Expression of natural cytotoxicity receptors on peritoneal fluid natural killer cell and cytokine production by peritoneal fluid natural killer cell in women with endometriosis

Causal association of immune cells and endometriosis: a Mendelian randomization study

Objective

To investigate the causal effect of immune cells on endometriosis (EMS), we performed a Mendelian randomization analysis.

Methods

Mendelian randomization (MR) uses genetic variants as instrumental variables to investigate the causal effects of exposures on outcomes in observational data. In this study, we conducted a thorough two-sample MR analysis to investigate the causal relationship between 731 immune cells and endometriosis. We used complementary Mendelian randomization (MR) methods, including weighted median estimator (WME) and inverse variance weighted (IVW), and performed sensitivity analyses to assess the robustness of our results.

Results

Four immune phenotypes have been found to be significantly associated with the risk of developing EMS: B cell %lymphocyte (WME: OR: 1.074, p = 0.027 and IVW: OR: 1.058, p = 0.008), CD14 on Mo MDSC (WME: OR: 1.056, p =0.021 and IVW: OR: 1.047, p = 0.021), CD14+ CD16- monocyte %monocyte (WME: OR: 0.947, p = 0.024 and IVW: OR: 0.958, p = 0.011), CD25 on unsw mem (WME: OR: 1.055, p = 0.030 and IVW: OR: 1.048, p = 0.003). Sensitivity analyses confirmed the main findings, demonstrating consistency across analyses.

Conclusions

Our MR analysis provides compelling evidence for a direct causal link between immune cells and EMS, thereby advancing our understanding of the disease. It also provides new avenues and opportunities for the development of immunomodulatory therapeutic strategies in the future.

Downregulation of pattern recognition receptors on macrophages involved in aggravation of endometriosis

PROBLEM

In women of reproductive age, endometriosis may contribute to dysmenorrhea, chronic pelvic pain, dyspareunia, infertility, adenomyosis, and endometrial ovarian cyst (EOC). Recent studies have shown that chronic inflammation occurs in the pelvis of endometriosis patients and that this inflammation is exacerbated by immunosuppression, leading to survival endometrial debris. However, the detailed immunological mechanisms underlying the aggravation of inflammation and immunosuppression in endometriosis patients remain unclear.

METHOD OF STUDY

We investigate the alarmins (high-mobility group box-1, IL-33, IL-1α, and S100B protein), proinflammatory cytokines (IL-6 and IL-1β), and immune cells (CD8+ T cells, CD4+ T cells, natural killer cells, natural killer T cells, dendritic cells, and macrophages) in peritoneal fluid of patients with EOC using enzyme-linked immunosorbent assay, electrochemiluminescence, and flow cytometry. Then, we analyzed the correlation between these factors and the aggravating indicators of endometriosis, tumor size and revised American Society for Reproductive Medicine (r-ASRM) score.

RESULTS

Unexpectedly, there was no correlation between each alarmin level and aggravating indicators. However, the expression of pattern recognition receptors, toll-like receptor 4, and receptor of advanced glycation end-products on macrophages was inversely correlated with aggravating indicators.

CONCLUSIONS

The aggravation of endometriosis is associated with a decrease in alarmin receptors but not alarmin levels. Investigation of innate immune systems, such as alarmins and their receptors, may help elucidate new mechanisms of endometriosis.

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.

Co-expression of activating and inhibitory receptors on peritoneal fluid NK cells in women with endometriosis

The detailed mechanism underlying endometriosis development remains unclear; few reports have suggested the involvement of immune and genetic factors. This study aims to investigate the role of NK cells in endometriosis by analyzing the co-expression of activating (NKp46, NKG2C, and NKG2D) and inhibitory receptors (NKG2A and CD158a) on NK cells and their subsequent cytokine production in the peritoneal fluid (PF). Sixty-two patients were enrolled for this study from Hyogo Medical University between February 2018 and April 2022. Results showed that the proportions of CD56⁺/NKp46⁺, CD56^dim/NKp46^＋, NKG2C^＋/NKp46^＋, and NKG2D^＋/NKp46^＋ NK cells were significantly lower in the endometriosis group than those in the control group. Meanwhile, within the peritoneal endometriosis (n = 21) and deep infiltrating endometriosis (n = 11) groups, the co-expression of NKG2D^＋/NKp46^＋ and CD16^＋/NKp46^＋. Additionally, the abundance of IFN-γ-producing NK cells was significantly increased in the endometriosis group compared to controls, and a significant negative correlation was noted between NKp46 expression on NK cells and type 1 cytokine (IFN-γ and TNF-α) production. Taken together, the findings of this study indicate that NK cell cytotoxicity in endometriosis is reduced due to changes in NKp46 expression, as well as activating receptors co-expressed with NKp46. Consequently, NK cells do not eliminate endometrial cells in the abdominal cavity, resulting in the production of TNF-α and IFN-γ.

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.

Natural Killer Cell Receptors and Endometriosis: A Systematic Review

Endometriosis is a chronic inflammatory disorder, characterized by the presence of endometrial cells outside the uterine cavity. An increasing number of studies correlate the immune system with endometriosis, particularly NK receptors (NKR), which have been suggested to play an essential role in the pathogenesis of the disease. This systematic review aims to enlighten the role of NKR in endometriosis. A literature search was performed independently by two reviewers, to identify studies assessing the role of NKR in endometriosis. In total, 18 studies were included. Endometriosis pathogenesis seems to be marked by the overexpression of NK inhibitor receptors (KIRS), namely, CD158a+, KIR2DL1, CD94/NKG2A, PD-1, NKB1, and EB6, and inhibiting ligands such as PD-L1, HLA-E, HLA-G, and HLA-I. Concurrently, there is a decrease in NK-activating receptors and natural cytotoxicity receptors (NCRs), such as NKp46, NKp30, and NKG2D. The immune shift from NK surveillance to NK suppression is also apparent in the greater relative number of ITIM domains compared with ITAM domains in NKRs. In conclusion, NK receptor activity seems to dictate the immunocompetency of women to clear endometriotic cells from the peritoneal cavity. Future research could explore NKRs as therapeutic targets, such as that which is now well established in cancer therapy through immunotherapy.

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

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

Endometrial galectin-3 causes endometriosis by supporting eutopic endometrial cell survival and engraftment in the peritoneal cavity

PROBLEM

The pathogenesis of endometriosis remains unclear. Endometrial cells in retrograde menstruation are considered the source of endometriosis; therefore, we hypothesized that the eutopic endometrium may provide clues regarding the pathogenesis. We aimed to clarify the role of eutopic endometrial cells in endometriosis development.

METHOD OF STUDY

Eutopic endometrial tissues were obtained from patients with or without endometriosis, and expression of cell surface molecules in eutopic endometrial stromal cells (ESCs) was evaluated via iTRAQ-based proteomic analysis. Based on the results, we focused on galectin-3. Galectin-3 expression in clinical samples was confirmed by immunohistochemistry and Western blot analysis. The concentration of secreted galectin-3 was measured using enzyme-linked immunosorbent assays. Adhesion and migration of ESCs were evaluated by in vitro adhesion and wound healing assays. The cytotoxicity of natural killer cells was measured via calcein release assays. Cell proliferation was measured using the CyQUANT Cell Proliferation Assay Kit.

RESULTS

iTRAQ analysis revealed that galectin-3 expression was specifically elevated in the ESCs from endometriosis patients. Immunohistochemistry confirmed galectin-3 overexpression in the eutopic endometrium of endometriosis, irrespective of the menstrual phase. Galectin-3 was overexpressed and secreted by the eutopic ESCs from patients with endometriosis compared to that from patients without endometriosis. Galectin-3 expression in ESCs increased adhesion and migration, whereas galectin-3 inhibitors impaired these processes. Galectin-3 reduced the cytotoxicity of natural killer cells toward ESCs, while not affecting cell proliferation.

CONCLUSION

Galectin-3 promotes peritoneal engraftment of ESCs due to impaired immune surveillance in the peritoneal cavity and increases ESCs adhesion and migration to the peritoneum.

Infiltrating T lymphocytes and programmed cell death protein-1/programmed death-ligand 1 expression in endometriosis-associated ovarian cancer

OBJECTIVE

To characterize T lymphocyte infiltration and programmed cell death protein-1 (PD-1)/programmed death-ligand 1 (PD-L1) expression in early-stage endometriosis-associated ovarian cancer (EAOC), ovarian endometriosis (OE), atypical endometriosis (AE), and deep endometriosis (DE).

DESIGN

Case-control, retrospective study.

SETTING

Research University Hospital.

PATIENT(S)

A total of 362 patients with a histologic diagnosis of EAOC, OE, AE, or DE were identified between 2000 and 2019 from Fondazione Policlinico Universitario Agostino Gemelli IRCCS and Gemelli Molise SpA tissue data banks. A 1:1 propensity score-matched method yielded matched pairs of 55 subjects with EAOC, 55 patients with OE, 12 patients with AE, and 42 patients with DE, resulting in no differences in family history of cancer, parity, and use of oral contraceptives.

INTERVENTION(S)

Immunohistochemistry assays using the following primary antibodies: CD3+; CD4+; CD8+; PD-1; and PD-L1.

MAIN OUTCOME MEASURE(S)

To characterize T lymphocyte infiltration and PD-1/PD-L1 expression in 4 different endometriosis-related diseases.

RESULT(S)

Endometriosis-associated ovarian cancer cases displayed significantly higher levels of PD-1/PD-L1 expression compared with all other endometriosis-related diseases (vs. OE vs. AE vs. DE). Moreover, a significantly lower count of infiltrating T lymphocytes was observed in EAOC cases compared with OE ones. Finally, one-third of OE cases showed a cancer-like PD-1/PD-L1 expression profile.

CONCLUSION(S)

Endometriosis-associated ovarian cancer is characterized by higher levels of PD-1/PD-L1 expression compared with benign endometriosis-related diseases. This profile was found in one-third of clinically benign cases, suggesting that it develops early in the carcinogenesis process.

Effect of combined contraceptive pill on immune cell of ovarian endometriotic tissue

BACKGROUND

Dysregulation of immune response is associated with development of endometriosis. The study aim was to evaluate effect of combined oral contraceptive pills (COCs) consisting of ethinyl estradiol (EE) and desogestrel on the expression of macrophage, natural killer cells, and regulatory T cells of ovarian endometriotic cysts.

METHODS

Endometriotic cyst wall tissues were collected from women with endometriosis who were treated (n = 22) with COCs (one table per day of EE 0.03 mg and desogestrel 0.15 mg administered for 28 to 35 days before surgery) or untreated (n = 22). The tissues were collected from endometriotic cyst wall during laparoscopic or laparotomy ovarian cystectomy. Immunohistochemistry for anti-CD68, anti-CD56, and anti-forkhead-winged helix transcription factor (FoxP3), a marker for macrophages, natural killer cells, and regulatory T cells, respectively, were investigated.

RESULTS

The median (interquartile range [IQR]) number of anti-CD68 positive cells in the COC group was significantly lower than in the untreated group (12.7; 4.9-19.3) versus 45.7 (26.0-70.7), p < 0.001). Tissue infiltration of anti-CD56 positive cells in endometriotic cyst was significantly higher after the treatment when compared with tissue from untreated group (42.9, 27.4-68.9 versus 25.3 (14.1-37.3; p = 0.009). The number of regulatory T cells was also significantly increased in the COC group (6.3, 2.8-15.5) versus 0 (0-1.8; p < 0.001).

CONCLUSIONS

The effects of COC, containing EE 0.30 mg with desogestrel 0.15 mg, on the immune system was demonstrated by a significant decrease in the number of macrophages and an increase in natural killer and regulatory T cells.

Inflammation related to high-mobility group box-1 in endometrial ovarian cyst

Endometriosis is a chronic inflammatory disease often associated with dysmenorrhea, infertility, adenomyosis, and endometrial ovarian cyst (EOC). In particular, EOC can sometimes become malignant in a longitudinal follow-up. This study aimed to investigate the involvement of high-mobility group box-1 (HMGB1) in an inflammatory milieu and the characteristics of immune cells in EOC. The samples were obtained from patients who underwent ovarian cystectomy for benign ovarian cyst. The participants were divided into two groups: patients with EOC (EOC group) and those without EOC (nEOC group). We divided a part of the removed ovary into small sections and isolated the tissue cells. Thereafter, the cytoplasmic HMGB1 levels in DCs, macrophages, and non-immune cells were analyzed by flow cytometry. We also evaluated the proportions of immune, T, NK, iNKT, NK, and regulatory T (Treg) cells. Results showed that the DCs, macrophages, and non-immune cells of EOC had significantly higher cytoplasmic HMGB1 levels than those of nEOC. The expression of CD69 and CD107a on CD8⁺ T and CD4⁺ T cells of EOC was also more enhanced than that of nEOC. Furthermore, the M2 macrophages and Tregs highly accumulated in EOC. These results indicate that HMGB1 may aggravate chronic inflammation related to T-cell activation and simultaneously facilitate development of the immunosuppressive milieu in EOCs.

Harmful and beneficial effects of inflammatory response on reproduction: sterile and pathogen-associated inflammation

In reproduction, inflammatory processes play important roles in the development of many pregnancy complications such as preterm labor/birth, recurrent pregnancy loss, recurrent implantation failure, and preeclampsia. Inflammation can be initiated by both microbial and non-microbial causes. Bacterial infection in the feto-maternal interface and uterus can provoke preterm labor/birth, miscarriage, and chronic endometritis. By contrast, inflammation without infection, or 'sterile inflammation,' can also lead to many kinds of complications, such as preterm labor/birth, miscarriage, or preeclampsia. Aberrant inflammation is facilitated by immune cells such as macrophages, dendritic cells, natural killer cells, and invariant natural killer T cells. In addition, cytokines, chemokines, and several kinds of inflammatory mediators are involved. On the other hand, appropriate inflammation is required for a successful offspring during the progression of the entire pregnancy. Herein, we discuss the relation between pregnancy and inflammation with immunological alterations. Understanding the role of inflammation in complications during pregnancy may establish new perspectives of the progress of normal pregnancy as well as treatments during pregnancy complications.

Involvement of natural killer cells in the pathogenesis of endometriosis in patients with pelvic pain

Objectives

To detect the involvement of immune cells in the pathogenesis of endometriosis in patients with stable status or pelvic pain.

Methods

Blood was collected from patients with endometriosis with and without pelvic pain. Natural killer (NK) and Th17 cells were analyzed by flow cytometry, and secretion of inflammatory cytokines (tumor necrosis factor-α, interleukin (IL)-1β, IL-6, IL-7) was verified by enzyme-linked immunosorbent assay. We isolated immune cells from blood by density-gradient centrifugation to investigate the expression of functional molecules including sterile alpha motif domain-containing protein 9 (SAMD9), Ral guanine nucleotide dissociation stimulator-like 2 (RGL2), early growth response protein 1, and Akirin2. We also searched the BIOGPS database for protein expression profiles.

Results

SAMD9 and RGL2 expression levels were significantly upregulated in patients with pelvic pain. Furthermore, lysophosphatidic acid receptor 1 expression was higher in endometrial tissues from patients with pelvic pain, and was mainly localized in stromal and glandular epithelial cells in ectopic lesions.

Conclusion

NK cells play an important role in the pathogenesis of endometriosis in patients with pelvic pain. Suppressing the cytotoxic activity of NK cells may thus help to reduce the progression of pelvic pain in patients with endometriosis.

Interleukin-22 secreted by ectopic endometrial stromal cells and natural killer cells promotes the recruitment of macrophages through promoting CCL2 secretion

PROBLEM

During endometriosis, there is an increase in the number of dysfunctional macrophages; however, the mechanisms underlying macrophage recruitment are not well understood. The aim of the present study was to determine the role of natural killer (NK) cell-mediated secretion of chemokine (C-C motif) ligand 2 (CCL2) from endometrial stromal cells (ESCs) in the recruitment of macrophages.

METHOD OF STUDY

Normal ESCs (nESC) and ectopic ESCs (eESCs) were separately co-cultured with NK cells for a macrophage chemotaxis assay, and the number of chemotactic macrophages was counted. The expression of interleukin-22 (IL-22) and IL-22 receptors was detected by ELISA and flow cytometry, respectively. eESCs were treated with 0.01, 0.1, and 1 ng/mL recombinant human IL-22 (rhIL-22) to determine the most effective concentration for stimulating CCL2 production. Following treatment with 1 ng/mL rhIL-22, secretion of CCL2 was detected from both the eESC monoculture and the eESC/NK co-culture.

RESULTS

Compared with the eESC monoculture, the eESC/NK co-culture recruited a significantly higher number of chemotactic macrophages. There was also an increase in the levels of IL-22 and CCL2 secreted when eESCs were co-cultured compared with the monoculture. Treatment with rhIL-22 resulted in an increase in the levels of CCL2 secreted by eESCs, and the IL-22-induced CCL2 secretion was reversed by the IL-22 antagonist, αIL-22. Increased expression of IL-22 resulted in an increase in the number of chemotactic macrophages, but was reversed by αIL-22 and CCL2 antagonist (αCCL2).

CONCLUSION

Interleukin-22 and CCL2 secretion by eESCs stimulated by NK cells contributes to the induction of macrophage recruitment and is thus implicated in the development of endometriosis.

Expressions of natural cytotoxicity receptor, NKG2D and NKG2D ligands in endometriosis

Pathogenesis of endometriosis is still unknown, and the relationship between NK cell activating receptors and endometriosis remains to be explored. We investigated the expression of NCRs and NKG2D in NK cells in peripheral blood (PB) and peritoneal fluid (PF) as well as expression of NKG2D ligands in endometrial cells, and illuminated their relationship with ovarian endometriosis. 20 patients with ovarian endometriosis and 13 subjects for control group were recruited. Flow cytometry was used for examining expressions of NCRs and NKG2D on NK cells. In PF with endometriosis, the expressions of NKp30 (P = 0. 006) and NKG2D (P = 0. 010) on CD56⁺NK cells were decreased, whereas the expression of NKp46 (P = 0. 040) on CD16⁺NK cells was higher than that of control. Real time PCR and Western blotting were used for detecting expression of NKG2D ligands. mRNA level of NKG2D ligands on endometrial cells showed no noticeable difference. As for protein expression, the ULBP-2 expression on eutopic endometrial cells with pelvic endometriosis was lower than that on ectopic endometrial cells and eutopic endometrial cells without endometriosis (P < 0.05), and the ULBP-3 expression on ectopic endometrial cells was lower than that on eutopic endometrial cells with or without endometriosis (P < 0.05). These findings indicate that change of NKp30, NKp46 and NKG2D on NK cells in PF and ULBP-2, 3 on endometrial cells may relate to the pathogenesis of pelvic endometriosis. Especially, change of NK cell activating receptors in PF implies that pelvic endometriosis is probably due to local immune changes.

Endometriosis-associated ovarian cancer: What have we learned so far?

Endometriosis is defined as the presence of ectopic endometrial tissue outside of the uterine cavity, most commonly in the ovaries and peritoneum. It is a complex disease that is influenced by multiple factors. It is also a common gynecological disorder and affects approximately 10-15% of all women of reproductive age. Recent molecular and pathological studies indicate that endometriosis may serve as a precursor of ovarian cancer (endometriosis-associated ovarian cancer, EAOC), particularly endometrioid and clear cell ovarian cancers. Although histological and epidemiological studies have demonstrated that endometriosis has a malignant potential, the molecular mechanism that underlies the malignant transformation of endometriosis is still controversial, and the precise mechanism of carcinogenesis must be fully elucidated. Currently, the development and improvement of a new sequencing technology, next-generation sequencing (NGS), has been increasingly relevant in cancer genomics research. Recently, NGS has also been utilized in clinical oncology to advance the personalized treatment of cancer. In addition, the sensitivity, speed, and cost make NGS a highly attractive platform compared to other sequencing modalities. For this reason, NGS may lead to the identification of driver mutations and underlying pathways associated with EAOC. Here, we present an overview of the molecular pathways that have led to the current opinions on the relationship between endometriosis and ovarian cancer.

Suppression of autophagy and HCK signaling promotes PTGS2high FCGR3- NK cell differentiation triggered by ectopic endometrial stromal cells

Impaired NK cell cytotoxic activity contributes to the local dysfunctional immune environment in endometriosis (EMS), which is an estrogen-dependent gynecological disease that affects the function of ectopic endometrial tissue clearance. The reason for the impaired cytotoxic activity of NK cells in an ectopic lesion microenvironment (ELM) is largely unknown. In this study, we show that the macroautophagy/autophagy level of endometrial stromal cells (ESCs) from EMS decreased under negative regulation of estrogen. The ratio of peritoneal FCGR3^- NK to FCGR3⁺ NK cells increases as EMS progresses. Moreover, the autophagy suppression results in the downregulation of HCK (hematopoietic cellular kinase) by inactivating STAT3 (signal transducer and activator of transcription 3), as well as the increased secretion of the downstream molecules CXCL8/IL8 and IL23A by ESCs, and this increase induced the upregulation of FCGR3^- NK cells and decline of cytotoxic activity in ELM. This process is mediated through the depression of microRNA MIR1185-1-3p, which is associated with the activation of the target gene PTGS2 in NK cells. FCGR3^- NK with a phenotype of PTGS2/COX2^high IFNG^low PRF1^low GZMB^low induced by hck knockout (hck^-/-) or 3-methyladenine (3-MA, an autophagy inhibitor)-stimulated ESCs accelerates ESC's growth both in vitro and in vivo. These results suggest that the estrogen-autophagy-STAT3-HCK axis participates in the differentiation of PTGS2^high IFNG^low PRF1^low GZMB^low FCGR3^- NK cells in ELM and contributes to the development of EMS. This result provides a scientific basis for potential therapeutic strategies to treat diseases related to impaired NK cell cytotoxic activity.

ABBREVIATIONS

anti-FCGR3: anti-FCGR3 with neutralizing antibody; Ctrl-ESC: untreated ESCs; CXCL8: C-X-C motif chemokine ligand 8; ectoESC: ESCs from ectopic lesion; ELM: ectopic lesion microenvironment; EMS: endometriosis; ESCs: endometrial stromal cells; eutoESC:eutopic ESCs; HCK: hematopoietic cellular kinase; HCK(OE): overexpression of HCK; IFNG: interferon gamma; IL23A (OE): overexpression of IL23A; KLRK1: Killer cell lectin like receptor K1; MAP1LC3B/LC3B: microtubule-associated protein 1 light chain 3 beta; 3 -MA: 3-methyladenine; 3-MA-ESC: 3-MA-treated ESCs; MIR1185-1-3p⁺: overexpression of HsMIR1185-1-3p; NK: natural killer; normESCs: normal ESCs; Rap-ESC:rapamycin-treated ESCs; PCNA: proliferating cell nuclear antigen; PF: peritoneal fluid; SFKs: SRC family of cytoplasmic tyrosine kinases; si-HCK: silencing of HCK; siIL23A: silencing of IL23A; USCs: uterus stromal cells.

MDSCs drive the process of endometriosis by enhancing angiogenesis and are a new potential therapeutic target

Endometriosis affects women of reproductive age via unclear immunological mechanism(s). Myeloid-derived suppressor cells (MDSCs) are a heterogeneous group of myeloid cells with potent immunosuppressive and angiogenic properties. Here, we found MDSCs significantly increased in the peripheral blood of patients with endometriosis and in the peritoneal cavity of a mouse model of surgically induced endometriosis. Majority of MDSCs were granulocytic, produced ROS, and arginase, and suppressed T-cell proliferation. Depletion of MDSCs by antiGr-1 antibody dramatically suppressed development of endometrial lesions in mice. The chemokines CXCL1, 2, and 5 were expressed at sites of lesion while MDSCs expressed CXCR-2. These CXC-chemokines promoted MDSC migration toward endometriotic implants both in vitro and in vivo. Also, CXCR2-deficient mice show significantly decreased MDSC induction, endometrial lesions, and angiogenesis. Importantly, adoptive transfer of MDSCs into CXCR2-KO mice restored endometriotic growth and angiogenesis. Together, this study demonstrates that MDSCs play a role in the pathogenesis of endometriosis and identifies a novel CXC-chemokine and receptor for the recruitment of MDSCs, thereby providing a potential target for endometriosis treatment.

Treg and NK cells related cytokines are associated with deep rectosigmoid endometriosis and clinical symptoms related to the disease

The aim of this study was to evaluate Treg and NK cells related cytokines in deep infiltrating endometriosis lesions and its relationship with clinical symptoms of the disease. mRNA expression of Transforming Growth Factor Beta (TGFB), Interleukin (IL)10, Interferon Gamma (IFNG), IL7, and IL15 was analyzed by Real-Time PCR in eutopic endometrium and rectosigmoid lesions from 11 women with deep infiltrating endometriosis and in eutopic endometrium from 11 healthy women. IL10, IFNG, and IL7 expression was significantly higher in endometriotic bowel lesions than in eutopic endometrium from women with endometriosis. IL10 and TGFB expression was significantly higher in endometriotic bowel lesions than in eutopic endometrium from healthy women. In addition, TGFB and IL15 levels correlated positively with deep dyspareunia and cyclic dyschezia, respectively, while IL7 levels correlated negatively with dysmenorrhea. Deep infiltrating rectosigmoid endometriosis displays alterations in Treg and NK cells related cytokine, and TGFB, IL7 and IL15 expression is related with dyspareunia, dysmenorrhea and cyclic dyschezia, respectively, in patients with the disease.

Platelets impair natural killer cell reactivity and function in endometriosis through multiple mechanisms

Study question

Do platelets have any role in the reduced cytotoxicity of natural killer (NK) cells in endometriosis?

Summary answer

Platelets impair NK cell reactivity and function in endometriosis through multiple mechanisms.

What is known already

Platelets play an important role in the development of endometriosis, and platelet-derived transforming growth factor-β1 (TGF-β1) suppresses the expression of NK Group 2, Member D (NKG2D) on NK cells, resulting in reduced cytotoxicity in women with endometriosis.

Study design size, duration

Experiments on mice with induced endometriosis in which either platelets, NK cells or both were depleted and controls (none depleted). In vitro experiments with NK cells, platelets and, as target cells, endometriotic epithelial cell and endometrial stromal cell lines.

Participants/materials setting methods

Immunohistochemistry analysis of ectopic endometrial tissues from mice with induced endometriosis receiving either platelet depletion (PD), NK cell depletion, or both or none. Immunofluorescence, flow cytometry and gene expression analysis for major histocompatibility complex class I (MHC-I) expression in target cells. Cytotoxicity and degranulation assays and the measurement of interferon (IFN)-γ secretion for the evaluation of NK cytotoxicity. Flow cytometry and gene expression for the expression of NK cell receptors.

Main results and the role of chance

PD resulted in significantly reduced lesion weight in mice with induced endometriosis, but NK cell depletion as well as concomitant platelet and NK cell depletion increased the weight, suggesting that the anti-endometriosis effect of PD is mediated, at least in part, by increased NK cell cytotoxicity against endometriotic cells. Co-incubation of target cells with platelets resulted in rapid platelet coating as well as increased MHC-I expression in these cells, effectively providing a cloak of 'pseudo-self' to these cells to shield against NK cell lysis. It also reduced the expression of NKG2D ligands MICA and MICB and reduced the NK cell cytotoxicity. In addition, co-incubation of NK cells with platelets impaired the NK cell cytotoxicity as well. This impaired NK cell cytotoxicity was not due to the increased NK cell apoptosis, but, rather, through reduced NK cell degranulation and IFN-γ production, and reduced expression of activating receptors NKG2D and NKp46 and increased expression of inhibitory receptor KIR2DL1 in NK cells. Inhibition of TGF-β1 signaling partially restored the aberrant expression of NKG2D, NKp46 and KIR2DL1, and partially restored the impaired NK cell cytotoxicity induced by activated platelets and their releasate.

Large scale data

Not applicable.

Limitations reasons for caution

This study is confined by the limitation of animal and in vitro experimentation and the lack of direct human data.

Wider implications of the findings

Anti-platelet treatment holds promise in treating endometriosis.

Study funding/competing interests

The National Natural Science Foundation of China (81471434 to S.W.G., 81270676 to S.W.G., 81370695 to X.S.L. and 81671436 to X.S.L). None of the authors has anything to disclose.

Expression of natural cytotoxicity receptors and cytokine production on endometrial natural killer cells in women with recurrent pregnancy loss or implantation failure, and the expression of natural cytotoxicity receptors on peripheral blood natural killer cells in pregnant women with a history of recurrent pregnancy loss

AIM

Natural cytotoxicity receptors (NCR) are unique markers that regulate natural killer (NK) cell cytotoxicity and cytokine production. In this study, we investigated the expression of NCR (NKp46, NKp44, and NKp30) and cytokine production in NK cells derived from the uterine endometrium of women with recurrent pregnancy loss (RPL). We also investigated the expression of NCR in peripheral blood NK cells in pregnant women with and without a history of RPL.

METHODS

The expression of NCR (NKp46, NKp44, and NKp30) in NK cells (CD56^dim and CD56^bright ) in the uterine endometrium was analyzed using 3-color flow cytometry. Cytokine (tumor necrosis factor-α and interferon-γ) production was also analyzed. NK cells from the mid-secretory endometrium of 28 women with RPL, 34 women with implantation failure, and 74 controls were collected and mechanically dispersed using a tissue grinder. The expression of NCR in peripheral blood NK cells from pregnant women with (n = 17) and without (n = 91) a history of RPL was analyzed.

RESULTS

The percentages of NKp46⁺ NK cells were significantly lower in both women with RPL and pregnant women with a history of RPL. The percentages of tumor necrosis factor-α- and/or interferon-γ-producing uterine endometrial NK cells were significantly lower in women with RPL compared with controls.

CONCLUSION

The changes in NCR expression and cytokine production, especially decreased NKp46 expression in endometrial NK cells, suggests the presence of abnormal NK cell regulation in women with reproductive failures.

Expression of retinoid-related orphan receptor (ROR)γt on NK22 cells in the peripheral blood and uterine endometrium of women with unexplained recurrent pregnancy loss and unexplained infertility

AIM

Recently, NK22 cells, a subset of interleukin (IL)-22-producing natural killer (NK) cells, were identified. We have previously reported the higher percentage of NK22 cells in women suffering recurrent pregnancy loss (RPL). Moreover, we have also reported lower expression of NKp46, a kind of natural cytotoxicity receptor (NCR), on NK cells and the changes of NK cell producing cytokines in women who experience RPL. NK22 cells express NCRs, such as NKp44 or NKp46. Retinoid-related orphan receptor γt (RORγt) is known as a regulator of NK22 cells; however, in NK22 cells of peripheral blood (PB) and the uterine endometrium (UE), the relationship between NCRs and RORγt is unclear. We investigate RORγt expression NK22 cells in the PB and UE of women with unexplained infertility (uI) or unexplained RPL (uRPL).

METHODS

Lymphocytes were extracted from PB and UE, derived from women with uI or uRPL. Expression of RORγt and NCRs in NK cells and NK cell-produced cytokines were analyzed by flow cytometry.

RESULTS

CD56+ /NKp46+ /RORγt+ cells were positively correlated with CD56+ /IL-22+ cells in both PB and UE. CD56bright /NKp46bright /RORγt+ cells were significantly higher in uRPL than in uI, and endometrial CD56bright /NKp46bright /RORγt+ cells were positively correlated with PB. In UE, CD56bright /RORγt+ cells were negatively correlated with CD56bright /interferon-γ+ and CD56bright /tumor necrosis factor-α+ cells of uRPL.

CONCLUSION

RORγt may be associated with NK22 cells in reproduction. Particularly, higher expression of RORγt may be associated with elevated NK22 cells in uRPL.

Natural Killer Receptor 1 Dampens the Development of Allergic Eosinophilic Airway Inflammation

The function of NCR1 was studied in a model of experimental asthma, classified as a type 1 hypersensitivity reaction, in mice. IgE levels were significantly increased in the serum of OVA immunized NCR1 deficient (NCR1gfp/gfp) mice in comparison to OVA immunized wild type (NCR1+/+) and adjuvant immunized mice. Histological analysis of OVA immunized NCR1gfp/gfp mice revealed no preservation of the lung structure and overwhelming peribronchial and perivascular granulocytes together with mononuclear cells infiltration. OVA immunized NCR+/+ mice demonstrated preserved lung structure and peribronchial and perivascular immune cell infiltration to a lower extent than that in NCR1gfp/gfp mice. Adjuvant immunized mice demonstrated lung structure preservation and no immune cell infiltration. OVA immunization caused an increase in PAS production independently of NCR1 presence. Bronchoalveolar lavage (BAL) revealed NCR1 dependent decreased percentages of eosinophils and increased percentages of lymphocytes and macrophages following OVA immunization. In the OVA immunized NCR1gfp/gfp mice the protein levels of eosinophils' (CCL24) and Th2 CD4+ T-cells' chemoattractants (CCL17, and CCL24) in the BAL are increased in comparison with OVA immunized NCR+/+ mice. In the presence of NCR1, OVA immunization caused an increase in NK cells numbers and decreased NCR1 ligand expression on CD11c+GR1+ cells and decreased NCR1 mRNA expression in the BAL. OVA immunization resulted in significantly increased IL-13, IL-4 and CCL17 mRNA expression in NCR1+/+ and NCR1gfp/gfp mice. IL-17 and TNFα expression increased only in OVA-immunized NCR1+/+mice. IL-6 mRNA increased only in OVA immunized NCR1gfp/gfp mice. Collectively, it is demonstrated that NCR1 dampens allergic eosinophilic airway inflammation.

Decreased Cytotoxicity of Peripheral and Peritoneal Natural Killer Cell in Endometriosis

Endometriosis causes significant chronic pelvic pain, dysmenorrhea, and infertility and affects 10% of all women. In endometriosis, ectopic endometrium surviving after retrograde menstruation exhibits an abnormal immune response characterized by increased levels of activated macrophages and inflammatory cytokines. Particularly, dysfunctional natural killer (NK) cells play an important role in the pathogenesis of the disease by either facilitating or inhibiting the survival, implantation, and proliferation of endometrial cells. NK cells in the peritoneum and peritoneal fluid exhibit reduced levels of cytotoxicity in women with endometriosis. Several cytokines and inhibitory factors in the serum and peritoneal fluid also dysregulate NK cell cytotoxicity. Additionally, increased numbers of immature peripheral NK cells and induction of NK cell apoptosis are evident in the peritoneal fluid of women with endometriosis. The high rate of endometriosis recurrence after pharmaceutical or surgical treatment, which is associated with dysfunctional NK cells, indicates that new immunomodulatory management strategies are required. A good understanding of immune dysfunction would enable improvement of current treatments for endometriosis.

Endometriosis: where are we and where are we going?

Endometriosis currently affects ~5.5 million reproductive-aged women in the U.S. with symptoms such as painful periods (dysmenorrhea), chronic pelvic pain, pain with intercourse (dyspareunia), and infertility. It is defined as the presence of endometrial tissue outside the uterine cavity and is found predominately attached to sites within the peritoneal cavity. Diagnosis for endometriosis is solely made through surgery as no consistent biomarkers for disease diagnosis exist. There is no cure for endometriosis and treatments only target symptoms and not the underlying mechanism(s) of disease. The nature of individual predisposing factors or inherent defects in the endometrium, immune system, and/or peritoneal cavity of women with endometriosis remains unclear. The literature over the last 5 years (2010-2015) has advanced our critical knowledge related to hormones, hormone receptors, immune dysregulation, hormonal treatments, and the transformation of endometriosis to ovarian cancer. In this review, we cover the aforementioned topics with the goal of providing the reader an overview and related references for further study to highlight the progress made in endometriosis research, while concluding with critical areas of endometriosis research that are urgently needed.

Platelet-derived TGF-β1 mediates the down-modulation of NKG2D expression and may be responsible for impaired natural killer (NK) cytotoxicity in women with endometriosis

STUDY QUESTION

Does platelet-derived transforming growth factor-β1 (TGF-β1) have any role in the reduced cytotoxicity of natural killer (NK) cells in women with endometriosis?

SUMMARY ANSWER

Platelet-derived TGF-β1 suppresses the expression of NK Group 2, Member D (NKG2D) on NK cells, resulting in reduced cytotoxicity in women with endometriosis, but neutralization of TGF-β1 reverses the reduction.

WHAT IS KNOWN ALREADY

NK cells are cytotoxic lymphocytes that play an important role in peritoneal immune surveillance, and their function is known to be impaired in women with endometriosis. There is increased platelet aggregation in endometriotic lesions and increased platelet activation rate in the peripheral blood in women with endometriosis, yet activated platelets release copiousTGF-β1, which is known to be a potent immunosuppressive molecule that suppresses NK cell function and NKG2D expression.

STUDY DESIGN, SIZE, DURATION

Cross-sectional clinical studies of 30 women with endometriosis and 33 women without endometriosis and in vitro experimentation with and without TGF-β1 blockade.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Peritoneal fluid (PF) samples from premenopausal women with endometriosis and age- and menstrual phase-matched controls were collected. Platelet count, white blood cell (WBC) count, mean platelet volume (MPV), platelet activation rate, TGF-β1 concentration, expression levels of NKG2D on NK cells in the PF were evaluated. The apoptosis of freshly isolated NK cells treated with PF from women with endometriosis, the NK cytotoxicity and NKG2D expression treated with PF in the presence or absence of an anti-TGF-β1 antibody were also determined.

MAIN RESULTS AND THE ROLE OF CHANCE

The platelet count, WBC count, MPV, platelet activation rate and the TGF-β1 concentration in the PF from women with endometriosis were significantly elevated when compared with those of women without endometriosis. The TGF-β1 concentration correlated positively with the platelet activation rate (r = 0.59, P < 0.01), suggesting that activated platelets are responsible, at least in part, for the increased TGF-β1 concentration. The cytotoxicity of freshly isolated NK cells treated with PF of women with endometriosis is significantly reduced when compared with that of women without endometriosis. Both the platelet activation rate and the TGF-β1 concentration in the PF correlated negatively with the NKG2D expression in NK cells isolated from the PF (r = -0.36, P < 0.01, and r = -0.45, P < 0.01, respectively). In addition, the NKG2D expression level and the cytotoxicity in freshly isolated NK cells were found to be significantly reduced if co-cultured with PF from women with endometriosis, but the TGF-β1 blockade effectively reverses the reduction.

LIMITATIONS, REASONS FOR CAUTION

This study is limited by the cross-sectional nature of the study.

WIDER IMPLICATIONS OF THE FINDINGS

NKG2D is known to potently activate NK cells, so potent that it even overrides inhibitory signals transduced by other inhibitory receptors. This is the first time we demonstrate that platelet-derived TGF-β1 may be responsible for reduced NKG2D expression as well as reduced cytotoxicity of NK cells in women with endometriosis. This study provides yet another piece of evidence that platelets play critical roles in the development of endometriosis, and anti-platelet treatment should improve NK cell functionality in treating endometriosis. Equally important, this study highlights the critical role of the lesion microenvironment in shaping NK cell-mediated anti-endometriotic immunity.

STUDY FUNDING/COMPETING INTERESTS

This research was supported in part by grants 81270676 (S.-W.G.), 81471434 (S.-W.G.), 81530040 (S.-W.G.), and 81370695 (X.L.) from the National Natural Science Foundation of China, and grant 2013ZYJB0019 (X.L.) from Shanghai Municipal Commission of Health and Family Planning. None of the authors has anything to disclose.

To serve and to protect: the role of decidual innate immune cells on human pregnancy

The maternal-fetal interface undergoes dynamic changes that promote successful development of the embryo/fetal allograft during pregnancy. This immune privilege of the conceptus is mediated through local and systemic cellular responses. In species in which endometrial decidualization accompanies pregnancy, unique immune cell niches are found. Many studies have addressed the enigmatic roles of uterine (u)NK cells as killers and helpers because they are frequently found in the uterine lining and decidua of normal and pathological pregnancies. Accumulating evidence indicates that uNK cells are induced and transformed by sensing signals within their microenvironment to both protect the mother from the fetal allograft and support the fetus during its development. Here, we review the mechanisms that modulate these functions of uNK cells during pregnancy. We suggest that uNK cells must be tightly regulated in order to serve these two roles and support a healthy pregnancy.

NK cell abnormality and its treatment in women with reproductive failures such as recurrent pregnancy loss, implantation failures, preeclampsia, and pelvic endometriosis

The regulation of uterine and peripheral blood natural killer (NK) cells has been associated with problems related to reproductive immunology such as recurrent pregnancy loss (RPL), implantation failure or preeclampsia. NKp46, one of the natural cytotoxicity receptors (NCRs), is a unique marker that functions in NK cell cytotoxicity and cytokine production. Expression of NKp46 on NK cells is lower in women with recurrent pregnancy loss and pregnancy-induced hypertension. Moreover, expression of NKp46 on peritoneal fluid NK cells is lower in women with pelvic endometriosis. Therefore, evaluation of NKp46 on peripheral blood NK cells may provide a means of screening for reproductive abnormalities. Recently, a new type of NK cell, the NK22 cell, has been reported. This cell may be a regulator not only of the mucosal barrier but also of reproduction. For women with RPL showing abnormal uterine and/or peripheral blood NK cells, both intravenous immunoglobulin treatment and intralipid treatment have been reported. The effects of these treatments are still controversial, and further studies are needed in order to clarify their true impact. The present review examines variations in the expression of NCRs on NK cells, the participation of NK22 cells in reproduction, and the possible use of intravenous immunoglobulin or intralipid treatment for women with recurrent pregnancy loss and NK cell abnormality.

Soluble ligands for the NKG2D receptor are released during endometriosis and correlate with disease severity

BACKGROUND

Endometriosis is a benign gynaecological disease. Abundant bulk of evidence suggests that patients with endometriosis have an immunity dysfunction that enables ectopic endometrial cells to implant and proliferate. Previous studies show that natural killer cells have a pivotal role in the immune control of endometriosis.

METHODS AND FINDINGS

This is a prospective laboratory study conducted in a tertiary-care university hospital between January 2011 and April 2013. We investigated non-pregnant, younger than 42-year-old patients (n= 202) during surgery for benign gynaecological conditions. After complete surgical exploration of the abdominopelvic cavity, 121 women with histologically proven endometriosis and 81 endometriosis-free controls women were enrolled. Patients with endometriosis were classified according to a surgical classification in three different types of endometriosis: superficial peritoneal endometriosis (SUP), ovarian endometrioma (OMA) and deep infiltrating endometriosis (DIE). Peritoneal fluid samples were obtained from all study participants during the surgery in order to detect soluble NKG2D ligands (MICA, MICB and ULBP-2). When samples with undetectable peritoneal fluid levels of MICA, MICB and ULBP-2 were excluded, MICA ratio levels were significantly higher in endometriosis patients than in controls (median, 1.1 pg/mg; range, 0.1-143.5 versus median, 0.6 pg/mg; range, 0.1-3.5; p=0.003). In a similar manner peritoneal fluid MICB levels were also increased in endometriosis-affected patients compared with disease-free women (median, 4.6 pg/mg; range, 1.2-4702 versus median, 3.4 pg/mg; range, 0.7-20.1; p=0.001). According to the surgical classification, peritoneal fluid soluble MICA, MICB and ULBP-2 ratio levels were significantly increased in DIE as compared to controls (p=0.015, p=0.003 and p=0.045 respectively). MICA ratio levels also correlated with dysmenorrhea (r=0.232; p=0.029), total rAFS score (r=0.221; p=0.031) and adhesions rAFS score (r=0.221; p=0.031).

CONCLUSIONS

We demonstrate a significant increase of peritoneal fluid NKG2D ligands in women with endometriosis especially in those cases presenting DIE. This study suggests that NKG2D ligands shedding is a novel pathway in endometriosis complex pathogenesis that impairs NK cell function.

Chronic inflammation in endometriosis and endometriosis-associated ovarian cancer: New roles for the "old" complement pathway

Immune escape is consequential for cancer development. Identifying abnormalities of the immune microenvironment during early carcinogenesis can provide insight into disease pathogenesis and unravel new preventive or therapeutic targets. We recently conducted a comprehensive immune gene expression analysis in endometriosis and endometriosis-associated ovarian cancer and explored new mechanistic roles for the complement pathway.

B7-H6-mediated downregulation of NKp30 in NK cells contributes to ovarian carcinoma immune escape

In this study the phenotype and function of tumor-associated NK cells from peritoneal fluids of a selected cohort of patients with seropapillary ovarian carcinoma were analyzed. In > 50% of these patients, the expression of the activating receptor NKp30 in tumor-associated NK cells was substantially reduced as compared to autologous peripheral blood (PB) NK cells. The impaired expression of this receptor was associated with the presence of one of its cellular ligands (B7-H6), which was detectable as a surface/cytosolic molecule in tumor cells and as a soluble molecule in the peritoneal fluid. NK cells from patients expressing this NKp30low phenotype displayed an impaired interferon-gamma (IFNγ) production and cytolytic function when tested against target cells expressing surface B7-H6. Our data also suggest that in these patients, the defective expression and function of NKp30 may be induced by the chronic engagement of this receptor by soluble B7-H6 or by tumor cells expressing this ligand. The impairment of NK cell functions described herein could represent a novel mechanism by which the tumor microenvironment may contribute to the escape from immune surveillance.

NK22 Cells in the Uterine Mid-Secretory Endometrium and Peripheral Blood of Women with Recurrent Pregnancy Loss and Unexplained Infertility

PROBLEM

We aimed to investigate natural killer 22 (NK22) cells in the peripheral blood and the uterine endometrium of women with unexplained recurrent pregnancy loss (URPL) and unexplained infertility (UI).

METHOD OF STUDY

Peripheral blood and endometrial samples were collected from women with URPL (n = 43) and UI (n = 38). Intracellular cytokine production, such as IL-22, IFN-γ and TNF-α, and the expression of NKp46 on NK cells were analyzed by three-color flow cytometry.

RESULTS

The percentages of endometrial CD56(+) /IL-22(+) and CD56(dim) /IL-22(+) cells in women with URPL were significantly higher than those of UI (P < 0.05, respectively). In addition, the percentage of CD56(bright) /IL-22(+) cells in women with RPL was negatively correlated with those of CD56(bright) /IFN-γ(+) and CD56(bright) /TNF-α(+) in both peripheral blood and endometrial NK cells. This was not seen in women with UI. The percentage of CD56(bright) /IL-22(+) cells was negatively correlated with CD56(bright) /NKp46 expressing NK cells in peripheral blood.

CONCLUSION

Endometrial NK22 cells are differently regulated in women with URPL and UI. Women with URPL have higher level of NK22 cells with a potential to induce NK2 shift than women with UI.

Complement pathway is frequently altered in endometriosis and endometriosis-associated ovarian cancer

PURPOSE

Mechanisms of immune dysregulation associated with advanced tumors are relatively well understood. Much less is known about the role of immune effectors against cancer precursor lesions. Endometrioid and clear-cell ovarian tumors partly derive from endometriosis, a commonly diagnosed chronic inflammatory disease. We performed here a comprehensive immune gene expression analysis of pelvic inflammation in endometriosis and endometriosis-associated ovarian cancer (EAOC).

EXPERIMENTAL DESIGN

RNA was extracted from 120 paraffin tissue blocks comprising of normal endometrium (n = 32), benign endometriosis (n = 30), atypical endometriosis (n = 15), and EAOC (n = 43). Serous tumors (n = 15) were included as nonendometriosis-associated controls. The immune microenvironment was profiled using Nanostring and the nCounter GX Human Immunology Kit, comprising probes for a total of 511 immune genes.

RESULTS

One third of the patients with endometriosis revealed a tumor-like inflammation profile, suggesting that cancer-like immune signatures may develop earlier, in patients classified as clinically benign. Gene expression analyses revealed the complement pathway as most prominently involved in both endometriosis and EAOC. Complement proteins are abundantly present in epithelial cells in both benign and malignant lesions. Mechanistic studies in ovarian surface epithelial cells from mice with conditional (Cre-loxP) mutations show intrinsic production of complement in epithelia and demonstrate an early link between Kras- and Pten-driven pathways and complement upregulation. Downregulation of complement in these cells interferes with cell proliferation.

CONCLUSIONS

These findings reveal new characteristics of inflammation in precursor lesions and point to previously unknown roles of complement in endometriosis and EAOC.

Enhanced prevalence of plasmatic soluble MHC class I chain-related molecule in vascular pregnancy diseases

The major histocompatibility complex class I related chain (MIC) is a stress-inducible protein modulating the function of immune natural killer (NK) cells, a major leukocyte subset involved in proper trophoblast invasion and spiral artery remodeling. Aim of the study was to evaluate whether upregulation of soluble MIC (sMIC) may reflect immune disorders associated to vascular pregnancy diseases (VPD). sMIC was more frequently detected in the plasma of women with a diagnostic of VPD (32%) than in normal term-matched pregnancies (1.6%, P < 0.0001), with highest prevalence in intrauterine fetal death (IUDF, 44%) and vascular intrauterine growth restriction (IUGR, 39%). sMIC levels were higher in preeclampsia (PE) than in IUFD (P < 0.01) and vascular IUGR (P < 0.05). sMIC detection was associated with bilateral early diastolic uterine notches (P = 0.037), thrombocytopenia (P = 0.03), and high proteinuria (P = 0.03) in PE and with the vascular etiology of IUGR (P = 0.0038). Incubation of sMIC-positive PE plasma resulted in downregulation of NKG2D expression and NK cell-mediated IFN-γ production in vitro. Our work thus suggests that detection of sMIC molecule in maternal plasma may constitute a hallmark of altered maternal immune functions that contributes to vascular disorders that complicate pregnancy, notably by impairing NK-cell mediated production of IFN-γ, an essential cytokine favoring vascular modeling.