Review: Functional role of uterine natural killer (uNK) cells in human early pregnancy decidua

Leukocytes comprise approximately 30–40% of decidual stromal cells in early human pregnancy. The major leukocyte component is the uterine natural killer (uNK) cells. Despite over 20 years of research the functional role of these cells in situ remains unknown although they have been proposed to play roles in immunotolerance, regulation of trophoblast invasion and remodeling of the spiral arteries. Herein we review the functional roles of this important decidual cell type.     

早孕蜕膜组织淋巴细胞在妊娠中的作用

目的 探讨子宫内膜局部免疫细胞在妊娠中的作用,方法 采用免疫组化技术和原位杂交技术,研究２０例正常孕妇的早孕蜕膜组织内淋巴细胞的分布,表型特征及穿孔素蛋白和ｍＲＮＡ的表达。结果 早孕蜕膜组织内Ｔ总淋巴细胞（ＣＤ３淋巴细胞）抑制或杀伤了Ｔ淋巴细胞（ＣＤ８淋巴细胞）较少,约占３％,辅助Ｔ淋巴细胞（ＣＤ４淋巴细胞）极少,甚至看不到,早孕蜕膜组织内大部分淋巴细胞为表达穿孔素的自然杀伤样细胞ＣＤ（５６非典型     

Side population cells in the human decidua of early pregnancy exhibit stem/progenitor cell-like characteristics

It is proposed that human decidua contains a population of stem cells that are responsible for the proliferation ability during the process of embryo implantation and placenta formation and that factors in the crosstalk between the decidua and chorion may mediate decidual stem cell differentiation. This study analysed the phenotype of side population (SP) cells and investigated the clonogenicity and differentiation ability of SP cells in human decidua of early pregnancy. Serum-free culture-conditioned media of human decidua and chorion were obtained from decidua and chorion explant culture. Decidual SP cells were isolated by fluorescence-activated cell sorting. Different inducing media were added and the functional differentiation of decidual SP cells was examined. Decidual SP cells were negative for the mature decidual cell marker CD13 and prolactin and negative for CD34 and CD45 expression. Decidual SP cells formed clones after culture in colony-forming medium and they could form clones again. Differentiated cells expressing CD13 and prolactin were observed and stroma-like structures expressing CD13 were obtained. These results indicate that decidual SP cells are enriched for stem cell activity. Oestradiol, progesterone and factors in culture-conditioned media of human decidua and chorion induced their proliferation and differentiation.     

uNK细胞在早孕蜕膜促血管生成作用的研究进展

胚胎种植于子宫内膜是人类妊娠的关键步骤,血管生成/重建是胚胎种植过程中子宫内膜蜕膜化的一个重要变化,但参与调节的因素目前尚不清楚。近年来对子宫自然杀伤细胞(uNK细胞)的研究表明,其通过细胞因子对血管生成/重建具有重要作用,而其本身又受到多方面因素的调节。本文就对uNK细胞的促血管生成作用及其调节因素进行综述。     

胰岛素样生长因子-Ⅱ在人早孕期绒毛和蜕膜中的表达

目的：探讨胰岛素样生长因子－Ⅱ（IGF－Ⅱ）在人早孕期绒毛和蜕膜中的表达及IGF－Ⅱ与ER、PR表达之间的相互关系。方法：采用单克隆抗体SP免疫组化法测定IGF－Ⅱ、ER、PR在人早孕期绒毛、蜕膜中的表达，并用组织学积分法进行半定量分析和相关分析。结果：IGF－Ⅱ在绒毛细胞滋养细胞、合体滋养细胞和蜕膜间质细胞中均有表达，绒毛中的表达高于蜕膜。蜕膜中ER、PR的表达呈正相关（P＜0．01）。而IGF－Ⅱ与ER、PR之间无显著相关性（P＞0．05）。结论：推测IGF－Ⅱ与促进母体蜕膜和胚胎的生长发育有关，ER、PR的平衡有利于早孕期蜕膜的正常发育。     

正常早孕蜕膜非免疫细胞免疫活性的实验研究

目的 了解蜕膜中非免疫细胞的免疫活性。方法 取蜕膜中非免疫细胞培养的上清液,用放射免疫方法（ＲＩＡ）测定其对人外周血Ｔ细胞的转化、自然杀伤（ＮＫ）细胞的杀伤率、淋巴细胞分泌白细胞介素２（ＩＬ－２）及Ｂ细胞分泌ＩｇＢ的影响。结果 蜕膜非免疫细胞培养的上清液可使Ｔ细胞、ＮＫ细胞、Ｂ细胞的免疫学活性不同程度地受到抑制,其最大抑制率分别为２２．７％、５２．３％和１４．８％,但对淋巴细胞ＩＬ－２的分泌无显著     

妊娠早期蜕膜组织巨噬细胞分泌IL-10/IFN-γ功能的特征

目的:探讨正常妊娠早期母胎界面蜕膜组织与外周血中细胞因子分泌的格局以及单核/巨噬细胞分泌IL-10/IFN-γ的功能特征。方法:收集9例接受人工流产的正常早孕妇女外周血和蜕膜组织,用MACS法富集单核/巨噬细胞,用ELISPOT法检测细胞因子。结果:在正常妊娠早期,母胎界面蜕膜组织分泌IL-10的细胞细胞和分泌IFN-γ细胞比值显著高于外周血;蜕膜巨噬细胞分泌IL-10数量明显高于外周血单核细胞,亦明显高于蜕膜组织非巨噬细胞。结论:蜕膜组织分泌细胞因子格局的特征与外周血有差异,可能是母胎免疫耐受形成的重要途径。蜕膜巨噬细胞可通过增强IL-10的分泌调节母胎界面细胞因子格局,有利于诱导母胎免疫耐受。     

米非司酮抗早孕蜕膜雌,孕激素受体的免疫组织化学研究

目的了解米非司酮及米索前列醇（米索）对人早孕蜕膜雌激素受体（ＥＲ）、孕激素受体（ＰＲ）的影响。方法取正常早孕、服米非司酮及服米非司酮配伍米索后各１０例的蜕膜,应用单克隆抗体链菌素亲生物蛋白过氧化酶（ＳＰ）免疫组织化学方法及电子计算机图象分析技术,观察ＥＲ、ＰＲ的变化。结果正常早孕蜕膜ＥＲ和ＰＲ位于大部分蜕膜间质细胞及少数腺上皮细胞胞核内,受体水平积分ＥＲ为５８６０７９０±３１１６９１,ＰＲ为４９０５９７０±１５７３１９;服米非司酮后蜕膜ＥＲ、ＰＲ水平积分为３５４７１８０±１９１８５８、３７００７５０±１８８３２２;服米非司酮配伍米索后蜕膜ＥＲ和ＰＲ水平积分为２０２１７２１±１４５２８１、２５２８５８０±２４０５３５。３者间差异有显著性（Ｐ＜０．０５,Ｐ＜０．０１）。结论米非司酮及米索可使早孕蜕膜ＥＲ、ＰＲ水平下降,这可能与药物流产后子宫出血时间长有关。     

Demonstration of immunoreactive somatostatin-like substance in villi and decidua in early pregnancy.

With the use of the radioimmunoassay for growth hormone--releasing inhibiting factor (GIF), it was found that measurable amounts of GIF-like substance existed in the chorionic villi and decidua of pregnant women. The indirect immunofluorescent method revealed that the higher intensity of GIF-like immunofluorescence was presented in cytotrophoblasts rather than in syncytiotrophoblasts of the villi and in stromal cells of the decidua.     

米非司酮对早孕绒毛、蜕膜的影响

胚胎d13—21绒毛逐渐形成，经初级绒毛、二级绒毛发展转变为三级绒毛。在妊娠d5中绒毛内血管形成，胎儿循环开始。孕卵着床后，子宫内膜致密层蜕膜样细胞继续增大，逐渐变成蜕膜细胞。     

Relation between steroid receptor levels and prolactin level in the decidua of early human pregnancy

To clarify the relation between steroids and prolactin (PRL) production in human decidua, the levels of estrogen receptors (ERs), progesterone receptors (PRs), and androgen receptors (ARs) and the level of PRL in the decidua were determined simultaneously during early pregnancy. Cytosol, nuclear, and total ER levels and the cytosol PRL level were found to increase with the advance of gestation; whereas levels of PRs and ARs remained constant. Multiple regression analysis showed that the multiple correlation coefficient in the relationships of cellular ERs and cytosol PRL with gestational age was 0.722 and relatively high among the others. These results suggest an association between estrogen and decidual growth. Significant correlations between the cytosol PRL level and cellular PR or AR levels were seen during early pregnancy, suggesting that progestin and androgen may regulate PRL synthesis.     

外源性细胞因子对早孕蜕膜T细胞免疫活性的研究

目的 :探讨外源性细胞因子对早孕蜕膜T细胞免疫活性作用的方式。方法 :在培养的蜕膜细胞中加入γ干扰素、白细胞介素 2、白细胞介素 6和表皮生长因子 ,共同培养 12、2 4、4 8h后收集上清液 ,并加入培养的T细胞中 ,用氚 胸苷 (3 H TdR)掺入法测定T细胞的转化值。结果 :在蜕膜与细胞因子共同培养的上清液作用下 ,各实验组T细胞的转化有不同程度的升高 ,有的T细胞转化效应显著增强 (P <0 .0 5 ) ,但增强的T细胞转化效应未显示出与作用于蜕膜的细胞因子种类、浓度及作用时间有相关性。结论 :在外源性细胞因子的作用下 ,早孕蜕膜细胞可以增强T细胞的转化作用 ,从而破坏蜕膜免疫微环境细胞因子网络的平衡状态 ,危害妊娠。     

Ultrastructural alterations in human decidua in miscarriages compared to normal pregnancy decidua

BACKGROUND: Pregnant endometrial stroma, an immunologically privileged site in the female reproductive system, is enriched by decidual and natural killer (NK) cells. Since the cellular microenvironment in early pregnancy from the decidual tissues of normal and miscarriage cases has gained importance, with special emphasis on cell-to-cell contacts, we aimed to document the plastic structure of the cellular milieu in normal and miscarriage decidua. METHODS: Endometrial biopsies were obtained from women after legal curettage or women who had been treated by curettage after miscarriage. Samples were analysed in a light microscope (LM), a scanning electron microscope (SEM) and a transmission electron microscope (TEM). RESULTS: Decidual cells possess several polyploidic protrusions on cell membranes. NK cells were distributed among decidual cells. Decidual cells were found to develop gap junctions in the interfaces between each other. Their cytoplasms were also found to possess well-developed protein synthesising organelles. Decidual cells obtained from miscarriages showed a moderate degree of degeneration and, in between, a decreased number of junctional complexes. Mononuclear cell infiltration was found to be significantly low. CONCLUSION: We conclude that decidual cells during early pregnancy build a series of miniature cell-cell contacts to assemble a proper endometrial milieu. In contrast, in miscarriage samples, those intercellular communications seem lacking, associated with an increased number of NK cells, a phenomenon which obviously alters proper implantation and leads to the induction of embryonic disgenesis and miscarriage.     

Suppressor cells in human decidua

Decidual suppressor cells have been found in the murine system. These cells are absent at the implantation sites of interspecies mouse embryos which become infiltrated by maternal cytotoxic cells. Suppression is also deficient at the sites of the spontaneous resorption of fetuses in allomated intraspecies pregnancies. This study was carried out to determine whether similar suppressor cells were present in the decidua during successful human allopregnancies. Decidua was obtained from gestations of 13 to 15 weeks and from term gestations, and the lymphocytes were tested for their ability to suppress the response of their peripheral blood lymphocytes to concanavalin A. Eight of eight 13- to 15-week decidual lymphocytes proved to be suppressive. At term seven of twelve lymphocyte preparations at a lower concentration of cells and six of seven at a higher concentration showed suppression. Suppressor cells appear to be present in human decidua and may play a role in preventing maternal immunologic attack on the allogenic embryo, thereby preventing spontaneous abortion.     

Expression of interleukin-22 in decidua of patients with early pregnancy and unexplained recurrent pregnancy loss

Purpose

Researchers have hypothesized that an imbalance of immune cells in the uterine decidua and a dysfunction in cytokines they produce may contribute to recurrent pregnancy loss (RPL). The objective of this study was to determine if IL-22, IL-23 and IL-17 are expressed abnormally in the decidua of patients with RPL compared to those women with a normal pregnancy. We also sought to confirm that uterine natural killer (uNK) cells are lower in the decidua of patients with RPL, as well as identify IL-22 expression by uNK cells.

Methods

After meeting strict inclusion criteria, maternal decidua of nine patients with unexplained RPL and a confirmed euploid fetal loss, and 11 gestational age-matched patients undergoing elective pregnancy termination were included in our analysis. Quantitative real time-polymerase chain reaction (qRT-PCR) was performed to quantify RNA expression, Western blot was performed to quantify protein expression and immunohistochemistry (IHC) was performed to identify IL-22 and uNK cells.

Results

We found that women with unexplained RPL and a euploid fetal loss had significantly less gene and protein expression of IL-22 in the decidua. Additionally, we found that IL-22 is primarily expressed by uNK cells in the decidua.

Conclusions

In conclusion, our results suggest that lower levels of IL-22 in the uterine decidua in patients with unexplained RPL may contribute to a disruption of decidual homeostasis and ultimately lead to early pregnancy loss.     

RU486抗早孕蜕膜血管形态计量学研究

目的:研究RU486抗早孕子宫出血时间长的机理。方法:应用MIPS图象分析系统,测定RU486药物流产(药流)者的蜕膜及负压吸引人工流产者的蜕膜血管总截面积及血管密度。结果:RU486药物流产后蜕膜血管总截面积及血管密度均明显小于人工流产组者,差异有显著性(P<0.05)。结论:药流者子宫出血时间长可能与RU486、米索前列醇二者合用影响人蜕膜血供有关。     

米非司酮药物流产时绒毛膜及蜕膜组织的超微结构改变

目的 探讨米非司酮药物流产时,绒毛膜及蜕膜的形成学变化。方法 应用光镜和透射电镜对10例米非司酮药物流产患者（观察组）和10例人工流产患者（对照组）在流产当时留取绒毛膜和蜕膜进行形态学观察。结果 观察组标本中绒毛膜和蜕膜组织细胞均表现出一种自噬性凋亡倾向。蜕膜组织中颗粒细胞内的分泌颗粒减少或消失,间质内网状纤维溶解,断裂。结论 米非司酮药物流产时,绒毛膜及蜕膜细胞均呈现一种自噬性凋亡倾向,同时释放大量松弛素,引起网状纤维溶解。断裂,蜕膜组织崩解,剥脱。