17Beta-estradiol suppresses TLR3-induced cytokine and chemokine production in endometrial epithelial cells

Sex-related immunity: could Toll-like receptors be the answer in acute inflammatory response?

An increasing number of studies have highlighted the existence of a sex-specific immune response, wherein men experience a worse prognosis in cases of acute inflammatory diseases. Initially, this sex-dependent inflammatory response was attributed to the influence of sex hormones. However, a growing body of evidence has shifted the focus toward the influence of chromosomes rather than sex hormones in shaping these inflammatory sex disparities. Notably, certain pattern recognition receptors, such as Toll-like receptors (TLRs), and their associated immune pathways have been implicated in driving the sex-specific immune response. These receptors are encoded by genes located on the X chromosome. TLRs are pivotal components of the innate immune system, playing crucial roles in responding to infectious diseases, including bacterial and viral pathogens, as well as trauma-related conditions. Importantly, the TLR-mediated inflammatory responses, as indicated by the production of specific proteins and cytokines, exhibit discernible sex-dependent patterns. In this review, we delve into the subject of sex bias in TLR activation and explore its clinical implications relatively to both the X chromosome and the hormonal environment. The overarching objective is to enhance our understanding of the fundamental mechanisms underlying these sex differences.

Ovarian sex steroid and epithelial control of immune responses in the uterus and oviduct: human and animal models†

The female reproductive tract (FRT), including the uterus and oviduct (Fallopian tube), is responsible for maintaining an optimal microenvironment for reproductive processes, such as gamete activation and transportation, sperm capacitation, fertilization, and early embryonic and fetal development. The mucosal surface of the FRT may be exposed to pathogens and sexually transmitted microorganisms due to the opening of the cervix during mating. Pathogens and endotoxins may also reach the oviduct through the peritoneal fluid. To maintain an optimum reproductive environment while recognizing and killing pathogenic bacterial and viral agents, the oviduct and uterus should be equipped with an efficient and rigorously controlled immune system. Ovarian sex steroids can affect epithelial cells and underlying stromal cells, which have been shown to mediate innate and adaptive immune responses. This, in turn, protects against potential infections while maintaining an optimal milieu for reproductive events, highlighting the homeostatic involvement of ovarian sex steroids and reproductive epithelial cells. This article will discuss how ovarian sex steroids affect the immune reactions elicited by the epithelial cells of the non-pregnant uterus and oviduct in the bovine, murine, and human species. Finally, we propose that there are regional and species-specific differences in the immune responses in FRT.

Pattern-recognition receptors in endometriosis: A narrative review

Endometriosis is closely associated with ectopic focal inflammation and immunosuppressive microenvironment. Multiple types of pattern recognition receptors (PRRs) are present in the innate immune system, which are able to detect pathogen-associated molecular patterns (PAMPs) and danger-associated molecular patterns (DAMPs) in both intracellular and external environments. However, the exact role of PRRs in endometriosis and the underlying molecular mechanism are unclear. PRRs are necessary for the innate immune system to identify and destroy invasive foreign infectious agents. Mammals mainly have two types of microbial recognition systems. The first one consists of the membrane-bound receptors, such as toll-like receptors (TLRs), which recognize extracellular microorganisms and activate intracellular signals to stimulate immune responses. The second one consists of the intracellular PRRs, including nod-like receptors (NLRs) and antiviral proteins retinoic acid-inducible gene I (RIG-I) and melanoma differentiation-associated gene 5 (MDA-5) with helix enzyme domain. In this review, we mainly focus on the key role of PRRs in the pathological processes associated with endometriosis. PRRs recognize PAMPs and can distinguish pathogenic microorganisms from self, triggering receptor ligand reaction followed by the stimulation of host immune response. Activated immune response promotes the transmission of microbial infection signals to the cells. As endometriosis is characterized by dysregulated inflammation and immune response, PRRs may potentially be involved in the activation of endometriosis-associated inflammation and immune disorders. Toll-like receptor 2 (TLR2), toll-like receptor 3 (TLR3), toll-like receptor 4 (TLR4), nod-like receptor family caspase activation and recruitment domain (CARD) domain containing 5 (NLRC5), nod-like receptor family pyrin domain containing 3 (NLRP3), and c-type lectin receptors (CLRs) play essential roles in endometriosis development by regulating immune and inflammatory responses. Absent in melanoma 2 (AIM2)-like receptors (ALRs) and retinoic acid-inducible gene I-like receptors (RLRs) may be involved in the activation of endometriosis-associated immune and inflammation disorders. PRRs, especially TLRs, may serve as potential therapeutic targets for alleviating pain in endometriosis patients. PRRs and their ligands interact with the innate immune system to enhance inflammation in the stromal cells during endometriosis. Thus, targeting PRRs and their new synthetic ligands may provide new therapeutic options for treating endometriosis.

Protective role of 17β-estradiol treatment in renal injury on female rats submitted to brain death

Background

Clinical and experimental data highlight the consequences of brain death on the quality of organs and demonstrate the importance of donor state to the results of transplantation. Female rats show higher cardio-pulmonary injury linked to decreased concentrations of female sex hormones after brain-dead (BD). This study evaluated the effect of 17β-estradiol on brain death induced renal injury in female rats.

Methods

Female Wistar rats were randomically allocated into 4 groups: false-operation (Sham), BD, treatment with 17β-estradiol (50 µg/mL, 2 mL/h) 3 h after brain death (E2-T3), or immediately after brain death confirmation (E2-T0). Creatinine, urea, cytokines, and complement system components were quantified. Renal injury markers, such as KIM-1, Caspase-3, BCL-2 and MMP2/9 were evaluated.

Results

Brain death leads to increased kidney KIM-1 expression and longer 17β-estradiol treatment resulted in downregulation (P<0.0001). There was increase of neutrophil numbers in kidney from BD rats and E2 treatment was able to reduce it (P=0.018). Regarding complement elements, E2-T3 group evidenced E2 therapeutic effects, reducing C5b-9 (P=0.0004), C3aR (P=0.054) and C5aR (P=0.019). In parallel, there were 17β-estradiol effects in reducing MMP2 (P=0.0043), MMP9 (P=0.011), and IL-6 (P=0.024). Moreover, E2-T3 group improved renal function in comparison to BD group (P=0.0938).

Conclusions

17β-estradiol treatment was able to reduce acute kidney damage in BD female rats owing to its ability to prevent tissue damage, formation of C5b-9, and local synthesis of inflammatory mediators.

The impact of aging on innate and adaptive immunity in the human female genital tract

Mucosal tissues in the human female reproductive tract (FRT) are primary sites for both gynecological cancers and infections by a spectrum of sexually transmitted pathogens, including human immunodeficiency virus (HIV), that compromise women's health. While the regulation of innate and adaptive immune protection in the FRT by hormonal cyclic changes across the menstrual cycle and pregnancy are being intensely studied, little to nothing is known about the alterations in mucosal immune protection that occur throughout the FRT as women age following menopause. The immune system in the FRT has two key functions: defense against pathogens and reproduction. After menopause, natural reproductive function ends, and therefore, two overlapping processes contribute to alterations in immune protection in aging women: menopause and immunosenescence. The goal of this review is to summarize the multiple immune changes that occur in the FRT with aging, including the impact on the function of epithelial cells, immune cells, and stromal fibroblasts. These studies indicate that major aspects of innate and adaptive immunity in the FRT are compromised in a site‐specific manner in the FRT as women age. Further, at some FRT sites, immunological compensation occurs. Overall, alterations in mucosal immune protection contribute to the increased risk of sexually transmitted infections (STI), urogenital infections, and gynecological cancers. Further studies are essential to provide a foundation for the development of novel therapeutic interventions to restore immune protection and reverse conditions that threaten women's lives as they age.

Evaluation of Toll-like receptor 3 (TLR3) signaling pathway genes and its genetic polymorphisms in ectopic and eutopic endometrium of women with endometriosis

OBJECTIVE

Toll-like receptors (TLRs, as members of the innate immune system) are expressed in the human endometrium and their aberrant regulation and expression are involved in the pathogenesis of endometrial diseases. This study is aimed at evaluation of TLR3 signaling pathway genes and its genetic changes in endometriosis patients.

MATERIALS AND METHODS

Blood samples were collected from 83 endometriosis patients and 93 healthy fertile women and PCR was performed in blood-derived DNA for detection of SNP of TLR3. Also, ectopic (EC) and eutopic (EU) endometrial biopsies were obtained from endometriosis patients (n = 20), as well as endometrium from healthy women (n = 16, CE). Q-PCR was performed for determination of mRNA expression level of TLR3 signaling pathway genes (TLR3, TICAM, NF-kB1A, CXCL10, IRF3, IFN-B1, IL-6 and IL-8). Also, serum protein levels of TLR3, IFN-β, IL-6 and IL-8 were determined using ELISA.

RESULTS

The mRNA expression levels of TLR3, NF-kB1A, IFN-B1, IRF3, TICAM1, IL-6 and IL-8 were significantly higher in EU compared to ectopic ones and also compared to CE. SNPs frequency (rs3775291 and rs3775290) was not significantly different between patients and controls. Serum protein levels of TLR3, IFN-β, IL-6 and IL-8 were significantly increased in endometriosis patients.

CONCLUSION

Significant changes were observed in the expression of IL-6 and IL-8 cytokines and other genes in TLR3 cascade in diseased EU, demonstrating that EU similarly to EC is in an intensive inflammatory state. These fundamental alterations in the concept of immune response in EU may lead to its activation, escapes from apoptosis, and displaced implantation of the endometrium.

Fever Induced by Zymosan A and Polyinosinic-Polycytidylic Acid in Female Rats: Influence of Sex Hormones and the Participation of Endothelin-1

Sex differences in the immune response can also affect the febrile response, particularly the fever induced by lipopolysaccharide (LPS). However, other pathogen-associated molecular patterns, such as zymosan A (Zym) and polyinosinic-polycytidylic acid (Poly I:C), also induce fever in male rats with a different time course of cytokine release and different mediators such as endothelin-1 (ET-1). This study investigated whether female sex hormones affect Zym- and Poly I:C-induced fever and the involvement of ET-1 in this response. The fever that was induced by Zym and Poly I:C was higher in ovariectomized (OVX) female rats compared with sham-operated female rats. Estrogen replacement in OVX females reduced Zym- and Poly I:C-induced fever. The ET_B receptor antagonist BQ788 reversed the LPS-induced fever in cycling females but not in OVX females. BQ788 did not alter the fever that was induced by Zym or Poly I:C in either cycling or OVX females. These findings suggest that the febrile response in cycling females is lower, independently of the stimulus that is inducing it and is probably controlled by estrogen. Also, ET-1 seems to participate in the febrile response that was induced by LPS in males and cycling females but not in the LPS-induced fever in OVX females. Additionally, ET-1 was not involved in the febrile response that was induced by Zym or Poly I:C in females.

Toll-like receptor 3 dynamics in female C57BL/6J mice: Regulation of alcohol intake

Although there are sex differences in the effects of alcohol on immune responses, it is unclear if sex differences in immune response can influence drinking behavior. Activation of toll-like receptor 3 (TLR3) by polyinosinic:polycytidylic acid (poly(I:C)) produced a rapid proinflammatory response in males that increased alcohol intake over time (Warden et al., 2019). Poly(I:C) produced a delayed and prolonged innate immune response in females. We hypothesized that the timecourse of innate immune activation could regulate drinking behavior in females. Therefore, we chose to test the effect of two time points in the innate immune activation timecourse on every-other-day two-bottle-choice drinking: (1) peak activation; (2) descending limb of activation. Poly(I:C) reduced ethanol consumption when alcohol access occurred during peak activation. Poly(I:C) did not change ethanol consumption when alcohol access occurred on the descending limb of activation. Decreased levels of MyD88-dependent pathway correlated with decreased alcohol intake and increased levels of TRIF-dependent pathway correlated with increased alcohol intake in females. To validate the effects of poly(I:C) were mediated through MyD88, we tested female mice lacking Myd88. Poly(I:C) did not change alcohol intake in Myd88 knockouts, indicating that poly(I:C)-induced changes in alcohol intake are dependent on MyD88 in females. We next determined if the innate immune timecourse also regulated drinking behavior in males. Poly(I:C) reduced ethanol consumption in males when alcohol was presented at peak activation. Therefore, the timecourse of innate immune activation regulates drinking behavior and sex-specific dynamics of innate immune response must be considered when designing therapeutics to treat excessive drinking.

Mechanism of penehyclidine hydrochloride on a dysmenorrhea rat model

Primary dysmenorrhea affects the quality of life in young women, particularly school and work performance. This study investigated the mechanisms of penehyclidine hydrochloride (PHC) efficacy on a rat model of primary dysmenorrhea. The model was induced by injecting both estradiol benzoate and oxytocin. Different doses of PHC were administrated intraperitoneally following estradiol benzoate administration. Writhing scores were assessed, and pathological changes of the uterus were observed via hematoxylin and eosin staining. Western blot and real-time PCR were used to evaluate the expression level of the M₃ receptor, both TLR₃ and TLR₄ in uterine tissue, and the level of Ca²⁺ was measured in uterine tissues. Writhing scores significantly decreased in the PHC treatment group compared to model, and PHC alleviated the occurrence of edema or necrosis in the uteri compared to model group. PHC can decrease the M₃ receptor, TLR₃ , TLR₄ expression, and the Ca²⁺ level compared to the model group. PHC is a potential candidate for the future treatment of primary dysmenorrhea due to its ability to attenuate muscarinic receptors and TLRs. Preclinical Research & Development.

Sex-specific immunomodulatory action of the environmentalestrogen 17α-ethynylestradiol alongside with reproductive impairment in fish

Estrogenic endocrine disrupting chemicals (EEDCs) are present ubiquitously in sediments and aquatic ecosystems worldwide. The detrimental impact of EEDCs on the reproduction of wildlife is widely recognized. Increasing evidence shows the immunosuppressive effects of EEDCs in vertebrates. Yet, no studies have considered concomitantly EEDC-induced impacts on reproductive impairment and immune suppression in vivo, which are deemed essential for risk assessment and environmental monitoring. In this study, EE2 was used as a representative EEDC, for parallel evaluation of EEDC-induced immune suppression (immune marker gene expression, leukocyte numbers, host resistance assay, and immune competence index) and reproductive impairment (estrogen responsive gene expression, fecundity, fertilization success, hatching success, and reproductive competence index) in an established fish model (marine medaka Oryzias melastigma), considering sex-specific induction and adaptation and recovery responses under different EE2 exposure scenarios. The findings in marine medaka reveal distinct sex differences in the EE2-mediated biological responses. For female fish, low concentration of exogenous EE2 (33 ng/L) could induce hormesis (immune enhancement), enable adaptation (restored reproduction) and even boost fish resistance to bacterial challenge after abatement of EE2. However, a prolonged exposure to high levels of EE2 (113 ng/L) not only impaired F0 immune function, but also perturbed females recovering from reproductive impairment, resulting in a persistent impact on the F1 generation output. Thus, for female fish, the exposure concentration of EE2 is more critical than the dose of EE2 in determining the impacts of EE2 on immune function and reproduction. Conversely, male fish are far more sensitive than females to the presence of low levels of exogenous EE2 in water and the EE2-mediated biological impacts are clearly dose-dependent. It is also evident in male fish that direct contact of EE2 is essential to sustain impairments of immune competence and reproductive output as well as deregulation of immune function genes in vivo. The immunomodulatory pathways altered by EE2 were deciphered for male and female fish, separately. Downregulation of hepatic tlr3 and c3 (in female) and tlr3, tlr5 and c3 (in male) may be indicative of impaired fish immune competence. Taken together, impaired immune competence in the EE2-exposed fish poses an immediate thread on the survival of F0 population. Impaired reproduction in the EE2-exposed fish can directly affect F1 output. Parallel evaluation of immune competence and reproduction are important considerations when assessing the risk of sublethal levels of EE2/EEDCs in aquatic environments.

Immunomodulatory Effects of 17β-Estradiol on Epithelial Cells during Bacterial Infections

The innate immune system can function under hormonal control. 17β-Estradiol (E2) is an important sexual hormone for the reproductive cycle of mammals, and it has immunomodulatory effects on epithelial cells, which are the first line of defense against incoming bacteria. E2 regulates various pathophysiological processes, including the response to infection in epithelial cells, and its effects involve the regulation of innate immune signaling pathways, which are mediated through estrogen receptors (ERs). E2 modulates the expression of inflammatory and antimicrobial elements such as cytokines and antimicrobial peptides. The E2 effects on epithelial cells during bacterial infections are characterized by an increase in the production of antimicrobial peptides and by the diminution of the inflammatory response to abrogate proinflammatory cytokine induction by bacteria. Here, we review several novel molecular mechanisms through which E2 regulates the innate immune response of epithelial cells against bacterial infections.

Nucleophosmin/B23 is a negative regulator of estrogen receptor α expression via AP2γ in endometrial cancer cells

Endometrial cancers expressing estrogen and progesterone receptors respond to hormonal therapy. The disappearance of steroid hormone receptor expression is common in patients with recurrent disease, ultimately hampering the clinical utility of hormonal therapy. Here, we demonstrate for the first time that nucleophosmin (NPM1/B23) suppression can restore the expression of estrogen receptor α (ESR1/ERα) in endometrial cancer cells. Mechanistically, B23 and activator protein-2γ (TFAP2C/AP2γ) form a complex that acts as a transcriptional repressor of ERα. Our results indicate that B23 or AP2γ knockdown can restore ERα levels and activate ERα-regulated genes (e.g., cathepsin D, EBAG9, and TFF1/pS2). Moreover, AP2γ knockdown in a xenograft model sensitizes endometrial cancer cells to megesterol acetate through the upregulation of ERα expression. An increased immunohistochemical expression of AP2γ is an adverse prognostic factor in endometrial cancer. In summary, B23 and AP2γ may act in combination to suppress ERα expression in endometrial cancer cells. The inhibition of B23 or AP2γ can restore ERα expression and can serve as a potential strategy for sensitizing hormone-refractory endometrial cancers to endocrine therapy.

The Effect of Estradiol and Progesterone on Toll Like Receptor Gene Expression in A Human Fallopian Tube Epithelial Cell Line

Objective

Toll like receptors (TLRs) are one of the main components of the innate im- mune system. It has been reported that expression of these receptors are altered in the female reproductive tract (FRT) during menstrual cycle. Here we used a fallopian tube epithelial cell line (OE-E6/E7) to evaluate the effect of two sex hormones in modulating TLR expression.

Materials and Methods

In this experimental study, initially TLR gene expression in OE- E6/E7 cells was evaluated and compared with that of fallopian tube tissue using quanti- tative real time-polymerase chain reaction (qRT-PCR) and immunostaining. Thereafter, OE-E6/E7 cells were cultured with different concentrations of estradiol and progesterone, and combination of both. qRT-PCR was performed to reveal any changes in expression of TLR genes as a result of hormonal treatment.

Results

TLR1-10 genes were expressed in human fallopian tube tissue. TLR1-6 genes and their respective proteins were expressed in the OE-E6/E7 cell line. Although estradiol and progesterone separately had no significant effect on TLR expression, their combined treatment altered the expression of TLRs in this cell line. Also, the pattern of TLR expres- sion in preovulation (P), mensturation (M) and window of implantation (W) were the same for all TLRs with no significant differences between P, M and W groups.

Conclusion

These data show the significant involvement of the combination of es- tradiol and progesterone in modulation of TLR gene expression in this human fal- lopian tube cell line. Further experiments may reveal the regulatory mechanism and signalling pathway behind the effect of sex hormones in modulating TLRs in the hu- man FRT.

Regulation of mucosal immunity in the female reproductive tract: the role of sex hormones in immune protection against sexually transmitted pathogens

The immune system in the female reproductive tract (FRT) does not mount an attack against human immunodeficiency virus (HIV) or other sexually transmitted infections (STI) with a single endogenously produced microbicide or with a single arm of the immune system. Instead, the body deploys dozens of innate antimicrobials to the secretions of the FRT. Working together, these antimicrobials along with mucosal antibodies attack viral, bacterial, and fungal targets. Within the FRT, the unique challenges of protection against sexually transmitted pathogens coupled with the need to sustain the development of an allogeneic fetus, has evolved in such a way that sex hormones precisely regulate immune function to accomplish both tasks. The studies presented in this review demonstrate that estradiol (E2 ) and progesterone secreted during the menstrual cycle act both directly and indirectly on epithelial cells, fibroblasts and immune cells in the reproductive tract to modify immune function in a way that is unique to specific sites throughout the FRT. As presented in this review, studies from our laboratory and others demonstrate that the innate and adaptive immune systems are under hormonal control, that protection varies with the stage of the menstrual cycle and as such, is dampened during the secretory stage of the cycle to optimize conditions for fertilization and pregnancy. In doing so, a window of STI vulnerability is created during which potential pathogens including HIV enter the reproductive tract to infect host targets.

Role of the innate immunity in female reproductive tract

The mucosal immune system in the female reproductive tract (FRT) is well equipped to meet the sexually transmitted pathogens, allogeneic sperm, and the immunologically distinct fetus. Analysis of the FRT indicates that epithelial cells provide a physical barrier against pathogens and microbial infections as well as secretions containing anti-microbial peptides, cytokines, and chemokines which recruit and activate immune cells. Epithelial and immune cells confer protection in part through Toll-like receptors. The aim of this literature is to review the diverse components of the innate immune system, contributing to an exclusive protection system throughout the FRT.

IRAK4 and TLR3 Sequence Variants may Alter Breast Cancer Risk among African-American Women

Mounting evidence suggests that imbalances in immune regulation contribute to cell transformation. Women of African descent are an understudied group at high risk for developing aggressive breast cancer (BrCa). Therefore, we examined the role of 16 innate immune single nucleotide polymorphisms (SNPs) in relation to BrCa susceptibility among 174 African-American women in Atlanta, GA, USA. SNPs were examined in germ-line DNA collected from 102 BrCa patients and 72 women with benign nodules using SNPstream methodology. Inheritance of the TLR3 rs10025405 GG genotype was associated with an 82% decrease in BrCa risk. In contrast, individuals who possessed at least one IRAK4 rs4251545 T allele had a 1.68- to 4.99-fold increase in the risk of developing BrCa relative to those with the referent genotype (OR = 4.99; 95% CI = 1.00, 25.00; p = 0.0605). However, the IRAK4 rs4251545 locus was only significant under the additive genetic model (p trend = 0.0406). In silico predictions suggest IRAK4 rs4251545 SNP falls within a transcription enhancer/silencer region of the gene and codes for an Ala428Thr amino acid change. This missense mutation introduces a potential phosphorylation site in the extreme carboxy terminus (XCT) of the IRAK4 kinase domain. Preliminary molecular modeling predicts that this SNP stabilizes two alpha helices within the XCT on the surface of the IRAK4 kinase domain and increases the size of the groove between them. Our in silico results, combined with previous reports noting the presence of IRAK4 and XCT fragments in mouse and human serum, suggest the possibility that the XCT subdomain of IRAK4 possesses biological function. These findings require further evaluation and validation in larger populations, additional molecular modeling as well as functional studies to explore the role of IRAK4 and its XCT in cell transformation and innate immunity.

Ovarian steroid hormones: effects on immune responses and Chlamydia trachomatis infections of the female genital tract

Female sex hormones are known to regulate the adaptive and innate immune functions of the female reproductive tract. This review aims to update our current knowledge of the effects of the sex hormones estradiol and progesterone in the female reproductive tract on innate immunity, antigen presentation, specific immune responses, antibody secretion, genital tract infections caused by Chlamydia trachomatis, and vaccine-induced immunity.

Differential profiles of immune mediators and in vitro HIV infectivity between endocervical and vaginal secretions from women with Chlamydia trachomatis infection: a pilot study

Chlamydia trachomatis infection is one of the most prevalent bacterial STIs in the USA and worldwide, and women with C. trachomatis infection are at increased risk of acquiring HIV. Because immune activation at the genital mucosa facilitates HIV/SIV infection, C. trachomatis-mediated cytokine induction may contribute to increased HIV transmission in asymptomatic women. To begin to elucidate the mechanisms, we longitudinally analyzed profiles of innate immune factors and HIV infectivity in genital secretions from anatomically specific sites in asymptomatic women during C. trachomatis infection and post-antibiotic treatment. We found higher levels of cytokines and chemokines in endocervical secretions than vaginal secretions. Compared with the convalescent state, G-CSF, IL-1α, and RANTES were elevated in endocervical secretions, IFN-γ and TNF-α were elevated in vaginal secretions, and IFNγ, IL-1β, and MIP1-α were elevated in cervicolavage fluid (CVL), before adjustment of multiple comparisons. Elevated endocervical levels of IP-10 and MCP-1 were associated with the use of hormonal contraception in infected women after successful treatment, suggesting the role of hormonal contraception in inflammation independent of STIs. Importantly, soluble factors found in endocervical secretions during infection enhanced HIV infectivity while no difference in HIV infectivity was found with vaginal secretions or CVL during infection or at convalescence. Taken together, the profiles of immune mediators and in vitro HIV infectivity indicate that the endocervical and vaginal mucosa are immunologically distinct. Our results underscore the importance of considering anatomical site and local sampling methodology when measuring mucosal responses, particularly in the presence of C. trachomatis infection.

Uterine epithelial cells specifically induce interferon-stimulated genes in response to polyinosinic-polycytidylic acid independently of estradiol

Interferon β (IFNβ) is an antiviral cytokine secreted in response to pathogenic exposure that creates a restrictive intracellular environment through the action of downstream interferon-stimulated genes (ISG). The objective of this study was to examine the expression of IFNβ and ISG in both human uterine epithelial cells (UEC) and the ECC-1 uterine epithelial cell line and determine if expression changes with TLR stimulation and hormone exposure. Stimulation of primary uterine epithelial cells and ECC-1 cells with the TLR3 agonist poly (I:C) induced the mRNA expression of IFNβ, MxA, OAS2 and PKR. Other TLR agonists including imiquimod and CpG had no effect on either IFNβ or ISG expression. In contrast to ECC-1 cell responses which were slower, maximal IFNβ upregulation in UEC occurred 3 hours post-stimulation and preceded the ISG response which peaked approximately 12 hours after poly (I:C) exposure. Unexpectedly, estradiol, either alone or prior to treatment with poly (I:C), had no effect on IFNβ or ISG expression. Blockade of the IFN receptor abrogated the upregulation of MxA, OAS2 and PKR. Furthermore, neutralizing antibodies against IFNβ partially inhibited the upregulation of all three ISG. Estradiol, directly and in the presence of poly (I:C) had no effect on IFNβ and ISG expression. These results indicate that uterine epithelial cells are important sentinels of the innate immune system and demonstrate that uterine epithelial cells are capable of mounting a rapid IFN-mediated antiviral response that is independent of estradiol and is therefore potentially sustained throughout the menstrual cycle to aid in the defense of the uterus against potential pathogens.

Menstrual cycle influences Toll-like receptor responses

BACKGROUND

Toll-like receptors (TLRs) are pattern recognition receptors that play an important role as mediators of innate immunity. Human studies have shown changes in endometrial TLR expression during the menstrual cycle and during pregnancy. Our objective was to measure peripheral TLR activity over the course of the menstrual cycle.

METHODS

We recruited 11 healthy females, and using ELISA we measured sex hormone levels and IL-1β, IL-6, IL-8 and TNF-α following stimulation of whole blood with different TLR agonists during follicular, and early and late luteal phases of the menstrual cycle.

RESULTS

During the follicular phase, we observed lower levels of IL-6 and TNF-α following stimulation with the TLR2 agonist HKLM when compared with the early luteal phase; lower levels of IL-1β, IL-6 and TNF-α following stimulation with the TLR4 agonist LPS, and lower levels of IL-1β and TNF-α following stimulation with the TLR5 agonist flagellin. Decreased IL-6 levels in the late compared to the early luteal phase were also observed following stimulation with the TLR5 agonist flagellin. Compared with the follicular phase, the late luteal phase of the cycle resulted in decreased levels of IL-1β and TNF-α following stimulation with the TLR1/TLR2 agonist Pam3CSK and the TLR6/TLR2 agonist FSL1, as well as decreased levels of TNF-α following stimulation with the TLR8 agonist ssRNA40. There were no differences in cytokine release across the menstrual cycle following stimulation with the TLR3 agonist polyriboinosinic polyribocytidylic acid, or the TLR7 agonist Imiquimod.

CONCLUSION

This study is the first to demonstrate that TLR responsivity in peripheral blood fluctuates throughout the menstrual cycle.

Modulation of innate immunity in human pancreatic islets infected with enterovirus in vitro

Present knowledge of innate immunity in infected cells relies on studies of cell lines and animal models. In this study, primary human pancreatic islets of Langerhans were used to study virus-host interactions in a model of the possible induction of type 1 diabetes by enterovirus (EV). Human islets were infected with a strain of EV isolated at onset of type 1 diabetes, or exposed to synthetic dsRNA (poly(I:C)), used commonly to mimic viral infection. Induction of innate immunity and the effect of the female sex hormone 17β-estradiol, known to have cell-protective effects, on islet chemokine secretion were investigated. 17β-Estradiol reduced EV-but not poly(I:C)-induced IP-10/CXCL10 secretion from human islets, suggesting that separate signaling pathways of the innate immune response are triggered by EV and poly(I:C), respectively. Infection with EV increased the gene-expression of toll-like receptor 3, interferon-β, and the intracellular helicase MDA5, involved in antiviral innate immunity, multi-fold over time, whereas poly(I:C) increased the expression of these genes transiently. The induced expression pattern was similar in all donors, but the expression levels varied greatly. Pre-exposure to poly(I:C) blocked viral replication in islets from 56% of the donors. These data provide insight on the innate immune responses induced by EV in human islets, and show that this can be modulated by 17β-estradiol, and suggest an important difference between virus- and poly(I:C)-induced signaling.

Clinical significance of interleukin (IL)-6 in cancer metastasis to bone: potential of anti-IL-6 therapies

Metastatic events to the bone occur frequently in numerous cancer types such as breast, prostate, lung, and renal carcinomas, melanoma, neuroblastoma, and multiple myeloma. Accumulating evidence suggests that the inflammatory cytokine interleukin (IL)-6 is frequently upregulated and is implicated in the ability of cancer cells to metastasize to bone. IL-6 is able to activate various cell signaling cascades that include the STAT (signal transducer and activator of transcription) pathway, the PI3K (phosphatidylinositol-3 kinase) pathway, and the MAPK (mitogen-activated protein kinase) pathway. Activation of these pathways may explain the ability of IL-6 to mediate various aspects of normal and pathogenic bone remodeling, inflammation, cell survival, proliferation, and pro-tumorigenic effects. This review article will discuss the role of IL-6: 1) in bone metabolism, 2) in cancer metastasis to bone, 3) in cancer prognosis, and 4) as potential therapies for metastatic bone cancer.

Expression pattern of matrix metalloproteinases in human gynecological cancer cell lines

Background

Matrix metalloproteinases (MMPs) are involved in the degradation of protein components of the extracellular matrix and thus play an important role in tumor invasion and metastasis. Their expression is related to the progression of gynecological cancers (e.g. endometrial, cervical or ovarian carcinoma). In this study we investigated the expression pattern of the 23 MMPs, currently known in humans, in different gynecological cancer cell lines.

Methods

In total, cell lines from three endometrium carcinomas (Ishikawa, HEC-1-A, AN3 CA), three cervical carcinomas (HeLa, Caski, SiHa), three chorioncarcinomas (JEG, JAR, BeWo), two ovarian cancers (BG-1, OAW-42) and one teratocarcinoma (PA-1) were examined. The expression of MMPs was analyzed by RT-PCR, Western blot and gelatin zymography.

Results

We demonstrated that the cell lines examined can constitutively express a wide variety of MMPs on mRNA and protein level. While MMP-2, -11, -14 and -24 were widely expressed, no expression was seen for MMP-12, -16, -20, -25, -26, -27 in any of the cell lines. A broad range of 16 MMPs could be found in the PA1 cells and thus this cell line could be used as a positive control for general MMP experiments. While the three cervical cancer cell lines expressed 10-14 different MMPs, the median expression in endometrial and choriocarcinoma cells was 7 different enzymes. The two investigated ovarian cancer cell lines showed a distinctive difference in the number of expressed MMPs (2 vs. 10).

Conclusions

Ishikawa, Caski, OAW-42 and BeWo cell lines could be the best choice for all future experiments on MMP regulation and their role in endometrial, cervical, ovarian or choriocarcinoma development, whereas the teratocarcinoma cell line PA1 could be used as a positive control for general MMP experiments.

Differential modulation of TLR3- and TLR4-mediated dendritic cell maturation and function by progesterone

The role of progesterone in modulating dendritic cell (DC) function following stimulation of different TLRs is relatively unknown. We compared the ability of progesterone to modulate murine bone marrow-derived DC cytokine production (IL-6 and IL-12) and costimulatory molecule expression (CD40, CD80, and CD86) induced by either TLR3 or TLR4 ligation and determined whether activity was via the progesterone receptor (PR) or glucocorticoid receptor (GR) by comparative studies with the PR-specific agonist norgestrel and the GR agonist dexamethasone. Progesterone was found to downregulate, albeit with different sensitivities, both TLR3- and TLR4-induced IL-6 production entirely via the GR, but IL-12p40 production via either the GR or PR. Of particular significance was that progesterone was able to significantly inhibit TLR3- but not TLR4-induced CD40 expression in bone marrow-derived DCs. Stimulation of the PR (with progesterone and norgestrel) by pretreatment of DCs was found to sustain IFN regulatory factor-3 phosphorylation following TLR3 ligation, but not TLR4 ligation. Overall, these studies demonstrate that progesterone can differentially regulate the signaling pathways employed by TLR3 and TLR4 agonists to affect costimulatory molecule expression and cytokine production.

Oestrogen and progesterone regulation of inflammatory processes in the human endometrium

The human endometrium is a unique tissue that has to undergo cycles of proliferation, differentiation, destruction and repair. This ensures that the endometrium is optimally prepared for potential embryo implantation but in the absence of an embryo, menstruation occurs to allow endometrial regeneration. These cycles of tissue remodelling occur under the sequential influence of the sex steroid hormones, oestrogen and progesterone. The physiological events of implantation and menstruation display features of inflammation, tightly regulated by oestrogen and progesterone. After menstruation cellular proliferation and blood vessel growth is modulated by oestrogen while after ovulation progesterone is the dominant hormone. In preparation for implantation, progesterone regulates decidualization of the endometrium, uterine natural killer cell numbers within the endometrium and chemokine and cytokine expression. Menstruation, in contrast, is preceded by progesterone withdrawal, which results in an influx of leukocytes into the endometrium and increased production of chemokines and matrix metalloproteinases allowing tissue degradation. The aim of this article is to review the current knowledge on the regulation of inflammatory events within the endometrium by oestrogen and progesterone, in relation to two pivotal events for human reproduction, implantation and menstruation.

Pattern recognition via the toll-like receptor system in the human female genital tract

The mucosal surface of the female genital tract is a complex biosystem, which provides a barrier against the outside world and participates in both innate and acquired immune defense systems. This mucosal compartment has adapted to a dynamic, non-sterile environment challenged by a variety of antigenic/inflammatory stimuli associated with sexual intercourse and endogenous vaginal microbiota. Rapid innate immune defenses against microbial infection usually involve the recognition of invading pathogens by specific pattern-recognition receptors recently attributed to the family of Toll-like receptors (TLRs). TLRs recognize conserved pathogen-associated molecular patterns (PAMPs) synthesized by microorganisms including bacteria, fungi, parasites, and viruses as well as endogenous ligands associated with cell damage. Members of the TLR family, which includes 10 human TLRs identified to date, recognize distinct PAMPs produced by various bacterial, fungal, and viral pathogens. The available literature regarding the innate immune system of the female genital tract during human reproductive processes was reviewed in order to identify studies specifically related to the expression and function of TLRs under normal as well as pathological conditions. Increased understanding of these molecules may provide insight into site-specific immunoregulatory mechanisms in the female reproductive tract.

Sex hormone regulation of innate immunity in the female reproductive tract: the role of epithelial cells in balancing reproductive potential with protection against sexually transmitted pathogens

The immune system in the female reproductive tract (FRT) does not mount an attack against HIV or other sexually transmitted infections (STI) with a single endogenously produced microbicide or with a single arm of the immune system. Instead, the body deploys dozens of innate antimicrobials to the secretions of the female reproductive tract. Working together, these antimicrobials along with mucosal antibodies attack many different viral, bacterial and fungal targets. Within the FRT, the unique challenges of protection against sexually transmitted pathogens coupled with the need to sustain the development of an allogeneic fetus have evolved in such a way that sex hormones precisely regulate immune function to accomplish both tasks. The studies presented in this review demonstrate that estradiol and progesterone secreted during the menstrual cycle act both directly and indirectly on epithelial cells and other immune cells in the reproductive tract to modify immune function in a way that is unique to specific sites throughout the FRT. As presented in this review, studies from our laboratory and others demonstrate that the innate immune response is under hormonal control, varies with the stage of the menstrual cycle, and as such is suppressed at mid-cycle to optimize conditions for successful fertilization and pregnancy. In doing so, a window of STI vulnerability is created during which potential pathogens including HIV enter the reproductive tract to infect host targets.

Innate immunity and disorders of the female reproductive tract

Sexually transmitted infections, and their associated sequelae, such as tubal infertility, ectopic pregnancy and preterm labour, are a major worldwide health problem. Chlamydia trachomatis infection is thought to be the leading global cause of tubal infertility and tubal ectopic pregnancy. Preterm birth occurs in around 10% of all deliveries, and nearly 30% of preterm deliveries are associated with intrauterine infection. The mucosal innate immune system of the female reproductive tract has evolved to eliminate such sexually transmitted pathogens whilst maintaining its ability to accommodate specialized physiological functions that include menstruation, fertilization, implantation, pregnancy and parturition. The aim of this review was to describe the role and distribution of key mediators of the innate immune system, the natural antimicrobial peptides (secretory leukocyte protease inhibitor, elafin and the defensins) and the pattern recognition toll-like receptors in the normal female reproductive tract and in the context of these pathological processes.

17beta-Estradiol inhibits Ca2+-dependent homeostasis of airway surface liquid volume in human cystic fibrosis airway epithelia

Normal airways homeostatically regulate the volume of airway surface liquid (ASL) through both cAMP- and Ca2+-dependent regulation of ion and water transport. In cystic fibrosis (CF), a genetic defect causes a lack of cAMP-regulated CFTR activity, leading to diminished Cl- and water secretion from airway epithelial cells and subsequent mucus plugging, which serves as the focus for infections. Females with CF exhibit reduced survival compared with males with CF, although the mechanisms underlying this sex-related disadvantage are unknown. Despite the lack of CFTR, CF airways retain a limited capability to regulate ASL volume, as breathing-induced ATP release activates salvage purinergic pathways that raise intracellular Ca2+ concentration to stimulate an alternate pathway to Cl- secretion. We hypothesized that estrogen might affect this pathway by reducing the ability of airway epithelia to respond appropriately to nucleotides. We found that uridine triphosphate-mediated (UTP-mediated) Cl- secretion was reduced during the periovulatory estrogen maxima in both women with CF and normal, healthy women. Estrogen also inhibited Ca2+ signaling and ASL volume homeostasis in non-CF and CF airway epithelia by attenuating Ca2+ influx. This inhibition of Ca2+ signaling was prevented and even potentiated by estrogen antagonists such as tamoxifen, suggesting that antiestrogens may be beneficial in the treatment of CF lung disease because they increase Cl- secretion in the airways.

TLR3 and TLR4 expression in healthy and diseased human endometrium

BACKGROUND

Toll-like receptors (TLRs) play an essential role in the innate immune system by initiating and directing immune response to pathogens. TLRs are expressed in the human endometrium and their regulation might be crucial for the pathogenesis of endometrial diseases.

METHODS

TLR3 and TLR4 expression was investigated during the menstrual cycle and in postmenopausal endometrium considering peritoneal endometriosis, hyperplasia, and endometrial adenocarcinoma specimens (grade 1 to 3). The expression studies applied quantitative RT-PCR and immunolabelling of both proteins.

RESULTS

TLR3 and TLR4 proteins were mostly localised to the glandular and luminal epithelium. In addition, TLR4 was present on endometrial dendritic cells, monocytes and macrophages. TLR3 and TLR4 mRNA levels did not show significant changes during the menstrual cycle. In patients with peritoneal endometriosis, TLR3 and TLR4 mRNA expression decreased significantly in proliferative diseased endometrium compared to controls. Interestingly, ectopic endometriotic lesions showed a significant increase of TLR3 und TLR4 mRNA expression compared to corresponding eutopic tissues, indicating a local gain of TLR expression. Endometrial hyperplasia and adenocarcinoma revealed significantly reduced receptor levels when compared with postmenopausal controls. The lowest TLR expression levels were determined in poor differentiated carcinoma (grade 3).

CONCLUSION

Our data suggest an involvement of TLR3 and TLR4 in endometrial diseases as demonstrated by altered expression levels in endometriosis and endometrial cancer.

Estradiol selectively regulates innate immune function by polarized human uterine epithelial cells in culture

The goal of this study was to examine the role of E(2) in regulating innate immune protection by human uterine epithelial cells (UECs). Recognizing that UECs produce cytokines and chemokines to recruit and activate immune cells as well as viral and bacterial antimicrobials, we sought to examine the effect of E(2) on constitutive and Toll-like receptor (TLR) agonist (lipopolysaccharide (LPS) and poly (I:C))-induced immune responses. The secretion by polarized UECs in culture of interleukin (IL)-6, macrophage inhibitory factor (MIF), and secretory leukocyte protease inhibitor (SLPI) was examined as well as the mRNA expression of human beta-defensin-2 (HBD2), tumor necrosis factor (TNF)-alpha, IL-8, and nuclear factor (NF)-kB. When incubated with E(2) for 24-48 h, we found that E(2) stimulated UEC secretion of SLPI (fourfold) and mRNA expression of HBD2 (fivefold). Moreover, when antibacterial activity in UEC secretions was measured using Staphylococcus aureus, E(2) increased the secretion of soluble factor(s) with antibacterial activity. In contrast, E(2) had no effect on constitutive secretion of proinflammatory cytokines and chemokines by UECs but completely inhibited LPS- and poly (I:C)-induced secretion of MIF, IL-6, and IL-8. Estradiol also reversed the stimulatory effects of IL-1beta on mRNA expression of TNF-alpha, IL-8, and NF-kB by 85, 95, and 70%, respectively. As SLPI is known to inhibit NF-kB expression, these findings suggest that E(2) inhibition of proinflammatory cytokines may be mediated through SLPI regulation of NF-kB. Overall, these findings indicate that the production of cytokines, chemokines, and antimicrobials by UECs are differentially regulated by E(2). Further, it suggests that with E(2) regulation, epithelial cells that line the uterine cavity have evolved immunologically to be sensitive to viral and bacterial infections as well as the constraints of procreation.

Toll-like receptors in female reproductive tract and their menstrual cycle dependent expression

Rapid innate immune defences against infection usually involve the recognition of invading pathogens by specific pattern recognition receptors recently attributed to the family of Toll-like receptors (TLR). TLRs constitute a major part of innate immune system, and have been characterised in different tissues and organs. Reports from our laboratory and others have demonstrated the existence of TLRs in the female reproductive tract, yet TLRs have not been explored completely in this system. There is little known about variation in TLR expression during the menstrual cycle and the effects that sex hormones may have on their expression and function. Here, we review recent information regarding the existence of TLRs in the female reproductive tract, their function in the maintenance of innate immune system in this tract and their potential role in pregnancy.

Expression of toll-like receptors 2, 3, 4, and 9 genes in the human endometrium during the menstrual cycle

Innate immunity in the endometrium has fundamental significance for reproduction. Although toll-like receptors (TLRs) play central roles in innate immune responses, their expression in the human endometrium remains to be fully elucidated. We have examined the gene expression of TLR2, TLR3, TLR4, and TLR9 in endometrial tissues by real-time quantitative PCR and in situ hybridization. The expression levels of the four genes in endometrial tissues varied in a similar pattern during the menstrual cycle; the levels were high in the perimenstrual period and low in the periovulatory period. Expression of the four genes was detected in both epithelial cells and stromal cells throughout the menstrual cycle. Expression levels were higher in epithelial cells for TLR3 and in stromal cells for TLR4, while they were comparable in epithelial cells and stromal cells for TLR2 and TLR9. These findings imply that differential spatio-temporal expression patterns of TLRs subserve proper innate immunity of the endometrium.

Menstrual cycle-dependent changes of Toll-like receptors in endometrium

BACKGROUND

Rapid innate immune defences against infection usually involve the recognition of invading pathogens by specific pattern recognition receptors recently attributed to the family of Toll-like receptors (TLRs). Reports from our laboratory and others have demonstrated the existence of TLRs 1-6 in the female reproductive tract. However, little has been done to identify TLRs 7-10 in the female reproductive tract, particularly in the uterus. Also little information exists regarding variation in TLRs in the female reproductive tract during the menstrual cycle.

METHOD

The distribution of TLR7-10 protein was detected by immunostaining in timed endometrial biopsies from normal women. RT-PCR was used to show the existence of TLR1-10 genes in endometrial tissue and real-time PCR analysis to investigate the relative expression of these genes during the menstrual cycle in normal human endometrium.

RESULTS

TLR7-10 proteins were detected in endometrial epithelium and stroma. TLR1-10 genes were expressed in human endometrial tissue, and the mean relative expression of TLR2-6, 9 and 10 genes was significantly higher during the secretory phase compared with other phases of the menstrual cycle.

CONCLUSIONS

TLR7-10 localization is not limited to endometrial epithelium but is also present in the stroma of the endometrial tissue. Endometrial TLR2-6, 9 and 10 genes are cyclically expressed during the menstrual cycle.