IL-27 triggers IL-10 production in Th17 cells via a c-Maf/RORγt/Blimp-1 signal to promote the progression of endometriosis

Increased circulating T helper 17 (TH17) cells and endometrial tissue IL-17-producing cells in patients with endometriosis compared with non-endometriotic subjects

Endometriosis, an inflammatory disease, is characterized by the aberrant presence of endometrial tissues at ectopic locations. Accumulating evidence suggests that inflammatory cells, such as interleukin-17 (IL-17)-producing cells, may be involved in the pathogenesis of endometriosis. This investigation assessed the frequency of IL-17A (commonly known as IL-17)-producing cells in peripheral blood mononuclear cells (PBMCs), ectopic, and eutopic endometrial tissues in patients with endometriosis compared to non-endometriotic subjects. PBMCs, ectopic, and eutopic endometrial tissues were collected from 23 patients with endometriosis. PBMCs and endometrial tissues from 20 non-endometriotic women were used as the control group. The frequency of T helper 17 (TH17) lymphocytes in PBMCs was assessed using flow cytometry, and the expression level of IL-17 in eutopic and ectopic endometrial tissues was evaluated through immunohistochemistry. The percentage of TH17 and IL-17-producing lymphocytes was significantly higher in the PBMCs of patients with endometriosis compared to non-endometriotic subjects (P < 0.01 and P < 0.001, respectively). The expression of IL-17 protein in ectopic (P < 0.001) and eutopic (P < 0.05) endometrial tissues of patients with endometriosis increased compared to controls' endometrial tissue. Furthermore, the eutopic endometrium of patients with endometriosis showed a higher expression of IL-17 protein than the eutopic endometrial tissue of control subjects (P < 0.05). The findings suggest that the higher frequency of IL-17-producing cells in the PBMCs and endometrial tissues of patients with endometriosis contributes to the pathogenesis of endometriosis.

Gut microbiome in patients with early-stage and late-stage endometriosis

BACKGROUND

Endometriosis is a chronic inflammatory gynecological disease. Previous studies have explored relationships between endometriosis and the microbiota, but none have focused on differences in gut microbiota between early-stage and late-stage endometriosis patients or their connections to dysmenorrhea symptoms. This study compared gut microbiota compositions between early-stage and late-stage endometriosis patients using amplicon sequencing and further analyzed their dysmenorrhea symptoms.

METHODS

To minimize seasonal and dietary impacts, we recruited Guangdong residents hospitalized for surgery at Zhujiang Hospital. Participants underwent preoperative screening based on enrollment criteria and fecal samples were collected. Endometriosis was classified according to the American Society for Reproductive Medicine (ASRM) staging system based on surgincal and pathological findings. Stage I-II cases were designated as early-stage endometriosis, and Stage III-IV as late-stage endometriosis.

RESULTS

A total of 112 patient fecal samples were collected, with 75 (median age, 32 years [range, 18-49 years]) meeting the enrollment criteria, including 39 early-stage (32 Stage I and 7 Stage II) and 36 late-stage (16 Stage III and 20 Stage IV) patients. The gut microbiota structure and functions in early-stage patients significantly differed from those in late-stage cases. Dysmenorrhea was associated with specific microbial traits. Late-stage patients with dysmenorrhea displayed distinctly different gut profiles compared to other endometriosis groups. Bartonella, Snodgrassella, and other taxa were enriched in late-stage cases, while Bacteroides, and Prevotella were decreased.

CONCLUSION

The gut microbial community structure in early-stage endometriosis patients significantly differs from that in late-stage cases, with late-stage patients experiencing dysmenorrhea displaying particularly distinct gut profiles. Predicted functional analysis indicated suppressed steroid biosynthesis pathways in the gut of late-stage endometriosis patients. In conclusion, it is plausible that the multiple effects of steroids on the lower gastrointestinal tract may involve microbiota alterations, suggesting the need for further investigations.

Th17 Response in Uveitis: A Double-Edged Sword in Ocular Inflammation and Immune Regulation

Uveitis involves a complex interplay of immune cell infiltration and cytokine imbalances, with Th17 cells playing a central role in this process. Th17 cells contribute to disease pathogenesis by promoting inflammation, recruiting additional immune cells, and directly damaging retinal tissues. This review discusses the current knowledge on therapeutic strategies targeting Th17-related cytokines, including cytokine blockade, small molecule inhibitors, and immunomodulatory approaches. Traditionally, Th17-related cytokines have been viewed as pro-inflammatory agents in uveitis. However, emerging research has highlighted the capacity of the Th17 response to express immunoregulatory cytokines, notably IL-10, IL-24, and TGF-β. This suggest that the Th17 response may have a dualistic role that includes immune suppression. In this review, we will discuss this paradoxical nature of Th17 cells in immune regulation and inflammation that they can both promote and mitigate uveitis. We expected that a deeper understanding of these mechanisms is imperative for the innovation of novel therapeutics that could consider the dual role of Th17 response in the pathogenesis of uveitis. By finely tuning the Th17 response to preserve retinal integrity and function, these new treatments could bring significant benefits to patients with uveitis. This review aims to shed light on the complexities of the Th17 response in uveitis and its implications for future therapeutic strategies.

Harnessing IL-27: challenges and potential in cancer immunotherapy

IL-27 is structurally an immune-enhancing and pleiotropic two-chain cytokine associated with IL-12 and IL-6 families. IL-27 contains two subunits, namely IL-27p28 and EBI3. A heterodimer receptor of IL-27, composed of IL27Rα (WSX1) and IL6ST (gp130) chains, mediates the IL-27 function following the activation of STAT1 and STAT3 signaling pathways. Specifically, IL-27 is identified as augmenting cytokine of immune responses, including Th1 cell differentiation, TCd4 + cell proliferation, and IFN-γ production with the help of IL-12. According to several published studies, due to the pro-inflammatory or anti-inflammatory functions of cytokine related to the biological context in various disorders and diseases, IL-27 has been considered a complex regulator of the immune system. Surprisingly, the dual role of IL-27, the same as the double-edged sword, has also been evidenced in clinical models of various hematological or solid tumors. Predominantly, Il-27 applies anti-tumor functions by inducing the responses of a cytotoxic T lymphocyte (CTL) and Th1 and suppressing the growth, proliferation, angiogenesis, invasiveness, metastasis, and survival of tumor cells. On the other hand, IL-27 may also play a protumor role in cancers and induce tumor progression. The current update study aimed to summarize the protumor anti-tumor and biological functions of IL-27 in different hematological malignancies and solid tumors.

Decreased CCL5 expression in endometrial stromal cells induces deficient CCR5 +CD4 + T cells in endometriosis

Endometriosis (EMS) is a benign gynecological disease characterized by the growth of endometrial tissue outside the uterine cavity. Evidence shows that the survival of patients with ectopic endometrial implants is associated with a dysregulated immune microenvironment. CD4 + T cells can regulate EMS through diverse cytokines, the inflammatory response, and angiogenesis. CCR5 +CD4 + T cells exhibit increased cellular immunogenicity and play a role in infectious diseases, host defense, and cancer progression. However, the specific mechanisms of CCR5 +CD4 + T cells in EMS remain unknown. In the present study, flow cytometry and RNA-seq are utilized to assess the proportions and features of CCR5 +CD4 + T cells in EMS patients, RT-PCR and ELISA are used to assess the production of CCL5 by ectopic endometrial stromal cells (ecESCs). Two EMS models are established through C57B6 wild-type and CCL5 ‒/‒ mice and utilized to explore the in vivo effects of CCR5 +CD4 + T cells on ectopic lesions. Compared with CCR5 ‒CD4 + T cells, CCR5 +CD4 + T cells display a more activated and cytotoxic phenotype. Diminished CCR5 +CD4 + T cells and their impaired ability to produce IFN-γ are observed in the ectopic lesions of EMS patients and in murine EMS models. Impaired production of CCL5 has been detected in human ecESCs. Moreover, endometria stripped from CCL5 ‒/‒ mice are more likely to generate ectopic lesions in the peritoneum of recipient mice. These findings demonstrate that the attenuated recruitment of CCR5 + CD4 + T cells in ectopic lesions caused by decreased production of CCL5 in ecESCs may facilitate the progression of EMS.

Diagnostic Potential of Cytokine Biomarkers in Endometriosis: Challenges and Insights

Endometriosis is a common gynecological condition affecting approximately 10% of women of reproductive age, characterized by the abnormal presence of endometrial-like tissue outside the uterus. Although endometriosis was first described over 300 years ago, its underlying mechanisms remain poorly understood, and accurate, prompt diagnosis continues to be challenging. Currently, there is a lack of effective, non-invasive diagnostic methods, and available treatments often come with significant side effects and high recurrence rates. This has spurred interest in investigating the role of pro- and anti-inflammatory molecules, particularly cytokines, in endometriosis, as these molecules play a key role in its progression by influencing cell growth and differentiation. Previous studies suggest that various cytokines could serve as potential biomarkers for diagnosing endometriosis, as they are detectable in both serum and peritoneal fluid. This review provides an overview of the expression, origin, function, and regulation of specific cytokines in endometriosis, along with a brief discussion on their potential clinical implications for diagnosis. Due to the complexity of endometriosis, a panel of multiple biomarkers may ultimately be necessary for accurate diagnosis. It is essential to consider factors such as patient selection, sample collection, and analytical variability when initiating or evaluating biomarker studies.

The impact of persistent organic pollutants on fertility: exposure to the environmental toxicant 2,3,7,8-tetrachlorodibenzo-p-dioxin alters reproductive tract immune responses

Exposure to environmental contaminants can result in profound effects on the host immune system. One class of environmental toxicants, known as dioxins, are persistent environmental contaminants termed "forever chemicals". The archetype toxicant from this group of chemicals is 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin (TCDD), an immunotoxicant that activates the aryl-hydrocarbon receptor pathway leading to a variety of changes in immune cell responses. Immune cell functions are crucial to the development and maintenance of healthy reproduction. Immune cells facilitate tolerance between at the maternal-fetal interface between the parent and the semi-allogenic fetus and help defend the gravid reproductive tract from infectious assault. Epidemiological studies reveal that exposure to environmental contaminants (such as TCDD) are linked to adverse reproductive health outcomes including endometriosis, placental inflammation, and preterm birth. However, little is known about the molecular mechanisms that underpin how environmental toxicant exposures impact immune functions at the maternal-fetal interface or within the reproductive tract in general. This review presents the most recent published work that studies interactions between dioxin or TCDD exposure, the host immune system, and reproduction.

Impaired IL-27 signaling aggravates macrophage senescence and sensitizes premature ovarian insufficiency induction by high-fat diet

Premature ovarian insufficiency (POI) critically affects female reproductive health, with obesity being a significant and recognized risk factor. Interleukin-27 (IL-27), known for its role in immune modulation and inflammation, has garnered attention in metabolic syndrome research. Nonetheless, the role of these immunometabolic factors on the initiation of POI remains to be unraveled. Our investigation delves into the influence of impaired IL-27 signaling on POI induction, particularly under the challenge of a high-fat diet (HFD). We analyzed patients' serum profiles and established a correlation of increased serum triglycerides with decreased IL-27 levels in POI cases. Experiments on C57BL/6 mice lacking the IL-27 receptor alpha (Il27ra-/-) revealed that when subjected to HFD, these mice developed hallmark POI symptoms. This includes escalated lipid deposition in both liver and ovarian tissues, increased ovarian macrophages cellular aging, and diminished follicle count, all pointing to compromised ovarian function. These findings unveil a novel pathway wherein impaired IL-27 signaling potentiates the onset of POI in the presence of HFD. Understanding the intricate interplay between IL-27, metabolic alterations, and immune dysregulation sheds light on potential therapeutic avenues for managing POI, offering hope for improved reproductive health outcomes.

Emerging Roles of IL-27 in Trophoblast Cells and Pregnancy Complications

PROBLEM

Pregnancy complications such as spontaneous abortion, preeclampsia, and preterm birth persist, despite current interventions aimed at their prevention and treatment largely proving unsuccessful. Interleukin-27 (IL-27), composed of p28 and EBI3 subunits, binds to IL-27R, which consists of gp130 and IL-27Rα (also known as WSX-1 or TCCR), and plays a pivotal role in tumor development and inflammation regulation. At the maternal-fetal interface, IL-27 expression has been detected in trophoblasts, endometrial stromal cells, and decidual cells. Abnormal levels of IL-27/IL-27R have been linked to adverse pregnancy outcomes, including spontaneous miscarriage, preeclampsia, and preterm birth. This review aims to explore the expression of IL-27 at the maternal-fetal interface and its signaling pathway, uncovering the complex role of IL-27 in pregnancy complications.

METHOD OF STUDY

A comprehensive literature review was conducted using PubMed/Medline, Scopus, and Embase databases, analyzing studies on IL-27 expression and its signaling pathways at the maternal-fetal interface. The review focused on identifying the presence of IL-27 in various cell types and linking abnormal IL-27/IL-27R expression to pregnancy complications such as spontaneous miscarriage, preeclampsia, and preterm birth.

DISCUSSION AND CONCLUSION

IL-27 plays a complex role at the maternal-fetal interface, with abnormal expression linked to several pregnancy complications. These findings highlight the need for further research to elucidate IL-27's mechanisms and develop targeted interventions. Future studies should aim to develop targeted interventions and improve therapeutic strategies for managing pregnancy complications.

The interplay between systemic inflammatory factors and endometriosis: A bidirectional mendelian randomization study

OBJECTIVE

To utilize vast genetic data to reveal the interplay between 41 systemic inflammatory factors and endometriosis.

DESIGN

Bidirectional Mendelian randomization study.

MAINS OUTCOME MEASURES

This study obtained believable genetic instrumental variables for systemic inflammatory factors. The effect of systemic inflammatory factors on different endometriosis phenotypes, and the effect of endometriosis on the concentrations of systemic inflammatory factors were investigated.

RESULTS

In this mendelian randomization study, we found 20 causal relationships involving 18 systemic inflammatory factors and it was shown that Monocyte chemotactic protein-1, Macrophage inflammatory protein-1a, Granulocyte colony-stimulating factor, Macrophage migration inhibitory factor, Interleukin-4, Interleukin-5, Interleukin-8, Interleukin-9, Interleukin-12p70, Interleukin-16, and Interleukin-17 may be the upstream causes of endometriosis (P<0.05). Additionally, if the definition of exposure in the mendelian randomization was endometriosis, it could suggestively cause an increase in Eotaxin, cutaneous T-cell attracting chemokine, and Interferon gamma-induced protein 10 levels, and a decrease in growth-regulated oncogene-alpha, Interleukin-2 receptor, alpha subunit, platelet-derived growth factor BB, and Interleukin-18 (P<0.05). Reverse causality was not observed between a single systemic inflammatory factor and endometriosis.

CONCLUSIONS

Our findings indicate that several systemic inflammatory factors may act as the initiator at the onset of endometriosis. Additionally, several other inflammatory factors are far more probable to involved downstream during disease development.

IL-27/Blimp-1 axis regulates the differentiation and function of Tim-3+ Tregs during early pregnancy

Decidual regulatory T cells (Tregs) are essential for successful pregnancy outcome. A subset of Tregs, T cell immunoglobulin and mucin domain-containing protein 3-positive regulatory T cells (TregsTim-3+), plays a central role in the acceptance of the fetus during early stages of normal pregnancy. The molecular mechanism regulating the differentiation and function of TregsTim-3+ is unknown. Here, we investigated the role of the transcription factor B lymphocyte-induced maturation protein 1 (Blimp-1) on decidual TregTim-3+ differentiation. We demonstrated that Blimp-1 enhanced the coexpression of negative costimulatory molecules (Tim-3, T cell immunoreceptor with Ig and ITIM domains, and programmed cell death protein 1) on Tregs and improved their immunosuppressive functions, including increased IL-10 secretion, suppression of effector T cell proliferation, and promotion of macrophage polarization toward the M2 phenotype. Furthermore, we showed that IL-27 regulated the expression of Tim-3 and Blimp-1 through the STAT1 signaling pathway and that transfer of TregsBlimp-1+ into an abortion-prone mouse model effectively reduced embryo absorption rate. We postulated that abnormalities in the IL-27/Blimp-1 axis might be associated with recurrent pregnancy loss (RPL). These findings provided insights for developing more efficient immunotherapies for women with RPL.

The dysfunction of CD8+ T cells triggered by endometriotic stromal cells promotes the immune survival of endometriosis

Endometriosis is defined as an oestrogen-dependent and inflammatory gynaecological disease of which the pathogenesis remains unclear. This study aimed to investigate the cellular heterogeneity and reveal the effect of CD8+ T cells on the progress of endometriosis. Three ovarian endometriosis patients were collected, and single-cell RNA sequencing (scRNA-seq) progressed and delineated the cellular landscape of endometriosis containing five cell clusters. The endometrial cells (EMCs) were the major component, of which the mesenchymal cells were preponderant and characterized with increased inflammation and oestrogen synthesis in endometriosis. The proportion of T cells, mainly CD8+ T cells rather than CD4+, was reduced in endometriotic lesions, and the cytokines and cytotoxicity of ectopic T cells were depressed. CD8+ T cells depressed the proliferation of ESCs through inhibiting CDK1/CCNB1 pathway to arrest the cell cycle and triggered inflammation through activating STAT1 pathway. Correspondingly, the coculture with ESCs resulted in the dysfunction of CD8+ T cells through upregulating STAT1/PDCD1 pathway and glycolysis-promoted metabolism reprogramming. The endometriotic lesions were larger in nude mouse models with T-cell deficiency than the normal mouse models. The inhibition of T cells via CD90.2 or CD8A antibody increased the endometriotic lesions in mouse models, and the supplement of T cells to nude mouse models diminished the lesion sizes. In conclusion, this study revealed the global cellular variation of endometriosis among which the cellular count and physiology of EMCs and T cells were significantly changed. The depressed cytotoxicity and aberrant metabolism of CD8+ T cells were induced by ESCs with the activation of STAT1/PDCD1 pathway resulting in immune survival to promote endometriosis.

Endometriosis, Pain, and Related Psychological Disorders: Unveiling the Interplay among the Microbiome, Inflammation, and Oxidative Stress as a Common Thread

Endometriosis (EM), a chronic condition in endometrial tissue outside the uterus, affects around 10% of reproductive-age women, significantly affecting fertility. Its prevalence remains elusive due to the surgical confirmation needed for diagnosis. Manifesting with a range of symptoms, including dysmenorrhea, dyschezia, dysuria, dyspareunia, fatigue, and gastrointestinal discomfort, EM significantly impairs quality of life due to severe chronic pelvic pain (CPP). Psychological manifestations, notably depression and anxiety, frequently accompany the physical symptoms, with CPP serving as a key mediator. Pain stems from endometrial lesions, involving oxidative stress, neuroinflammation, angiogenesis, and sensitization processes. Microbial dysbiosis appears to be crucial in the inflammatory mechanisms underlying EM and associated CPP, as well as psychological symptoms. In this scenario, dietary interventions and nutritional supplements could help manage EM symptoms by targeting inflammation, oxidative stress, and the microbiome. Our manuscript starts by delving into the complex relationship between EM pain and psychological comorbidities. It subsequently addresses the emerging roles of the microbiome, inflammation, and oxidative stress as common links among these abovementioned conditions. Furthermore, the review explores how dietary and nutritional interventions may influence the composition and function of the microbiome, reduce inflammation and oxidative stress, alleviate pain, and potentially affect EM-associated psychological disorders.

The IL-33-ST2 axis plays a vital role in endometriosis via promoting epithelial-mesenchymal transition by phosphorylating β-catenin

OBJECTIVES

Interleukin 33 (IL-33) is a crucial inflammatory factor that functions as an alarm signal in endometriosis (EMs). Epithelial-mesenchymal transition (EMT), a process related to inflammatory signals, intracellular reactive oxygen species (ROS) production, and lipid peroxidation, have been proposed as potential mechanisms that contribute to the development and progression of EMs. IL-33 is highly upregulated in the ectopic milieu. Moreover, ectopic endometrial cells constitutively express interleukin-33 receptor ST2 (IL-33R). However, the role of IL-33/ST2 in the EMT of EMs remains largely unknown. In this study, we aimed to mechanistically determine the role of IL-33/ST2 in EMs-associated fibrosis.

MATERIALS AND METHODS

We established a non-lethal oxidative stress model to explore the conditions that trigger IL-33 induction. We performed α-smooth muscle actin (α-SMA) protein detection, cell counting kit-8 (CCK-8) assays, and scratch assays to analyze the impact of IL-33 on primary endometrial stromal cells (ESCs) proliferation and invasion. Clinical samples from patients with or without EMs were subjected to immunohistochemical (IHC) and and immunofluorescence(IF) staining to assess the clinical relevance of IL-33 receptor ST2 and EMT-related proteins. Furthermore, we used the ectopic human endometrial epithelial cell line 12Z and normal human epithelial cell line EEC to evaluate the effects of IL-33 on Wnt/β-catenin signaling. The effect of IL-33 on EMT-associated fibrosis was validated in vivo by intraperitoneal injections of IL-33 and antiST2.

RESULTS

We observed that ectopic milieu, characterized by ROS, TGF-β1, and high level of estrogen, triggers the secretion of IL-33 from ectopic ESCs. Ectopic endometrial lesions exhibited higher level of fibrotic characteristics and ST2 expression than that in the normal endometrium. Exogenous recombinant human (rhIL-33) enhanced ESC migration and survival. Similarly, 12Z cells displayed a higher degree of EMT characteristics with elevated expression of CCN4 and Fra-1, downstream target genes of the WNT/β-catenin pathway, than that observed in EECs. Conversely, blocking IL-33 with neutralizing antibodies, knocking down ST2 or β-catenin with siRNA, and β-catenin dephosphorylation abolished its effects on EMT promotion. In vivo validation demonstrated that IL-33 significantly promotes EMs-related fibrosis through the activation of Wnt/β-catenin signaling.

CONCLUSION

Our data strongly support the vital role of the IL-33/ST2 pathway in EMs-associated fibrosis and emphasize the importance of the EMT in the pathophysiology of fibrosis. Targeting the IL-33/ST2/Wnt/β-catenin axis may hold promise as a feasible therapeutic approach for controlling fibrosis in EMs.

The mysterious association between adiponectin and endometriosis

Adiponectin is a pleiotropic cytokine predominantly derived from adipose tissue. In addition to its role in regulating energy metabolism, adiponectin may also be related to estrogen-dependent diseases, and many studies have confirmed its involvement in mediating diverse biological processes, including apoptosis, autophagy, inflammation, angiogenesis, and fibrosis, all of which are related to the pathogenesis of endometriosis. Although many researchers have reported low levels of adiponectin in patients with endometriosis and suggested that it may serve as a protective factor against the development of the disease. Therefore, the purpose of this review was to provide an up-to-date summary of the roles of adiponectin and its downstream cytokines and signaling pathways in the aforementioned biological processes. Further systematic studies on the molecular and cellular mechanisms of action of adiponectin may provide novel insights into the pathophysiology of endometriosis as well as potential therapeutic targets.

Interleukin 27, like interferons, activates JAK-STAT signaling and promotes pro-inflammatory and antiviral states that interfere with dengue and chikungunya viruses replication in human macrophages

Interferons (IFNs) are a family of cytokines that activate the JAK-STAT signaling pathway to induce an antiviral state in cells. Interleukin 27 (IL-27) is a member of the IL-6 and/or IL-12 family that elicits both pro- and anti-inflammatory responses. Recent studies have reported that IL-27 also induces a robust antiviral response against diverse viruses, both in vitro and in vivo, suggesting that IFNs and IL-27 share many similarities at the functional level. However, it is still unknown how similar or different IFN- and IL-27-dependent signaling pathways are. To address this question, we conducted a comparative analysis of the transcriptomic profiles of human monocyte-derived macrophages (MDMs) exposed to IL-27 and those exposed to recombinant human IFN-α, IFN-γ, and IFN-λ. We utilized bioinformatics approaches to identify common differentially expressed genes between the different transcriptomes. To verify the accuracy of this approach, we used RT-qPCR, ELISA, flow cytometry, and microarrays data. We found that IFNs and IL-27 induce transcriptional changes in several genes, including those involved in JAK-STAT signaling, and induce shared pro-inflammatory and antiviral pathways in MDMs, leading to the common and unique expression of inflammatory factors and IFN-stimulated genes (ISGs)Importantly, the ability of IL-27 to induce those responses is independent of IFN induction and cellular lineage. Additionally, functional analysis demonstrated that like IFNs, IL-27-mediated response reduced chikungunya and dengue viruses replication in MDMs. In summary, IL-27 exhibits properties similar to those of all three types of human IFN, including the ability to stimulate a protective antiviral response. Given this similarity, we propose that IL-27 could be classified as a distinct type of IFN, possibly categorized as IFN-pi (IFN-π), the type V IFN (IFN-V).

Immune pathway through endometriosis to ovarian cancer

Endometriosis is an estrogen-dependent inflammatory disease, defined by the presence of functional endometrial tissue outside of the uterine cavity. This disease is one of the main gynecological diseases, affecting around 10%-15% women and girls of reproductive age, being a common gynecologic disorder. Although endometriosis is a benign disease, it shares several characteristics with invasive cancer. Studies support that it has been linked with an increased chance of developing endometrial ovarian cancer, representing an earlier stage of neoplastic processes. This is particularly true for women with clear cell carcinoma, low-grade serous carcinoma and endometrioid. However, the carcinogenic pathways between both pathologies remain poorly understood. Current studies suggest a connection between endometriosis and endometriosis-associated ovarian cancers (EAOCs) via pathways associated with oxidative stress, inflammation, and hyperestrogenism. This article aims to review current data on the molecular events linked to the development of EAOCs from endometriosis, specifically focusing on the complex relationship between the immune response to endometriosis and cancer, including the molecular mechanisms and their ramifications. Examining recent developments in immunotherapy and their potential to boost the effectiveness of future treatments.

Blood lipids mediate the effects of gut microbiome on endometriosis: a mendelian randomization study

BACKGROUND

There is evidence for an association between the gut microbiome and endometriosis. However, their causal relationship and the mediating role of lipid metabolism remain unclear.

METHODS

Using genome-wide association study (GWAS) data, we conducted a bidirectional Mendelian randomization (MR) analysis to investigate the causal relationships between gut microbiome and endometriosis. The inverse variance weighted (IVW) method was used as the primary model, with other MR models used for comparison. Sensitivity analysis based on different statistical assumptions was used to evaluate whether the results were robust. A two-step MR analysis was further conducted to explore the mediating effects of lipids, by integrating univariable MR and the multivariate MR method based on the Bayesian model averaging method (MR-BMA).

RESULTS

We identified four possible intestinal bacteria genera associated with the risk of endometriosis through the IVW method, including Eubacterium ruminantium group (odds ratio [OR] = 0.881, 95% CI: 0.795-0.976, P = 0.015), Anaerotruncus (OR = 1.252, 95% CI: 1.028-1.525, P = 0.025), Olsenella (OR = 1.110, 95% CI: 1.007-1.223, P = 0.036), and Oscillospira (OR = 1.215, 95% CI: 1.014-1.456, P = 0.035). The further two-step MR analysis identified that the effect of Olsenella on endometriosis was mediated by triglycerides (proportion mediated: 3.3%; 95% CI = 1.5-5.1%).

CONCLUSION

This MR study found evidence for specific gut microbiomes associated with the risk of endometriosis, which might partially be mediated by triglycerides.

Soluble MICA in endometriosis pathophysiology: Impairs NK cell degranulation and effector functions

PROBLEM

Endometriosis exhibits several immune dysfunctions, including deficient natural killer (NK) cell cytotoxicity. MICA (MHC class I chain-related molecule A) is induced by biological stress and soluble MICA (sMICA) negatively modulates the expression of the activating receptor, NKG2D, reducing NK cells activities. We investigated the involvement of soluble MICA in NK cell-deficient activity in endometriosis.

METHODS OF STUDY

sMICA levels (serum and peritoneal fluid-PF) were evaluated by ELISA. Circulating NK cell subsets quantification and its NKG2D receptor expression, NK cell cytotoxicity and CD107a, IFN-γ and IL-10 expressions by NK cells stimulated with K562 cells were determined by flow cytometry.

RESULTS

We found higher sMICA levels (serum and PF) in endometriosis, especially in advanced and deep endometriosis. Endometriosis presented lower percentages of CD56dim CD16+ cytotoxic cells and impaired NK cell responses upon stimulation, resulting in lower CD107a and IFN-γ expressions, and deficient NK cell cytotoxicity. NK cell stimulation in the MICA-blocked condition (mimicking the effect of sMICA) showed decreased cytotoxicity in initial endometriosis stages and the emergence of a negative correlation between CD107a expression and sMICA levels.

CONCLUSIONS

We suggest that soluble MICA is a potential player in endometriosis pathophysiology with involvement in disease progression and severity, contributing to NK cell impaired IFN-γ response and degranulation. NK cell compartment exhibits multiple perturbations, including quantitative deficiency and impaired cytotoxicity, contributing to inadequate elimination of ectopic endometrial tissue.

The dynamic shifts of IL-10-producing Th17 and IL-17-producing Treg in health and disease: a crosstalk between ancient "Yin-Yang" theory and modern immunology

The changes in T regulatory cell (Treg) and T helper cell (Th) 17 ratios holds paramount importance in ensuring internal homeostasis and disease progression. Recently, novel subsets of Treg and Th17, namely IL-17-producing Treg and IL-10-producing Th17 have been identified. IL-17-producing Treg and IL-10-producing Th17 are widely considered as the intermediates during Treg/Th17 transformation. These "bi-functional" cells exhibit plasticity and have been demonstrated with important roles in multiple physiological functions and disease processes. Yin and Yang represent opposing aspects of phenomena according to the ancient Chinese philosophy "Yin-Yang" theory. Furthermore, Yin can transform into Yang, and vice versa, under specific conditions. This theory has been widely used to describe the contrasting functions of immune cells and molecules. Therefore, immune-activating populations (Th17, M1 macrophage, etc.) and immune overreaction (inflammation, autoimmunity) can be considered Yang, while immunosuppressive populations (Treg, M2 macrophage, etc.) and immunosuppression (tumor, immunodeficiency) can be considered Yin. However, another important connotation of "Yin-Yang" theory, the conversion between Yin and Yang, has been rarely documented in immune studies. The discovery of IL-17-producing Treg and IL-10-producing Th17 enriches the meaning of "Yin-Yang" theory and further promotes the relationship between ancient "Yin-Yang" theory and modern immunology. Besides, illustrating the functions of IL-17-producing Treg and IL-10-producing Th17 and mechanisms governing their differentiation provides valuable insights into the mechanisms underlying the dynamically changing statement of immune statement in health and diseases.

Immunosuppressive tumor microenvironment and uterine fibroids: Role in collagen synthesis

Uterine fibroids (UF), also called uterine leiomyoma, is one of the most prevalent uterine tumors. UF represents a serious women's health global problem with a significant physical, emotional, and socioeconomic impact. Risk factors for UF include racial disparities, age, race, hormonal factors, obesity, and lifestyle (diet, physical activity, and stress. There are several biological contributors to UF pathogenesis such as cellular proliferation, angiogenesis, and extracellular matrix (ECM) accumulation. This review addresses tumor immune microenvironment as a novel mediator of ECM deposition. Polarization of immune microenvironment towards the immunosuppressive phenotype has been associated with ECM deposition. Immunosuppressive cells include M2 macrophage, myeloid-derived suppressor cells (MDSCs), and Th17 cells, and their secretomes include interleukin 4 (IL-4), IL-10, IL-13, IL-17, IL-22, arginase 1, and transforming growth factor-beta (TGF-β1). The change in the immune microenvironment not only increase tumor growth but also aids in collagen synthesis and ECM disposition, which is one of the main hallmarks of UF pathogenesis. This review invites further investigations on the change in the UF immune microenvironment as well as a novel targeting approach instead of the traditional UF hormonal and supportive treatment.

Extracellular succinate derived from ectopic milieu drives adhesion and implantation growth of ectopic endometrial stromal cells via the SUCNR1 signal in endometriosis

BACKGROUND

As a dual-function metabolite, succinate has emerged in cell function and plays a key signaling role in linking mitochondrial function to other cellular functions. Succinate accumulation in the cytoplasm is commonly associated with hypoxia in the microenvironment and immune cell activation. Extracellular succinate released into the microenvironment is considered an inflammatory alarm that can be sensed by its membrane receptor SUCNR1, which boosts proinflammatory responses and acts akin to classical hormones and cytokines. Succinate plays an important role in the development of inflammatory diseases. Whether succinate facilitates the progression of endometriosis (EMs), characterized by chronic inflammation and peritoneal adhesion, is worth exploring.

OBJECTIVE

We mimicked the ectopic milieu in vitro and in vivo to evaluate the main source and potential role of succinate in endometriosis. We assessed the molecular and functional effects of succinate on macrophages and peritoneal mesothelial cells in peritoneal cavity. The effect of succinate/SUCNR1 signaling on ectopic endometrial stromal cells (ESCs) was further explored in this study.

METHODS

In this study, we used targeted organic acid metabolomics analysis and in vitro assays to assess the potential accumulation of succinate in the peritoneal fluid of EMs patients. We examined its correlation with disease severity, Visual Analogue Scale, and the Endometriosis Fertility Index. Flow cytometry, enzyme linked immunosorbent assay, western blot assay, quantitative real-time PCR, and other molecular biology techniques were used to explore the potential mechanisms.

RESULTS

By mimicking the ectopic milieu, we constructed an in vitro co-culture system and found that M1 polarized macrophages and that the peritoneal mesothelial cell line (HMrSV5) mainly released succinate into their microenvironment and activated the succinate receptor (SUCNR1) signal, which further polarized the macrophages and significantly enhanced the invasive survival of ESCs, and the adhesion to the peritoneum. We further investigated the pathological effects of extracellular succinate in vivo using a xenograft mouse models of endometriosis.

CONCLUSIONS

Succinate-SUCNR1 signaling facilitates the creation of inflammatory cells and plays a vital role in EMs progression and peritoneal adhesion. Our work on the molecular mechanisms underlying succinate accumulation and function will help elucidate the phenotypic mysteries of pain and infertility in EMs. Video Abstract.

Unraveling immunotherapeutic targets for endometriosis: a transcriptomic and single-cell analysis

Background

Endometriosis (EMs), a common gynecological disorder, adversely affects the quality of life of females. The pathogenesis of EMs has not been elucidated and the diagnostic methods for EMs have limitations. This study aimed to identify potential molecular biomarkers for the diagnosis and treatment of EMs.

Methods

Differential gene expression (DEG) and functional enrichment analyses were performed using the R language. WGCNA, Random Forest, SVM-REF and LASSO methods were used to identify core immune genes. The CIBERSORT algorithm was then used to analyse the differences in immune cell infiltration and to explore the correlation between immune cells and core genes. In addition, the extent of immune cell infiltration and the expression of immune core genes were investigated using single-cell RNA (scRNA) sequencing data. Finally, we performed molecular docking of three core genes with dienogest and goserelin to screen for potential drug targets.

Results

DEGs enriched in immune response, angiogenesis and estrogen processes. CXCL12, ROBO3 and SCG2 were identified as core immune genes. RT-PCR confirmed that the expression of CXCL12 and SCG2 was significantly upregulated in 12Z cells compared to hESCs cells. ROC curves showed high diagnostic value for these genes. Abnormal immune cell distribution, particularly increased macrophages, was observed in endometriosis. CXCL12, ROBO3 and SCG2 correlated with immune cell levels. Molecular docking suggested their potential as drug targets.

Conclusion

This study investigated the correlation between EMs and the immune system and identified potential immune-related biomarkers. These findings provided valuable insights for developing clinically relevant diagnostic and therapeutic strategies for EMs.

Synergy between Th1 and Th2 responses during endometriosis: A review of current understanding

Endometriosis is widely perceived as an estrogen-dependent chronic disorder with infertility and pelvic pain. Although the etiology of endometriosis has remained elusive, many studies have proclaimed the relevance of immune system disorders with endometriosis. With the discovery that the dysregulation of multiple biological functions in endometriosis is caused by the aberrant differentiation of T helper cells, a shift towards Th2 immune response may account for the disease progression. This review attempts to present mechanisms of cytokines, chemokines, signal pathways, transcription factors and some other factors related with the derivation of Th1/Th2 immune response involved in the development of endometriosis. The current understanding of treatment approaches and potential therapeutic targets will also be outlined with brief discussion.

How Do Microorganisms Influence the Development of Endometriosis? Participation of Genital, Intestinal and Oral Microbiota in Metabolic Regulation and Immunopathogenesis of Endometriosis

Microorganisms inhabiting the human body play an extremely key role in its proper functioning, as well as in the development of the immune system, which, by maintaining the immune balance, allows you to enjoy health. Dysbiosis of the intestinal microbiota, or in the oral cavity or reproductive tract, understood as a change in the number and diversity of all microorganisms inhabiting them, may correlate with the development of many diseases, including endometriosis, as researchers have emphasized. Endometriosis is an inflammatory, estrogen-dependent gynecological condition defined by the growth of endometrial cells outside the uterine cavity. Deregulation of immune homeostasis resulting from microbiological disorders may generate chronic inflammation, thus creating an environment conducive to the increased adhesion and angiogenesis involved in the development of endometriosis. In addition, research in recent years has implicated bacterial contamination and immune activation, reduced gastrointestinal function by cytokines, altered estrogen metabolism and signaling, and abnormal progenitor and stem cell homeostasis, in the pathogenesis of endometriosis. The aim of this review was to present the influence of intestinal, oral and genital microbiota dysbiosis in the metabolic regulation and immunopathogenesis of endometriosis.

Distinct subtypes of endometriosis identified based on stromal-immune microenvironment and gene expression: implications for hormone therapy

Background

Endometriosis (EMs) is a chronic inflammatory condition that is highly heterogeneous. Current clinical staging fails to accurately predict drug responses and prognosis. In this study, we aimed to reveal the heterogeneity of ectopic lesions and investigate the possible underlying mechanisms using transcriptomic data and clinical information.

Methods

The EMs microarray dataset GSE141549 was obtained from the Gene Expression Omnibus database. Unsupervised hierarchical clustering was performed to identify EMs subtypes, which was followed by the functional enrichment analysis and estimation of immune infiltrates. Subtype-associated gene signatures were identified and further validated in other independent datasets, including GSE25628, E-MTAB-694, and GSE23339. Additionally, tissue microarrays (TMAs) were generated from premenopausal patients with EMs to investigate the potential clinical implications of the two identified subtypes.

Results

The unsupervised clustering analysis revealed that ectopic EMs lesions can be classified into two distinct subtypes: stroma-enriched (S1) and immune-enriched (S2). The functional analysis revealed that S1 correlated with fibroblast activation and extracellular matrix remodeling in the ectopic milieu, whereas S2 was characterized by the upregulation of immune pathways and a higher positive correlation with the immunotherapy response. Moreover, we identified a subtype signature composed of FHL1 and SORBS1, and constructed a subtype diagnostic model. Based on the cohort data from the TMAs, we found that S2 was strongly associated with the failure of/intolerance to hormone therapy.

Conclusions

This study identified two distinct subtypes that are varyingly associated with hormone resistance, stroma-immunity, and molecular features, thereby highlighting the importance of this stromal-immune heterogeneity in identifying EMs subtypes and providing novel insights into future personalized hormone-free therapy in EMs.

The multifaceted nature of IL-10: regulation, role in immunological homeostasis and its relevance to cancer, COVID-19 and post-COVID conditions

Interleukin-10 (IL-10) is a pleiotropic cytokine that has a fundamental role in modulating inflammation and in maintaining cell homeostasis. It primarily acts as an anti-inflammatory cytokine, protecting the body from an uncontrolled immune response, mostly through the Jak1/Tyk2 and STAT3 signaling pathway. On the other hand, IL-10 can also have immunostimulating functions under certain conditions. Given the pivotal role of IL-10 in immune modulation, this cytokine could have relevant implications in pathologies characterized by hyperinflammatory state, such as cancer, or infectious diseases as in the case of COVID-19 and Post-COVID-19 syndrome. Recent evidence proposed IL-10 as a predictor of severity and mortality for patients with acute or post-acute SARS-CoV-2 infection. In this context, IL-10 can act as an endogenous danger signal, released by tissues undergoing damage in an attempt to protect the organism from harmful hyperinflammation. Pharmacological strategies aimed to potentiate or restore IL-10 immunomodulatory action may represent novel promising avenues to counteract cytokine storm arising from hyperinflammation and effectively mitigate severe complications. Natural bioactive compounds, derived from terrestrial or marine photosynthetic organisms and able to increase IL-10 expression, could represent a useful prevention strategy to curb inflammation through IL-10 elevation and will be discussed here. However, the multifaceted nature of IL-10 has to be taken into account in the attempts to modulate its levels.

TH17 cell immune adaptation

At mucosal barriers, the T helper 17 (T_H17) cell population plays a fundamental role in controlling tissue homeostasis. The adaptability of this population to a more pro-inflammatory or anti-inflammatory function - that is, their functional plasticity and consequently heterogeneity - primarily depends on the environment. We would like to term this process environmental immune adaptation. Interfering with T_H17 cell adaptation leads to pathological consequences, including development of immune-mediated inflammatory diseases or even cancer. Several molecular mechanisms have been shown to participate in this process and recently, a better understanding of the transcriptional and metabolic profiling of T_H17 cells has shed light on a new level of complexity. Here, we offer a summary on the role of T_H17 cell plasticity in inflammatory diseases and cancer as well as the latest discoveries and controversies regarding the mechanisms that control the adaptability of the T_H17 cell population.

Expression of B lymphocyte-induced maturation protein 1 (Blimp-1) in keratinocyte and cytokine signalling drives human Th17 response in psoriasis

Transcriptional factor B lymphocyte-induced maturation protein 1 (Blimp-1) is pivotally implicated in T helper 17 (Th17) cell differentiation. This study investigated expression of the Blimp-1 protein, positive regulatory domain 1 (PRDM1), and cytokine genes in psoriasis (PsO). Affected (AS-PsO) and non-affected skin (nAS-PsO) samples were used to assess gene and protein expressions by reverse transcription-quantitative PCR (RT-qPCR), and immunostaining and confocal microscopy, respectively; the normalised public transcriptomic data permitted differential gene expression analyses. On RT-qPCR, PRDM1 and IL17A transcripts showed higher expression in AS-PsO than in nAS-PsO (n = 34) (p < 0.001; p < 0.0001, respectively). Confocal microscopy showed Blimp-1 protein expression in epidermal layer keratinocytes in AS-PsO, but not in nAS-PsO. Bioinformatic analysis of the transcriptomic dataset GSE13355 corroborated the increased PRDM1, signal transducer and activator of transcription 3 (STAT3), IL12B, TNF, IL17A, IL6, IL1B, IL22, and IL10 gene expression in AS-PsO, when compared to normal skin and nAS-PsO (p < 0.001). PRDM1 expression correlated positively (p < 0.0001) with that of IL17A (r = 0.7), IL1B (r = 0.67), IL12B (r = 0.6), IL6 (r = 0.59), IL22 (r = 0.53), IL23A (r = 0.47), IL21 (r = 0.47), IL27 (r = 0.34), IL23R (r = 0.32), S100 calcium binding protein A9 (r = 0.63), and lipocalin 2 (r = 0.50), and negatively with that of TGFB1 (r = - 0.28) and RORC (r = - 0.60). Blimp-1 may be critical in the pathogenesis of PsO dysregulation involving the Th17 inflammatory pathway. This knowledge may accelerate the development of new treatments.

Peritoneal immune microenvironment of endometriosis: Role and therapeutic perspectives

Endometriosis, an estrogen-dependent chronic inflammatory disease characterized by the growth of endometrium-like tissues outside the uterine cavity, affects 10% of reproductive-age women. Although the pathogenesis of endometriosis is uncertain, it is widely accepted that retrograde menstruation results in ectopic endometrial tissue implantation. Given that not all women with retrograde menstruation develop endometriosis, immune factors have been hypothesized to affect the pathogenesis of endometriosis. In this review, we demonstrate that the peritoneal immune microenvironment, including innate immunity and adaptive immunity, plays a central role in the pathogenesis of endometriosis. Current evidence supports the fact that immune cells, such as macrophages, natural killer (NK) cells, dendritic cells (DCs), neutrophils, T cells, and B cells, as well as cytokines and inflammatory mediators, contribute to the vascularization and fibrogenesis of endometriotic lesions, accelerating the implantation and development of ectopic endometrial lesions. Endocrine system dysfunction influences the immune microenvironment through overexpressed estrogen and progesterone resistance. In light of the limitations of hormonal therapy, we describe the prospects for potential diagnostic biomarkers and nonhormonal therapy based on the regulation of the immune microenvironment. Further studies are warranted to explore the available diagnostic biomarkers and immunological therapeutic strategies for endometriosis.

IL-27 deficiency inhibits proliferation and invasion of trophoblasts via the SFRP2/Wnt/β-catenin pathway in fetal growth restriction

Background: Fetal growth restriction (FGR) is characterized by restricted fetal growth and dysregulated placental development. The etiology and pathogenesis still remain elusive. IL-27 shows multiple roles in regulating various biological processes, however, how IL-27 involves in placentation in FGR pregnancy hasn't been demonstrated. Methods: The levels of IL-27 and IL-27RA in FGR and normal placentae were determined by immunohistochemistry, western blot and RT-PCR. HTR-8/SVneo cells and Il27ra-/- murine models have been adopted to evaluate the effects of IL-27 on the bio-functions of trophoblast cells. GO enrichment and GSEA analysis were performed to explore the underlying mechanism. Findings: IL-27 and IL-27RA was lowly expressed in FGR placentae and administration of IL-27 on HTR-8/SVneo could promote its proliferation, migration and invasion. Comparing with wildtypes, Il27ra-/- embryos were smaller and lighter, and the placentae from which were poorly developed. In mechanism, the molecules of canonical Wnt/β-catenin pathway (CCND1, CMYC, SOX9) were downregulated in Il27ra-/- placentae. In contrast, the expression of SFRP2 (negative regulator of Wnt) was increased. Overexpression of SFRP2 in vitro could impair trophoblast migration and invasion capacity. Interpretation: IL-27/IL-27RA negatively regulates SFRP2 to activate Wnt/β-catenin, and thus promotes migration and invasion of trophoblasts during pregnancy. However, IL-27 deficiency may contribute to the development of FGR by restricting the Wnt activity.

RNA binding protein DDX5 restricts RORγt+ Treg suppressor function to promote intestine inflammation

Retinoid-related orphan receptor (RAR) gamma (RORγt)-expressing regulatory T cells (RORγt+ Tregs) play pivotal roles in preventing T cell hyperactivation and maintaining tissue homeostasis, in part by secreting the anti-inflammation cytokine interleukin-10 (IL-10). Here, we report that hypoxia-induced factor 1α (HIF1α) is the master transcription factor for Il10 in RORγt+ Tregs. This critical anti-inflammatory pathway is negatively regulated by an RNA binding protein DEAD box helicase 5 (DDX5). As a transcriptional corepressor, DDX5 restricts the expression of HIF1α and its downstream target gene Il10 in RORγt+ Tregs. T cell-specific Ddx5 knockout (DDX5ΔT) mice have augmented RORγt+ Treg suppressor activities and are better protected from intestinal inflammation. Genetic ablation or pharmacologic inhibition of HIF1α restores enteropathy susceptibility in DDX5ΔT mice. The DDX5-HIF1α-IL-10 pathway is conserved in mice and humans. These findings reveal potential therapeutic targets for intestinal inflammatory diseases.

Association between gene polymorphisms of IL-12, IL-12 receptor and IL-27 and organ involvement in Iranian endometriosis patients

Endometriosis is an inflammatory disease characterized by the presence of ectopic endometrial tissue, immune cell dysfunction and abnormal cytokine secretion. In addition to immunological factors, genetic variations that influence endometriosis severity and cytokine expression levels play important roles in the pathogenesis of this disease. Interleukin-12 (IL-12), specifically its p40 subunit encoded by IL-12B gene and the interleukin-12 receptor β1 (IL-12Rβ2) chain of its receptor, as well as interleukin-27 (IL-27) are important in the establishment of endometriosis. So, in this study, we measured IL-12 and IL-27 serum levels and investigated the possible links between IL-12B rs3212227, IL-12Rβ2 rs3790565 and IL-27 rs153109 polymorphisms and the risk of developing endometriosis in a group of Iranian women. In this case-control study, 162 endometriosis patients and 151 healthy women were included and tested for the aforementioned polymorphisms using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique. The enzyme-linked immunosorbent assay (ELISA) method was also used to measure IL-12 and IL-27 serum levels. Although there was no statistically significant association between the genotypes and alleles of the studied polymorphisms and the development of endometriosis in general, the AA genotype of IL-12B rs3212227 showed a significant association with uterine endometriosis when compared to AC+CC genotypes (p = .04, CI = 0.270-0.988, OR = 0.517). Indeed, the AA genotype of the IL-12B rs3212227 single nucleotide polymorphism (SNP) may be linked with a lower risk of developing uterine endometriosis. There was no significant difference in IL-27 levels between the two studied groups (p = .49), and IL-12 levels were undetectable in both groups. In conclusion, the AA genotype of IL-12B rs3212227 might be associated with a decreased risk of uterine involvement in endometriosis patients.

Interleukin-27 Promotes Divergent Effects on HIV-1 Infection in Peripheral Blood Mononuclear Cells through BST-2/Tetherin

Interleukin-27 (IL-27) is able to inhibit HIV-1 replication in peripheral blood mononuclear cells (PBMCs), macrophages, and dendritic cells. Here, we identify that IL-27 can produce opposing effects on HIV-1 replication in PBMCs and that the HIV-1 restriction factor BST-2/Tetherin is involved in both inhibitory and enhancing effects on HIV-1 infection induced by IL-27. IL-27 inhibited HIV-1 replication when added to cells 2 h after infection, promoting the prototypical BST-2/Tetherin-induced virion accumulation at the cell membrane of HIV-1-infected PBMCs. BST-2/Tetherin gene expression was significantly upregulated in the IL-27-treated PBMCs, with a simultaneous increase in the number of BST-2/Tetherin⁺ cells. The silencing of BST-2/Tetherin diminished the anti-HIV-1 effect of IL-27. In contrast, IL-27 increased HIV-1 production when added to infected cells 4 days after infection. This enhancing effect was prevented by BST-2/Tetherin gene knockdown, which also permitted IL-27 to function again as an HIV-1 inhibitory factor. These contrasting roles of IL-27 were associated with the dynamic of viral production, since the IL-27-mediated enhancement of virus replication was prevented by antiretroviral treatment of infected cells, as well as by keeping cells under agitation to avoid cell-to-cell contact. Likewise, inhibition of CD11a, an integrin associated with HIV-1 cell-to-cell transmission, abrogated the IL-27 enhancement of HIV-1 production. Our findings illustrate the complexity of the HIV-1-host interactions and may impact the potential therapeutic use of IL-27 and other soluble mediators that induce BST-2/Tetherin expression for HIV-1 infection. IMPORTANCE Here, we describe new findings related to the ability of the cytokine IL-27 to regulate the growth of HIV-1 in CD4⁺ T lymphocytes. IL-27 has long been considered a potent inhibitor of HIV-1 replication, a notion based on several reports showing that this cytokine controls HIV-1 infection in peripheral blood mononuclear cells (PBMCs), monocyte-derived macrophages, and dendritic cells. However, our present results are contrary to the current knowledge that IL-27 acts only as a powerful downregulator of HIV-1 replication. We observed that IL-27 can either prevent or enhance viral growth in PBMCs, an outcome dependent on when this cytokine is added to the infected cells. We detected that the increase of HIV-1 dissemination is due to enhanced cell-to-cell transmission with the involvement of the interferon-induced HIV-1 restriction factor BST-2/Tetherin and CD11a (LFA-1), an integrin that participates in formation of virological synapse.

IL-10 is not anti-fibrotic but pro-fibrotic in endometriosis: IL-10 treatment of endometriotic stromal cells in vitro promotes myofibroblast proliferation and collagen type I protein expression

STUDY QUESTION

Is interleukin-10 (IL-10) anti-fibrotic in endometriosis?

SUMMARY ANSWER

IL-10 is not anti-fibrotic but pro-fibrotic in endometriosis, because IL-10 treatment of endometriotic stromal cells in vitro promotes myofibroblast proliferation and collagen type I protein expression.

WHAT IS KNOWN ALREADY

We previously showed that persistent activation of signal transducer and activator of transcription 3 (STAT3) via IL-6 trans-signaling promotes fibrosis of endometriosis. Studies showed marked anti-fibrotic effects of IL-10 via the STAT3 signaling pathway, which is generally considered to be anti-inflammatory, in various organs.

STUDY DESIGN, SIZE, DURATION

Endometrial and/or endometriotic samples of 54 patients who had histological evidence of deep endometriosis, and endometrial samples from 30 healthy fertile women were analyzed.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The effects of IL-10/STAT3 signaling as well as inhibition of STAT3 activation by knockdown of STAT3 gene on the pro-fibrotic phenotype in endometrial and endometriotic stromal cells in vitro were investigated. Then, the effects of various time points of IL-10 treatment in combination with transforming growth factor (TGF)-β1 and/or IL-6/soluble IL-6 receptor (sIL-6R) on the profibrotic phenotype of endometrial and endometriotic stromal cells were investigated.

MAIN RESULTS AND THE ROLE OF CHANCE

IL-10 induced pro-fibrotic phenotype (cell proliferation, collagen type I synthesis, α-smooth muscle actin positive stress fibers and collagen gel contraction) of endometriotic stromal cells. Knockdown of STAT3 gene decreased the IL-10 induced pro-fibrotic phenotype of endometriotic stromal cells. In contrast, IL-10 had no significant effects on pro-fibrotic phenotype of endometrial stromal cells of healthy women. Sequential IL-10 treatment with or without TGF-β1 and/or IL-6/sIL-6R induced persistent activation of STAT3 and significantly increased proliferation of myofibroblasts (cells with α-smooth muscle actin positive stress fibers) and protein expression of collagen type I in endometriotic stromal cells. TGF-β1 and/or IL-6/sIL6RIL-6/sIL6R treatment significantly increased tissue inhibitor of metalloproteinase 1 (TIMP1) protein expression, whereas IL-10 had no significant effects. Knockdown of STAT3 gene significantly decreased the TGF-β1 and/or IL-6/sIL6R induced TIMP1 protein expression. In contrast, pre-treatment with IL-10 before TGF-β1 and/or IL-6/sIL-6R treatment and sequential IL-10 treatment with or without TGF-β1 and/or IL-6/sIL-6R significantly decreased proliferation of fibroblasts (cells without α-smooth muscle actin positive stress fibers) and collagen type I protein expression in endometrial stromal cells of healthy women.

LARGE SCALE DATA

N/A.

LIMITATIONS, REASONS FOR CAUTION

Given the large number of complex interactions and signaling pathways of pro- and anti-inflammatory mediators that are involved in the pathophysiology of endometriosis, the present study investigated only a very small portion of the whole. Further in vivo studies are required to validate the present findings.

WIDER IMPLICATIONS OF THE FINDINGS

Inflammatory mediators in the pathophysiology of endometriosis have been extensively investigated as potential therapeutic targets. However, the present study showed that anti-inflammatory signals of IL-10 and IL-6 through persistent STAT3 activation may promote endometriosis fibrosis. Therapeutic strategies, such as suppression of 'inflammation', might dysregulate the cross-regulation of 'pro- and anti-inflammatory mediators', leading to detrimental effects in patients with endometriosis, such as fibrosis. To develop new, but not deleterious, therapeutic strategies, studies are required to investigate whether, how and what 'anti-inflammatory mediators' along with pro-inflammatory mediators are involved in individual patients with endometriosis.

STUDY FUNDING/COMPETING INTEREST(S)

This study was supported in part by KARL STORZ SE & Co. KG (Tuttlingen, Germany). The authors have no conflict of interest to disclose.

Non-invasive diagnosis of endometriosis: Immunologic and genetic markers

Endometriosis, a benign gynecologic and chronic inflammatory disease, is defined by the presence of endometrial tissue outside the uterus characterized mainly by pelvic pain and infertility. Because endometriosis affects approximately 10% of females, it represents a significant socioeconomic burden worldwide having tremendous impact on daily quality of life. Accurate and prompt diagnosis is crucial for the management of this debilitating disorder. Unfortunately, diagnosis is typically delayed to lack of specific symptoms and readily accessible biomarkers. Although histopathologic examination remains the current gold standard, this approach is highly invasive and not applicable for early screening. Recent work has focused on the identification of reliable biomarkers including immunologic, ie, immune cells, antibodies and cytokines, as well as genetic and biochemical markers, ie, microRNAs, lncRNAs, circulating and mitochondrial nucleic acids, along with some hormones, glycoproteins and signaling molecules. Confirmatory research studies are, however, needed to more fully establish these markers in the diagnosis, progression and staging of these endometrial lesions.

Myeloid-derived suppressor cells: A new emerging player in endometriosis

Endometriosis is a common gynecological disorder defined by the presence of endometrial tissue outside the uterus. This is commonly associated with chronic pelvic pain, infertility, and dysmenorrhea, which occurs in approximately 10% of women of reproductive age. Although the exact mechanism remains uncertain, it has been widely accepted to be an estrogen-dependent and inflammatory disease. Myeloid-derived suppressor cells (MDSCs) are a heterogeneous group of immune cells with immunosuppressive capacity and non-immunological functions. They have been found to be aggressively involved in the pathologies of various disorders. In regards to tumors, the functions of MDSCs have been profoundly shown to inhibit tumor immune response and to promote angiogenesis, tumor metastasis, fibrosis, and epithelial-mesenchymal transition (EMT). In recent years, the elevation of MDSCs in endometriosis was reported by several studies that provoke the assumption that MDSCs might exert similar roles to promote the development of endometriosis. Such that, precision treatments targeting MDSCs might be a promising direction for future study. Herein, we will review the research progress of MDSCs in endometriosis and its potential relevance to the pathogenesis, progression, and therapeutics strategy of endometriosis.

The N6-Methyladenosine Regulator ALKBH5 Mediated Stromal Cell-Macrophage Interaction via VEGF Signaling to Promote Recurrent Spontaneous Abortion: A Bioinformatic and In Vitro Study

Successful conception requires the synchrony of multiple systems and organs. Dysregulation of stromal cell-immune cell interactions has been proposed to be associated with recurrent spontaneous abortion. However, the mechanism of this regulation has not been well elucidated. N6-methyladenosine is one of the most common RNA modifications, and is involved in many pathological processes. Our group has demonstrated that abnormal patterns of m6A modification inhibit trophoblast invasion and contribute to adverse pregnancy outcomes. The association between m6A regulators and stromal cell-immune cell interactions is unclear. We obtained RNA-seq profiles from a GEO dataset and identified differentially expressed m6A regulators between healthy controls and patients with a recurrent spontaneous abortion history. ROC curves, functional enrichment and subclassification analysis were applied to elucidate the role of m6A regulators in pregnancy. We verified the expression of m6A regulators and constructed an overexpression cell line in a coculture system to reveal ALKBH5 function in stromal cell-macrophage interactions. We identified 11 differentially expressed m6A regulators between healthy controls and patients with a recurrent spontaneous abortion history. Then, we identified the correlation between "eraser" genes and "writer" genes. We tested the predictive abilities of the 11 m6A regulators based on another dataset and verified their expression in primary human endometrial stromal cells. We then subclassified three distinct patterns using the 11 genes and visualized genes related to immune infiltration and macrophage function in each cluster. ALKBH5 was proven to be correlated with recurrent spontaneous abortion. To verify the role of ALKBH5 in RSA, we constructed an ALKBH5-overexpression cell line. Finally, we cocultured the overexpression cell line with THP-1 cells. A decrease in M2 differentiation was observed, and this bias could be attributed to the hyposecretion of VEGF in stromal cells. N6-methyladenosine regulators play a pivotal role in stromal cell-immune cell interactions at the maternal-fetal interface. Overexpression of the m6A "eraser" gene ALKBH5 in stromal cells resulted in the hyposecretion of VEGF. Dysregulation of VEGF might impair macrophage recruitment and M2 differentiation, which could be the potential cause of recurrent spontaneous abortion.

Potential impact of COVID-19 pandemic on endometriosis

The impact of coronavirus disease 2019 (COVID-19) on endometriosis (EM) is currently unclear. Here, we aimed to describe the potential influence of COVID-19 on the pathogenesis, clinical symptoms, and treatment of EM. The cytokine storm caused by COVID-19 may induce the occurrence and progression of EM, and immunosuppression of COVID-19 may help the ectopic endometrium escape from immune clearance. Consequently, the forced social isolation and the cancelation of non-emergency medical treatment during the COVID-19 pandemic aggravate anxiety and psychological pressure, which can aggravate the symptoms related to EM and delay routine medical services.

“Iron triangle” of regulating the uterine microecology: Endometrial microbiota, immunity and endometrium

The uterus is the core place for breeding new life. The balance and imbalance of uterine microecology can directly affect or even dominate the female reproductive health. Emerging data demonstrate that endometrial microbiota, endometrium and immunity play an irreplaceable role in regulating uterine microecology, forming a dynamic iron triangle relationship. Up to nowadays, it remains unclear how the three factors affect and interact with each other, which is also a frontier topic in the emerging field of reproductive tract microecology. From this new perspective, we aim to clarify the relationship and mechanism of the interaction of these three factors, especially their pairwise interactions. Finally, the limitations and future perspectives of the current studies are summarized. In general, these three factors have a dynamic relationship of mutual dependence, promotion and restriction under the physiological or pathological conditions of uterus, among which the regulatory mechanism of microbiota and immunity plays a role of bridge. These findings can provide new insights and measures for the regulation of uterine microecology, the prevention and treatment of endometrial diseases, and the further multi-disciplinary integration between microbiology, immunology and reproductive medicine.

T helper 17 axis and endometrial macrophage disruption in menstrual effluent provides potential insights into the pathogenesis of endometriosis

OBJECTIVE

To identify immune cells, cytokines, and immune cell transcriptome in the menstrual effluent (ME) of women with endometriosis compared with that of healthy donors.

DESIGN

Live immune cells were isolated from human ME samples and were analyzed by flow cytometry to identify various immune cell populations. Selected cytokines from the same patients were evaluated using multiplex cytokine analyses. The transcriptome of the immune cell population was subsequently profiled using NanoString nCounter's PanCancer Immune panel.

SETTING

Academic institution.

PATIENT(S)

Surgically confirmed endometriosis patients (n = 14) and healthy fertile donors (n = 19).

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

In-depth immune cell profiling of ME obtained from women with endometriosis compared with that of healthy donors.

RESULT(S)

ME analysis revealed that the number of T helper 17 (T_H17) cells was significantly lower in patients with endometriosis compared with that of healthy donors; the number of macrophages was also lower (P=.06) in the former. Multiplex cytokine analysis revealed significantly lower transforming growth factor α in the ME "serum" of patients with endometriosis. Transcriptomic analysis of CD45⁺ cells revealed 47 differentially expressed genes, mainly associated with the T_H17 axis (IL10, IL23A, and IL6), as well as genes associated with macrophage signaling/activation (CD74, CD83, CXCL16, and CCL3).

CONCLUSION(S)

We demonstrate for the first time that the levels of T_H17 axis, macrophages, and transforming growth factor α were altered in the ME of women with endometriosis compared with that of healthy donors. These findings shed light on the potential immune pathways that could partly explain the pathogenesis and progression of endometriosis. Future large-scale studies on ME samples are warranted to exploit the use of these markers to study the pathogenesis of endometriosis.

CCR1 antagonist J-113863 corrects the imbalance of pro- and anti-inflammatory cytokines in a SJL/J mouse model of relapsing-remitting multiple sclerosis

Multiple sclerosis (MS), an immune-mediated and neurodegenerative disorder of the central nervous system (CNS), is characterized by infiltrating myelin-reactive T lymphocytes and demyelinating lesions. Experimental autoimmune encephalomyelitis (EAE) is a well-established animal model used to study MS. To explore the impact of chemokine receptor CCR1 blockade in EAE and the underlying mechanisms, we used CCR1 antagonist J-113863 in PLP_139-151-induced EAE in SJL/J mice. Following EAE induction, mice were treated with J-113863 (10 mg/kg) daily from day 14 until day 25. We investigated the effect of J-113863 on expression levels of GM-CSF, IL-6, IL-10, IL-27 in CD4⁺ spleen cells, using flow cytometry. We also analyzed the effect of J-113863 on GM-CSF, IL-6, IL-10, IL-27 mRNA and protein expression levels using RT-PCR and Western blot analysis in brain tissues. J-113863 treatment decreased the populations of CD4⁺GM-CSF⁺ and CD4⁺IL-6⁺ cells and increased CD4⁺IL-27⁺ and CD4⁺IL-10⁺ cells in the spleen. J-113863 had a suppressive effect on the mRNA and protein expression levels of GM-CSF, and IL-6 in the brain tissue. On the other hand, J-113863 treatment increased the mRNA and protein expression of IL-10 and IL-27 in the brain tissue. Our results highlighted J-113863's potential role in suppressing pro-inflammatory expression and up-regulating anti-inflammatory mediators, which could represent a beneficial alternative approach to MS treatment.

Emerging Roles of T Helper Cells in Non-Infectious Neuroinflammation: Savior or Sinner

CD4⁺ T cells, also known as T helper (Th) cells, contribute to the adaptive immunity both in the periphery and in the central nervous system (CNS). At least seven subsets of Th cells along with their signature cytokines have been identified nowadays. Neuroinflammation denotes the brain’s immune response to inflammatory conditions. In recent years, various CNS disorders have been related to the dysregulation of adaptive immunity, especially the process concerning Th cells and their cytokines. However, as the functions of Th cells are being discovered, it’s also found that their roles in different neuroinflammatory conditions, or even the participation of a specific Th subset in one CNS disorder may differ, and sometimes contrast. Based on those recent and contradictory evidence, the conflicting roles of Th cells in multiple sclerosis, Alzheimer’s disease, Parkinson’s disease, epilepsy, traumatic brain injury as well as some typical mental disorders will be reviewed herein. Research progress, limitations and novel approaches concerning different neuroinflammatory conditions will also be mentioned and compared.

In vitro modeling of endometriosis and endometriotic microenvironment - Challenges and recent advances

Endometriosis is a chronic condition with high prevalence in reproductive age women, defined as the growth of endometrial tissue outside the uterine cavity, most commonly on the pelvic peritoneum. The ectopic endometrial lesions exist in a unique microenvironment created by the interaction of epithelial, stromal, endothelial, glandular, and immune cell components, dominated by inflammatory, angiogenic, and endocrine signals. Current research is directed at understanding the complex microenvironment of the lesions and its relationship with different endometriosis stages, phenotypes, and disease symptoms and at the development of novel diagnostic and therapeutic concepts that minimalize the undesirable side effects of current medical management. Recreating pathophysiological cellular and molecular mechanisms and identifying clinically relevant metrics to assess drug efficacy is a great challenge for the experimental disease models. This review summarizes the complete range of available in vitro experimental systems used in endometriotic studies, which reflect the multifactorial nature of the endometriotic lesion. The article discusses the simplistic in vitro models such as primary endometrial cells and endometriotic cell lines to heterogeneous 2D co-cultures, and recently more common, 3D systems based on self-organization and controlled assembly, both in microfluidic or bioprinting methodologies. Basic research models allow studying fundamental pathological mechanisms by which menstrual endometrium adheres, invades, and establishes lesions in ectopic sites. The advanced endometriosis experimental models address the critical challenges and unsolved problems and provide an approach to drug screening and medicine discovery by mimicking the complicated behaviors of the endometriotic lesion.

IL-27 promotes decidualization via the STAT3-ESR/PGR regulatory axis

Appropriate decidualization is of great importance for embryo implantation, placental development and successful pregnancy. Although it has been well-acknowledged that decidualization relies on activation of progesterone-mediated signaling pathway, the exact mechanisms have not been elucidated. Here, we demonstrated that both IL-27 and IL27RA were highly expressed in decidua than those in endometrium during secretory phase. Estrogen plus progesterone significantly upregulated the expression of IL-27 and IL-27RA in endometrium stromal cells (ESCs). In addition, inhibiting IL-27 signaling with IL-27 neutralization antibody (anti-IL-27) suppressed the expression of decidualization-related molecules, receptors of estrogen (gene coded by ESR) and progesterone (PGR) induced by cAMP or estrogen plus progesterone. Similar results were obtained from Il27ra-/- (knockout of Il27ra) female mice. Moreover, knockout of Il27ra did not affect the estrus cycle and folliculogenesis in mice but reduced implantation rate with the impairing decidualization. Mechanistically, IL-27 upregulated the expression of ESR1, ESR2 and PGR in ESCs and DSCs, as well as the phosphorylation level of STAT3. In the presence of estrogen plus progesterone, treatment with ESCs with anti-IL-27 inhibited the activation of STAT3. Also, the expression of ESR, PGR was decreased in Il27ra-/- mice. In conclusion, these findings demonstrate that IL-27 upregulated by estrogen and progestogen promotes decidualization possibly through a STAT3-dominant pathway.

Immunopathogenesis of endometriosis: An overview of the role of innate and adaptive immune cells and their mediators

BACKGROUND

Endometriosis is a chronic inflammatory disease associated with the growth and proliferation of endometrial-like tissues outside the uterus. Although the exact etiology and mechanism of the pathogenesis of the disease have not been fully elucidated, the immune system cells and the mediators produced by them can be named as effective factors in the onset and progression of the disease.

AIMS

We aim to attempt to review studies on the role of the immune system in endometriosis to better understand the pathogenesis of endometriosis.

CONTENT

Abundant production of inflammatory mediators by neutrophils and macrophages and reduced cytotoxicity of defined cells promote endometriosis at the early stages of the disease. Following an increase in the inflammation of the environment, the body takes compensatory mechanisms to reduce inflammation and establish homeostasis. For this purpose, the body produces remodeling and anti-inflammatory factors leading to slow conversion of the inflammatory environment into a non-inflammatory environment with proliferative and immunosuppressive properties. Environmental conditions induce M2 macrophages, TH2 cells, and Tregs differentiation, promoting disease progression by producing angiogenic and immunosuppressive factors. However, the exact molecular mechanism involved in changing inflammatory to non-inflammatory conditions is not yet fully understood.

IMPLICATIONS

Due to the common characteristics of endometriotic cells and cancer cells, most potential treatment options for endometriosis have been suggested due to the results of these methods in the treatment of cancer. In this pathway, immune system cells and soluble mediators can be used as targets.

IL-17: an important pathogenic factor in endometriosis

Interleukin-17 (IL-17) is known as a Th17-cell-derived proinflammatory cytokine, which plays a pivotal role in several inflammatory and autoimmune diseases such as systemic lupus erythematosus (SLE), rheumatoid arthritis, and psoriasis. Emerging evidence has shown that IL-17 is linked to endometriosis, although the etiology of endometriosis is still unknown. The IL-17 expression is up-regulated in serum, peritoneal fluid (PF) and endometriotic lesions from patients with endometriosis but the related regulation mechanisms are complex and obscure. Meanwhile, the specific roles of IL-17 in endometriosis are also worthy of further exploration. Through the integration and summary of literature, we conclude that the secretion of IL-17 increases under the regulation of ectopic microenvironment and other factors, and then IL-17 is deeply involved in endometriosis in the regulation of immune microenvironment, the invasion and growth of ectopic lesions, and so on, which implies its therapeutic value in this disorder.

Effects of Fisetin on Allergic Contact Dermatitis via Regulating the Balance of Th17/Treg in Mice

Background. Allergic contact dermatitis (ACD) is a form of chronic cutaneous inflammatory disease of immunological origin that has adverse impacts on patient quality of life, underscoring the need for the development of safe and effective therapeutic agents to treat affected individuals. Fisetin is a Chinese herbal preparation that reportedly exhibits antitumor, antioxidant, antimicrobial, anticoagulatory, and antimalarial activity. In the current report, the immunomodulatory activity of fisetin was appraised by assessing its impact on balance between regulatory T (Treg) and Th17 cells in an ACD model. Methods. BALB/c mice ( $n=60$ ) were randomized into control, ACD model, CTX positive control (20 mg/kg), and fisetin treatment groups (three dose levels: 2, 4, or 8 mg/kg). ACD induction was achieved by sensitizing mice on the shaved ventral abdomen via the application of 5% DNFB (50 μL) on days 1 and 2, followed by rechallenge in the right ear with 5% DNFB (20 μL) on day 5. Beginning on day 1, immunized mice were intraperitoneally injected with the appropriate fisetin dose (in saline) once per day for 7 days. On day 7, ear swelling, transcription factor expression, Th17/Treg cell populations, and cytokine production were assessed in vivo. Results. Fisetin treatment significantly suppressed ear swelling and associated inflammatory cell infiltration, besides reducing the production of Th17 cytokines (IL-17, TNF-α, and IL-6) and the expression of the Th17 lineage transcription factor RORγt while simultaneously enhancing Treg-specific cytokine production (TGF-β and IL-10) and the expression of the Treg lineage transcription factor Foxp3, thereby restoring the Th17/Treg cell in ACD mice. Conclusions. These data indicate that fisetin exhibits immunomodulatory activity and can alter the Th17/Treg cell balance, highlighting its potential value as a treatment drug for ACD.

Molecular Mechanisms Driving IL-10- Producing B Cells Functions: STAT3 and c-MAF as Underestimated Central Key Regulators?

Regulatory B cells (Bregs) have been highlighted in very different pathology settings including autoimmune diseases, allergy, graft rejection, and cancer. Improving tools for the characterization of Bregs has become the main objective especially in humans. Transitional, mature B cells and plasma cells can differentiate into IL-10 producing Bregs in both mice and humans, suggesting that Bregs are not derived from unique precursors but may arise from different competent progenitors at unrestricted development stages. Moreover, in addition to IL-10 production, regulatory B cells used a broad range of suppressing mechanisms to modulate the immune response. Although Bregs have been consistently described in the literature, only a few reports described the molecular aspects that control the acquisition of the regulatory function. In this manuscript, we detailed the latest reports describing the control of IL-10, TGFβ, and GZMB production in different Breg subsets at the molecular level. We focused on the understanding of the role of the transcription factors STAT3 and c-MAF in controlling IL-10 production in murine and human B cells and how these factors may represent an important crossroad of several key drivers of the Breg response. Finally, we provided original data supporting the evidence that MAF is expressed in human IL-10- producing plasmablast and could be induced in vitro following different stimulation cocktails. At steady state, we reported that MAF is expressed in specific human B-cell tonsillar subsets including the IgD⁺ CD27⁺ unswitched population, germinal center cells and plasmablast.

CSF-1-induced DC-SIGN+ macrophages are present in the ovarian endometriosis

BACKGROUND

Researchers have found that macrophages are the predominant cells in the peritoneal fluid (PF) of endometriosis patients. CSF-1 has been found to accumulate in the lesions and PF of endometriosis patients, and CSF-1 induces THP-1-derived macrophages to polarize toward a CD169⁺ DC-SIGN⁺ phenotype. Does the cytokine CSF-1 induce monocytes to differentiate into macrophages with a DC-SIGN⁺ phenotype in endometriosis?

METHODS

The level of CSF-1 in the endometrium of control subjects, and the eutopic, and ectopic endometrium of endometriosis patients was evaluated by real-time polymerase chain reaction (qRT-PCR) and was determined by enzyme-linked immunosorbent assay (ELISA) in the PF of control and endometriosis patients. CSF-1 expression was examined with a MILLIPLEX MAP Mouse Cytokine/Chemokine Magnetic Bead Panel. DC-SIGN⁺ macrophages were detected by immunohistochemical staining of tissues and flow cytometric analysis of the PF of control subjects (N = 25) and endometriosis (N = 35) patients. The phenotypes and biological activities of CSF-1 -induced macrophages were compared in an in vitro coculture system with peripheral blood lymphocytes from control subjects.

RESULTS

In this study, we found that the proportion of DC-SIGN⁺ CD169⁺ macrophages was higher in the abdominal immune microenvironment of endometriosis patients. CSF-1 was primarily secreted from ectopic lesions and peritoneum in mice with endometriosis. In addition, CSF-1 induced the polarization of macrophages toward a DC-SIGN⁺ CD169⁺ phenotype; this effect was abolished by the addition of an anti-CSF-1R antibody. CSF-1 induced the generation of DC-SIGN⁺ macrophages, leading to a depressed status of peripheral blood lymphocytes, including a high percentage of Treg cells and a low percentage of CD8⁺ T cells. Similarly, blockade with the anti-CSF-1R antibody abrogated this biological effect.

CONCLUSIONS

This is the first study on the role of DC-SIGN⁺ macrophages in the immune microenvironment of endometriosis. Further study of the mechanism and biological activities of CSF-1-induced DC-SIGN⁺ macrophages will enhance our understanding of the physiology of endometriosis.