过继转输TSA诱导的CD4^＋CD25^＋调节性T细胞对不明原因复发性流产的治疗作用

目的观察过继转输TSA诱导的CD4^＋CD25^＋调节性T细胞（CD4＋CD25＋Treg）对不明原因流产的作用机制及妊娠预后的影响。方法以雌性CBA/J×雄性BALB/c为正常妊娠模型,以雌性CBA/J×雄性DBA/2J为自然流产模型,使用免疫磁珠方法分选雌性CBA/J小鼠脾脏CD4^＋CD25^＋Treg细胞,并使用流式细胞术检测分选纯度。采用TSA对流产孕鼠外周CD4^＋/CD25^-T细胞Foxp3基因特定位点进行表观修饰,以实现Foxp3稳定、持久的表达,并将CD4^＋Treg分别转输至流产模型孕4d（着床期）的雌性CBA/J孕鼠,于孕14d分别观察宿主孕鼠的胚胎吸收率。结果与对照组比较,过继转输TSA诱导的CD4^＋CD25^＋Treg细胞的宿主孕鼠的胚胎吸收率（11.27%）显著下降。结论孕早期过继转输TSA诱导的CD4^＋CD25^＋Treg细胞疗法能诱导宿主母胎免疫耐受,有利于妊娠的维持。     

不明原因复发性流产小鼠模型CD4~+CD25~+ Treg的比例及Foxp3表达的变化

目的分析比较小鼠正常妊娠模型和流产模型中CD4+CD25+调节性T细胞CD4+CD25+Treg的比例、Foxp3蛋白表达水平及胎盘吸收率,探讨CD4+CD25+Treg与不明原因复发性流产的关系。方法以雌性CBA/J×雄性Balb/c为对照组,以雌性CBA/J×雄性DBA/2J为流产组,各10对,于妊娠第14天采用流式细胞术(flow cytometry,FCM)分析CD4+CD25+Treg在CD4+细胞中所占比例,Western blot检测并比较2组CD4+T细胞中Foxp3的表达,并观察2组小鼠的胎盘吸收情况。结果流产组CD4+CD25+Treg所占比例为(10.1±0.59)%低于对照组(15.5±0.78)%(P<0.05)。流产组胚胎吸收率为(25.6±3.5)%,明显高于对照组(2.4±1.6)%(P<0.01)。流产组Foxp3谱带密度相对值为0.30±0.018,低于正常组的0.68±0.025(P<0.05)。结论小鼠的自然流产模型建立成功,流产组孕鼠CD4+CD25+Treg的比例和Foxp3蛋白表达水平明显低于正常妊娠组,提示流产组高流产率可能与CD4+CD25+Treg数量和Foxp3的表达减少有关,CD4+CD25+Treg细胞的数量减少和功能缺陷可能是不明原因复发性流产的发生机制之一。     

原因不明复发性流产中CD4+ Notch1+T细胞与IL-10的相关性分析

探讨原因不明复发性流产（URSA）中CD4＋Notch1＋T细胞（Notch1＋占CD4＋T细胞的比例）与白介素-10（IL-10）表达水平的相关性。以雌性CBA/J×雄性Balb/c为正常妊娠模型,以雌性CBA/J×雄性DBA/2J为自然流产模型,采用流式细胞术检测6例未孕CBA/J雌性小鼠、6例正常妊娠模型孕14天CBA/J雌性小鼠和6例自然流产模型孕14天CBA/J雌性小鼠脾细胞中CD4＋Notch1＋T细胞,同时运用ELISA法检测其血清中IL-10的表达水平。相比于未孕组,正常妊娠模型中CD4＋Notch1＋T细胞比例减少,而自然流产模型中CD4＋Notch1＋T细胞比例增加,正常妊娠模型与自然流产模型中CD4＋Notch1＋T细胞比例差异有统计学意义（P〈0.05）。CD4＋Notch1＋T细胞比例与IL-10负相关（r=-0.568,P〈0.05）。结论：CD4＋Notch1＋T细胞可能参与原因不明复发性流产发病机制,拮抗Notch1＋表达有可能成为治疗URSA新途径。     

Reduced stathmin-1 expression in natural killer cells associated with spontaneous abortion

Female CBA/J mice impregnated by male DBA/2J mice (CBA/J×DBA/2J matings) are prone to spontaneous abortion, although the reason for this is unclear. In this study, the stathmin-1 expression pattern was evaluated in uterine natural killer (uNK) cells purified from CBA/J×DBA/2J matings. Results were compared with those in a CBA/J×BALB/c control group that yields successful pregnancies. The mean ± SD percentage of stathmin-1(+) cells in the CD49b(+) uNK cell population was lower in CBA/J×DBA/2J mice (0.7% ± 0.4%) than in control CBA/J×BALB/c mice (4.9% ± 1.5%, P < 0.01) using flow cytometry, and the intracellular stathmin-1 level in uNK cells was lower in CBA/J×DBA/2J mice than in control mice using Western blot analysis. Co-localization of lectin from Dolichos biflorus agglutinin (DBA-lectin) and stathmin-1 was confirmed using multivision immunohistochemical analysis. The frequency of stathmin-1(+)DBA-lectin(+) cells was lower in CBA/J×DBA/2J mice than in CBA/J×BALB/c mice. A similar trend in the frequency of stathmin-1(+)CD56(+) cells was seen in patients with unexplained spontaneous abortion compared with normal early pregnancy. A neutralizing antibody against stathmin-1 further increased the percentage of embryo loss in CBA/J×DBA/2J matings. These results provide evidence that stathmin-1 expression in uNK cells at the maternal-fetal interface may help modulate uNK cell function and may be beneficial for a successful pregnancy.     

CD4+ CD25+ regulatory T cells in human pregnancy: development of a Treg-MLC-ELISPOT suppression assay and indications of paternal specific Tregs

The current study was aimed at developing a one-way mixed leucocyte culture-enzyme-linked immunospot (MLC-ELISPOT) assay for the study of CD4(+) CD25(+) regulatory T (T(reg)) cells and applying this method in the study of antifetal immune reactions during human pregnancy. Twenty-one pregnant women and the corresponding fathers-to-be, and 10 non-pregnant control women and men, participated in the study. CD4(+) CD25(+) cells were isolated from peripheral blood mononuclear cells (PBMC) by immunomagnetic selection. Maternal/control PBMC were stimulated with paternal or unrelated PBMC in MLC. Secretion of interleukin-4 (IL-4) and interferon-gamma (IFN-gamma) from responder cells, with or without the presence of autologous T(reg) cells, was analysed by ELISPOT. PBMC from pregnant women showed increased secretion of IL-4 compared to controls. In pregnant and non-pregnant controls, T(reg) cells suppressed IFN-gamma reactivity against paternal and unrelated alloantigens. Interestingly, T(reg) cells suppressed IL-4 secretion against paternal but not unrelated alloantigens during pregnancy. We have successfully developed a model for studying T(reg) cells in antifetal cytokine reactions during pregnancy. Results indicate that T(reg) cells contribute to strict regulation of both T helper type 1-like and type 2-like antifetal immune reactions. Interestingly, T helper type 2-like cells specific to unrelated alloantigens are able to escape the suppression of T(reg) cells, which would allow for IL-4, alongside CD4(+) CD25(+) T(reg) cells, to control potentially detrimental IFN-gamma reactions during pregnancy.     

Development and function of naturally occurring CD4+CD25+ regulatory T cells

The immune system has evolved numerous mechanisms of peripheral T cell immunoregulation, including a network of regulatory T (Treg) cells, to modulate and down-regulate immune responses at various times and locations and in various inflammatory circumstances. Amongst these, naturally occurring CD4(+)CD25(+) Treg cells (nTreg) represent a major lymphocyte population engaged in the dominant control of self-reactive T responses and maintaining tolerance in several models of autoimmunity. CD4(+)CD25(+) Treg cells differentiate in the normal thymus as a functionally distinct subpopulation of T cells bearing a broad T cell receptor repertoire, endowing these cells with the capacity to recognize a wide range of self and nonself antigen specificities. The generation of CD4(+)CD25(+) Treg cells in the immune system is genetically controlled, influenced by antigen recognition, and various signals, in particular, cytokines such as interleukin-2 and transforming growth factor-beta1, control their activation, expansion, and suppressive effector activity. Functional abrogation of these cells in vivo or genetic defects that affect their development or function unequivocally promote the development of autoimmune and other inflammatory diseases in animals and humans. Recent progress has shed light on our understanding of the cellular and molecular basis of CD4(+)CD25(+) Treg cell-mediated immune regulation. This article discusses the relative contribution of CD4(+)CD25(+) nTreg cells in the induction of immunologic self-tolerance and provides a comprehensive overview of recent finding regarding the functional properties and effector mechanism of these cells, as revealed from various in vitro and in vivo models.     

Decidual and peripheral blood CD4+CD25+ regulatory T cells in early pregnancy subjects and spontaneous abortion cases

Human pregnancy represents a situation of semiallograft to maternal host. Therefore, it has been reported that tolerance to the fetal allograft represents a mechanism for maintaining a pregnancy. CD4(+)CD25(bright) regulatory T cells are known to play an important role in the development and maintenance of tolerance in peripheral tissues. However, the potential role of CD4(+)CD25(bright) T cells in maintaining human pregnancy has not been reported. In this study, we show that early human pregnancy decidua contains an abundance of CD4(+)CD25(bright) T cells, which express CD152(CTLA-4) at a high level. CD4(+)CD25(bright) T cells mediate potent inhibition of autologous T-cell proliferation by anti-CD3 stimulation. Furthermore, these cells inhibit the proliferation of autologous CD4(+)CD25(-) T cells in a dose-dependent fashion. This suppressive function of decidual CD4(+)CD25(+) T cells required cell-to-cell contact. The proportion of decidual CD4(+)CD25(bright) T cells was significantly lower in specimens from spontaneous abortion compared to those from specimens from induced abortions. These results suggest that decidual CD4(+)CD25(bright) T cells contribute to the mechanisms mediating maternal immune tolerance of conceptus antigens and therefore might contribute to the maintenance of pregnancy.     

1140915445Increased numbers of FoxP3+ cells in vaginal mucus from normal pregnant mice suggest early antigen-specific tolerance mechanism during pregnancy

The fetal survival within the maternal uterus is thought to be due to a transient immunological tolerance, being CD4⁺CD25⁺ T regulatory cells (Tregs) crucial players. Former studies confirmed diminished total numbers of this unique population in abortion-prone mice (DBA/2J-mated CBA/J females) as compared to a control with normal pregnancy outcome (BALB/c-mated CBA/J females) and suggested that Tregs act in an antigen-specific fashion. This hypothesis led us to investigate the kinetics of Tregs during pregnancy (day 0, 2, 5, 8, 10 or 12 of pregnancy) in abortion-prone mice and the control group. Our data confirmed diminished number of Tregs in immunological relevant organs such as lymph nodes and thymus within the abortion-prone mice. The enormous augmentation in the number of FoxP3⁺ cells in vaginal mucus already on day 0.5 after conception, followed by increased Tregs levels at early pregnancy stages, suggest, that Tregs need to be activated by male antigens for being protective. Notably, the abortion-prone mice displayed again a lower total amount of Tregs as compared to the control. Similar progesterone levels in spite of different pregnancy outcome reinforce the theory of antigen specificity of pregnancy-induced Tregs. The antigen presentation would take place in the periphery e.g. in vaginal mucus, the first site of contact with paternal antigens, directly after insemination. Interestingly the transfer of Tregs from normal pregnant mice at this time point prevented fetal rejection. Our results suggest the crucial role of Tregs already shortly after conception.     

BALB/c mice have more CD4+CD25+ T regulatory cells and show greater susceptibility to suppression of their CD4+CD25- responder T cells than C57BL/6 mice

Increasing evidence indicates that CD4(+)CD25(+) T regulatory (Treg) cells control a wide spectrum of immune responses. The initial identification of CD4(+)CD25(+) Treg cell as a "professional suppressor" was based on observations made in BALB/c mice. This mouse strain is well known to preferentially develop T helper cell type 2 responses, to be more susceptible to intracellular parasite infection, to have a higher tumor incidence, and to be more resistant to the induction of autoimmune diseases, as compared with C57BL/6 (B6) mice. We therefore decided to compare Treg cell function of B6 and BALB/c mice. We observed that the frequency of CD4(+)CD25(+) T cells in the thymus and peripheral lymphoid organs of BALB/c mice was higher than in B6 mice. CD4(+)CD25(+) Treg cells from both mouse strains shared similar phenotypic properties, including expression of characteristic immunological markers and hyporesponsiveness to T cell receptor cross-linking and in their capacity to suppress proliferation of BALB/c CD4(+)CD25(-) T responder (Tres) cells. However, CD4(+)CD25(-) Tres cells from B6 mice were notably less susceptible to suppression by CD4(+)CD25(+) Treg cells from either mouse strain. Our data suggest that the number and the level of suppression of CD4(+)CD25(+) Treg cells for CD4(+)CD25(-) Tres cells may be dictated by genetic background. Our data also suggest that differences in the CD4(+)CD25(+) Treg cell number and the susceptibility of CD4(+)CD25(-) Tres cells may, at least in part, account for the differences in immune response between B6 and BALB/c strains of mice.     

PD-1 but not CTLA-4 Blockage Abrogates the Protective Effect of Regulatory T Cells in a Pregnancy Murine Model

Problem  Regulatory T cells (Treg) play an important role in fetal protection. They expand during normal pregnancy and protect paternal/fetal antigens from rejection by maternal effector cells. Accordingly, the transfer of Treg obtained from BALB/c-mated CBA/J females prevents abortion in DBA/2J-mated animals. The actual mechanism through which Treg mediate their protective effect is still inconclusive. Cytotoxic T lymphocyte antigen-4 (CTLA-4) and Programmed cell death 1 (PD-1) are some of known Treg-associated molecules; however, their role in Treg-mediated fetal protection in murine model has not been investigated.
Method of study  Treg obtained from normal pregnant animals (NP; CBA/J × BALB/c) on day 14 were adoptively transferred into abortion-prone mice (AP; CBA/J × DBA/2J) intravenously on day 2 of pregnancy. An amount of 250 μg of either anti-PD-1 or anti-CTLA-4 mAb were injected intraperitoneally on days 0, 3, 6 and 9 of pregnancy. Controls received Treg + IgG or Treg + PBS. NP or AP treated with PBS served as additional controls.
Results  Blocking PD-1 abrogated the protective effect of Treg, resulting in a higher median abortion rate in comparison with the Treg/isotype-treated control while CTLA-4 blockage did not interfere with the protective effect of Treg. This was associated with a diminished number of vascular endothelial growth factor-A⁺ cells, previously reported as stimulators of lymphocyte extravasation in preterm labor.
Conclusion  Our data suggest PD-1 as an important mediator in Treg-induced fetal protection in the CBA/J × DBA/2J murine model.     

ASRI2005-88 Comparable levels of CD4+CD25+ CTLA4+ Treg cells in peripheral blood of pre-eclampsia and normal pregnant patients

The acceptance of the semiallogeneic fetus within the maternal environment requires tolerance mechanisms not fully characterized yet. Normal pregnancy is known to be associated with a Th2 profile. Furthermore, T-regulatory cells were proposed to regulate the Th2/Th1 balance at early stages of pregnancy. Treg may avoid the shift to a Th1 profile preventing miscarriage. Accordingly, spontaneous abortion is characterized by a Th1 dominance and diminished levels of Tregulatory cells (Treg). The major aim of the present work was to investigate if pre-eclampsia, a late immunological complication of pregnancy, is characterized by similar hallmarks. Therefore, we measured the surface antigens CD4, CD25, CD8, CTLA4 (as well as the secretion of IL-10) in peripheral blood from patients suffering from pre-eclampsia (n = 8) and age-matched patients undergoing normal pregnancies (n = 9) by 4-colour flow-cytometry. We were not able to find any significant differences in the levels of CD4⁺, CD25⁺, CD8⁺, CTLA4, CD4⁺/CD25⁺, CD4⁺/CD25^bright, CD4⁺/CTLA4, CD25⁺/CTLA4, CD4⁺/CD25⁺/CTLA4, CD8⁺/CD25⁺, CD8⁺/CTLA4 or CD8⁺/CD25⁺/CTLA4 cell subsets. Our data suggest that Treg may not participate in the onset of pre-eclampsia and suggest other regulatory mechanisms during late pregnancy.     

Systemic lupus erythematosus, regulatory T cells and pregnancy

Systemic lupus erythematosus (SLE) is the most common autoimmune disease affecting women of reproductive age and is associated with poor maternal and fetal outcomes. CD4(+)CD25(+) Treg cells are a subset of T lymphocytes with potent immunosuppressive activity that play crucial roles in controlling immunological self tolerance. Evidence suggests that they are augmented in pregnancy, especially in the first trimester, suggesting an important role in early placental development. The literature describing Treg cells in SLE is conflicting, but SLE is associated with reduced numbers and functionally defective Treg cells, which may predispose pregnant women with the disease to pregnancy complications. This article discusses the role of Treg cells in SLE and pregnancy, and how these cells may contribute to poor pregnancy outcome in SLE-affected women.     

Changes of CD4+CD25+Foxp3+ regulatory T cells in aged Balb/c mice

A progressive decline in the integrity of the immune system is one of the physiologic changes during aging. The frequency of autoimmune diseases or immune disorders increases in the aging population, but the state of regulatory T (Treg) cells in aged individuals has not been well determined. In the present study, we investigated the levels, phenotypes, and function of CD4(+)CD25(+) Treg cells in Balb/c mice, which were older than 20 months. Significantly enhanced percentages of CD4(+)CD25(+) Treg cells in the periphery (blood, spleen, and lymph nodes) of the aged mice were observed. These Treg cells showed modified Vbeta family distribution, reduced levels of CD45 receptor B and CD62 ligand molecules, as well as normal levels of forkhead box p3. However, when the inhibiting function of Treg cells was assayed in the in vitro assays and in a delayed-type hypersensitivity (DTH) model, CD4(+)CD25(+) Treg cells of aged mice displayed significantly lower inhibiting ability on alloantigen-induced DTH reaction or cytokine productions (IL-2 and IFN-gamma) but not cell proliferation of effector T cells, as compared with CD4(+)CD25(+) Treg cells of young mice. In addition, the percentages of CD4(+)CD8(-)CD25(+) Treg cells in the thymi of aged mice increased significantly, but their total cell numbers decreased markedly in these mice. Our present studies indicated collectively that the percentages, phenotypes, the size of TCR repertoire, and function of CD4(+)CD25(+) Treg cells were altered significantly with aging in mice. The functional defects of CD4(+)CD25(+) Treg cells may shed light on the role of CD4(+)CD25(+) Treg cells in the increased sensitivity to autoimmune diseases of aged populations.     

Prevention of spontaneous abortion in the CBA x DBA/2 mouse model by intravaginal TGF-beta and local recruitment of CD4+8+ FOXP3+ cells.

PROBLEM: Activation of latent transforming growth factor (TGF)-beta in seminal plasma has been suggested by Robertson et al. to promote maternal tolerance to paternal antigens. A possible consequence reported by Tremellen et al. is increased pregnancy rates in women undergoing IVF. A decreased spontaneous abortion rate has also been postulated. Seminal plasma contains many factors besides TGF-beta, and a critical test of the hypothesis was required. The purpose of the present study was to directly test the effect of pure TGF-beta. METHOD OF STUDY: Pharmaceutical grade bioactive TGF-beta3 with a bovine serum albumin (BSA) carrier 0.1-1% in phosphate-buffered saline (PBS) was given into the vaginal tract of CBA/J female mice at the time of mating with DBA/2 males. One microgram Salmonella enteritidis lipopolysaccharide was given intraperitoneally to augment occult losses and spontaneous resorptions assessed on day 13.5 of pregnancy. The effect of TGF-beta3 on recruitment of lymphomyeloid cells to the vaginal wall and vaginal lumen of unmated mice in estrus was assessed using immunohistochemistry and flow cytometry. RESULTS: Two nanogram of intravaginal TGF-beta3 in 0.1% BSA-PBS or 20 ng in 1% BSA-PBS reduced abortion rates. Protection was comparable to that achieved by immunization with BALB/c spleen cells. Fraction V BSA, a binder of TGF-betas, had some activity, and could reduce availability of added TGF-beta3. CD11c dendritic cells, CD3+ T cells, and CD25+ cells were recruited to the vaginal wall by 48 hr after TGF-beta3 treatment, and cellularity of vaginal exudates increased. Foxp3+ cells were present in increased numbers, and appeared to be CD8+ and CD4+ 8+. Semen, but not TGF-beta3, stimulated a physiological polymorphonuclear leukocyte exudate. CONCLUSION: Intravaginal bioactive TGF-beta3 can enhance success of pregnancy in vivo in an established model of abortion. The result could be explained by the independent ability of TGF-beta to promote a regulatory T-cell response.     

1140918040Prevention of abortion in the CBAxDBA/2 model by intravaginal TGF-β is associated with local recruitment of predominantly CD8+ Foxp3+ T cells to the genital tract

Problem: Spontaneous abortions in DBA/2‐mated CBA/J mice can be prevented by an immune response to BALB/c, and CD4⁺25⁺ Treg cells as well as CD8⁺ T cells have been proposed to confer protection. Recently a 2 ng dose of intravaginal TGF‐β3 at the time of exposure to DBA/2 semen was shown to be effective. TGF‐β is known to facilitate development of Treg cells. Is there evidence for local Treg induction? Methods: The phenotype of cellular recruitment to the vaginal wall and uterus was established by immunostaining tissue sections from CBA/J females following intravaginal TGF‐β treatment. The phenotype of cells in vaginal washings 48 hr after TGF‐β was determined by flow cytometry. Results: Increased numbers of CD3⁺, CD25⁺, and CD11c⁺ cells were found in vaginal mucosa with increasing doses of TGF‐β. A 2 ng TGF‐β3 treatment at the time of estrus recruited Foxp3⁺ cells to the vaginal lumen, and the majority of these were CD8⁺; CD4⁺ cells were also present, but expressed only low levels of CD25 and CTLA4. A 20 ng dose recruited predominantly CD4⁺8⁺ Foxp3⁺ cells. Conclusion: Induction of Tregs to semen‐associated DBA/2 antigens may prevent pregnancy loss in the CBAxDBA/2 model without the need for BALB/c as an immunogen. The Treg phenotype in the genital tract is compatible with additional members of the Treg family that recognize Class I MHC and associated paternal peptides and prevent abortions.     

胎盘NKT细胞在小鼠原因不明多发性流产中的作用研究

目的:通过检测原因不明多发性流产模型(CBA/J雌鼠×DBA/J雄鼠)小鼠胎盘中的NKT的细胞数量、成熟度和细胞因子的分泌格局,以探索NKT细胞失调在原因不明多发性流产中的可能作用.方法:分别建立正常妊娠模型(CBA/J雌鼠×BALB/C雄鼠)和原因不明多发性流产模型,用流式细胞仪检测滋养层细胞中NKT细胞和CD3~+T数量的变化,用ELISA方法检测Th1/Th2相关细胞因子,而胎盘淋巴细胞T-bet表达水平用荧光定量PCR法检测.结果:正常妊娠组与原因不明多发性流产组CD3~+T细胞数量无显著性变化(P＞0.05);正常妊娠过程中,胎盘淋巴细胞分泌IFN-γ的量逐渐下降,伴随有NKT细胞数量、成熟型比例逐渐下降,而原因不明多发性流产妊娠过程中则相反;多发性流产组与正常妊娠组相比,T-bet mRNA存在表达异常,并与NKT细胞成熟型比例、胎盘淋巴细胞分泌IFN-γ的量成正相关.结论:原因不明多发性流产的发生,可能与NKT细胞失调相关,妊娠早期与胎盘NKT细胞成熟型比例偏低,分泌IFN-γ不足有关,而妊娠中后期则与NKT细胞成熟型比例偏高,分泌IFN-γ过量有关,T-bet mRNA的表达异常是造成NKT细胞失调的因素之一.     

Regulatory T cells in pregnancy

Tolerance mechanisms are responsible for the survival of the fetus within the maternal uterus without being attacked by the cells of the maternal immune system despite their direct contact. Regulatory T cells (Treg) were claimed to be important players in the tolerance towards the fetus bearing alloantigens. Recent evidence confirmed an augmentation in the number of Treg during pregnancy and, most importantly, diminished numbers of Treg were associated with immunological rejection of the fetus. This could be prevented by adoptively transferring CD4⁺/CD25⁺ Treg cells from normal pregnant mice into abortion-prone animals. Treg prevented abortion while creating a transient tolerant microenvironment characterized by high levels of TGF-β, LIF, and HO-1. Downregulated levels of Treg were accordingly also reported during human miscarriage. Furthermore, we have evidence suggesting that, to be protective, Treg need to be activated by male antigens during pregnancy.     

The different effects of indirubin on effector and CD4+CD25+ regulatory T cells in mice: potential implication for the treatment of autoimmune diseases

CD4(+)CD25(+) regulatory T (Treg) cells play an essential role in the induction and maintenance of peripheral self-tolerance. Indirubin, a traditional Chinese medicine, was clinically used in the treatment of chronic myelocytic leukemia as well as some autoimmune diseases, including Alzheimer's disease, diabetes, and so on. The effects of indirubin on CD4(+)CD25(+)Treg cells, which play a critical role in controlling autoimmunity, have not been addressed. In the present study, we observed the cell levels, phenotypes, and immunoregulatory function of CD4(+)CD25(+)Treg cells in indirubin-treated mice. Treatment with indirubin significantly enhanced the ratios of CD4(+)CD25(+)Treg cells or CD4(+)CD25(+)Foxp3(+)Treg cells to CD4(+)T cells in peripheral blood, lymph nodes, and spleens (P < 0.01 compared with control mice). CD4(+)CD25(+)Foxp3(+)Treg cells to CD4 single positive cells in the thymi of indirubin-treated mice were significantly higher than those in control mice. Furthermore, splenic CD4(+)CD25(+)Treg cells in indirubin-treated mice showed immunosuppressive ability on the immune response of T effector cells to alloantigens or mitogen as efficiently as the control CD4(+)CD25(+)Treg cells in vitro. The present studies indicate that CD4(+)CD25(+)Treg cells are more resistant to indirubin than effector T cells in vivo. The selectively enhanced CD4(+)CD25(+)Treg cell levels by indirubin made host to be more favorable for immune tolerance induction, which opened one possibility for indirubin to treat autoimmune diseases.     

过继转输胚胎抗原耐受T细胞诱导自然流产孕鼠母胎免疫耐受

探讨过继转输胚胎抗原耐受T细胞对小鼠自然流产模型妊娠预后及宿主孕鼠免疫细胞对父系抗原免疫耐受状态的影响。以CBA/J×BALB/c为正常妊娠模型 ,CBA/J×DBA/ 2为自然流产模型 ,将自然流产模型CBA/J孕鼠于孕 4d (着床期 )分别腹腔注射大鼠抗小鼠CD80和CD86mAb或大鼠同型IgG。于孕 9d ,应用免疫磁珠阴性分选三组孕鼠的脾脏T细胞 ,并将三组T细胞分别转输至孕 4d的CBA/J×DBA/ 2孕鼠。于宿主孕鼠孕第 9天 ,采用单向混合淋巴细胞反应分析宿主孕鼠脾脏免疫细胞对父系抗原的增殖能力 ,并用流式细胞术分析经父系抗原刺激的宿主孕鼠脾脏T细胞内IL 2表达水平。于孕 1 4d分别观察宿主孕鼠的胚胎吸收率。结果显示 ,过继转输胚胎抗原耐受T细胞和转输正常妊娠模型孕鼠的T细胞均可诱导宿主孕鼠脾脏免疫细胞对父系抗原的增殖能力及IL 2的表达显著下降 (P <0 0 5 ) ,孕 1 4d胚胎吸收率也显著下降 (P <0 0 5 )。这些结果表明 ,于孕早期过继转输胚胎抗原耐受T细胞和转输正常妊娠模型孕鼠的T细胞能诱导宿主孕鼠母 胎免疫耐受 ,防止母体对胚胎的免疫排斥 ,从而使自然流产模型的妊娠预后达到正常妊娠水平。     

早期不明原因反复自然流产发生与蜕膜中免疫细胞的研究进展

人类妊娠被认为是一种半同种异体抗原移植，母胎间存在着某种免疫耐受机制来维持妊娠的进行，但目前为止这种免疫耐受机制尚不明确。大量的研究发现不明原因反复自然流产患者蜕膜中调节性T细胞的数量和功能均显著降低，表明调节性T细胞在避免胎儿免疫排斥中发挥着重要的作用。同时NK细胞作为早期妊娠蜕膜中的优势淋巴细胞亦对妊娠的维持起着重要的作用，不明原因反复自然流产患者蜕膜NK细胞数量和活性比正常妊娠妇女明显升高，同时CD56^＋CD16^＋／CD56^＋CD16^-NK细胞比例失衡。由此可见，妊娠早期不明原因反复自然流产的发生与蜕膜中淋巴细胞的异常表达相关，通过对这种复杂机制的研究可以为不明原因反复自然流产的预防和治疗提供依据。