scholarly journals Uterine natural killer cells: insights into their cellular and molecular biology from mouse modelling

Reproduction ◽  
2003 ◽  
pp. 149-160 ◽  
Author(s):  
BA Croy ◽  
H He ◽  
S Esadeg ◽  
Q Wei ◽  
D McCartney ◽  
...  

In primates, including women, and in rodents, natural killer lymphocytes (NK cells) have a unique relationship with the decidualizing uterus. Implantation sites from genetically modified and transplanted mice have proven useful models for understanding potential mechanisms involved in the recruitment, activation and functions of human CD56(bright) uterine (u)NK cells. Key findings are reviewed in this article. In mice, uNK precursor cells are recruited from secondary lymphoid tissues and are activated coincident with their uterine arrival. uNK cells proliferate, produce cytokines (interferon gamma (IFN-gamma) and interleukin 18 (IL-18) and IL-27), and terminally differentiate into granulated lymphocytes. Many uNK cells proliferate within the myometrium at each implantation site forming a structure, the mesometrial lymphoid aggregate of pregnancy (MLAp) that surrounds blood vessels servicing each placenta. Post-mitotic uNK cells are abundant within decidua basalis; frequently (<25%) associating with spiral arteries, intramurally and intraluminally. From mid-gestation, numbers of uNK cells decline. Studies of implantation sites in mice lacking uNK cells, IFN-gamma, components of IFN-gamma-induction and -signalling pathways or IFN-gamma-regulated genes indicate that uNK cell-derived IFN-gamma is essential in triggering pregnancy-induced spiral artery modification. Decidual maintenance and uNK cell death are additional effects of uNK cell-derived IFN-gamma. Thus, during the first half of gestation, uNK cells contribute to and sustain important changes in the maternal placental bed.

Endocrinology ◽  
2009 ◽  
Vol 150 (6) ◽  
pp. 2882-2888 ◽  
Author(s):  
Nicole Kane ◽  
Rodney Kelly ◽  
Philippa T. K. Saunders ◽  
Hilary O. D. Critchley

The endometrial lining of the human uterus contains a population of phenotypically distinct (CD56bright, CD16dim), tissue-specific, natural killer [uterine natural killer (uNK)] cells that play a key role in the establishment of a successful pregnancy. An increase in the number of endometrial uNK cells occurs when the conceptus implants, and there is a further increase during the early stages of placentation. Here, we describe studies that have identified human chorionic gonadotrophin (hCG), a glycoprotein synthesized by the preimplantation conceptus, as a novel regulator of uNK cell proliferation. The impact of hCG on uNK cells was mediated via the mannose receptor (CD206) rather than by the classical hCG/LH receptor that was not expressed. The mannose receptor and hCG were colocalized on the surface of uNK cells, and proliferation did not occur if cells were incubated with deglycosylated hCG or intact hCG in the presence of excess d-Mannose. These novel observations provide new insight into the endocrine-immune dialogue that exists between the conceptus and immune cells within the receptive endometrium, and have implications for the role of uNK cell-trophoblast interactions and pregnancy outcome.


2005 ◽  
Vol 17 (9) ◽  
pp. 120
Author(s):  
M. Hickey ◽  
J. M. Crewe ◽  
D. Doherty ◽  
I. S. Fraser ◽  
L. A. Salamonsen

Menopausal hormone therapy (HT) causes irregular bleeding in up to 60% of user. This is extremely unpopular with patients, and commonly leads to invasive and expensive investigations to rule out underlying pelvic pathology. In most cases no cause is found. The aim of this study was to further elucidate the mechanisms of vascular fragility. Uterine NK cells are known to increase vascular fragility during the normal menstrual cycle. We hypothesise that HT is associated with an increase in uterine natural killer (uNK) cells. Eighty six endometrial biopsies were obtained from 59 postmenopausal users of continuous combined HT. Uterine NK cells were identified using immunohistochemistry as being CD56+. Image analysis was used to identify absolute number of CD56+ cells and their distribution within the stroma. Endometrial histology was classified using Noyes criteria. A statistically significant increase in endometrial uNK cell density was observed in HT users compared to postmenopausal women not using HT (P < 0.001). uNK cell populations were more marked in biopsies taken during a bleeding episode compared to those HT users with amenorrhoea (P = 031). uNK cells are a major regulator of endometrial vascular integrity and are known to be disrupted in irregular bleeding with progestin only contraceptives. This is the first study to report the presence of uNK cells in postmenopausal endometrium and the first to report a significant association between bleeding patterns and uNK cell density. We postulate that HT induces an increase in endometrial uNK cell populations and that their presence stimulates endometrial vascular fragility leading to bleeding.


2015 ◽  
pp. 427-432 ◽  
Author(s):  
B. ZAVAN ◽  
A. M. DO AMARANTE-PAFFARO ◽  
V. A. PAFFARO

One of the most abundant immunologic cell types in early decidua is the uterine natural killer (UNK) cell that despite the presence of cytoplasmic granules rich in perforin and granzymes does not degranulate in normal pregnancy. UNK cells are important producers of angiogenic factors that permit normal dilation of uterine arteries to provide increased blood flow for the growing feto-placental unit. Gram-negative bacteria lipopolysaccharide (LPS) administration can trigger an imbalance of pro-inflammatory and anti-inflammatory cytokines impairing the normal immune cells activity as well as uterine homeostasis. The present study aimed to evaluate by immunohistochemistry the reactivity of perforin and α-actin on UNK cell from LPS-treated pregnant mice. For the first time, we demonstrate that LPS injection in pregnant mice causes α-actin down regulation, concomitantly with perforin loss in UNK cells. This suggests that LPS alters UNK cell migration and activates cytotoxic granule release.


2020 ◽  
Author(s):  
Chow-Seng Kong ◽  
Alexandra Almansa Ordoñez ◽  
Sarah Turner ◽  
Tina Tremaine ◽  
Joanne Muter ◽  
...  

AbstractDecidualizing endometrial stromal cells (EnSC) critically determine the maternal response to an implanting conceptus, triggering either menstruation-like disposal of low-fitness embryos or creating an environment that promotes further development. However, the mechanism that couples maternal recognition of low-quality embryos to tissue breakdown remains poorly understood. Recently, we demonstrated that successful transition of the cycling endometrium to a pregnancy state requires selective elimination of pro-inflammatory senescent decidual cells by activated uterine natural killer (uNK) cells. Here we report that uNK cells express CD44, the canonical hyaluronan (HA) receptor, and demonstrate that high-molecular weight HA (HMWHA) inhibits uNK cell-mediated killing of senescent decidual cells. By contrast, low-molecular weight HA (LMWHA) did not attenuate uNK cell activity in co-culture experiments. Killing of senescent decidual cells by uNK cells was also inhibited upon exposure to medium conditioned by IVF embryos that failed to implant, but not successful embryos. Embryo-mediated inhibition of uNK cell activity was reversed by recombinant hyaluronidase 2 (HYAL2), which hydrolyses HMWHA. We further report a correlation between the levels of HYAL2 secretion by human blastocysts, morphological scores, and implantation potential. Taken together, the data suggest a pivotal role for uNK cells in embryo biosensing and endometrial fate decisions at implantation.


2000 ◽  
Vol 192 (2) ◽  
pp. 259-270 ◽  
Author(s):  
Ali A. Ashkar ◽  
James P. Di Santo ◽  
B. Anne Croy

The dominant lymphocytes in human and murine implantation sites are transient, pregnancy-associated uterine natural killer (uNK) cells. These cells are a major source of interferon (IFN)-γ. Implantation sites in mice lacking uNK cells (alymphoid recombinase activating gene [RAG]-2−/− common cytokine receptor chain γ [γc]−/−) or IFN-γ signaling (IFN-γ−/− or IFN-γRα−/−) fail to initiate normal pregnancy-induced modification of decidual arteries and display hypocellularity or necrosis of decidua. To investigate the functions of uNK cell–derived IFN-γ during pregnancy, RAG-2−/−γc−/− females were engrafted with bone marrow from IFN-γ−/− mice, IFN-γ signal-disrupted mice (IFN-γRα−/− or signal transducer and activator of transcription [Stat]-1−/−), or from mice able to establish normal uNK cells (severe combined immunodeficient [SCID] or C57BL/6). Mated recipients were analyzed at midgestation. All grafts established uNK cells. Grafts from IFN-γ−/− mice did not reverse host vascular or decidual pathology. Grafts from all other donors promoted modification of decidual arteries and decidual cellularity. Grafts from IFN-γRα−/− or Stat-1−/− mice overproduced uNK cells, all of which were immature. Grafts from IFN-γ−/−, SCID, or C57BL/6 mice produced normal, mature uNK cells. Administration of murine recombinant IFN-γ to pregnant RAG-2−/−γc−/− mice initiated decidual vessel modification and promoted decidual cellularity in the absence of uNK cells. These in vivo findings strongly suggest that uNK cell–derived IFN-γ modifies the expression of genes in the uterine vasculature and stroma, which initiates vessel instability and facilitates pregnancy-induced remodeling of decidual arteries.


2022 ◽  
Vol 12 ◽  
Author(s):  
Ryland D. Mortlock ◽  
Chuanfeng Wu ◽  
E. Lake Potter ◽  
Diana M. Abraham ◽  
David S. J. Allan ◽  
...  

The in vivo tissue distribution and trafficking patterns of natural killer (NK) cells remain understudied. Animal models can help bridge the gap, and rhesus macaque (RM) primates faithfully recapitulate key elements of human NK cell biology. Here, we profiled the tissue distribution and localization patterns of three NK cell subsets across various RM tissues. We utilized serial intravascular staining (SIVS) to investigate the tissue trafficking kinetics at steady state and during recovery from CD16 depletion. We found that at steady state, CD16+ NK cells were selectively retained in the vasculature while CD56+ NK cells had a shorter residence time in peripheral blood. We also found that different subsets of NK cells had distinct trafficking kinetics to and from the lymph node as well as other lymphoid and non-lymphoid tissues. Lastly, we found that following administration of CD16-depleting antibody, CD16+ NK cells and their putative precursors retained a high proportion of continuously circulating cells, suggesting that regeneration of the CD16 NK compartment may take place in peripheral blood or the perivascular compartments of tissues.


Author(s):  
Emrah SUR ◽  
İlhami ÇELİK ◽  
Yasemin ÖZNURLU ◽  
Tuğba ÖZAYDIN ◽  
İbrahim AYDIN ◽  
...  

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Xiuhua Yang ◽  
Yahui Yang ◽  
Yiru Yuan ◽  
Lin Liu ◽  
Tao Meng

Preeclampsia (PE) is termed as a systemic disease that involves multiple organs; however, the exact etiology is still quite unclear. It is believed that the poor remodeling of uterine spiral arteries triggers PE, thereby causing failed placentation and producing inflammatory factors. The decline of blood flow results in lowering the nutrients and oxygen received by the fetus and augmenting the placental pressure in PE. Decidual immune cells, especially uterine natural killer (uNK) cells, are involved in the process of placentation. Decidual NK (dNK) cells significantly contribute to the vascular remodeling through the secretion of cytokines and angiogenic mediators in normal placental development. The abnormal activation of NK cells in both the peripheral blood and the decidua was counted among the causes leading to PE. The correlation existing between maternal killer cell immunoglobulin-like receptor (KIR) and HLA-C in trophoblast cells constitutes a robust evidence for the genetic etiology of PE. The combinations of the two kinds of gene systems, together with the KIR genotype in the mother and the HLA-C group in her fetus, are likely to exactly decide the pregnancy outcome. The women, who have the inappropriate match of KIR/HLA-C, are likely to be prone to the augmented risk of PE. However, the combinations of KIR/HLA-C in PE undergo ethnic changes. The extensive prospective research works in Europe, Asia, and Africa are required for providing more findings in PE patients.


2014 ◽  
Vol 2014 ◽  
pp. 1-15 ◽  
Author(s):  
Xin Gong ◽  
Zhenzhen Chen ◽  
Yanxia Liu ◽  
Qiudan Lu ◽  
Zhe Jin

The endometrium contains a population of immune cells that undergo changes during implantation and pregnancy. The majority of these cells are uterine natural killer (uNK) cells; however, it is unclear how these cells interact with endometrial epithelial cells. Therefore, we investigated the paracrine effects of the uNK cell-secretion medium on the gene expression profile of endometrial epithelial cellsin vitrothrough microarray analysis. Our results, which were verified by qRT-PCR and western blot, revealed that soluble factors from uNK cells alter the gene expression profiles of epithelial cells. The upregulated genes included interleukin-15 (IL-15) and interleukin-15 receptor alpha (IL-15RA), which result in a loop that stimulates uNK cell proliferation. In addition, vascular endothelial growth factor C (VEGF-C) and chemokine (C-X-C motif) ligand 10 (CXCL-10) were also determined to be upregulated in epithelial cells, which suggests that uNK cells work synergistically with epithelial cells to support implantation and pregnancy. In addition, oriental herbal medicines have been used to treat infertility since ancient times; however, we failed to find that Zi Dan Yin can regulate these endometrial paracrine effects.


Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 1031-1031
Author(s):  
Luxi Chen ◽  
Long Yi ◽  
Yuning Ren ◽  
Jianying Zhang ◽  
A. Douglas Kinghorn ◽  
...  

Abstract Natural killer (NK) cells are known to play a pivotal role in regulating immune defense against tumors and viruses. However, very few studies describe the effects of natural products or their derivatives on NK cell function. We previously showed that the natural product lignan phyllanthusmin C enhances human NK cell IFN-gamma production. In this study, we successfully synthesized dozens of phyllanthusmin derivatives and screened their activities to enhance IFN-gamma production by NK cells. We found that three of these derivatives possessed capacities to induce IFN-gamma production by NK cells. Among them, derivative No. 17 had the highest efficacy and was significantly superior (P < 0.05) to that of the original phyllanthusmin C. These three phyllanthusmin derivatives had no adverse effect on human NK cell survival or proliferation. All derivatives alone or in combination with IL-12 or IL-15 induced human NK cell interferon (IFN)-gamma in comparison with the corresponding vehicle control or cytokine alone (P < 0.05). These derivatives stimulated IFN-gamma production in both CD56bright and CD56dim human NK cell subsets (P < 0.01). Mechanistically, immunoblotting assays and chromatin immunoprecipitation (ChIP) analyses combined with promoter-reporter luciferase assays revealed that these phyllanthusmin derivatives induced the phosphorylation of NF-κB and STAT3, resulting in their increased binding on theIFN G promoter, which was dependent on the Toll-like receptor (TLR) 1 and the TLR3 signaling pathways, respectively. STAT3 knockdown with lentivirus shRNA and inhibition of NF-kB signaling with a specific inhibitor (TPCK) significantly attenuated IFN-gamma production induced by these phyllanthusmin derivatives in human NK cells (P < 0.05). Blockade of TLR1 or TLR3 with their corresponding neutralizing antibodies nearly abolished activation of NF-κB or STAT3 as well as IFN-γ induction by the phyllanthusmin derivatives (P < 0.05). In conclusion, we have successfully synthesized and screened phyllanthusmin derivatives and identified three compounds that induce IFN-gamma production in human NK cells, one of which had optimal potential. The induction of human NK cell IFN-gamma production by phyllanthusmin derivatives is mediated by TLR1-NF-κB and TLR3-STAT3 signaling pathways, rendering their potential for use as agents for cancer prevention or treatment. Disclosures No relevant conflicts of interest to declare.


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