Hum. Reprod. Advance Access originally published online on October 16, 2006
Human Reproduction 2007 22(2):586-593; doi:10.1093/humrep/del388
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Menstrual cycle-dependent changes of Toll-like receptors in endometrium
1 Academic Unit of Reproductive and Developmental Medicine 2 Biomedical Research Unit, The University of Sheffield, Jessop Wing, Sheffield, UK and 3 Research and Clinical Center for Infertility, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
4 To whom correspondence should be addressed at: Academic Unit of Reproductive and Developmental Medicine, The University of Sheffield, Level 4, Jessop Wing, Tree Root Walk, Sheffield, S10 2SF, UK. E-mail: a.fazeli{at}sheffield.ac.uk
 |
Abstract |
|---|
 Top Abstract IntroductionMaterials and methodsResultsDiscussionAcknowledgementsReferences |
|---|
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.
Key words: endometrium/menstrual cycle/Toll-like receptors
|
Introduction |
|---|
|
TopAbstractIntroductionMaterials and methodsResultsDiscussionAcknowledgementsReferences |
|---|
Sexually transmitted diseases (STDs) are a major worldwide health problem that compromise reproductive fecundity as well as cut short the lives of millions of men, women and children (Cates, 1986
; Piot et al., 1988). Despite advances in the management of these infections, only limited success has been achieved in curtailing the morbidity and mortality associated with them. The commoner STDs with the largest health and socio-economic impact include infections by the herpes simplex virus type 2 (HSV-2), Chlamydia trachomatis, the gonococcus and human immunodeficiency viruses (HIVs). In addition, maternal genital tract carriage of the group B streptococcus and bacterial vaginosis seems to be associated with premature birth and neonatal mortality and morbidity (Martius and Eschenbach, 1990). Because of this growing global health problem, prevention and effective treatment methodologies need to be developed. Understanding the mechanisms that regulate the female reproductive tract immune system holds therapeutic promise. If the immunological host defence mechanisms against these infections are clarified, effective vaccines can be developed.
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) (Medzhitov and Janeway, 2000; Janeway and Medzhitov, 2002). TLRs are expressed by cells involved in the first line of host defence, including neutrophils, macrophages, dendritic cells, dermal endothelial cells and mucosal epithelial cells. Collectively, TLRs function to alert the immune system to the presence of micro-organisms. Different members of the TLR family are expressed on different cell organelles and appear to mediate signal transduction to a range of antigenic stimuli by engaging with specific ligands leading to the production of various proinflammatory cytokines, chemokines and effector molecules, depending on the cell type that is activated. The members of the TLR family, of which at least 11 have been identified, recognize distinct pathogen-associated molecular patterns (PAMPs) produced by various bacterial, fungal and viral pathogens. TLR2 forms heterodimers with TLRs 1 and 6 and recognizes a broad range of microbial products from Gram-positive bacteria (peptidoglycan) (Schwandner et al., 1999), fungi (zymosan) (Underhill et al., 1999) and synthetic lipoproteins (Pam3Cys-Ser-(Lys)4) (Takeuchi et al., 2002). TLR3 recognizes double-stranded RNA of viral or cellular origin (Alexopoulou et al., 2001; Kariko et al., 2004). The major component of the outer membrane of Gram-negative bacteria, lipopolysaccharide (LPS), is recognized by TLR4 in association with CD14 and MD-2 (Akashi et al., 2001; da Silva Correia et al., 2001; Nagai et al., 2002). TLR5 recognizes bacterial flagellin (Hayashi et al., 2001), TLRs 7 and 8 recognize single-stranded RNA (ssRNA) and synthetic nucleotide derivatives (Hemmi et al., 2002; Heil et al., 2004), and TLR9 recognizes non-methylated CpG containing DNA (Hemmi et al., 2000). No specific ligand has yet been identified for TLR10 (Chuang and Ulevitch, 2001). Studies in mice have shown TLR11 binds to a profilin-like protein from Toxoplasma gondii (Yarovinsky et al., 2005; Yarovinsky and Sher, 2006).
Several reports exist on the determination and characterization of TLRs in different tissues and organs (Bsibsi et al., 2002; Zarember and Godowski, 2002; Backhed and Hornef, 2003; Basu and Fenton, 2004). However, little has been done to identify TLRs in the human female. Recently, we demonstrated the in vivo distribution of TLRs 1–6 in the human female reproductive tract using immunohistochemical techniques (Fazeli et al., 2005). With the exception of TLR4, all other TLRs studied were uniformly distributed throughout the tract. TLR7–10 mRNA has been shown to be expressed in human uterine tissue (Nishimura and Naito, 2005). TLRs have been predominantly described in the epithelial cells of the human endometrium. Primary human uterine epithelial cell cultures and the uterine epithelial cell line ECC-1 express TLR1–9 genes (Schaefer et al., 2004, 2005). However, in contrast to the studies utilizing cultured cells, Young et al. (2004) could not detect the expression of TLR7, 8 and 10 genes in endometrial tissue samples. No information exists regarding the potential immunohistochemical localization of TLR7–10 in the female reproductive tract and in particular in the endometrium in vivo. In the present investigation, we report the gene expression and the in vivo localization of TLR7–10 molecules in healthy human endometrial tissue biopsies.
Although reports from our laboratory and others have demonstrated the existence of TLRs in the female reproductive tract, little information exists regarding variation in TLR presence in the female reproductive tract during the menstrual cycle. Recently, Jorgenson et al. (2005) demonstrated the cycle-dependent expression of TLR3 in primary endometrial epithelial tissue. One can hypothesize that other TLR molecules may have a cycle-dependent expression in the endometrial tissue as well. We tested this hypothesis, and here, we report the alteration in the expression of TLR1–10 genes during the menstrual cycle in normal human endometrial tissue.
|
Materials and methods |
|---|
|
TopAbstractIntroductionMaterials and methodsResultsDiscussionAcknowledgementsReferences |
|---|
Tissue collection for immunostaining and genomic investigations
This investigation was approved by the Local Ethics Committee, and written informed consent was obtained prior to the collection of tissue samples. For immunohistochemical investigations, tissue samples were obtained from six fertile women, and for genomic studies, endometrial biopsies were obtained from 21 fertile women. All the women taking part in the investigation had regular cycles, showed no evidence of any pathological uterine disorder and had not used oral contraception or an intrauterine device in the previous 3 months. Biopsies were obtained in the operating theater between 1 and 29 days after the last menstrual period (LMP). The mean age of the women taking part in the study was 35 (range 24–40) years, and each had had at least one previous successful pregnancy. Endometrial biopsies for immunocytochemistry were immediately snap-frozen and stored in liquid nitrogen until processed. Cryosections were cut at 5 mm and stored at –70°C until use. For genomic studies, endometrial biopsies were immediately placed in RNAlater (Ambion, Huntingdon, UK) followed by immediate immersion in liquid nitrogen until processed.
Antibodies and peptides
Antibodies and peptides used in the experiments were obtained from Santa Cruz Biotechnology (CA, USA). These were goat polyclonal antibodies specific for N-terminal domains of TLRs 7 and 9 (catalogue number sc13207 and sc13212, respectively), goat polyclonal antibody specific for V-terminal domains of TLR10 (catalogue number sc23577) and rabbit polyclonal specific for D-terminal domains of TLR8 (catalogue number sc13212-R). Blocking peptides specific for the respective antibodies were used to detect non-specific staining.
Immunostaining
Cryosections were removed from –70°C freezer, fixed in 4% paraformaldehyde for 15 min, washed twice in phosphate-buffered saline (PBS) for 5 min and then immersed in methanol at –20°C for 4 min followed by 2 min in acetone at –20°C before being finally washed in PBS. Cryopreserved slides were timed according to LMP and morphology and divided into three groups (menstrual, proliferative or secretory phase). Slides were stained using a Vectorstain Elite ABC peroxidase kit, according to the manufacturer’s instructions (Vector Laboratories, Peterborough, UK). To avoid the non-specific binding of biotin, we used an avidin/biotin blocking kit (Vector Laboratories). Briefly, slides were blocked for 1 h at room temperature in PBS containing 0.2% appropriate serum and 250 µl/ml of avidin. The block was removed, and slides were incubated overnight at 4°C in primary antibody at an appropriate dilution using antibody diluent media (Dakocytomation, Ely, UK) containing 250 µl/ml of biotin. Binding was visualized by incubation with peroxidase substrate 3-amino-9-ethylcarbazole (AEC) (Vector Laboratories) for 10 min, washed in distilled water for 3 min and counterstained in 10% haematoxylin for 10 min. Slides were washed in tap water for 2 min and mounted with Aquamount (VWR).
Optimum staining was achieved by incubating tissue sections with 10 µg/ml of the specific TLR antibody. Negative control sections were obtained by blocking of primary antibody with its specific peptide. Immunostained sections were examined using an Olympus BH2 microscope (Olympus, London, UK).
RNA isolation, cDNA production and quantitative PCR
Tissues were removed from RNAlater and homogenized in 3 ml of TRI reagent (Sigma, Pool, UK) using an Ultra Turrax homogenizer (VWR) for 
2 min. Total RNA was extracted using TRI reagent standard protocol supplied by the manufacturer. Total RNA was treated with DNase I (DNA-free Kit; Ambion) to remove genomic DNA contamination from samples. First-strand cDNA synthesis was performed using oligo dT primers and the Superscript II reverse transcriptase system (Invitrogen, Paisley, UK).
Reverse-transcription polymerase chain reaction (RT–PCR) was performed using the prepared cDNA, primers for TLRs 1–10 (Table I) and Platinum Blue PCR Super Mix (Invitrogen) under the following conditions: 40 cycles at 95°C for 30 s, 59–70°C for 1 min (different temperature for different TLRs) and 72°C for 2 min.
|
Quantitative real-time PCR was performed using the prepared cDNA and primers for TLRs 1–10 and human
-actin. The forward and reverse primer sequences used are depicted in Table I. All experiments included negative controls with no cDNA. SYBR Green Jump Start (Sigma) master mix was added to each well of the PCR plate (10 µl of SYBR Green, 7 µl of water, 2 µl of primers and 1 µl of cDNA), and PCR was performed under the following conditions: 50 cycles at 95°C for 30 s, 59–70°C for 30 s (different temperature for different TLRs) and 72°C for 30 s. Samples were run in triplicate. Results were analyzed using an iCycler (Biorad laboratories, Hemel Hempstead, UK).
To compare the relative quantities of different TLRs during the menstrual cycle, we divided biopsies into the following three groups: menstrual (LMP+1–4; n = 3; consisting of patients at LMP+1, +4 and +4), proliferative (LMP+5–14; n = 9; consisting of patients at early proliferative LMP+5, +5, +7, mid-proliferative LMP+8, +9, +10 and late proliferative LMP+11, +12 and +13) and secretory (LMP+15–29; n = 9; consisting of patients at early secretory LMP+16, +16 and +17, mid-secretory LMP+20, +21 and +22 and late secretory LMP+26, +28 and +29). Relative TLR expression quantities were compared between these groups. The threshold cycle values were normalized against the threshold value of human -actin. Differences in normalized expression values between samples were tested for significance using ANOVA statistical test. The results were expressed as mean ± SEM. The level of statistical significance was set at P < 0.05.
|
Results |
|---|
|
TopAbstractIntroductionMaterials and methodsResultsDiscussionAcknowledgementsReferences |
|---|
Immunostaining
Cryosections were used to study the distribution of TLRs 7–10 in timed endometrial biopsies. Positive immunostaining for all these TLRs was observed in endometrial gland epithelium, luminal epithelium and stroma throughout the menstrual cycle (Figure 1). Moderate TLR7 staining was observed in gland and luminal proliferative epithelium with slight down-regulation of gland staining in the secretory phase. Weak TLR8 immunostaining was present in proliferative luminal and gland epithelium; up-regulation was observed in secretory luminal epithelium. Strong staining for TLR9 was observed in proliferative luminal epithelial cells with weaker staining in proliferative gland cells; gland staining increased in the secretory phase. Proliferative TLR10 immunostaining was similar to that of proliferative TLR9 staining. In contrast to TLR9, TLR10 epithelial gland cell staining decreased in the secretory phase although TLR10 luminal epithelium staining remained high. Diffuse stromal staining was observed for TLRs 7–10. In addition, specific intense staining of a sparse population of individual stromal cells was observed in both proliferative and secretory endometrial tissues stained for TLR9 (arrows, Figure 1).
|
RT–PCR and quantitative PCR
Figure 2 shows the results of RT–PCR for mRNA expression of TLR1–10 genes in human endometrial tissue. All amplified products were the predicted size for that particular gene. There was no product amplified in control samples indicative of the absence of genomic DNA contamination.
|
The quantitative expression profiles of TLR1–10 genes during the menstrual cycle in endometrial biopsies are shown in Figure 3 (A–J, respectively). TLRs 3–6, 9 and 10 showed a significantly higher expression of TLR in the secretory phase compared with the proliferative and menstrual phases of the cycle. Only, TLR2 expression was higher in the secretory phase compared with the proliferative phase but similar to menstrual phase. No significant difference was observed in the relative expression of genes for TLR1, 7 and 8 genes during the menstrual cycle.
|
|
Discussion |
|---|
|
TopAbstractIntroductionMaterials and methodsResultsDiscussionAcknowledgementsReferences |
|---|
Uterine endometrial epithelial cells are the first layer of uterine defence against pathogens ascending the female reproductive tract. Thus, as detectors of non-self entities, TLRs may be expected to be present in this tissue. In the present investigation, we found the presence of TLR1–10 mRNA in human endometrial biopsies. Our results are in agreement with another report regarding the presence of TLRs 1–6 and 9 in endometrial samples (Young et al., 2004
); however, in contrast to that report, we also detected the endometrial expression of TLRs 7, 8 and 10. None of the negative controls taken during our PCRs showed an amplified product (Figure 2), thus confirming the absence of genomic DNA contamination in our test PCR samples. The expression of all TLR molecules except TLR10 has been shown in endometrial cell lines (ECC-1) (Schaefer et al., 2004) and primary uterine epithelial cell cultures (Schaefer et al., 2005). The only significant difference between our investigations and that of Young et al. is that the TLR primers used for the amplification of TLR molecules in our study are different from those used previously. The immunohistochemical staining results of antibodies against TLRs 7–10 and their blocking with its specific peptides confirm the results of our gene expression studies regarding the presence of TLRs 7–10 in endometrial tissue.
Within the TLR family, TLRs 7–9 appear to be phylogenetically closely related to each other (Du et al., 2000) and form a functional subgroup that recognizes viral PAMPs in endosomal or lysosomal compartments (Heil et al., 2004). This is consistent with the fact that viral nucleic acid would be most likely detected by TLRs within an infected cell. For example, ssRNA viruses would reach the endosome through receptor-mediated uptake of a viral particle. There is evidence accumulating that, like TLR3, these TLRs can also respond to ‘self’ nucleic acid, which has been found to be immunostimulatory and may act as a ‘danger signal’ depending on its compartmentalization (Heil et al., 2004). Hence, it may be more correct to think of TLRs 7–9 as detectors of the abnormal localization of nucleic acid rather than as structures or motifs absent from the host (Diebold et al., 2004). It is reported that TLR9 recognizes unmethylated deoxycytidyl-phosphate-deoxyguanosine (CpG) dinucleotides that are common in bacterial and some viral nucleic acids (Hemmi et al., 2000; Bauer et al., 2001). Initially, TLRs 7 and 8 were shown to detect small antiviral compounds known as imidazoquinolines (Hemmi et al., 2002; Jurk et al., 2002). These were guanosine-based antiviral drugs. This indicated that the natural ligands for TLRs 7 and 8 could be viral nucleic acids. It has recently been reported that mouse TLR7 and human TLR8 (but not human TLR7) could recognize synthetic GU-rich ssRNA (Diebold et al., 2004; Lund et al., 2004).
Previously, we have reported the localization of TLRs 1–6 in various sections of the female reproductive tract using immunohistochemistry (Fazeli et al., 2005). Here, we provide further information regarding the localization of TLRs 7–10 in the endometrial tissue. For nearly all TLR molecules studied in the present investigation, the staining was not limited to epithelial cells and glands. It was also present in the stroma of the endometrium. No difference was found between proliferative- and secretory-stage endometrium staining with antibodies for different TLR molecules except slight increase in the stromal staining of TLR9. However, immunohistochemical staining is a qualitative technique and as such is not ideal for quantitative analysis. The specificity of staining for each TLR molecule was verified by blocking the staining using specific peptides for the respective antibody. Several other studies using immunohistochemistry have demonstrated the presence of TLR7 [tonsils (Mansson et al., 2006)] and TLR9 [liver (Martin-Armas, 2006), conjunctiva (Bonini et al., 2005) and gut (Rumio et al., 2004)] in different human tissues.
The endometrial environment is under the control of sex hormones during the menstrual cycle. The sex hormones not only regulate the anatomical and histological characteristics of endometrium (Beier and Beier-Hellwig, 1998; Classen-Linke et al., 1998) but are involved in the influx and localization of immune cells in the endometrium (Spornitz, 1992; Yeaman et al., 1997; von Rango, et al., 2001). For example, uterine natural killer (uNK) cells are found in the human uterus in large numbers spread throughout the endometrium with increasing numbers as the menstrual cycle progresses (Hunt, 1994; Givan et al., 1997). uNK cells mediate interferon-gamma production in the endometrium and are believed to be involved in the development of spiral arteries during early pregnancy and the control of trophoblast invasion. A recent article has shown that uNK cells express TLRs 2–4 (Eriksson et al., 2006) and that their response to TLR agonists is dependent on other cells within the endometrium. TLRs may therefore play a role in implantation other than the control of pathogens. Defensins, or cationic peptides, represent an important component of innate immune system at mucosal surfaces, including the female reproductive tract (Gallo et al., 2006; Lehrer and Ganz, 2002). Several of these broad-spectrum natural antimicrobial peptides are expressed in urogenital tissues, and their expression seems to be regulated by cycle-associated changes in sex hormones. For example, human intestinal defensin-5 (HD-5) mRNA is expressed in the vagina, ectocervix and variably in the endocervix, endometrium and Fallopian tube (Quayle et al., 1998). The endometrial expression of HD-5 mRNA has been reported to be higher during the early secretory phase of the cycle. The secreted HD-5 peptide in cervicovaginal lavage was also highest during the secretory phase of the menstrual cycle. The levels of other antimicrobials such as lactoferrin and lysozyme are also affected by oestradiol concentrations and the stage of the oestrous cycle (Cohen et al., 1984; Walmer et al., 1992). The adaptive immune system is also influenced by the altering levels of sex hormones during the menstrual cycle. Antigen presentation has been shown to be suppressed in response to increasing concentrations of oestrogen. Further to this, receptors for oestrogen have been found on both CD8 and CD4 T cells, so it is likely that their actions are also modified by changing concentrations of oestrogen. The actions of cytotoxic T cells appear to be down-regulated during days 14–28 of the menstrual cycle, when concentrations of progesterone and oestrogen are high (Beagley and Gockel, 2003). IgA and IgG have been shown to alter during the menstrual cycle, with the highest total levels of immunoglobulin occurring during menses, when oestrogen and progesterone are low and lowest at ovulation, when oestrogen is high and progesterone is low. However, responses vary in different parts of the reproductive tract with rising oestradiol increasing IgA in uterine secretions but suppressing levels in cervical mucus (Beagley and Gockel, 2003).
The present investigation clearly demonstrates alterations in relative expression of TLR2–6, 9 and 10 genes in the endometrial tissue during the menstrual cycle. Although these TLR molecules are expressed throughout the cycle, it seems the lowest amount of these genes is expressed during menstrual and proliferative stages of the cycle. The oestrogen levels are higher at the proliferative phase of the cycle compared with the secretory phase. At the same time, progesterone level is relatively higher at the secretory phase compared with the proliferative phase of the cycle. This may indicate an inhibitory effect of the oestrogen and/or a supporting influence of progesterone on the expression of TLR molecules in the endometrium. Further research should be focused towards understanding the regulation of expression of TLR molecules by sex hormones.
In agreement with our findings, Jorgenson et al. (2005) have recently demonstrated the cycle-dependent expression of TLR3 in primary endometrial epithelial tissue. Although Lesmeister et al. (2005) showed that in vitro treatment of endometrial epithelial cell lines with 17beta-oestradiol did not affect TLR3 mRNA or protein expression, treatment with 17beta-oestradiol did suppress cytokine and chemokine production resulting from TLR3 stimulation with poly I:C, suggesting that 17beta-oestradiol modulates TLR3 function.
In conclusion, we report the presence and localization of TLRs 7–10 for the first time in human endometrial biopsies. Our investigations indicate that the expression of TLRs 2–6, 9 and 10 is altered in the endometrium during the menstrual cycle. Further investigations should be directed towards understanding the underlying mechanism leading to changes in TLR expression in endometrium during the menstrual cycle as well as the significance of these cycle-dependent changes in mediating innate and adaptive immune responses in the female reproductive tract.
|
Acknowledgements |
|---|
|
TopAbstractIntroductionMaterials and methodsResultsDiscussionAcknowledgementsReferences |
|---|
We thank Dr E. Sostaic for her critical discussion during the course of the experiments and preparation of the manuscript and Dr M. Aarabi for statistical support.
|
References |
|---|
|
TopAbstractIntroductionMaterials and methodsResultsDiscussionAcknowledgementsReferences |
|---|
Akashi S, Nagai Y, Ogata H, Oikawa M, Fukase K, Kusumoto S, Kawasaki K, Nishijima M, Hayashi S, Kimoto M, et al. (2001) Human MD-2 confers on mouse Toll-like receptor 4 species-specific lipopolysaccharide recognition. Int Immunol 13:121595–1599.
Alexopoulou L, Holt AC, Medzhitov R, Flavell RA. (2001) Recognition of double-stranded RNA and activation of NF-kappaB by Toll-like receptor 3. Nature 413:6857732–738.[CrossRef][Medline]
Backhed F and Hornef M. (2003) Toll-like receptor 4-mediated signaling by epithelial surfaces necessity or threat? Microbes Infect 5:11951–959.[CrossRef][ISI][Medline]
Basu S and Fenton MJ. (2004) Toll-like receptors function and roles in lung disease. Am J Physiol Lung Cell Mol Physiol 286:5L887–L892.
Bauer S, Kirschning CJ, Hacker H, Redecke V, Hausmann S, Akira S, Wagner H, Lipford GB. (2001) Human TLR9 confers responsiveness to bacterial DNA via species-specific CpG motif recognition. Proc Natl Acad Sci USA 98:169237–9242.
Beagley KW and Gockel CM. (2003) Regulation of innate and adaptive immunity by the female sex hormones oestradiol and progesterone. FEMS Immunol Med Microbiol 38:113–22.[CrossRef][ISI][Medline]
Beier HM and Beier-Hellwig K. (1998) Molecular and cellular aspects of endometrial receptivity. Hum Reprod Update 4:448–458.
Bonini S, Micera A, Iovieno A, Lambiase A. (2005) Expression of Toll-like receptors in healthy and allergic conjunctiva. Ophthalmology 112:91528 discussion 1548–1549.[ISI][Medline]
Bsibsi M, Ravid R, Gveric D, van Noort JM. (2002) Broad expression of Toll-like receptors in the human central nervous system. J Neuropathol Exp Neurol 61:111013–1021.[ISI][Medline]
Cates W Jr. (1986) Priorities for sexually transmitted diseases in the late 1980s and beyond. Sex Transm Dis 13:2114–117.[ISI][Medline]
Chuang T and Ulevitch RJ. (2001) Identification of hTLR10: a novel human Toll-like receptor preferentially expressed in immune cells. Biochim Biophys Acta 1518:1–2157–161.[Medline]
Classen-Linke I, Alfer J, Hey S, Krusche CA, Kusche M, Beier HM. (1998) Marker molecules of human endometrial differentiation can be hormonally regulated under in-vitro conditions as in-vivo. Hum Reprod Update 4:539–549.
Cohen MS, Black JR, Proctor RA, Sparling PF. (1984) Host defences and the vaginal mucosa. A re-evaluation. Scand J Urol Nephrol Suppl 86:13–22.[Medline]
Diebold SS, Kaisho T, Hemmi H, Akira S, Reis e Sousa C. (2004) Innate antiviral responses by means of TLR7-mediated recognition of single-stranded RNA. Science 303:56631529–1531.
Du X, Poltorak A, Wei Y, Beutler B. (2000) Three novel mammalian toll-like receptors: gene structure, expression, and evolution. Eur Cytokine Netw 11:3362–371.[ISI][Medline]
Eriksson M, Meadows SK, Basu S, Mselle TF, Wira CR, Sentman CL. (2006) TLRs mediate IFN-(gamma) production by human uterine NK cells in endometrium. J Immunol 176:106219–6224.
Fazeli A, Bruce C, Anumba DO. (2005) Characterization of Toll-like receptors in the female reproductive tract in humans. Hum Reprod 20:51372–1378.
Gallo SA, Wang W, Rawat SS, Jung G, Waring AJ, Cole AM, Lu H, Yan X, Daly NL, Craik DJ, et al. (2006) Theta-defensins prevent HIV-1 env-mediated fusion by binding gp41 and blocking 6-helix bundle formation. J Biol Chem 281:2718787–18792.
Givan AL, White HD, Stern JE, Colby E, Gosselin EJ, Guyre PM, Wira CR. (1997) Flow cytometric analysis of leukocytes in the human female reproductive tract: comparison of fallopian tube, uterus, cervix, and vagina. Am J Reprod Immunol 38:5350–359.
Hayashi F, Smith KD, Ozinsky A, Hawn TR, Yi EC, Goodlett DR, Eng JK, Akira S, Underhill DM, Aderem A. (2001) The innate immune response to bacterial flagellin is mediated by Toll-like receptor 5. Nature 410:68321099–1103.[CrossRef][Medline]
Heil F, Hemmi H, Hochrein H, Ampenberger F, Kirschning C, Akira S, Lipford G, Wagner H, Bauer S. (2004) Species-specific recognition of single-stranded RNA via toll-like receptor 7 and 8. Science 303:56631526–1529.
Hemmi H, Takeuchi O, Kawai T, Kaisho T, Sato S, Sanjo H, Matsumoto M, Hoshino K, Wagner H, Takeda K, et al. (2000) A Toll-like receptor recognizes bacterial DNA. Nature 408:6813740–745.[CrossRef][Medline]
Hemmi H, Kaisho T, Takeuchi O, Sato S, Sanjo H, Hoshino K, Horiuchi T, Tomizawa H, Takeda K, Akira S. (2002) Small anti-viral compounds activate immune cells via the TLR7 MyD88-dependent signaling pathway. Nat Immunol 3:2196–200.[CrossRef][ISI][Medline]
Hunt JS. (1994) Immunologically relevant cells in the uterus. Biol Reprod 50:3461–466.[Abstract]
Janeway CA Jr and Medzhitov R. (2002) Innate immune recognition. Annu Rev Immunol 20:197–216.[CrossRef][ISI][Medline]
Jorgenson RL, Young SL, Lesmeister MJ, Lyddon TD, Misfeldt ML. (2005) Human endometrial epithelial cells cyclically express Toll-like receptor 3 (TLR3) and exhibit TLR3-dependent responses to dsRNA. Hum Immunol 66:5469–482.[CrossRef][ISI][Medline]
Jurk M, Heil F, Vollmer J, Schetter C, Krieg AM, Wagner H, Lipford G, Bauer S. (2002) Human TLR7 or TLR8 independently confer responsiveness to the antiviral compound R-848. Nat Immunol 3:6499.[CrossRef][ISI][Medline]
Kariko K, Ni H, Capodici J, Lamphier M, Weissman D. (2004) mRNA is an endogenous ligand for Toll-like receptor 3. J Biol Chem 279:1312542–12550.
Lehrer RI and Ganz T. (2002) Defensins of vertebrate animals. Curr Opin Immunol 14:196–102.[CrossRef][ISI][Medline]
Lesmeister MJ, Jorgenson RL, Young SL, Misfeldt ML. (2005) 17Beta-estradiol suppresses TLR3-induced cytokine and chemokine production in endometrial epithelial cells. Reprod Biol Endocrinol 3:74.[CrossRef][Medline]
Lund JM, Alexopoulou L, Sato A, Karow M, Adams NC, Gale NW, Iwasaki A, Flavell RA. (2004) Recognition of single-stranded RNA viruses by Toll-like receptor 7. Proc Natl Acad Sci USA 101:155598–5603.
Mansson A, Adner M, Cardell LO. (2006) Toll-like receptors in cellular subsets of human tonsil T cells: altered expression during recurrent tonsillitis. Respir Res 7:136.[CrossRef][Medline]
Martin-Armas M, Simon-Santamaria J, Pettersen I, Moens U, Smedsrod B, Sveinbjornsson B. (2006) Toll-like receptor 9 (TLR9) is present in murine liver sinusoidal endothelial cells (LSECs) and mediates the effect of CpG-oligonucleotides. J Hepatol 44:5939–946.[CrossRef][ISI][Medline]
Martius J and Eschenbach DA. (1990) The role of bacterial vaginosis as a cause of amniotic fluid infection, chorioamnionitis and prematurity—a review. Arch Gynecol Obstet 247:11–13.[CrossRef][ISI][Medline]
Medzhitov R and Janeway C Jr. (2000) Innate immunity. N Engl J Med 343:5338–344.
Nagai Y, Akashi S, Nagafuku M, Ogata M, Iwakura Y, Akira S, Kitamura T, Kosugi A, Kimoto M, Miyake K. (2002) Essential role of MD-2 in LPS responsiveness and TLR4 distribution. Nat Immunol 3:7667–672.[ISI][Medline]
Nishimura M and Naito S. (2005) Tissue-specific mRNA expression profiles of human toll-like receptors and related genes. Biol Pharm Bull 28:5886–892.[CrossRef][ISI][Medline]
Piot P, Plummer FA, Mhalu FS, Lamboray JL, Chin J, Mann JM. (1988) AIDS: an international perspective. Science 239:4840573–579.
Quayle AJ, Porter EM, Nussbaum AA, Wang YM, Brabec C, Yip KP, Mok SC. (1998) Gene expression, immunolocalization, and secretion of human defensin-5 in human female reproductive tract. Am J Pathol 152:51247–1258.[Abstract]
von Rango U, Classen-Linke I, Kertschanska S, Kemp B, Beier HM. (2001) Effects of trophoblast invasion on the distribution of leukocytes in uterine and tubal implantation sites. Fertil Steril 76:116–124.[CrossRef][ISI][Medline]
Rumio C, Besusso D, Palazzo M, Selleri S, Sfondrini L, Dubini F, Menard S, Balsari A. (2004) Degranulation of paneth cells via toll-like receptor 9. Am J Pathol 165:2373–381.
Schaefer TM, Desouza K, Fahey JV, Beagley KW, Wira CR. (2004) Toll-like receptor (TLR) expression and TLR-mediated cytokine/chemokine production by human uterine epithelial cells. Immunology 112:3428–436.[CrossRef][ISI][Medline]
Schaefer TM, Fahey JV, Wright JA, Wira CR. (2005) Innate immunity in the human female reproductive tract: antiviral response of uterine epithelial cells to the TLR3 agonist poly(I: C). J Immunol 174:2992–1002.
Schwandner R, Dziarski R, Wesche H, Rothe M, Kirschning CJ. (1999) Peptidoglycan- and lipoteichoic acid-induced cell activation is mediated by toll-like receptor 2. J Biol Chem 274:2517406–17409.
da Silva Correia J, Soldau K, Christen U, Tobias PS, Ulevitch RJ. (2001) Lipopolysaccharide is in close proximity to each of the proteins in its membrane receptor complex: transfer from CD14 to TLR4 and MD-2. J Biol Chem 276:2421129–21135.
Spornitz UM. (1992) The functional morphology of the human endometrium and decidua. Adv Anat Embryol Cell Biol 124:1–99.[Medline]
Takeuchi O, Sato S, Horiuchi T, Hoshino K, Takeda K, Dong Z, Modlin RL, Akira S. (2002) Cutting edge role of Toll-like receptor 1 in mediating immune response to microbial lipoproteins. J Immunol 169:110–14.
Underhill DM, Ozinsky A, Hajjar AM, Stevens A, Wilson CB, Bassetti M, Aderem A. (1999) The Toll-like receptor 2 is recruited to macrophage phagosomes and discriminates between pathogens. Nature 401:6755811–815.[CrossRef][Medline]
Walmer DK, Wrona MA, Hughes CL, Nelson KG. (1992) Lactoferrin expression in the mouse reproductive tract during the natural estrous cycle: correlation with circulating estradiol and progesterone. Endocrinology 131:31458–1466.[Abstract]
Yarovinsky F and Sher A. (2006) Toll-like receptor recognition of Toxoplasma gondii. Int J Parasitol 36:3255–259.[CrossRef][ISI][Medline]
Yarovinsky F, Zhang D, Andersen JF, Bannenberg GL, Serhan CN, Hayden MS, Hieny S, Sutterwala FS, Flavell RA, Ghosh S, et al. (2005) TLR11 activation of dendritic cells by a protozoan profilin-like protein. Science 308:57281626–1629.
Yeaman GR, Guyre PM, Fanger MW, Collins JE, White HD, Rathbun W, Orndorff KA, Gonzalez J, Stern JE, Wira CR. (1997) Unique CD8+ T cell-rich lymphoid aggregates in human uterine endometrium. J Leukoc Biol 61:4427–435.[Abstract]
Young SL, Lyddon TD, Jorgenson RL, Misfeldt ML. (2004) Expression of Toll-like receptors in human endometrial epithelial cells and cell lines. Am J Reprod Immunol 52:167–73.
Zarember KA and Godowski PJ. (2002) Tissue expression of human Toll-like receptors and differential regulation of Toll-like receptor mRNAs in leukocytes in response to microbes, their products, and cytokines. J Immunol 168:2554–561.
Submitted on May 30, 2006; resubmitted on August 29, 2006; accepted on September 11, 2006.
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  K. N. Khan, M. Kitajima, T. Imamura, K. Hiraki, A. Fujishita, I. Sekine, T. Ishimaru, and H. Masuzaki Toll-like receptor 4-mediated growth of endometriosis by human heat-shock protein 70 Hum. Reprod., July 1, 2008; (2008) den195v1. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. W Horne, S. J Stock, and A. E King Innate immunity and disorders of the female reproductive tract Reproduction, June 1, 2008; 135(6): 739 - 749. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 K. Koga and G. Mor Review Article: Expression and Function of Toll-Like Receptors at the Maternal--Fetal Interface Reproductive Sciences, March 1, 2008; 15(3): 231 - 242. [Abstract] [PDF]
|
|
|
|
 |
|
 K. S. Monkkonen, R. Aflatoonian, K.-F. Lee, W. S.B. Yeung, S.-W. Tsao, J. T. Laitinen, and A. Fazeli Hormonal regulation of G{alpha}i2 and mPR{alpha} in immortalized human oviductal cell line OE-E6/E7 Mol. Hum. Reprod., December 1, 2007; 13(12): 845 - 851. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. G Lea and O. Sandra Immunoendocrine aspects of endometrial function and implantation Reproduction, September 1, 2007; 134(3): 389 - 404. [Abstract] [Full Text] [PDF]
|
|
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||