Quantitative analysis of adhesion molecules on cellular constituents of the human uterine microenvironment under the influence of estrogen and progesterone

Role of tumor-associated glycoprotein-72 in the progression of endometrial adenocarcinoma: a proposed study

Endometrial adenocarcinoma is on the basis of the molecular, immunohistological and clinicopathologic features broadly divided into two groups, referred as type I and type II. Type I appears more frequently and in principle patients have a good prognosis; however a significant number of patients develop local recurrences. We hypothesize that TAG-72, expressed on endometrial carcinoma binds and internalizes endocytic pattern recognition receptors on surrounding tissue antigen presenting cells (dendritic cells and macrophages), powers their anti-inflammatory maturation program and make them capable to elicit or modulated tolerogenic immune response mediated by local T and NK effectors. This could support uncontrolled local tumor growth, deeper tumor invasion into surrounding tissues, frequent local recurrences and/or lymph node metastasis. To test this hypothesis, we propose a semi-quantitative immunohistochemical analysis of TAG-72 expression in endometrial adenocarcinoma samples and to correlate the results with clinical and pathological parameters (age, type and histological grade of the tumor, estrogen and progesterone receptor expression, invasion into the myometrium and capillaries, presence of lymph node metastases, FIGO stage, and TNM classification). It would be worthwhile to investigate the local tissue immune response in the tumor environment using tissue samples removed during surgery. These studies could elucidate the underlying immunopathological mechanisms that govern the early recurrence and possibly distant metastases of TAG-72-expressing adenocarcinomas and might help in deciding the type of treatment to be applied in a selected group of cancer patients including application of biological therapy with anti-TAG-72 antibodies, according the principle of personalized oncology treatments.

Tumor-associated glycoprotein (TAG-72) is a natural ligand for the C-type lectin-like domain that induces anti-inflammatory orientation of early pregnancy decidual CD1a+ dendritic cells

Tumor-associated glycoprotein-72 (TAG-72) is physiologically present in secretory phase endometrium, but its presence and possible immunological role in early normal human pregnancy decidua has not received attention. The double labeling of paraffin-embedded early pregnancy decidua sections using B-72.4 anti-TAG-72 mAb and MNF 116 anti-cytokeratin mAb revealed the absence of TAG-72 in uterine decidua of normal and pathological pregnancies (non-embryonic pregnancy and missed abortion) at the implantation sites, although it was present in epithelial cells at and away from the tubal implantation site of an ectopic pregnancy. TAG-72 binds and internalizes by reacting with the mannose receptor (MR-CD206) or with DC-specific ICAM reacting non-integrin (DC-SIGN-CD209) on decidual CD1a+ cells. Decidual CD1a+ cells stimulated with TAG-72 decreased CD83 expression and diminished IL-15 and IFN-γ intracellular production. TAG-72-treated CD1a+ cells decreased IFN-γ production in syngenic decidual and allogenic cord blood T cells even in the presence of lipopolysaccharide. TAG-72- and lipopolysaccharide-pre-treated CD1a+ cells significantly increased IL-4 expression in allogenic cord blood T cells. TAG-72 increased allogenic cord blood T cell proliferation, mediated by decidual CD1a+ cells, compared with its effect on the proliferation of syngenic decidual T cells. All these data emphasize the anti-inflammatory properties of TAG-72-treated decidual CD1a+ cells in terms of their interaction with T cells. Thus, the absence of TAG-72 at the maternal-fetal interface during early pregnancy could lead to a mild pro-inflammatory response that may be beneficial for pregnancy success and trophoblast growth control.

CD56bright cells increase expression of {alpha}4 integrin at ovulation in fertile cycles

Leukocyte content of human endometrium changes rapidly after ovulation, particularly as a result of gains in CD56(bright) uterine NK (uNK) cells. We have proposed that uNK precursor cells are found within the blood CD56(bright) pool and are recruited to decidualizing endometrium through functional changes in their adhesion molecules and chemokine receptors. This study sought to quantify alterations in adhesion molecules, cytokines, chemokines, and receptors induced in circulating CD56(+) cells of fertile and infertile women by ovulation. Blood was drawn from 12 fertile volunteers and six female-infertility patients at Menstrual Cycle Day (d) 5 and on the day following the preovulatory surge of luteinizing hormone (LH). CD56(bright), CD56(dim), and CD56(+)CD3(+) cell subsets were isolated and evaluated by flow cytometry, quantitative PCR, or Western blotting. In CD56(bright) cells from fertile but not infertile women, alpha(4) integrin increased between d5 and the preovulatory LH surge. CD56(dim) and NKT cells did not show a change in alpha(4) integrin but differed significantly between fertile and infertile donors, and infertile donors had reduced homing molecule expression in CD56(dim) and NKT cells, and at ovulation, their NKT cells showed elevated cytokine production. None of the circulating CD56(+) cell subsets had transcripts for receptors for estrogen, progesterone, LH, or prolactin. Thus, immunological events associated with the LH surge induce alterations in all subsets of CD56(+) cells, and the unique induction of alpha(4) integrin in CD56(bright) cells of fertile women constitutes a potential method to promote uterine homing.

Post-ovulatory rise of endometrial CD16(-) natural killer cells: in situ proliferation of residual cells or selective recruitment from circulating peripheral blood?

In the human endometrium, unique endometrial CD16(-) NK cells acutely increase in number after ovulation. Endometrial CD16(-) NK cells are thought to play a role in uterus-specific events, such as pregnancy or menstruation, because these NK cells are a minor leukocyte subset in circulating peripheral blood and other organs. The mechanism underlying the post-ovulatory rise of endometrial CD16(-) NK cells is largely unknown. By analogy with other organ systems, two potential mechanisms are proposed: one is in situ proliferation of residual cells and the other is selective recruitment from circulating peripheral blood. Our recent studies focus on the expression and function of potential molecules (including cytokines, chemokines and adhesion molecules) involved in these mechanisms in the human endometrium, and the regulation of these molecules by ovarian steroids. Based upon our findings, we discuss the possibility and relevance of these two potential mechanisms.

Human first-trimester trophoblast cells recruit CD56brightCD16- NK cells into decidua by way of expressing and secreting of CXCL12/stromal cell-derived factor 1

More than 70% of decidual lymphocytes are NK cells characterized by CD56(bright)CD16(-) phenotype, but the mechanisms by which these NK cells are recruited in the decidua are still almost unrevealed. In this study, we first analyzed the transcription of 18 chemokine receptors in the first-trimester decidual CD56(bright)CD16(-) NK cells. Among these receptors, CXCR4 and CXCR3 were found highly transcribed, and the expression of CXCR4 was verified in most of the decidual CD56(bright)CD16(-) NK cells by flow cytometry. The first-trimester human trophoblasts were found expressing CXCL12/stromal cell-derived factor 1, the specific ligand of CXCR4, by way of in situ hybridization and immunohistochemistry. The primary cultured trophoblast cells were also found to secrete stromal cell-derived factor 1alpha spontaneously, and its concentration was 384.6 +/- 90.7 pg/ml after the trophoblast cells had been cultured for 60 h. All of the ligands for CXCR3 were below the minimal detectable concentration when trophoblast cells were cultured for up to 48 h. Both recombinant human SDF-1alpha and supernatants of the cultured trophoblast cells exhibited chemotactic activity on decidual CD56(bright)CD16(-) NK cells. Our findings suggest that human first-trimester trophoblast cells produce CXCL12, which in turn chemoattracts decidual CD56(bright)CD16(-) NK cells. This activity could contribute to the recruitment mechanism of decidual lymphocytes, especially CD56(bright)CD16(-) NK cells, in decidua, and may be used at a local level to modulate the immune milieu at the materno-fetal interface.

The presence of functional mannose receptor on macrophages at the maternal-fetal interface

BACKGROUND

The mannose receptor (MR) is involved in the initiation of the immune response and regulation of homeostasis during inflammation and tissue remodeling.

METHODS

Distribution, endocytosis and possible natural ligand tumor associated glycoprotein-72 (TAG-72) for the MR have been examined by immunohistology, immunocytochemistry and flow cytometry at the maternal-fetal interface, characterized by extensive tissue remodeling.

RESULTS

Contrary to disseminated distribution of the MR positive (MR+) cells in term placenta, the MR+ cells of early pregnancy decidua intimately surrounded glands and followed tissue distribution of CD14 positive cells. The mannose receptor was present on freshly isolated first trimester decidual mononuclear cells and distributed mostly on macrophages (77.08 +/- 10.55%, mean +/- SD). The expression of the MR on CD14 positive cells decreased following 18 h culture (P < 0.01) and was accompanied by the reduction of fluorescein isothiocyanate (FITC)-dextran uptake. PAM-1 anti-MR antibody, mannan and TAG-72 reduced FITC-dextran uptake by decidual macrophages.

CONCLUSIONS

These data indicate that the MR+ macrophages, surrounding early decidual glands, are able to internalize ligands for carbohydrate recognition domain of the receptor, including decidual secretory phase mucin TAG-72.

Immunology of human endometrium

In pregnancy, the endometrium represents the hosting surface for invading semi-allogeneic cells. A very fine tuning of cellular interactions is indispensible for the successful symbiosis of mother and fetus. Such interactions include a variety of immune cells, which are present in extremely high concentrations, and trophoblast cells. A wide spectrum of soluble and surface molecules is involved in homing, activation and switching of lymphocyte functions, but also in regulation of embryo implantation and control of trophoblast invasion. This mini-review provides a brief overview of immunological features of the endometrium.

A three-dimensional organotypic culture of the human uterine exocervix for studying mucosal epithelial differentiation and migrating leukocytes

We report on a three-dimensional organotypic culture in vitro of explants from the human uterine exocervix. Exocervical fragments (2-3 mm3) from pre-menopausal women were cultured on sponges submerged in Dulbecco's Modified Eagle's Medium containing p-nonylphenol and 10% fetal bovine serum for up to 3 weeks and the viability and cellular responses were assayed. The fragments were analyzed by immunohistochemistry for the expression and distribution of a broad spectrum of cellular markers: p63, Ki-67, involucrin, high molecular weight cytokeratins, estrogen receptor-alpha, vimentin, CD45, and CD31. The fragments preserved their tissue architecture and cellular heterogeneity comparable to that observed in exocervical tissue in vivo. Prior to culture, the original epithelium was composed of stratified multilayered keratinocytes with integrated monocyte/dendritic-like cells in the basal and suprabasal layers. The epithelium began to exfoliate in culture and within 4 days appeared to have lost its differentiated high-zone layers of keratinocytes. After 10 days a new epithelium, slightly different from the original one, was formed; it displayed an increasing prominence of basal and suprabasal keratinocyte layers, containing infiltrating leukocytes that had probably migrated from the submucosa. The epithelium subsequently lost its organization, concomitant with a progressive involution of the stroma. Subepithelial capillaries appeared to be well maintained throughout the culture period. Aside from the maintenance of cellular heterogeneity within the fragments of exocervix, these culture systems are a valuable tool for studying the mechanisms of epithelial regeneration, and may prove to be a useful model for studying mucosal immunity.

Coordinate regulation of lymphocyte-endothelial interactions by pregnancy-associated hormones

Precursors of uterine NK cells home to the uterus during early pregnancy from multiple lymphohemopoietic sources. In mouse uterine tissue, pregnancy markedly up-regulates both L-selectin- and alpha(4) integrin-dependent adhesion pathways for circulating human CD56(bright) cells, the phenotype of human uterine NK cells. Based on roles for these adhesion molecules in lymphocyte homing, we examined effects of pregnancy or the steroid hormones 17beta-estradiol or progesterone on lymphocyte-endothelial interactions in secondary lymphoid tissues and in uterus. From preimplantation gestation day 3, specialized high endothelial venules in peripheral lymph nodes and Peyer's patches supported elevated L-selectin and alpha(4)beta(7) integrin-dependent lymphocyte adhesion under shear throughout pregnancy, as compared with high endothelial venules of virgin or postpartum donors. Squamous endothelium from nonlymphoid tissue was not affected. Pregnancy-equivalent endothelial responses were observed in lymph nodes and Peyer's patches from ovariectomized mice receiving 17beta-estradiol and/or progesterone replacement therapy. Adhesion of human CD56(bright) cells to uteri from pregnant or hormone-treated ovariectomized mice was enhanced through L-selectin- and alpha(4) integrin-dependent mechanisms and involved multiple vascular adhesion molecules including mucosal addressin cell adhesion molecule-1, VCAM-1, and peripheral lymph node addressin. Analysis of Tie2-green fluorescence protein transgenic mice demonstrated that CD56(bright) cells adhered primarily to vascular endothelium within the decidua basalis. Microdomain localization of adhesion involving large clusters of lymphocytes was induced on uteri from natural matings, but not pseudopregnancy. Steroid hormones also had independent effects on L-selectin function in splenic lymphocytes that mimicked physiological stimulation induced by pregnancy or fever-range temperatures. These results provide the first evidence for coordinated, organ-specific, steroid hormone-induced changes in lymphocyte homing mechanisms that could contribute to local and systemic immune responses during pregnancy.

Activation of the protein kinase A pathway in human endometrial stromal cells reveals sequential categorical gene regulation

Decidualization of endometrial stromal cells is a prerequisite for human implantation and occurs in vivo in response to progesterone and involves activation of the protein kinase A (PKA) pathway. The objective of this study was to determine the molecular signatures and patterns of gene expression during stimulation of this pathway with an analog of cAMP. Endometrial stromal cells from two subjects were treated with or without 8-Br-cAMP (1 mM) for 0, 2, 12, 24, 36, and 48 h and were processed for microarray analysis, screening for 12,686 genes and ESTs. Most abundantly upregulated genes included neuropeptides, immune genes, IGF family members, cell cycle regulators, extracellular matrix proteases, cholesterol trafficking, cell growth and differentiation, hormone signaling, and signal transduction. Most abundantly downregulated genes included activator of NF-kappaB, actin/tropomyosin/calmodulin binding protein, cyclin B, IGFBP-5, alpha1 type XVI collagen, lipocortin III, l-kynurenine hydrolase, frizzle-related protein, and cyclin E2. RT-PCR validated upregulation of IGFBP-1, preprosomatostatin, and IL-11, and Northern analysis validated their kinetic upregulation. RT-PCR confirmed downregulation of IGFBP-5, cyclin B, and TIL-4. K-means analysis revealed four major patterns of up- and downregulated genes, and genes within each ontological group were categorized into these four kinetic patterns. Within each ontological group different patterns of temporal gene expression were observed, indicating that even genes within one functional category are regulated differently during activation of the PKA pathway in human endometrial stromal cells. Overall, the data demonstrate kinetic reprogramming of genes within specific functional groups and changes in genes associated with nucleic acid binding, cell proliferation, decreased G protein signaling, increased STAT pathway signaling, structural proteins, cellular differentiation, and secretory processes. These changes are consistent with cAMP modulating early events (0-6 h) primarily involving cell cycle regulation, subsequent events (12-24 h) involving cellular differentiation (including changes in morphology and secretory phenotype), and late events (24-48 h) mediating more specialized function, including immune modulators, in the human endometrial stromal cell.