TWEAK Appears as a Modulator of Endometrial IL-18 Related Cytotoxic Activity of Uterine Natural Killers

BACKGROUND: TWEAK (Tumor necrosis factor like WEAK inducer of apoptosis) is highly expressed by different immune cells and triggers multiple cellular responses, including control of angiogenesis. Our objective was to investigate its role in the human endometrium during the implantation window, using an ex-vivo endometrial microhistoculture model. Indeed, previous results suggested that basic TWEAK expression influences the IL-18 related uNK recruitment and local cytotoxicity. METHODOLOGY/PRINCIPAL FINDINGS: Endometrial biopsies were performed 7 to 9 days after the ovulation surge of women in monitored natural cycles. Biopsies were cut in micro-pieces and cultured on collagen sponge with appropriate medium. Morphology, functionality and cell death were analysed at different time of the culture. We used this ex vivo model to study mRNA expressions of NKp46 (a uNK cytotoxic receptor) and TGF-beta1 (protein which regulates uNK cytokine production) after adjunction of excess of recombinant IL-18 and either recombinant TWEAK or its antibody. NKp46 protein expression was also detailed by immunohistochemistry in selected patients with high basic mRNA level of IL-18 and either low or high mRNA level of TWEAK. The NKp46 immunostaining was stronger in patients with an IL-18 over-expression and a low TWEAK expression, when compared with patients with both IL-18 and TWEAK high expressions. We did not observe any difference for TWEAK expression when recombinant protein IL-18 or its antibody was added, or conversely, for IL-18 expression when TWEAK or its antibody was added in the culture medium. In a pro-inflammatory environment (obtained by an excess of IL-18), inhibition of TWEAK was able to increase significantly NKp46 and TGF-beta1 mRNA expressions. CONCLUSIONS/SIGNIFICANCE: TWEAK doesn't act on IL-18 expression but seems to control IL-18 related cytotoxicity on uNK cells when IL-18 is over-expressed. Thus, TWEAK appears as a crucial physiological modulator to prevent endometrial uNK cytotoxicity in human

Regulation of milk protein gene expression

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New pre-conception immune biomarkers for clinical practice: interleukin-18, interleukin-15 and TWEAK on the endometrial side, G-CSF on the follicular side.

dentification of biomarkers of optimal uterine receptivity to the implanting embryo as well as biomarkers of oocyte competence would undoubtedly improve the efficiency of assisted reproductive technology (ART). Expression of IL-15 and IL-18 has been shown to be different in patients with failed implantation after IVF/ICSI compared with fertile controls and both correlate with local uNK (CD56+) recruitment and angiogenesis. Tumor necrosis factor weak inducer of apoptosis (TWEAK) has been described in mice as a potent early immune regulator able to protect the conceptus. The results of our studies in human suggest that TWEAK modulates the IL-18 related cytotoxicity of uNK cells. Quantification of IL-18, TWEAK and IL-15 mRNA expression by real-time PCR in endometrial tissue collected in mid-luteal phase of non-conception cycles allowed documentation of physiological events that occur at the time of uterine receptivity. Such information may be useful for the physician especially in patients where embryos fail to implant. Cytokine quantification may assist in understanding the mechanisms leading to repeated IVF/ICSI failure: either depletion of cytokines necessary for the apposition-adhesion, or an excess of cytokines leading to local cytotoxicity, may impair the implantation of the embryo. Other new data suggest that a pre-conception dialogue mediated by the oocyte and the follicular fluid and the oocyte may contribute to later implantation success. Follicular concentration of G-CSF appears as a useful biomarker of oocyte competence before fertilization. Moreover both in human and animal models, evidence of a role of the endometrium as a biosensor of the embryo is emerging

Noradrenaline is also implicated in the ram effect

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Early regulators in abortion and implications for a preeclampsia model.

This paper reports a summary of our comparative analysis of the uterine expression of interleukin-23 (IL-23), IL-27 and TWEAK in the CBA/J femalexDBA/2 male mouse mating combination, a model of immune-mediated early pregnancy loss. Compared with the MHC-identical CBA/JxBALB/c mating combination, which yields successful pregnancies, immunohistochemistry and qPCR in uterine tissue showed an immediate post-mating IL-27 hyper-expression after mating with DBA/2 males. Intra-uterine TWEAK expression was present in females mated with DBA/2 or Balb/c males from days 0.5 to 4.5 post-coitum (pc), peaking on day 0.5 pc together with uterine TNFalpha. In uteri of DBA/2 mated mice, TWEAK declined to almost undetectable levels on days 6.5-9.5 pc, a steeper drop than in BALB/c mated mice where TWEAK remained detectable. In both mating combinations, neutralisation of TWEAK by antibodies increased resorption rates, but surprisingly, so did IL-27 neutralisation. The complement regulator mannan binding lectin-A (MBL-A), but not MBL-C, was present on day 4.5 pc especially after mating with DBA/2 males. High levels of MBL are present in the uterine luminal fluid of sterile women, and possible functions for TWEAK and MBL in human implantation are indicated by their protein and mRNA expression in uterine biopsies from infertile and fertile individuals. Consistent with the results in mice, increased MBL expression is linked with pregnancy failure. Serum and uterine VEGF and VEGF receptor levels are also different between fertile and sterile patients. The implications of these findings for utilising the CBA/JxDBA/2 mating combination as an early onset model of preeclampsia are discussed

Preconceptional immune biomarkers in assisted reproduction: G-CSF in the follicular fluid -Interleukin-18, -15 and TWEAK in the endometrium

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An insight into normal and pathological pregnancies using large-scale microarrays: lessons from microarrays

In the introduction, we briefly recall old but classic evidence that there is no tolerance to paternal alloantigens in a first pregnancy. Therefore, we performed small- and large-scale microarrays in CBA × DBA/2 and CBA × BALB/c combinations, recently described as a murine model for preeclampsia. Our results are in line with other data suggesting a very early deregulation of local immune vascular events rather than a break of immune tolerance. Other data presented at the Tioman 2010 Preeclampsia Workshop supporting this hypothesis are briefly summarised, as well as indications and caveats from a recent human microarray on implantation failure and recurrent pregnancy loss