泰山磐石散对复发性流产小鼠母胎界面Th1/Th2细胞因子及妊娠预后的影响

目的:观察泰山磐石散对复发性流产小鼠母胎界面Th1/Th2细胞因子及妊娠预后的影响,为泰山磐石散临床应用提供新的实验依据。方法:采用经典造模方式DBA/2小鼠与CBA/J杂交,获得复发性流产小鼠模型,随机将与DBA/2小鼠合笼的60只CBA/J妊娠小鼠分为模型组、中药低剂量组、中药中剂量组、中药高剂量组和阳性对照组;与BALB/C合笼的10只CBA/J孕鼠作为正常妊娠模型。于妊娠14 d后处死孕鼠,观察小鼠胎盘丢失情况,并提取培养胎界母细胞,24 h后收集细胞上清液,酶联免疫吸附测定(ELISA)法检测上清液中肿瘤坏死因子α(TNF-α)、γ干扰素(IFN-γ)、白细胞介素4(IL-4)和IL-10含量。结果:经泰山磐石散治疗后,与模型组比较,复发性流产小鼠胎盘丢失率明显改善,母胎界面细胞上清液中Th1型细胞因子IFN-γ明显降低,Th2型细胞因子IL-4、IL-10明显升高,Th1/Th2免疫调节失衡明显改善,以中药高剂量组改善最为明显。结论:泰山磐石散能改善复发性流产小鼠胎盘丢失情况,其具体机制可能是通过调节Th1/Th2免疫调节平衡实现。     

Blockade of CD80 and CD86 at the time of implantation inhibits maternal rejection to the allogeneic fetus in abortion-prone matings

CD28/CTLA-4 interactions with their specific B7-ligands (CD80 and CD86) play a decisive role in antigenic and allogenic responses. Recently, experimental transplant studies demonstrated that donor-specific tolerance was achieved by blocking these interactions. However, the role of blockade of CD28/B7 costimulatory pathway in the maintenance of materno-fetal tolerance has received little attention. In the present study, abortion-prone CBA/J females mated with DBA/2 males were administered with anti-CD80 and anti-CD86 monoclonal antibodies (mAbs) on day 4 of gestation (time of murine implantation). We demonstrated that the combined use of anti-CD80 and anti-CD86 mAbs induced maternal tolerance to the fetus in the abortion-prone CBA/J mice, and displayed expansion of the maternal CD4(+)CD25+ regulatory T cell population and up-regulated expression of CTLA-4, suggesting an active mechanism of regulatory T cells in suppressing maternal rejection to the fetus. In addition, the anti-CD80/86 mAbs treatment enhanced Th2 and reduced Th1 cytokine production in mice, implying that the development of Th2 cells might contribute to maternal tolerance to her fetus. Together, these findings indicated that blocking CD80 and CD86 enhanced maternal tolerance to her fetus in mice by increasing regulatory T cell function and skewing toward a Th2 response. Our data might provide an enhanced understanding of the maternal-fetal immune relationship and be helpful in clinical trials for immunotherapy of recurrent spontaneous abortion.     

High expression of survivin and down-regulation of Stat-3 characterize the feto-maternal interface in failing murine pregnancies during the implantation period

The materno-fetal interface has for long been considered as an immune privileged biological site and thus understanding the mechanisms underlying fetal survival have been the focus of intense research. In adults, survivin and Stat-3 proteins are involved in tolerance as well as the induction of apoptosis. However, the role of these molecules in pregnancy and development has not been addressed. We have evaluated the expression of survivin and Stat-3 in allogeneic mouse models of low abortions (CBA/J x Balb/c), abortion prone (CBA/J x DBA/2J) and stress-triggered abortions from DBA/2J-mated CBA/J mice. We show that survivin is over-expressed in abortion-prone mating on gestation day 7.5. This effect was also found in stress-exposed mice, whereas expression was low in normal pregnancy mice. The phosphorylated Stat-3 (p-Stat-3) was down regulated in high abortion mating compared with low abortion mating, CBA/J x Balb/c. The level of apoptosis was similar in the three groups studied. Our results suggest that high expression of survivin and low expression of p-Stat-3 are involved in pregnancy loss in mice.     

干预CD86协同刺激信号对母胎界面Th1/Th2型细胞因子转录调控及妊娠结局的影响

目的探讨干预CD86协同刺激信号对母胎界面Th1/Th2型细胞因子转录调控及妊娠结局的影响。方法:将正常妊娠模型(CBA/J×BALB/c)和自然流产模型(CBA/J×DBA/2J)CBA孕鼠均分为两组:对照组(各10只)于孕d 4、d 6、d 8腹腔注射大鼠IgG;干预组(各10只)于孕d 4、d 6、d 8腹腔注射大鼠抗小鼠CD86 mAb。孕d 9竞争性半定量RT-PCR测定各组母胎界面组织中Th1型(IL-12、IFN-γ)/Th2型(IL-4、IL-10)细胞因子转录水平;孕d 12比较两种模型各组的胚胎吸收率。结果:正常妊娠模型中,干预CD86协同刺激信号对母胎界面Th1/Th2型细胞因子转录水平及妊娠预后均无显著影响(P>0.05)。自然流产模型中,干预CD86协同刺激信号能够升调节母胎界面局部Th2型而降调节Th1型细胞因子转录水平,并显著改善其妊娠预后(P<0.05)。结论:于孕早期干预CD86协同刺激信号能够调控母胎界面局部Th1/Th2型细胞因子转录,形成维持正常妊娠所需的Th2型免疫偏倚,诱导母胎免疫耐受。     

妊娠早期阻断协同刺激分子诱导自然流产模型孕鼠脾脏细胞母-胎免疫耐受的研究

目的　探讨阻断协同刺激分子———CD80 和CD86对自然流产模型孕鼠妊娠结局及孕鼠脾脏免疫细胞对父系抗原免疫耐受状态的影响。方法　将雌性小鼠 (CBA/J)分别与BALB/c及DBA/2两种雄性小鼠合笼交配 ,分别建立正常妊娠模型CBA/J×BALB/c( 2 0只 ,对照组 )和自然流产模型CBA/J×DBA/2 ( 2 0只 ,研究组 )。CBA/J小鼠于妊娠第 4天 (着床期 )腹腔分别注射大鼠同型IgG 0 2mg( 10只 ) ,或大鼠抗小鼠CD80 和CD86单克隆抗体 ( 10只 )。妊娠第 9天 ,采用单向混合淋巴细胞反应 ,分析孕鼠脾脏免疫细胞对父系抗原的增殖能力 ,并测定细胞培养上清液中白细胞介素 2(IL 2 )水平 ,以研究脾脏细胞母 胎免疫耐受状态 ;妊娠第 14天观察两组的胚胎吸收率。结果　 ( 1)研究组中 ,腹腔注射大鼠IgG的孕鼠胚胎吸收率为 2 4 3% ,而注射大鼠抗小鼠CD80 和CD86单克隆抗体的孕鼠胚胎吸收率为 9 8% ,两者比较 ,差异有显著性 (P <0 0 5 )。 ( 2 )应用大鼠抗小鼠CD80 和CD86单克隆抗体 ,使妊娠 9d的孕鼠脾脏免疫细胞对父系抗原的增殖能力及IL 2水平显著下降(P <0 0 5 )。结论　孕早期阻断协同刺激分子 ,可诱导产生孕鼠脾脏免疫细胞对父系抗原的免疫耐受 ,从而使自然流产模型孕鼠的妊娠结局达到正常妊娠水平。     

寿胎丸对复发性流产小鼠蜕膜组织中螺旋动脉改变及怀孕结局的影响

目的：通过观察寿胎丸对复发性流产（RSA）小鼠蜕膜组织子宫螺旋动脉改变及怀孕结局的影响,探讨其保胎的作用机制。方法：以CBA/J雌鼠×BALB/c雄鼠建立正常怀孕小鼠模型（12只）,CBA/J雌鼠×DBA/2雄鼠建立RSA小鼠模型（43只）,RSA小鼠按怀孕先后顺序随机分为RSA模型对照组（11只）、寿胎丸低剂量组（11只）、寿胎丸中剂量组（11只）及寿胎丸高剂量组（10只）,于孕第4～9天灌胃给药,孕14 d处死孕鼠,计数吸收胚胎数,计算各组胚胎吸收率,光镜下观察各组蜕膜组织中螺旋动脉生理性改变的发生率,并测量螺旋动脉的管腔直径及管壁厚度,透射电镜下观察蜕膜组织中螺旋动脉超微结构。结果：RSA模型对照组胚胎吸收率高于正常怀孕模型组（29.49% vs. 4.55%,χ2=18.887,P=0.000）。寿胎丸低、中、高剂量组的胚胎吸收率比RSA模型对照组均降低（均P＜0.05）。RSA模型对照组蜕膜组织中子宫螺旋动脉生理性转变率低于正常怀孕模型组（11.90% vs. 44.68%, χ2=11.522,P=0.001）。RSA模型对照组蜕膜组织中子宫螺旋动脉平均管腔直径及管壁厚度均低于正常怀孕模型组（P＜0.05）。寿胎丸高剂量组子宫螺旋动脉生理性转变发生率增高,管腔扩张,管壁厚度变薄（均P＜0.05）。结论：寿胎丸可能通过促进RAS小鼠蜕膜组织中子宫螺旋动脉生理性重铸发挥保胎作用。     

CD4(+)CD25+ T regulatory cells in murine pregnancy

Mammalian pregnancy is thought to be a state of immunological tolerance and immunological pregnancy complications may result from incomplete allo-tolerance. We reported recently a higher frequency of Th1 cytokine-producing T cells specific against paternal antigens in abortion-prone mice compared to normal pregnant mice. Since Th2 cells were shown to be not essential for normal pregnancy; alloreactive Th1 cells must be differently regulated. In this context, T regulatory cells (Treg) were proposed to play an essential role. Normal pregnant mice show an expansion of CD4(+)CD25+ and IL-10+ Treg cells at the periphery compared to non-pregnant animals. Further, we reported significantly lower frequencies of Treg in abortion-prone mice. Interestingly, CD4(+)CD25+ Treg cells from normal pregnant mice were able to prevent fetal rejection. Accordingly, down-regulated levels of Treg were also reported during human miscarriage. The putative mechanisms involved in Treg-induced tolerance in mice and humans are discussed in this review.     

干预CD86协同刺激信号在诱导母胎界面Th2型免疫偏倚中的作用

目的 :探讨干预CD86协同刺激信号在诱导母胎界面局部形成Th2型免疫偏倚中的作用。方法 :将正常妊娠模型 (CBA×BALB/c)和自然流产模型 (CBA×DBA/ 2 )CBA孕鼠均分为两组 ,于孕第 4、6、8天 ,对照组腹腔注射大鼠IgG ,实验组腹腔注射大鼠抗小鼠CD86mAb ;孕第 9天 ,ELISA测定母胎界面组织培养上清中Th1型 (IFN γ、TNF α) /Th2型(IL 4、IL 10 )细胞因子表达水平 ,并计算IL 4 /IFN γ、IL 10 /IFN γ比值 ;孕第 12天比较两种模型各组的胚胎吸收率。结果 :正常妊娠模型中 ,干预CD86协同刺激信号对母胎界面原有的Th2型免疫偏离及妊娠预后均无显著影响。自然流产模型中 ,干预CD86协同刺激信号能够诱导母胎界面局部形成Th2型免疫偏倚并显著改善其妊娠预后。结论 :于孕早期 ,干预CD86协同刺激信号能够改善母胎界面局部细胞因子微环境 ,形成维持正常妊娠所需的Th2型免疫偏倚 ,诱导母胎免疫耐受     

阻断协同刺激分子对MMP-9/TIMP-3的表达及妊娠结局的影响

目的：探讨阻断CD86协同刺激分子对自然流产模型孕鼠母胎界面MMP-9和TIMP-3的表达及妊娠结局的影响。方法：实验组于妊娠d 4．5腹腔注射大鼠抗小鼠CD86单抗,对照组注射大鼠同型IgG2b,而正常组不作任何处理。于妊娠d 13．5计算胚胎吸收率,并用免疫组化测定MMP- 9和TIMP-3的表达。结果：实验组的胚胎吸收率和MMP-9均显著低于对照组(P＜0．05),与正常对照组间均无差异；TIMP-3的表达与对照组和正常组比较均无显著差异(P＞0．05)。结论：在妊娠早期阻断CD86协同刺激分子能够通过某些机制诱导自然流产鼠MMP-9/TIMP-3的比值降低并且降低自然流产模型的胚胎吸收率,使模型组的胚胎吸收率恢复至正常妊娠水平。     

Murine fetal resorption and experimental pre-eclampsia are induced by both excessive Th1 and Th2 activation

It has been proposed that immune responses in mammalian normal pregnancy are Th2-like, thereby protecting the fetus and placenta from being rejected. Administration of exogenous Th1 cytokines into pregnant mice is reported to induce feto-placental resorption. However, the effects of exogenous Th2 cytokines and Th2 directed responses in pregnant animals have not been well studied. In this study, we examined IL-4 and IL-12, which play decisive roles in the development of Th2 and Th1 responses, respectively, in the induction of fetal resorption and development of experimental pre-eclampsia. Transfer of either IL-4 and/or IL-12 stimulated splenocytes from BALB/C virgin female mice into BALB/C pregnant mice mated with either C57BL/6 or BALB/C male mice resulted in fetal resorption and glomerular nephritis associated with hypertension and proteinuria. In mice treated with IL-12 stimulated splenocytes, fatty liver degeneration associated with bile retention was observed. These results indicate that both excessive Th1 and Th2 activation contribute to the development of fetal resorption and pre-eclampsia, but that Th1 is critical to the development of liver degeneration.     

Murine CD45+CD86+ cells isolated from para-aortic lymph nodes in an abortion-prone model

The present study aims to address whether the analysis of CD45+CD86+ cells isolated from para-aortic lymph nodes (pLNs) is valuable in assessment of the status of local immunity at the murine feto-maternal interface. CBA/J x DBA/2 mice, virgin CBA/J mice, and CBA/J x BALB/c mice were used as an abortion-prone model (group A), nonpregnant controls (group N), and fertile controls (group F), respectively. The percentage of CD45+CD86+ cells in the CD45+ cell group (CD45+CD86+ percentage for short) and the absolute number of these cells were determined by means of flow cytometry (FCM), using mononuclear cells isolated from pLNs collected 5.5, 9.5, and 13.5 days post-coitum (dpc), respectively, and mononuclear cells isolated from placentas 13.5 dpc. To clarify the identity of these CD86+ cells, FCM was also performed with CD3, CD19, and DX5 as specific markers for murine T-cells, B-cells, and NK cells, respectively. Both resorption rate and absolute number of resorptions were significantly higher in group A (29.3%, 1.8+/-1.0) than in group F (4.8%, 0.3+/-0.5, P<0.001, respectively). Similarly, both cell percentage and absolute number of CD45+CD86+ cells in pLNs collected 13.5 dpc were significantly higher in group A than in group F (27.5+/-14.0% versus 12.3+/-7.1%, and 1362+/-687 versus 615+/-353, P=0.001, respectively). The CD45+CD86+ percentage was around 7.5% in nonpregnant CBA/J mice, similar to the 10.6% in CBA/JxDBA/2 mice 5.5 dpc, but had increased dramatically, to 23.9%, by 9.5 dpc (P<0.001 versus nonpregnant mice and P=0.002 versus CBA/JxDBA/2 mice 5.5 dpc), and remained at a higher level (27.5%) until 13.5 dpc. However, this trend was not observed in group F during pregnancy. The increased CD45+CD86+ percentage at day 9.5 of gestation, when resorption begins, may support the assumption that CD45+CD86+ cells play a role in the course of embryo resorption. Lymphocyte phenotypic analysis in the lymph nodes that drain the pregnant uterus may be helpful to assess the status of local immunity at the feto-maternal interface.     

The therapeutic potential of the recombinant antigen from Dirofilaria immitis (rDiAg) for immune-mediated pregnancy loss

The mammalian fetuses are semi-allograft for mothers. Therefore the failure of immunological tolerance often causes pregnancy loss. Recently, the effects of helminthes therapy for immune mediated diseases have been reported. In the present study we employed the murine model to examine the therapeutic potential of the recombinant antigen from a nematoda parasite, Dirofilaria immitis for immune mediated pregnancy loss. Recombinant D. immitis polyproteins (rDiAg) had been cloned and selected by us for the strongest immuno-regulatory activities in parasite antigens. Female CBA/J mice were injected with sterilized rDiAg or PBS solution using micro-osmotic pumps before mating. Pregnant CBA/J mice were sacrificed on day 13.5 for scoring the number of resorbed and viable fetuses for histological and immunological analysis. The serum cytokine concentrations were measured using suspension array system. The resorption rate of mock-treated mice was 42.9% (resorbed fetus 12/total fetus 28). The resorption rate was decreased to 11.1% (resorbed fetus 3/total fetus 27) with rDiAg treatments. The IL-4, IL-23 and TNF-α concentrations in serum were significantly lower in rDiAg-treated mice than mock-treated mice. The serum IL-17 level was also reduced in rDiAg-treated mice but the difference was not significant. The rDiAg treatment reduced the resorption rates of CBA/J×DBA/2J mouse model, which mimic human pregnancy failures with allo-immune backgrounds. Our observations suggest as the first time of therapeutic potentials of the rDiAg for pregnancy loss.     

Immunosuppressive effect of pregnant mouse serum on allostimulatory activity of dendritic cells

In normal pregnancy, the maternal immune system is directed towards tolerance or suppression in order to prevent rejection of the semi-allogenic fetus. Antigen-presenting cells, especially dendritic cells (DCs), are key cells in initiation and regulation of immune responses. The presence of potent immunostimulatory DCs in the decidual tissue of pregnancy has been demonstrated. The aim of this study was to determine how allostimulatory activity of DCs could be affected during pregnancy. DCs were isolated from spleen of pregnant or non-pregnant Balb/c mice and co-cultured with allogenic T lymphocytes prepared from brachial lymph nodes of C57BL/6 mice. Some cultures of non-pregnant female DCs were treated by 2.5% serum obtained from pregnant mice at early, middle or late gestational periods, and were used in the same mixed lymphocyte reaction (MLR) settings. Cell proliferation was measured by 3H-thymidine incorporation, and cytokine production measured in supernatants of MLR cultures using ELISA. The effect of pregnant mouse serum on expression of DC surface markers was evaluated by flow cytometry. No significant difference was found between stimulatory potential of splenic DCs from pregnant and non-pregnant mice in induction of allogenic T cell proliferative response. Moreover, serum of early or late pregnancy did not have any effect on DC function in comparison with non-pregnant mouse serum, while mid-pregnancy serum significantly inhibited allostimulatory activity of DCs. IFNgamma production in co-culture of DCs treated with pregnant mouse serum was significantly lower than that of the control group; however, no significant difference in IL-10 production was observed. Treatment of DCs with pregnant mouse serum did not influence the percentage of cells expressing MHC-II, CD86, CD8alpha or CD11b. However, a marked reduction of the mean fluorescence intensity of MHC-II was observed. Collectively, our results concerning the diminished capacity of DCs to induce production of Th1 cytokines and allogenic T cell proliferation after treatment with pregnant mouse serum reveal a new way of immunologic tolerance against the semi-allogenic fetus.     

协同刺激分子CD86在母-胎免疫调节中的作用

目的　探讨协同刺激分子CD86在母 胎免疫调节中的作用。方法　建立自然流产模型(CBA×DBA/ 2 )及正常妊娠模型 (CBA×BALB/c)。两种模型分别再分为 3个组 :(1)以大鼠的IgG为对照的对照组 ;(2 )于妊娠第 4、6、8、10天 ,分别给CBA孕鼠腹腔注射大鼠抗小鼠CD86单克隆抗体的多次干预组 ;(3)仅于妊娠第 4天 ,给CBA孕鼠单次腹腔注射抗CD86单克隆抗体的单次干预组。每次腹腔注射的抗体剂量均为 10 0 μg。于妊娠第 14天计算各组胚胎吸收率。 结果　 (1)自然流产模型与正常妊娠模型的对照组胚胎吸收率分别为 2 7 78%和 8 42 %。 (2 )于妊娠第 4、6、8、10天腹腔注射抗CD86单克隆抗体后 ,自然流产模型的多次干预组胚胎吸收率下降至 9 6 8% (P <0 0 5 ) ;而正常妊娠模型的多次干预组胚胎吸收率上升至 13 5 4% (P >0 0 5 )。 (3)妊娠第 4天单次腹腔注射抗CD86单克隆抗体 ,自然流产模型单次干预组的胚胎吸收率下降至 7 14% (P <0 0 0 1) ;而正常妊娠模型单次干预组的胚胎吸收率上升至 11 39% (P >0 0 5 )。结论　妊娠早期 ,尤其在胚胎对母体的致敏阶段 (着床期 ) ,阻断母 胎界面的CD86协同刺激信号 ,将诱导母体对胚胎的免疫耐受 ,从而减少胚胎吸收 ,提高妊娠成功率     

CD4＋T细胞在原因不明复发性流产中的研究进展

正常妊娠有赖于母体对胚胎半同种抗原的免疫耐受,一旦免疫耐受失衡,将导致免疫排斥、免疫攻击从而导致自然流产,原因不明复发性流产被认为与母胎免疫耐受失衡有关.CD4＋T在同种异体急性排斥反应中发挥重要作用,根据所分泌的细胞因子不同,CD4＋T 细胞分为Th1、Th2、调节性T细胞（Treg）及新近发现的Th17细胞.早期研究发现母体外周血、母胎界面CD4＋T细胞增高与复发性流产密切相关.随免疫耐受机制研究的不断深入,母胎免疫耐受的研究历经Th1/Th2平衡到Treg的免疫负调控作用,再到Th17/Treg平衡.综述CD4＋T细胞在原因不明复发性流产中的研究进展.     

Therapeutic benefit of mesenchymal stem cells in pregnant rats with angiotensin receptor agonistic autoantibody-induced hypertension: Implications for immunomodulation and cytoprotection

Immunomodulation by mesenchymal stem cells (MSCs) is potentially important for maintaining peripheral tolerance. Preeclampsia may be due to maternal immune rejection of the genetically foreign fetus. This study aimed to investigate the biological function of human umbilical cord–derived mesenchymal stem cells (HU-MSCs) for the treatment of angiotensin receptor agonistic autoantibody (AT1-AA)-induced hypertension during pregnancy. HU-MSCs were isolated, cultured, and labeled in vitro. AT1-AA and HU-MSCs were administered to pregnant rats. Green fluorescent protein (GFP)–positive HU-MSCs infused in vivo were identified by immunofluorescence. Systolic blood pressure (SBP) was evaluated. The effects of HU-MSCs on fetal weight, kidney burden, and spiral artery remodeling, as well as on the expression of tumor necrosis factor α (TNF-α), interleukin 10 (IL-10), and heme oxygenase 1 (HO-1), were investigated. The SBP levels in the HU-MSC-treated pregnant hypertension rats decreased by gestational day 19. The reduction in fetal weight was largely ameliorated after HU-MSC treatment. Lesion burden in the kidney was attenuated and spiral artery remodeling was improved in HU-MSC-treated pregnant hypertension rats. However, green fluorescent protein (GFP)–labeled cells were sparingly observed in the kidney and placenta. Intravenous infusion of HU-MSCs into AT1-AA-induced rats significantly downregulated serum TNF-α levels and upregulated IL-10 levels, concomitant with increased placenta and mesometrial triangle (MT) HO-1 expression. Taken together, intravenous infusion of HU-MSCs ameliorates AT1-AA-induced pregnancy hypertension, intrauterine growth retardation, kidney impairment, and spiral artery remodeling impairment. Moreover, the potential benefits of HU-MSCs may be attributable to both an interference with the pathogenic immune response and a paracrine cytoprotective action.     

Stress increases VCAM-1 expression at the fetomaternal interface in an abortion-prone mouse model

Sound stress exposure increases fetal loss via inflammatory pathways. Inflammation is known to up-regulate cell adhesion molecules, such as vascular cell adhesion molecule-1 (VCAM-1), which mediates the adhesion of leukocytes to the vascular endothelium. In this work, we studied the frequency of VCAM-1(+) vessels at the fetomaternal interface in stressed and non-stressed pregnant CBA/J female mice mated with DBA/2J (high fetal loss model) or BALB/c (low fetal loss model) males. The high fetal loss model had fewer large vessels on gestation day 6.5, and stress reduced the frequency of large vessels to a similar number in both high and low fetal loss models. In the high fetal loss model, however, the frequency of VCAM-1+ vessels was dramatically increased. This study shows that VCAM-1 expression is modulated by stress at the fetomaternal interface in abortion-prone cross-breeding.     

Adoptive transfer of CD4+CD25+ regulatory T cells for prevention and treatment of spontaneous abortion

Objectives

The purpose of this study was to examine whether adoptive transfer with in vitro expanded CD4⁺CD25⁺ regulatory T cells (Tregs) could prevent immune response-mediated spontaneous abortion in mice.

Study design

Female CBA/J mice were mated with male Balb/c as the control with normal pregnancy or with DBA/2J mice as a model of spontaneous abortion. The CBA/J mice mated with DBA/2J were treated intravenously with freshly isolated or in vitro expanded Tregs on day 1 or 4 of pregnancy, respectively. The numbers of surviving and reabsorbed fetuses in the different groups of mice were counted on day 14 of pregnancy, and the concentrations of cytokines in individual sera and the supernatants of cultured Tregs were measured by ELISA.

Results

Adoptive transfer with freshly isolated Tregs only slightly reduced the fetal resorption rate, which was not significantly different from that of the mice without Treg treatment, regardless of treatment at early stage and implementation of pregnancy. In contrast, adoptive transfer with in vitro expanded Tregs significantly reduced the fetal resorption rates, particularly for treatment at early stage of pregnancy (P < 0.05). Furthermore, adoptive transfer with in vitro expanded Tregs at early stage of pregnancy significantly increased the levels of serum IL-10, TGF-β1, and the ratios of IL-10 to IFN-γ.

Conclusions

Our data clearly indicated that adoptive transfer with in vitro expanded Tregs at early stage of pregnancy protected fetuses from spontaneous abortion by re-establishing immune tolerance in mice.     

Active suppression of host-vs-graft reaction in pregnant mice. IV. Local suppressor cells in decidua and uterine blood

The mammalian fetus bears a wide variety of antigens against which the maternal immune system can respond. Although some of these antigens are transplantation antigens, the type of immune response mounted by the mother seems incapable of mediating graft rejection. We have previously demonstrated suppressor cells in the lymph nodes draining the uterus (DLN) that regulate the immune response in allogeneically pregnant C3H/HeJ and CBA/J mice. The suppressor cells were shown to be small lymphocytes (sedimenting at 3 mm/h at unit gravity) resistant to anti-T cell serum + complement that elaborated a soluble suppressor activity and selectively inhibited the generation of cytotoxic T lymphocytes (CTL) reactive with paternal alloantigens. Suppression could be induced in the DLN by syngeneic pregnancy or pseudopregnancy, and behaved as an anatomically localized activity during pregnancy. We now report that during first allogeneic pregnancy, the most potent suppressor cell activity is found in lymphocytes in uterine venous blood and in decidual lymphocytes. This suppressor cell population also sediments at 3 mm/h and is associated with production of a soluble suppressor factor. Substantial suppressor cell activity can also be obtained from the deciduomata of pseudopregnant mice. Local suppressor cell activity within the uterus may play an important role in ensuring the immunological success of the fetal allograft.     

Reduction in popliteal lymph node graft-versus-host reactivity by homologous and heterologous pregnancy serum

The popliteal lymph node assay was used to investigate the effect of pregnancy on graft-versus-host reactivity (GvHR) of mouse spleen cells. After local injection of splenocytes from primiparous syngeneically pregnant (by BALB/cJ males) or allogeneically pregnant (by CBA/Ca males) mice no differences in lymph node weight gain were observed in F1 recipients (CBA/Ca x BALB/cJ) when compared to injections of cells from age-matched non-pregnant BALB/cJ mice. However, lymphocytes of pregnant BALB/cJ females which had previously been pregnant between 4 and 6 times by CBA/Ca males induced a significantly lower GvHR compared to cells of matched non-pregnant multiparous mice. These results suggested an inhibitory effect of gestation on cells possibly primed towards paternal antigens by multiple pregnancies. To test this hypothesis, virgin BALB/cJ mice were actively immunized with lymphocytes of male CBA/Ca mice. Before injection into F1 recipients, spleen cells of immunized animals were incubated for 1 h at 37 degrees C in heat-inactivated serum of primiparous pregnant or virgin non-pregnant mice. Pre-incubation in pregnancy serum had no effect on unprimed cells, but GvHR of cells derived from immunized donors was significantly depressed in female recipients. In male animals this effect was only irregularly observed. Inhibition of GvHR was also observed with serum from pregnant but not non-pregnant pigs. Depression of cellular immune response was observed as early as days 4-9 post-coitum (p.c.) with mouse serum and days 16-19 p.c. with pig serum. These results indicate that pregnancy serum contains factor(s) which modulates the GvHR of primed lymphocytes in both a species- and an antigen-non-specific manner while reactivity of naive spleen cells is not changed.