p-value = 0.0853). This finding suggests that B7-H4 might play an important role in mechanisms restoring reproductive tract homeostasis. Further research is necessary in regard to the role of B7-H4 in PA.

Soluble PD-L1 and B7-H4 serum levels during the course of physiological pregnancy

PROBLEM

The aim of this study was to evaluate the soluble programmed death-ligand (sPD-L1) and soluble B7-H4 (sB7-H4) serum concentration levels longitudinal throughout the three trimesters of uncomplicated pregnancies. METHOD OF THE STUDY: sPD-L1 and sB7-H4 levels were determined with enzyme-linked immunosorbent assay (ELISA). The patients (n = 26) were divided into three groups according to the pregnancy trimester. Among 26 women involved in the study 14 had longitudinal sB7-H4 and sPD-L1 measurements in each trimester of pregnancy.

RESULTS

During the course of pregnancy, the sB7-H4 blood serum levels were significant higher in second trimester than in first and third trimester, whereas sPD-L1 levels increased significantly over the course of pregnancy.

CONCLUSION

The highest serum levels of sPD-L1 in the third trimester suggest increasing suppression of maternal immunity throughout pregnancy, whereas elevated sB7-H4 concentration levels in second trimester suggests different profile of T-cell regulation in physiological pregnancy.

Abnormal expression of the costimulatory molecule B7-H4 in placental chorionic villous and decidual basalis tissues of patients with preeclampsia and HELLP syndrome

BACKGROUND

B7-H4, a checkpoint molecule of the B7 family, regulates a broad spectrum such as T-cell activation, cytokine secretion, tumour progression, and invasion capacities. Our previous data revealed that soluble B7-H4 (sB7-H4) blood serum levels are elevated in women at high risk for the hypertensive pregnancy disorder preeclampsia (PE) in the first trimester, as well as in patients with confirmed early/late-onset PE.

AIM

We here aim to investigate the expression pattern of B7-H4 in placental tissues of PE and HELLP Syndrome versus control group.

METHODS

B7-H4 protein expression and localization were investigated by immunoblotting and co-immunohistochemistry in placental chorionic villous and decidual basalis tissues.

RESULTS

B7-H4 protein was prominently expressed at the cell membrane, in the cytoplasm of the syncytiotrophoblast (STB) and interstitial extravillous trophoblast (EVT). B7-H4 protein levels in placental chorionic villous tissue were significantly higher in women with early-onset/late-onset PE and HELLP, while it was decreased in decidual basalis tissues of early-onset PE and HELLP compared with controls.

CONCLUSION

B7-H4 was inversely expressed in placental chorionic villous and decidual basalis tissues of PE and HELLP patients. The increase in B7-H4 in the STB in PE and HELLP may lead to excessive apical expression and release of soluble B7-H4 in the maternal circulation. In contrast, the decrease in B7-H4 in decidual basalis tissues could be related to the decrease in invasion ability of the EVT in PE. Thus, the current results strongly suggest that B7-H4 is involved in the pathogenesis of PE and HELLP.

The Role of B7 Family Molecules in Maternal-Fetal Immunity

Pregnancy is a complex but well-arranged process, and a healthy fetus requires immune privilege and surveillance in the presence of paternally derived antigens. Maternal and fetal cells interact at the maternal–fetal interface. The upregulation and downregulation of maternal immunity executed by the leukocyte population predominantly depend on the activity of decidual natural killer cells and trophoblasts and are further modulated by a series of duplex signals. The B7 family, which consists of B7-1, B7-2, B7-H1, B7-DC, B7-H2, B7-H3, B7-H4, B7-H5, BTNL2, B7-H6, and B7-H7, is one of the most characterized and widely distributed signaling molecule superfamilies and conducts both stimulatory and inhibitory signals through separate interactions. In particular, the roles of B7-1, B7-2, B7-H1, and their corresponding receptors in the progression of normal pregnancy and some pregnancy complications have been extensively studied. Together with the TCR–MHC complex, B7 and its receptors play a critical role in cell proliferation and cytokine secretion. Depending on this ligand–receptor crosstalk, the balance between the tolerance and rejection of the fetus is perfectly maintained. This review aims to provide an overview of the current knowledge of the B7 family and its functions in regulating maternal–fetal immunity through individual interactions.

B7-H4, a promising target for immunotherapy

The coinhibitory molecule B7-H4, an important member of the B7 family, is abnormally expressed in tumors, inflammation and autoimmune diseases. B7-H4 negatively regulates T cell immune response and promotes immune escape by inhibiting the proliferation, cytokine secretion, and cell cycle of T cells. Moreover, B7-H4 plays an extremely important role in tumorigenesis and tumor development including cell proliferation, invasion, metastasis, anti-apoptosis, etc. In addition, B7-H4 has the other biological functions, such as protection against type 1 diabetes (T1D) and islet cell transplantation. Therefore, B7-H4 has been identified as a novel marker or a therapeutic target for the treatment of tumors, inflammation, autoimmune diseases, and organ transplantation. Here, we summarized the expression profiles, physiological and pathological functions, and regulatory mechanisms of B7-H4, the signaling pathways involved, as well as B7-H4-based immunotherapy.

Soluble B7-H4 blood serum levels are elevated in women at high risk for preeclampsia in the first trimester, as well as in patients with confirmed preeclampsia

PROBLEM

B7-H4 negatively regulates T-cell-mediated immunity and might play an important role in preeclampsia (PE). Here, we have investigated the association between PE and maternal soluble B7-H4 (sB7-H4) serum levels and B7-H4 mRNA expression in the placenta.

METHOD OF STUDY

Maternal serum levels of sB7-H4 were determined by enzyme-linked immunosorbent assay in women between 11 and 13 weeks' gestation with elevated risk for PE (n = 48) and women without elevated risk for PE (n = 47). In the third trimester, sB7-H4 serum levels (n = 166) and B7-H4 mRNA expression in the placenta (n = 54) were determined in women with early-onset PE, late-onset PE, fetal growth restriction (FGR), and in healthy controls.

RESULTS

In the first trimester, significant higher levels of sB7-H4 were detected in women at elevated risk for PE compared to women without risk for PE (P < .0001). sB7-H4 has some predictive ability to identify cases with an elevated risk of developing PE with area under the curve (AUC) value of 0.88 (95% CI 0.8-0.94). Using a specificity of 90.0% led to a sensitivity of 47.9% and a threshold of 3.63 ng/mL. In the third trimester, the highest serum levels of sB7-H4 and B7-H4 mRNA expression in the placenta were observed in early-onset PE. Significant higher serum levels of sB7-H4 and B7-H4 mRNA expression in the placenta were observed in women with early-onset PE (P = .01 and P = .006, respectively) and late-onset PE (P = .03 and P = .004, respectively) compared to healthy controls, but not compared to FGR.

CONCLUSION

sB7-H4 is involved in the regulation of immune tolerance in women with PE in the third trimester. In the first trimester of pregnancy, sB7-H4 might serve as a predictive immunological biomarker for women who are at elevated risk of developing PE.