骨髓和脂肪来源间充质干细胞的免疫调节作用

背景：脂肪来源的间充质干细胞是否具有和骨髓来源间充质干细胞类似的免疫调节作用? 目的：观察骨髓来源和脂肪来源间充质干细胞的免疫学特征。 方法：分离骨髓和脂肪来源的间充质干细胞,分别检测它们对T细胞周期、活化、抑制和增殖的作用情况。 结果与结论：骨髓来源和脂肪来源的间充质干细胞同样具有抑制T细胞增殖的能力,在有丝分裂原刺激和混合淋巴细胞反应的T细胞增殖中这种作用都是具有剂量依赖性的,在1︰2时有极强的抑制作用,但是在1︰100时这种作用基本消失,在共培养时骨髓来源和脂肪来源的间充质干细胞都可以使更多的T细胞被抑制在G0/G1期,同时也可以抑制T细胞的早期活化,但是上述作用脂肪来源的间充质干细胞均较骨髓来源间充质干细胞弱,且脂肪来源的间充质干细胞并不具有抑制T细胞凋亡的作用。     

骨髓异常增生综合征患者骨髓来源的间充质干细胞免疫功能异常

目的 研究骨髓异常增生综合征(myelodysplastic syndromes,MDS)难治性贫血(refractory anemia,RA)型患者(MDS-RA)和健康成年人骨髓来源的间充质干细胞(bone marrow derived mesenchymal stem cell,BMSC)的免疫学特征,比较它们是否存在免疫功能的异常.方法 分离MDS-RA和健康成年人来源的间充质干细胞,分别检测它们对T细胞周期、活化、抑制和增殖的作用情况.结果 MDS-RA的BMSC抑制T细胞增殖和活化能力均减弱,但是抑制活化的T细胞凋亡的作用反而增强.结论 MDS-RA患者骨髓来源的MSC存在明显的免疫调节功能缺陷,MDS-RA患者骨髓微环境可能存在免疫异常,如果使用MDS患者自体的MSC移植治疗可能不是一种很好的选择.对于MDS患者最好是选用异基因的MSC移植.     

骨髓和脂肪来源的间充质干细胞免疫调节作用的比较

目的比较脂肪源间充质干细胞(AMSCs)和骨髓来源间充质干细胞(BMSCs)的免疫调节能力的差异。方法用流式细胞仪分析AMSCs和BMSCs的表型。通过MSCs和淋巴细胞共培养体系,检测MSCs对T细胞增殖、周期、活化、凋亡以及Th细胞分化的影响。结果表型分析结果显示AMSCs和BMSCs的表型基本一致。AMSCs和BMSCs都能抑制T细胞的增殖和早期活化,并在调节辅助性T细胞亚群的分化上作用类似。但在MSC对活化后T细胞的凋亡影响方面,BMSCs能够抑制活化T细胞的凋亡,而AMSC没有这种作用。结论 AMSCs和BMSCs对T淋巴细胞的影响基本类似,其对活化T细胞凋亡影响的差异还有待进一步的机制研究。     

Comparison of immuno-modulatory properties between bone-marrow derived MSCs and adipose derived MSCs

目的 比较脂肪源间充质干细胞(AMSCs)和骨髓来源间充质干细胞(BMSCs)的免疫调节能力的差异.方法 用流式细胞仪分析AMSCs和BMSCs的表型.通过MSCs和淋巴细胞共培养体系,检测MSCs对T细胞增殖、周期、活化、凋亡以及Th细胞分化的影响.结果 表型分析结果显示AMSCs和BMSCs的表型基本一致.AMSCs和BMSCs都能抑制T细胞的增殖和早期活化,并在调节辅助性T细胞亚群的分化上作用类似.但在MSC对活化后T细胞的凋亡影响方面,BMSCs能够抑制活化T细胞的凋亡,而AMSC没有这种作用.结论 AMSCs和BMSCs对T淋巴细胞的影响基本类似,其对活化T细胞凋亡影响的差异还有待进一步的机制研究.     

慢性粒细胞白血病肿瘤干细胞的免疫调节功能

目的 研究慢性粒细胞白血病(CML)骨髓来源的肿瘤干细胞的免疫学特征,比较其与正常人来源的间充质干细胞(MSC)是否存在免疫功能的异常.方法 分离正常人和CML患者骨髓中的MSC,MLR法检测其对T细胞增殖的影响,流式细胞术检测其对T细胞周期、凋亡的作用情况.结果 CML和正常志愿者骨髓来源的MSC的细胞形态和表型没有差异,CML患者来源的MSC抑制T细胞增殖能力和抑制T细胞停留在G0/G1期的作用均减弱(CML MSC组74.5%±1.2%,BMSC组94.0%±1.9%,P＜0.05),CML患者抑制T细胞凋亡的作用增强(CMLMSC组8.36%±1.31%,BMSC组14.10%±0.65%,P＜0.05).结论 CML患者骨髓来源的MSC存在明显的免疫调节功能缺陷,如果使用CML患者自体的MSC移植治疗可能不是一种很好的选择,对于CML患者最好是选用异基因的MSC移植.     

C57小鼠脂肪及骨髓间充质干细胞生物学特性的比较

背景：研究发现,脂肪源干细胞具有和骨髓间充质干细胞一样的贴壁和形成成纤维样克隆特性,并具有向骨、脂肪、软骨等多系分化的能力。 目的：比较C57小鼠脂肪源间充质干细胞和骨髓间充质干细胞的生物学特点。 方法：在无菌的条件下分别从C57小鼠的脂肪和骨髓中获取脂肪间充质干细胞和骨髓间充质干细胞。体外分离、培养并将脂肪间充质干细胞和骨髓间充质干细胞传至第3代,进行细胞形态、表面标记、生长动力学分化潜能测定和Notch信号相关基因的检测。 结果与结论：脂肪间充质干细胞和骨髓间充质干细胞形态学相似,第3代的脂肪间充质干细胞和骨髓间充质干细胞均表达CD29、CD105、Sca-1,不表达CD34、CD133,但骨髓间充质干细胞还表达CD45;生长曲线和细胞克隆分析显示脂肪间充质干细胞的增殖速度明显比骨髓间充质干细胞快;脂肪间充质干细胞和骨髓间充质干细胞均可向成骨、成脂、成软骨诱导分化,脂肪间充质干细胞更易向成骨诱导;Notch相关基因检测显示脂肪源干细胞的Jagged-1表达水平明显比骨髓间充质干细胞低,而Hes-1的表达水平脂肪源干细胞明显高于骨髓间充质干细胞的表达水平。提示脂肪间充质干细胞比骨髓间充质干细胞扩增能力更强,更易向成骨分化,可能与Hes-1表达水平有关。中国组织工程研究杂志出版内容重点：干细胞;骨髓干细胞;造血干细胞;脂肪干细胞;肿瘤干细胞;胚胎干细胞;脐带脐血干细胞;干细胞诱导;干细胞分化;组织工程全文链接：     

影响骨髓间充质干细胞成骨分化的力学信号传导机制研究进展

骨髓间充质干细胞(bone marrow stem cell,BMSC)是一种具有多向分化潜能的成体干细胞,适量的力学刺激能促进BMSC向成骨细胞分化。近几年来,一些学者利用力学刺激作用于体外培养的BMSC,促进其向成骨细胞分化,并且对其诱导分化的机制进行了大量研究。尽管这一机制目前尚不十分清楚,但是已有的研究表明,多条信号通路参与了该力学信号传导。本文就国内外近几年来关于力学信号影响BMSC成骨分化的信号转导机制研究进展做一综述。     

脂肪与骨髓来源间充质干细胞生物学特性的比较

背景：近几年来脂肪来源的间充质干细胞因其取材容易也被广泛研究。 目的：比较脂肪来源和骨髓来源间充质干细胞的生物学特性。 方法：分离及体外培养人骨髓源间充质干细胞和脂肪源间充质干细胞,比较它们的表型、细胞倍增时间及分泌因子水平等。 结果与结论：脂肪来源和骨髓来源的间充质干细胞在细胞表型上类似,只有CD106的表达有差异。脂肪来源间充质干细胞增殖速率比骨髓来源的间充质干细胞快。在相同体积的脂肪组织中能够得到的干细胞前体细胞的数量是骨髓的10倍以上。提示脂肪来源和骨髓来源的间充质干细胞具有相同功能,但脂肪组织是一个更有应用前景的干细胞来源。     

胚胎骨髓来源间充质干细胞对人Th17细胞的免疫调节

背景：众多研究表明间充质干细胞能发挥免疫调节功能,抑制T细胞增殖。 目的：观察胚胎骨髓来源间充质干细胞对人Th17细胞的调节作用。 方法：将人胚胎骨髓间充质干细胞与正常人外周血单个核细胞或CD4⁺ T细胞以1∶10比例共培养4 d,以单个核细胞或CD4⁺T细胞单独培养为对照。应用实时定量PCR检测细胞白细胞介素17 mRNA表达,酶联免疫吸附试验检测细胞上清中白细胞介素17蛋白水平,流式细胞术检测Th17细胞数量。 结果与结论：胚胎骨髓来源间充质干细胞与单个核细胞共培养组白细胞介素17 mRNA表达水平明显高于单个核细胞组(P < 0.01)。与此一致的是,胚胎骨髓来源间充质干细胞与单个核细胞或CD4⁺T细胞共培养组细胞上清中白细胞介素17蛋白水平明显高于单个核细胞组、CD4⁺ T细胞组(P < 0.05,P < 0.01)。胚胎骨髓来源间充质干细胞与CD4⁺ T细胞共培养组Th17细胞数量明显高于CD4⁺ T细胞组(P < 0.01),但胚胎骨髓来源间充质干细胞本身并不表达白细胞介素17。表明胚胎骨髓来源间充质干细胞可促进人Th17细胞增殖。     

慢性粒细胞白血病肿瘤干细胞的免疫功能

背景：研究认为间充质干细胞可能是骨髓造血微环境的免疫保护位点。由于慢性粒细胞白血病存在造血微环境异常和免疫异常,所以推测间充质干细胞可能在慢性粒细胞白血病的病理过程中扮演了一个重要角色。 目的：观察慢性粒细胞白血病骨髓来源的肿瘤干细胞的免疫学特征,比较其与正常人来源的间充质干细胞是否存在免疫功能的异常。 方法：分离正常人和慢性粒细胞白血病患者的骨髓间充质干细胞,分别检测它们对T细胞周期、活化、抑制和增殖的作用。 结果与结论：慢性粒细胞白血病和正常志愿者骨髓来源的间充质干细胞形态和表型没有差异,慢性粒细胞白血病患者来源的间充质干细胞抑制T细胞增殖的作用减弱,抑制T细胞周期及活化的能力减弱,慢性粒细胞白血病患者抑制T细胞凋亡的作用增强。提示慢性粒细胞白血病患者骨髓来源的间充质干细胞存在明显的免疫调节功能缺陷,如果使用慢性粒细胞白血病患者自体的间充质干细胞移植治疗可能不是一种很好的选择,对于骨髓增生异常综合征患者最好是选用异基因的间充质干细胞移植。     

Culture and properties of adipose-derived mesenchymal stem cells: characteristics in vitro and immunosuppression in vivo

Objective: To compare the two sources of adipose and bone marrow derived mesenchymal stem cells (BMSCs and AMSCs) in immune regulation and to evaluate the therapeutic effects of AMSCs on Con A induced hepatitis and the possible mechanism involved in it. Methods: We isolated bone marrow and adipose derived mesenchymal stem cells respectively and compared their differences on T lymphocyte activation, proliferation and suppression. We also test the anti-apoptosis ability of AMSCs on LO2 cell line. The effects of intravenous infusion of AMSCs on liver damage were also tested and we detected donor AMSCs in liver of recipient and their effects on the activity of intrahepatic NKT cells. Results: BMSCs and AMSCs were similar in cell phenotype and the difference existed only in the expression of CD106. The results showed that the capacity of suppressing T cells proliferation and activation was weakened in AMSCs. AMSCs ameliorated liver damage and this effect was time and dose dependent. We detected donor AMSCs in liver of recipient which suggested tissue damage could be a clue for AMSCs migration. We also found AMSCs suppress the activity of intrahepatic NKT cells, but this suppress effects was not restricted in liver only, but the whole body. Conclusion: Cell origin and abundance are decisive factors in stem cells applications and with the same premise of AMSCs and BMSCs, adipose tissue is a more promising origin source of stem cells. The immunoregulatory features of MSCs might play an important role in various MSCs cellular therapies.     

Human mesenchymal stromal cells modulate T‐cell responses through TNF‐α‐mediated activation of NF‐κB

Although mesenchymal stromal cells (MSCs) possess the capacity to modulate immune responses, little is known about the mechanisms that underpin these processes. In this study, we show that immunosupression is mediated by activation of nuclear factor kappa B (NF‐κB) in human MSCs. This pathway is activated by TNF‐α that is generated following TCR stimulation of T cells. Inhibition of NF‐κB through silencing of IκB kinase β or the TNF‐α receptor abolishes the immunosuppressive capacity of MSCs. Our data also indicate that MSC‐associated NF‐κB activation primarily leads to inhibition of T‐cell proliferation with little effect on expression of the activation markers CD69 and CD25. Thus, our data support the hypothesis that the TNF‐α/NF‐κB signalling pathway is required for the initial priming of immunosuppressive function in human MSCs. Interestingly, drugs that interfere with NF‐κB activation significantly antagonise the immunoregulatory effect of MSCs, which could have important implications for immunosuppression regimens in the clinic.     

Murine Mesenchymal Stem Cells Suppress T Lymphocyte Activation Through IL-2 Receptor α (CD25) Cleavage by Producing Matrix Metalloproteinases

Mesenchymal stem cells (MSCs) are multipotent, non-hematopoietic stem cells that exhibit the capacity to inhibit the proliferation of a variety of immune cells. However, the underlying mechanisms of the immunosuppressive effects of MSCs are still obscure. Therefore, we attempted to identify the mechanisms underlying immunosuppression toward the activated T lymphocytes by MSCs in a murine model. In particular, we aimed to find possible factors derived from MSCs that drive this phenomenon. We found that T lymphocytes incubated with conditioned media of MSCs (MSC CM) entered into apoptosis and were subjected to cell cycle arrest during the course of activation, and these phenomena were accompanied by the reduction of IL-2 production. Specifically, matrix metalloproteinases (MMPs) derived from MSCs caused cleavage of IL-2 receptor α (CD25) from the surface of activated T cells, and as a consequence, IL-2 signaling in response to engagement of the IL-2 receptor (IL-2R) was downregulated. The inhibition of MMP activity in the MSC CM by GM6001 abrogated CD25 cleavage and restored IL-2 production from the activated splenocytes. However, the blockade of MMP activity could not fully restore the proliferative response and apoptosis of T cells altered by MSC CM. In conclusion, MSC-derived MMPs have a significant role in the suppression of IL-2 production through induction of CD25 cleavage and have a partial role in the suppression of T cell proliferation.     

多发性骨髓瘤患者骨髓间充质干细胞免疫调节功能异常及其在骨髓瘤骨病中的作用

目的 探讨多发性骨髓瘤(MM)患者骨髓间充质干细胞(MSCs)免疫调节功能及其对骨髓瘤骨病的影响.方法 分离MM患者和正常对照MSCs,流式细胞技术比较二者的免疫表型.Real-time PCR检测实验组及对照组MSCs的TGF-β1、TGF-β2、TGF-β3、IL-6、IL-3、TNF-α、FasL和NF-κB配体的受体激活物(RANKL)表达量.共培养系统与流式细胞术检测MSCs对T细胞增殖、凋亡和早期活化标志CD25和CD69表达的影响.Von kossa染色、real-time PCR和Western blot等技术检测T细胞对正常对照MSCs向成骨细胞分化的影响.结果 MM来源和正常对照MSCs具有相似的形态学和免疫表型.MM来源的MSCs表达TGF-β1、IL-6、IL-3、TNF-α和RANKL较正常对照MSCs增加,而TGF-β2、TGF-β3和FasL的表达下降.MM来源的MSCs对T细胞增殖的抑制作用明显减弱.正常对照MSCs较MM来源MSCs使更多T细胞静止于G0/G1期.正常对照MSCs明显促进T细胞凋亡,而MM来源的MSCs对T细胞的促凋亡作用减弱.正常对照MSCs明显抑制T细胞活化分子表达,而MM患者的MSCs此抑制作用明显降低.与MM患者的MSCs共培养后的T细胞以及直接来源于MM患者的T细胞均可以明显抑制正常对照MSCs向成骨细胞分化.结论 MM患者的MSCs免疫调节功能较正常对照MSCs降低,主要表现为抑制T细胞活化的功能减弱,而活化的T细胞可抑制MSCs向成骨细胞分化,此可能为骨髓瘤骨病发病机制之一.     

Role for interferon-gamma in the immunomodulatory activity of human bone marrow mesenchymal stem cells

Mesenchymal stem cells (MSCs) inhibit the proliferation of HLA-unrelated T lymphocytes to allogeneic stimulation, but the mechanisms responsible for this activity are not fully understood. We show here that MSCs suppress the proliferation of both CD4+ and CD8+ T lymphocytes, as well as of natural killer (NK) cells, whereas they do not have an effect on the proliferation of B lymphocytes. The antiproliferative effect of MSCs was not associated with any effect on the expression of cell-activation markers, induction of cell apoptosis, or mimicry/enhancement of T regulatory cell activity. The suppressive activity of MSCs was not contact-dependent and required the presence of interferon (IFN)-gamma produced by activated T cells and NK cells. Accordingly, even activated B cells became susceptible to the suppressive activity of MSCs in the presence of exogenously added IFN-gamma. The suppressive effect of IFN-gamma was related to its ability to stimulate the production by MSCs of indoleamine 2,3-dioxygenase activity, which in turn inhibited the proliferation of activated T or NK cells. These findings suggest that the beneficial effect on graft-versus-host disease induced by in vivo coinfusion with the graft of MSCs may be due to the activation of the immunomodulatory properties of MSCs by T cell- derived IFN-gamma.     

MicroRNA-181a regulates local immune balance by inhibiting proliferation and immunosuppressive properties of mesenchymal stem cells

Mesenchymal stem cells (MSCs) exhibit extensive self-renewal potential and can modulate immunocyte activation. Our previous study reported that miR-181a expression was significantly increased in placenta from women with severe preeclampsia (PE), but the mechanisms by which miR-181a regulates MSCs are unknown. In this study, we asked if and how miR-181a regulates MSCs' proliferation and immunosuppressive properties. We found that the expression of miR-181a in the MSCs derived from the umbilical cord and decidua of PE patients increased relative to MSCs derived from normal patients. Transfection with miR-181a oligos prevented MSCs proliferation but did not affect MSCs apoptosis. Overexpression of miR-181a blocked activation of the TGF-β signaling pathway and caused downregulation of target gene (TGFBR1 and TGFBRAP1) mRNA and protein expression. Reporter genes with putative miR-181a binding sites from the TGFBR1 and TGFBRAP1 3'-untranslated regions (3'-UTRs) were downregulated in the presence of miR-181a, suggesting that miR-181a binds to TGFBR1 and TGFBRAP1 3'-UTRs. In contrast, transfection of MSCs with miR-181a oligo enhanced expression of IL-6 and indoleamine 2,3-dioxygenase by activating p38 and JNK signaling pathways, respectively. MSCs transfected with miR-181a also enhanced the proliferation of T cells in a short-term culture. Additionally, treatment with control MSCs, but not miR-181a transfected MSCs, improved dextran sulfate sodium-induced experimental colitis, suggesting that miR-181a attenuates the immunosuppressive properties of MSCs in vivo. Together, our data demonstrate that miR-181a is an important endogenous regulator in the proliferation and immunosuppressive properties of MSCs.     

Reciprocal effect of mesenchymal stem cell on experimental autoimmune encephalomyelitis is mediated by transforming growth factor‐β and interleukin‐6

Mesenchymal stem cells (MSCs) have the ability to suppress T cell proliferation and modulate cytokine production. Recently, MSCs have been shown to ameliorate autoimmune diseases such as experimental autoimmune encephalomyelitis (EAE), but in some cases shown to stimulate lymphocyte proliferation. So far, mechanisms through which MSCs modulate immune reactions are still undefined. In this report we demonstrate that MSCs have the capacity for either stimulating or inhibiting myelin basic protein‐specific T lymphocytes in a dose‐dependent manner and modulate antigen‐stimulated T cells to differentiate into either T helper type 17 or regulatory T cells, respectively, via pathways involving transforming growth factor‐β and interleukin‐6. These results may lead better utility of MSCs as a treatment for autoimmune disease.