TIGIT and CD155 as Immune-Modulator Receptor and Ligand on CD4+ T cells in Preeclampsia Patients

Immunological mechanisms in preeclampsia: A narrative review

Maternal immunologic mechanisms for tolerance are essential for a successful pregnancy because they prevent maladaptive immune responses to the placenta and semi-allogeneic fetus and promote fetal growth. Preeclampsia is a major global cause of fetal mortality and morbidity. It is characterized by new-onset hypertension and proteinuria that occurs at twenty weeks of pregnancy or later. Preeclampsia is defined by a rise in cytokines that are pro-inflammatory and antiangiogenic components in the fetoplacental unit and the vascular endothelium of pregnant women, as well as an excessive and increasing stimulation of the immune system. Crucially, inflammation can result in low birth weight and inadequate placental perfusion in neonates. Preeclampsia, which is ultimately connected to inflammatory responses, can be impacted by several immunological mechanisms. Our goal in this work was to compile the most recent research on the pathoimmunology of preeclampsia, including studies on angiogenic variables and, in particular, immunological components.

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.

Exploring Natural Killer Cell Testing in Embryo Implantation and Reproductive Failure: An Overview of Techniques and Controversies

The blastocyst nidation is the most crucial stage to a successful pregnancy, as the white cells work to promote a favorable endometrial microenvironment for this process. Intriguingly, this implantation window lasts, on average, 6 days in most regular women, and its quality is affected by many pathological conditions. Since the grounds of reproductive failure in healthy couples are still uncharted, studies have widely suggested a potential hostile role of the immune system in the equilibrium of the maternal-fetal interface. In recent years, natural killer cells have been the highlight as they represent the greatest lymphocyte in the uterus and have immune surveillance through cytotoxicity during the implantation window. This review explored the main techniques used for natural killer (NK) cell testing in the implantation window over the last 13 years on the PubMed® database. Of 2167 published articles potentially relevant for the review, only thirty-three were about cell evaluation in healthy women, met the inclusion criteria, and had their methodology critically analyzed. Here, we bring a summary from the study group and sample collection to evidence comments about their findings and correlations. Meanwhile, we also summarize the current relationship between NK cells and endometrial receptivity with reproductive failure to help enhance the possibilities for future research. In conclusion, our overview points out that restricted and unstandardized methods support the controversy between the NK population and unsuccessful embryo implantation, which is an obstacle to studying why healthy eggs do not thrive and finding a solution for one of the most controversial topics in human reproduction.

Diagnostic significance of blood lymphocyte activation markers in pre-eclampsia

The adaptive and innate immune system is important in both initiating and preventing functional disorders during pregnancy, one of which is pre-eclampsia. The research aims to conduct the comparative quantification of selected subpopulations of peripheral blood immunoregulatory cells in pregnant women with pre-eclampsia in the third trimester. The marker receptors CD4, CD8, CD95, CD25, and CD27 and the marker antigen HLA-DR were considered. The screening was performed by flow cytometry with dual phenotyping using phycoerythrin- and fluorescein-isothiocyanate-labeled monoclonal antibodies. Data processing consisted in calculating a likelihood value to assess the statistical significance of the difference between the samples. A statistically significant decrease in the subpopulation titer of T and B lymphocytes with marker receptors CD4, CD8, and CD19 was found in pre-eclampsia patients. In the CD4 carrier T-lymphocyte population, there was an increased expression of the CD25/CD95 activation and apoptosis markers. In the CD8 T-killer population, a decreased representation of the CD27/CD25/CD95 markers of differentiation, activation, and apoptosis was deterministic. The expression pattern of the major histocompatibility complex antigen HLA-DR did not change significantly in normality and pathology. The titer of peripheral natural killer cells carrying the CD56 marker increased in patients with various degrees of disease severity, while the number of CD16 natural killer remained at the level of the control group. The research results suggest that a change in the ratio of the above receptors is a diagnostic indicator for pre-eclampsia.

Functions of LncRNAs, exosomes derived MSCs and immune regulatory molecules in preeclampsia disease

Modulatory signaling pathway such as T cell immunoreceptor with Ig and ITIM domains (TIGIT), Cytotoxic T-Lymphocyte Associated Protein 4 (CTLA-4), P53 signaling and TIM (T-cell immunoglobin and mucin domain) are important in normal pregnancy and loss of their functions or dysregulation of related genes can lead to some disorders. Inflammation is a process by which your body's white blood cells and the things they make protect you from infection from outside invaders, such as bacteria and viruses. Some cellular and molecular signaling have been categorized to demonstrate the mechanism that protects tolerance to antigens. lncRNAs significantly impact physiological processes like immunity and metabolism, and are linked to tumors, cardiovascular diseases, nervous system disorders, and nephropathy.In this review article, we summarized recent studies about the role of TIGIT, CTLA-4, P53 and TIM regulatory molecules and reviewed dysregulation of these pathway in diseases.We will also talk about the role of lncRNAs and mesenchymal stem cells.

The effect of lymphocyte immunotherapy (LIT) in modulating immune responses in patients with recurrent pregnancy loss (RPL)

In order to prevent miscarriage in RPL patients, the goal of this study was to determine how well lymphocyte immunotherapy (LIT) works in modifying immunological responses produced by cells, cytokines, transcription factors, and microRNAs. 200 RPL patients and 200 healthy controls were included in the study. Using flow cytometry, it was possible to compare the frequency of cells before and after lymphocyte treatment. Real-time PCR was used to assess the gene expression levels of transcription factors, cytokines, and microRNAs. ELISA method was used to evaluate the level of secretion of cytokines in the serum. Primary evaluation of the immune profile between healthy controls and RPL cases showed a higher frequency of Th17, NK, B cells and a lower frequency of Treg cells in RPL cases. Also, pro-inflammatory cytokines showed increased expression at mRNA and protein levels in the RPL group in comparison with the control group. Whereas, anti-inflammatory cytokines showed decreased expression in RPL patients. Decreased and increased frequency of Th17 and Treg lymphocytes observed in RPL cases following LIT, respectively. The same results obtained for RORγt and FoxP3 mRNA expression as transcription factor of Th17 and Treg cells, respectively. NK cell cytotoxicity decreased after LIT in RPL patients. miR-326a and miR-155 expression after LIT reduced, but miR-146a and miR-10a expression increased in RPL instances. LIT in RPL cases causes to elevation and modulation of anti-inflammatory and pro-inflammatory cytokines. Our data showed that lymphocyte therapy can be proposed as an effective therapeutic agent in RPL patients with immunological background by a modulating inflammatory condition.

Observation of increased levels of autophagy-related genes and proteins in women with preeclampsia: a clinical study

BACKGROUND

Preeclampsia is a type of pregnancy-related disease that is not fully understood underlying mechanisms of it till now. Reported results from autophagy-related studies in PE show some controversial roles of this mechanism in PE development and progression. In this study, we aimed to evaluate the autophagy process in preeclampsia women.

MATERIALS AND METHODS

Peripheral blood was taken from 50 preeclampsia women and 50 healthy pregnant women. After PBMC isolation, Total RNA and total protein were extracted from PBMCs to cDNA synthesis and real-time PCR and western blotting, respectively. Atg5, Atg7, beclin1, LC3B, FOXO1, FOXO3a, FOXO4, and FOXO6 genes were evaluated using real-time PCR. Atg5, beclin1, LC3B, and FOXO1 expression at the protein level was evaluated by the western blot technique.

RESULTS

Real-time PCR results showed an increased expression of Atg5, Atg7, beclin1, LC3B, FOXO1, FOXO3a, FOXO4, and FOXO6 genes in PE patients compared to the healthy pregnant women and also in LOPE patients in comparison with EOPE cases. Western blotting results revealed higher expression of Atg5, beclin1, LC3B, and FOXO1 proteins in PE women compared to healthy pregnant group and in LOPE patients in comparison with EOPE cases. Our findings revealed a positive correlation between proteinuria and protein levels of Atg5, beclin1, LC3B, and FOXO1 in LOPE patients.

CONCLUSION

Our investigation showed an elevated activation of autophagy in PE women in comparison with healthy pregnant women which is in controversy with some other studies. More targeted and comprehensive studies regarding the relationship of autophagy in pre-eclamptic women are needed.

Preeclampsia-Derived Exosomes Imbalance the Activity of Th17 and Treg in PBMCs from Healthy Pregnant Women

The disturbance of maternofetal immune tolerance is identified as one of the important issues in the pathology of preeclampsia (PE). PE exosomes are believed to possess significant roles in immune abnormalities. In this study, to assess the possible effects of PE exosomes in the pathophysiology of preeclampsia patients, exosomes were isolated from the serum of PE patients and incubated with peripheral blood mononuclear cells (PBMCs) of healthy pregnant women. Also, exosomes from healthy pregnant women were utilized as the control. Th17/Treg ratio in PE and healthy pregnant women and the effects of PE exosomes on expression level of Th17 and Treg transcription factors, as well as their related cytokines in PBMCs of healthy pregnant women, were evaluated. A significant decrease in Treg cell number and increase in Th17 cells and Th17/Treg ratio were observed in PE patients. Following PE-exosome intervention, a significant increase in mRNA expression level of RORγt, IL-17, IL-23, IL-1β, and IL-6, and significant decrease in IL-10 and TGFβ were evident. On the other hand, no significant difference in FoxP3 level was detected. Additionally, increased IL-6, IL-17, IL-23, and IL-1β levels and decreased IL-10 level in the supernatant of cultured PBMCs from healthy pregnant women following PE-exosome intervention were exhibited. However, TGF-β level did not change significantly. Based on our findings, PE exosomes are able to alter the activity of Th17 and Treg cells as well as their related gene expression and cytokine profiles. These findings support the probable role of PE exosomes in PE pathogenesis.

The immunomodulatory effect of intradermal allogeneic PBMC therapy in patients with recurrent spontaneous abortion

BACKGROUND

There has been limited study on the impact of PBMC therapy in RSA patients with immunological disorders such as Th17 and Treg cell dysregulation, as well as their associated factors. This study aimed to assess the efficacy of PBMC therapy in modulating immune cell frequency, cytokine production, transcription factors, and miRNAs implicated in the regulation of their function, as well as their potential superiority to routine treatments.

METHODS

Fifty RSA women who had received PBMCs and 50 matched-paired control RSA women who had received the routine treatments were recruited and followed for three months. The frequencies of Th17, Treg, NK, and B cells were assessed using flow cytometry. Thereafter, the gene expression level of the transcription factors and related miRNAs of Treg cell and Th17 cell was quantified using RT-PCR. Then ELISA was employed to assess the cytokine production of Th17 and Treg cells. Finally, the live birth rate and miscarriage rate were evaluated as clinical outcomes in this study.

RESULTS

Flow cytometry analysis revealed that PBMC therapy significantly reduces the frequencies of Th17 and NK cells while enhancing the frequency of Treg cells. RT-PCR analysis confirmed that PBMC therapy significantly downregulates RORγt and upregulates FoxP3. Likewise, RT-PCR analysis showed that PBMC therapy reduces the expression of miR-25, miR-155, and miR-326 while increasing the expression of miR-10a. ELISA results demonstrated that PBMC therapy considerably decreases the concentration of inflammatory cytokines IL-1β, IL-17, and TNF-α and enhances the concentration of anti-inflammatory cytokines IL-10 and TGF-β. Following PBMC therapy live birth rate raised while miscarriage rate reduced.

CONCLUSION

Our findings suggested that, in contrast to routine treatments, PBMC therapy can significantly modulate the maternal immune system by enhancing the Treg/Th17 paradigm and regulating the expression of Treg and Th17 cell-associated cytokines, transcription factors, and miRNAs. This treatment also can increase the live birth rate in RSA patients.

Examination of the TIGIT-CD226-CD112-CD155 Immune Checkpoint Network during a Healthy Pregnancy

Background: The importance of immune checkpoint molecules is well known in tumor and transplantation immunology; however, much less information is available regarding human pregnancy. Despite the significant amount of information about the TIGIT and CD226 immune checkpoint receptors in immune therapies, very little research has been conducted to study the possible role of these surface molecules and their ligands (CD112 and CD155) during the three trimesters of pregnancy. Methods: From peripheral blood, immune cell subpopulations were studied, and the surface expression of immune checkpoint molecules was analyzed by flow cytometry. Soluble immune checkpoint molecule levels were measured by ELISA. Results: Notable changes were observed regarding the percentage of monocyte subpopulation and the expression of CD226 receptor by CD4⁺ T and NKT cells. Elevated granzyme B content by the intermediate and non-classical monocytes was assessed as pregnancy proceeded. Furthermore, we revealed an important relationship between the CD226 surface expression by NKT cells and the serum CD226 level in the third trimester of pregnancy. Conclusions: Our results confirm the importance of immune checkpoint molecules in immunoregulation during pregnancy. CD226 seems to be a significant regulator, especially in the case of CD4⁺ T and NKT cells, contributing to the maternal immune tolerance in the late phase of pregnancy.

Evaluation of CD39, CD73, HIF-1α, and their related miRNAs expression in decidua of preeclampsia cases compared to healthy pregnant women

BACKGROUND

The Preeclampsia (PE) molecular mechanisms are not fully revealed and different biological processes are involved in the pathogenesis of PE. We aimed to evaluate adenosine and hypoxia-related signaling molecules in PE patients in the current study.

METHODS

Decidua tissue and peripheral blood samples were taken from 25 healthy pregnant and 25 PE women at delivery time. CD39, CD73, and Hypoxia-inducible factor-alpha (HIF-α) were evaluated in mRNA and protein level using real-time PCR and western blotting techniques, respectively. Also, miR-30a, miR-206, and miR-18a expression were evaluated by real-time PCR. At last, secretion levels of IGF and TGF-β in the taken serum of blood samples were measured by ELISA.

RESULTS

Our results revealed that Expression of CD39 is decreased in PE cases versus healthy controls at mRNA and protein levels (p = 0.0003 for both). CD73 and HIF-α showed an increased level of expression in PE patients at RNA and protein status (p = 0.0157 and p < 0.0001 for protein evaluation of CD73 and HIF-α, respectively). The miRNA-30a (p = 0.0037) and miR-206 (p = 0.0113) showed elevated expression in the decidua of the PE group. The concentration of secreted IGF-1 (p = 0.0002) and TGF-β (p = 0.0101) in serum samples of PE cases compared to the healthy group were decreased.

CONCLUSION

In conclusion, our results showed that aberrant expression of molecules that are involved in ATP catabolism and the hypoxic conditions is observed in PE cases and involved in their hypertension and inflammation could be served as PE prognosis by more confirming in comprehensive future studies. miR-206 and miR-30a play a role by regulating CD39 and CD73 as molecules that are involved in ATP catabolism as well as regulating the production of IGF-1 in the process of hypertension, which is the main feature in patients with preeclampsia. On the other hand, decreased level of miR-18a lead to upregulation of HIF-1a, and the consequence condition of hypoxia increases hypertension and inflammation in these patients.

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.

Next generation of immune checkpoint molecules in maternal-fetal immunity

Successful pregnancy is a unique situation requires the maternal immune system to recognize and tolerate a semi-identical fetus and allow normal invasion of trophoblast cells. Although efforts have been made, the deep mechanisms of the maternal-fetal crosstalk have not yet been fully deciphered. Immune checkpoint molecules (ICMs) are a group of negative modulators of the immune response that avoid immune damage. They have been extensively studied in the fields of oncology and transplantation, while the latest evidence suggests that they are closely associated with pregnancy outcomes via multiple inhibitory mechanisms. Although studies have mostly demonstrated the regulatory role of the well-known PD-1, CTLA-4 at the maternal-fetal interface, what is unique about the newly discovered multiple ICMs remains a mystery. Here, we review the latest knowledge on ICMs, focusing on the first generation of checkpoints (PD-1, CTLA-4) and the next generation (Tim-3, Tigit, Lag-3, VISTA) highlighting their immunoregulatory roles in maternal-fetal tolerance and decidual vascular remodeling, and their involvement in pathological pregnancies. The content covers three aspects: the characteristics they possess, the dynamic expression profile of their expression at the maternal-fetal interface, and their involvement in pathological pregnancy. In immunotherapy strategies for pregnancy complications, upregulation of immune checkpoints may play a role. Meanwhile, the impact on pregnancy outcomes when using ICMs in clinical cancer treatment during pregnancy is a topic worth exploring. These may serve as a guide for future basic research and clinical applications of maternal-fetal immunity.

T lymphocytes and preeclampsia: The potential role of T-cell subsets and related MicroRNAs in the pathogenesis of preeclampsia

Innate and adaptive immune systems have a crucial role in initiating and progressing some pregnancy disorders such as preeclampsia (PE), which is one of the pregnancy-specific disorders that could result in neonatal and maternal morbidity and mortality. The dysregulation of the spiral artery and inadequate trophoblast invasion lead to PE symptoms through producing various inflammatory cytokines and anti-angiogenic factors from the placenta. T lymphocytes play a special role in the epithelium and stroma of the human endometrium. CD4+ T helper (Th) cells, Th1/Th2, and Th17/T regulatory (Treg) balance mainly contribute to the establishment of a pregnancy-favorable environment. This review examined the dysregulation of some cytokines produced from T cells, the dysregulation of the transcription factors of Th cells, the expression of chemokine receptors on T cells, as well as the effects of some factors including vitamin D on the activity of T cells, and finally, the dysregulation of various miRNAs related to T cells, which could cause PE.