脐带间充质干细胞治疗移植物抗宿主病患者的护理

目的总结18例异基因造血干细胞移植术后移植物抗宿主病患者进行脐带间充质干细胞治疗的护理经验。方法对18例异基因造血干细胞移植术后移植物抗宿主病患者进行脐带间充质干细胞治疗,脐带间充质干细胞细胞数量为107/U,患者每次均输入5U。结果 18例患者输注脐带间充质干细胞后+30d进行追踪观察疗效评价,完全缓解8例,部分缓解8例,无效2例(因Ⅳ度移植物抗宿主病合并肺部感染死亡)。结论细致的病情观察及执行规范的脐带间充质干细胞输注,是治疗异基因造血干细胞移植移植物抗宿主病患者的护理重点。     

门静脉输注供者脾细胞诱导的供者特异性免疫低反应性

目的 探讨经门静脉输注供者脾细胞能否诱导皮肤移植小鼠产生供者特异性的免疫低反应性及其可能机制.方法 取Balb/c小鼠,随机分为空白对照组(经小鼠门静脉输注RPMI 1640培养液)、受者脾细胞组(经小鼠门静脉输注Balb/c小鼠脾细胞)、供者脾细胞组(经小鼠门静脉输注C57BL/6小鼠脾细胞)、空白移植对照组(经小鼠门静脉输注RPMI 1640培养液,7 d后移植C57BL/6小鼠的皮肤)、实验对照组(经小鼠门静脉输注Balb/c小鼠脾细胞,7 d后移植C57BL/6小鼠的皮肤)、实验组(经小鼠门静脉输注C57BL/6小鼠脾细胞,7 d后移植C57BL/6小鼠的皮肤)以及第三方移植组(经小鼠门静脉输注C57BL/6小鼠脾细胞,7 d后移植C3H小鼠的皮肤).记录空白移植对照组、实验对照组、实验组和第三方移植组移植皮肤的存活时间,并观察移植皮肤的病理学变化;脾细胞输注后7 d,分别获取空白对照组、受者脾细胞组和供者脾细胞组小鼠的外周血、脾脏和肝脏,用流式细胞仪测定样本中CD4+CD25+Foxp3+调节性T淋巴细胞(CD4+CD25+Foxp3+Treg细胞)的比例.结果 实验组移植皮肤的存活时间为(19.8±4.6)d,明显长于空白移植对照组、实验对照组和第三方移植组,但仍未达到长期存活.皮肤移植后7 d,空白移植对照组和实验对照组的移植皮肤呈现重度急性排斥反应的病理学改变,而实验组移植皮肤呈现中度急性排斥反应的病理学改变.供者脾细胞组外周血、肝脏和脾脏中CD4+CD25+Foxp3+Treg细胞比例明显高于空白对照组和受者脾细胞组.结论 门静脉输注供者脾细胞可特异性地延长供者皮肤移植物的存活时间,减轻移植物的排斥反应,该效应可能与受者体内的CD4+CD25+Foxp3+Treg细胞增加有关.     

阻断T细胞生长因子信号通路治疗移植物抗宿主病

目的探讨通过抗γ公共链单克隆抗体封闭T细胞生长因子受体治疗小鼠移植物抗宿主病(GVHD)的效果。方法通过混合淋巴细胞培养观察抗γ公共链抗体在体外对T细胞的抑制作用。经静脉输注C57BL／6(H-2b)脾细胞给F1代小鼠(C57BL／6×Balb／cH-2b/d),建立移植物抗宿主病模型。对GVHD模型小鼠短期内给予抗γ公共链抗体,一共3次,并观察其治疗效果。结果抗γ公共链抗体可抑制T细胞增殖,使凋亡细胞数增加及M期细胞数下降。输注同种脾细胞能成功建立急性GVHD模型,主要引起肝脏损伤的病理改变。单次注射抗γ公共链抗体可使GVHD小鼠肝内浸润的淋巴细胞发生凋亡;短期内连续3次注射抗γ公共链抗体可使丙氨酸转氨酶、天冬氮酸转氨酶明显低于对照组(P<0．05),但肝内仍然可观察到淋巴细胞浸润。结论体外阻断T细胞生长因子受体途径可以完全清除反应性T细胞,亦适用于GVHD治疗;但短期治疗不能完全清除反应性T细胞。     

CXC趋化因子受体6在小鼠心脏移植排斥反应中的表达及意义

目的 研究CXC趋化因子受体6(CXCR6)在同种异体小鼠心脏移植中的表达及CXC趋化因子配体16(CXCL16)与CXCR6相互作用对移植物存活时间的影响.方法 以野生型Balb/c小鼠(H-2d)为供者(同种移植组),或以野生型C57BL/6小鼠(H-2b)为供者(同系移植组),以野生型C57BL/6小鼠为受者分别行小鼠腹腔异位心脏移植.测定同系和同种移植组小鼠移植心脏CXCR6mRNA的表达,并测定受者脾脏CD8+T淋巴细胞CXCR6的表达.另制作小鼠同种异位心脏移植模型(Balb/c小鼠为供者,C57BL/6小鼠为受者),将其分为实验组和对照组,实验组受者移植当天至发生排斥反应时腹腔注射抗CXCL16抗体,对照组受者同期注射对照抗体.记录两组移植心脏存活时间.进行CD8+T淋巴细胞的细胞毒试验,即用Balb/c小鼠脾细胞免疫C57BL/6小鼠后,获取C57BL/6小鼠脾脏CD8+T淋巴细胞,将Balb/c小鼠脾细胞与C57BL/6小鼠CD8+T淋巴细胞混合培养,分别加入抗CXCL16抗体、小鼠IgG(对照抗体)和抗CD40L抗体.结果 同种移植组移植心脏中CXCR6 mRNA的表达以及脾脏CD8+T淋巴细胞上CXCR6的表达均高于同系移植组和正常对照组.抗CXCL16抗体对CD8+T淋巴细胞的细胞毒活性无影响.与对照组相比较,实验组小鼠移植心脏存活时间并未明显延长.结论 小鼠心脏移植排斥反应中CD8+T淋巴细胞CXCR6的表达上升,阻断CXCL16/CXCR6相互作用并不能延长移植心脏的存活时间.     

CXC趋化因子受体6在小鼠心脏移植排斥反应中的表达及意义

目的 研究CXC趋化因子受体6(CXCR6)在同种异体小鼠心脏移植中的表达及CXC趋化因子配体16(CXCL16)与CXCR6相互作用对移植物存活时间的影响.方法 以野生型Balb/c小鼠(H-2d)为供者(同种移植组),或以野生型C57BL/6小鼠(H-2b)为供者(同系移植组),以野生型C57BL/6小鼠为受者分别行小鼠腹腔异位心脏移植.测定同系和同种移植组小鼠移植心脏CXCR6mRNA的表达,并测定受者脾脏CD8+T淋巴细胞CXCR6的表达.另制作小鼠同种异位心脏移植模型(Balb/c小鼠为供者,C57BL/6小鼠为受者),将其分为实验组和对照组,实验组受者移植当天至发生排斥反应时腹腔注射抗CXCL16抗体,对照组受者同期注射对照抗体.记录两组移植心脏存活时间.进行CD8+T淋巴细胞的细胞毒试验,即用Balb/c小鼠脾细胞免疫C57BL/6小鼠后,获取C57BL/6小鼠脾脏CD8+T淋巴细胞,将Balb/c小鼠脾细胞与C57BL/6小鼠CD8+T淋巴细胞混合培养,分别加入抗CXCL16抗体、小鼠IgG(对照抗体)和抗CD40L抗体.结果 同种移植组移植心脏中CXCR6 mRNA的表达以及脾脏CD8+T淋巴细胞上CXCR6的表达均高于同系移植组和正常对照组.抗CXCL16抗体对CD8+T淋巴细胞的细胞毒活性无影响.与对照组相比较,实验组小鼠移植心脏存活时间并未明显延长.结论 小鼠心脏移植排斥反应中CD8+T淋巴细胞CXCR6的表达上升,阻断CXCL16/CXCR6相互作用并不能延长移植心脏的存活时间.     

CXC趋化因子受体6在小鼠心脏移植排斥反应中的表达及意义

目的 研究CXC趋化因子受体6(CXCR6)在同种异体小鼠心脏移植中的表达及CXC趋化因子配体16(CXCL16)与CXCR6相互作用对移植物存活时间的影响.方法 以野生型Balb/c小鼠(H-2d)为供者(同种移植组),或以野生型C57BL/6小鼠(H-2b)为供者(同系移植组),以野生型C57BL/6小鼠为受者分别行小鼠腹腔异位心脏移植.测定同系和同种移植组小鼠移植心脏CXCR6mRNA的表达,并测定受者脾脏CD8+T淋巴细胞CXCR6的表达.另制作小鼠同种异位心脏移植模型(Balb/c小鼠为供者,C57BL/6小鼠为受者),将其分为实验组和对照组,实验组受者移植当天至发生排斥反应时腹腔注射抗CXCL16抗体,对照组受者同期注射对照抗体.记录两组移植心脏存活时间.进行CD8+T淋巴细胞的细胞毒试验,即用Balb/c小鼠脾细胞免疫C57BL/6小鼠后,获取C57BL/6小鼠脾脏CD8+T淋巴细胞,将Balb/c小鼠脾细胞与C57BL/6小鼠CD8+T淋巴细胞混合培养,分别加入抗CXCL16抗体、小鼠IgG(对照抗体)和抗CD40L抗体.结果 同种移植组移植心脏中CXCR6 mRNA的表达以及脾脏CD8+T淋巴细胞上CXCR6的表达均高于同系移植组和正常对照组.抗CXCL16抗体对CD8+T淋巴细胞的细胞毒活性无影响.与对照组相比较,实验组小鼠移植心脏存活时间并未明显延长.结论 小鼠心脏移植排斥反应中CD8+T淋巴细胞CXCR6的表达上升,阻断CXCL16/CXCR6相互作用并不能延长移植心脏的存活时间.     

间充质干细胞不抑制体内T淋巴细胞的增殖

目的 探讨不同种属来源的间充质干细胞(MSC)在体内是否具有相似的作用.方法 用尼绒毛法分离不含脾脏细胞灌注模型(C57/BL)源脾脏T淋巴细胞,CFSE膜荧光染料标志的胞进行细胞标记,按2×107/只与C57/BL来源的MSC(1×105～1×106/只)共输注给γ射线照射的雌性BALB/c(5Gy).不同时间段取受体的脾脏细胞,以单纯输注T淋巴细胞组为对照,流式细胞仪分析T淋巴细胞增殖状态.结果 与体外结果明显不同,MSC输注对外源淋巴细胞比例没有影响,共输注不能抑制T淋巴细胞的增殖.结论 异体MSC在组织工程构建和移植物抗宿主病治疗中的应用,提出了新的问题.     

单倍体相合造血干细胞移植联合间充质干细胞输注治疗异染性脑白质营养不良

目的探讨单倍体相合造血干细胞移植联合间充质干细胞输注治疗异染性脑白质营养不良的疗效。方法 7岁患儿,采用单倍体相合造血干细胞移植联合间充质干细胞输注的方法,经氟达拉滨、马利兰、环磷酰胺和抗人胸腺细胞球蛋白方案进行预处理,供者应用G-CSF动员和联合免疫抑制剂(包括环胞菌素A、氨甲喋呤、霉酚酸酯、CD25单抗)预防移植物抗宿主病。造血重建后,每周输注脐带来源的间充质干细胞1次,连续4周。结果患儿造血重建迅速,11 d时中性粒细胞0.5×109/L、血小板20×109/L;14 d时血白细胞芳基硫酸酯酶A水平明显上升;28 d时达正常水平。患者无急性GVHD发生。移植后1个月经植入证据检测,证实为完全供者造血,神经系统症状逐渐恢复。结论单倍体相合造血干细胞移植,联合间充质干细胞输注,治疗异染性脑白质营养不良,安全、有效,血白细胞芳基硫酸酯酶A水平回升迅速。这种新型疗法可能是治疗缺乏HLA全相合供者的异染性脑白质营养不良疾病患者的可靠选择。     

体外光化学疗法对皮肤移植小鼠产生调节性T细胞的影响

目的探讨输注体外光化学法处理的脾淋巴细胞对皮肤移植受体小鼠产生调节性T细胞(Treg)及移植物存活时间的影响。方法以C57BL/6小鼠为供体,BALB/c小鼠为受体,建立小鼠皮肤移植模型。分离C57BL/6和BALB/c小鼠脾淋巴细胞(CSP、BSP),制备经8-甲氧基补骨脂素联合长波紫外线(PUVA)处理的小鼠脾淋巴细胞(PUVA-SP)。根据受者静脉输注的成分将实验动物随机分为5组(每组12只):PUVA-BSP组、PUVA-CSP组、BSP组、CSP组及磷酸盐缓冲液(PBS)对照组,每组受体分别于术前7 d、手术当日和术后7 d按组别从尾静脉注入PUVA-BSP、PUVA-CSP、BSP、CSP或PBS。观察受体移植物的存活时间,检测受体外周血中CD4~+CD25~+Foxp3~+Treg表达情况。结果皮肤移植术后,PUVA-BSP组和PUVA-CSP组的受体小鼠外周细胞CD4~+CD25~+Foxp3~+Treg的比例明显高于输注BSP组、CSP组和PBS对照组;PUVA-CSP组高于PUVA-BSP,BSP组和CSP组低于PBS对照组。PUVA-BSP组和PUVA-CSP组的受者小鼠移植皮片存活时间明显长于BSP组、CSP组和PBS对照组(均为P0.05)。结论输注足够数量的PUVA-SP可诱导受体体内产生较多的CD4~+CD25~+Foxp3~+Treg,可以显著延长移植物的存活时间。     

肝细胞和脾细胞单独或联合输注对异种胰岛细胞移植排斥反应的影响

目的 探讨供者的肝细胞和脾细胞输注对同一供者胰岛细胞移植排斥反应的影响。方法 经尿静脉给BALB/c小鼠糖尿病模型注射供者（猪）的肝细胞和脾细胞，腹腔内注射途径进行猪胰岛细胞移植。移植后测定受者的血糖变化，观察小鼠移植物有功能存活时间。同时测定小鼠巨噬细胞吞噬功能，脾脏淋巴细胞转化功能和自然杀伤细胞活性的变化。结果 胰岛细胞移植前输注肝细胞，脾细胞以及肝细胞和脾细胞混合悬液者，移植物有功能存活时间延长，其淋巴细胞转化率。自然杀伤细胞活性及巨噬细胞的吞噬功能均较低，以肝细胞和脾细胞联合输注者为著。结论 移植前少量多次的供者肝细胞和脾细胞输注可以降低异种胰岛细胞移植排斥反应的强度。     

Involvement of interleukin-18 in acute graft-versus-host disease in mice

BACKGROUND: Interleukin (IL)-18 stimulates T helper 1 (Th1)-mediated immune responses and the development of cytotoxic T lymphocytes (CTLs). Antihost CTLs are major effectors in acute graft-versus-host disease (aGvHD), a potentially fatal complication after allogeneic stem-cell transplantation. We investigated the relevant role of IL-18 in the development of aGvHD in mice. METHODS: Irradiated (C57BL/6x DBA/2) F1 (BDF1) mice transplanted with wild-type (WT) C57BL/6 (B6) splenocytes were compared with those transplanted with IL-18Ralpha-deficient B6 splenocytes with respect to Th1 development, CTL activity, severity of aGvHD, and survival. RESULTS: Transplantation of WT B6 spleen cells into BDF1 mice induced aGvHD that was accompanied by elevation of both serum IL-18 levels and IL-18 receptor alpha chain (IL-18Ralpha) expression on engrafted T cells. The transplantation of WT B6 cells also induced high antihost CTL activity in host spleen, whereas transplantation of IL-18Ralpha-deficient B6 cells exhibited significantly reduced antihost-specific CTL activity, indicating that IL-18Ralpha-deficient CTLs were less cytotoxic than IL-18Ralpha-expressing CTLs. Moreover, the hosts receiving transplants with the IL-18Ralpha-deficient B6 cells had fewer fatal tissue injuries and increased their survival rates as compared with those receiving transplants with WT cells. Nevertheless, Th1 development in the hosts was the same, regardless of the type of donor cells. CONCLUSIONS: These results suggest that Th1 induction and baseline CTL activity in aGvHD occur in the absence of IL-18, but endogenous IL-18 further accelerates aGvHD reaction to its full-blown manifestation. Thus, IL-18 may be involved in the development aGvHD by enhancing CTL activity.     

Mesenchymal stem cells therapy protects fetuses from resorption and induces Th2 type cytokines profile in abortion prone mouse model

The imbalance of Th1/Th2 cytokines is well known in recurrent spontaneous abortion (RSA) mouse model. Mesenchymal stem cells (MSCs) possess potent immunoregulatory properties that could modulate the Th1 cytokine responses in benefit of Th2 types. In this study, we aimed to analyze the local and systemic balance of Th1/Th2 cytokines following MSCs therapy.Syngeneic adipose derived MSCs were administered to abortion prone mice during the implantation window. The abortion rate was determined and IL-4, IL-6, IL-12, IL-2, IFN-γ and GM-CSF gene expression was evaluated by Real-Time-PCR in decidual and placental tissues of pregnant mice at day 13.5 of pregnancy. Splenocytes of pregnant mice were co-cultured with mitomycin C treated paternal splenocytes and IL-2, IL-4, IL-10 and IFN-γ cytokines were measured in co-cultures supernatants by ELISA method. Proliferation response of female splenocytes to paternal antigens was also evaluated using the CFSE method.Our results showed a significant reduction in abortion rate following MSCs administration in abortion prone mice. We also observed a significant down-regulation of IL-2 and IFN-γ as well as up-regulation of IL-4 and IL-10 production from pregnant mouse splenocytes following MSCs therapy along with a significant reduction of splenocytes proliferation against paternal antigens. Our findings revealed that MSCs therapy increased the IL-4, IL-6, IL-10 and GM-CSF and at the same time decreased the IL-12, IL-2 and IFN-γ gene expression at feto-maternal interface.Here, we showed that MSCs therapy could modulate the systemic as well as local Th1/Th2 cytokines production along with protection of fetus from resorption in abortion prone mice. The fine balance of Th1/Th2 cytokine response could be considered as one of the possible mechanisms for fetal protection following MSCs therapy.     

Functional and phenotypic alteration of intrasplenic lymphocytes affected by mesenchymal stem cells in a murine allosplenocyte transfusion model

Previous data have demonstrated that mesenchymal stem cells (MSCs) can exert immunomodulatory activity in vitro, in which of the process nearly all kinds of immune cell subsets are involved. However, there is still a paucity of information about whether and why MSCs inhibit the ongoing immune responses in vivo. Working in a murine splenocyte transfusion model across the major histocompatibility barrier (C57BL/6 -BALB/c, H2b --> H2d), we have found that MSC coinfusion prolongs the mean survival time (MST) of the recipient mice in a dose-dependent manner and reduces graft-versus-host-associated histopathology in comparison to the allosplenocyte transfusion controls. In vivo eGFP tracing with polymerase chain reaction analysis revealed that grafted MSCs could migrate and settle into the lungs, spleen, liver, intestine, and skin shortly after administration. Further investigations into the functional characteristics of intrasplenic lymphocytes showed that their proliferation and cytotoxic activity against P815 cells (H2d) were significantly restrained by MSC cotransfer. FACS analysis demonstrated that MSC infusion not only increased the proportion of CD4+ subset but also decreased that of CD8+ cells at the belated observation points, resulting in the increase of the ratio of CD4+/CD8+ cells. Also, in contrast to the slight increase of the proportion of CD4+CD25+ T regulatory cells (Tregs) in MSC cotransfer mice, the ratio of Tregs/CD8+ cells was dramatically elevated. Furthermore, RT-PCR analysis on the cytokine array of IL-2, IL-4, IL-12, TNF-alpha, and TGF-beta in recipient splenocytes implied the Thl to Th2 polarization. Therefore, it is deducible that alteration in the proportions of different T-lymphocyte subsets may be one of the main mechanisms by which grafted MSCs suppress the ongoing immune responses in vivo. The study here might provide some new clues for the design of therapeutic approaches for MSC transplantation.     

Neutralization of interleukin-2 retards the growth of mouse renal cancer

OBJECTIVE: To examine the significance of the thymus and the neutralization of interleukin-2 (IL-2) in treating renal cancer, as the involvement of immunoregulatory cells in tumour development in vivo is well known, naturally occurring CD25+ CD4+ T cells possess potent immunoregulatory functions, and they are of thymic origin dependent on IL-2. MATERIALS AND METHODS: We first tested activity against mouse renal cell carcinoma (RENCA) cells by adoptively transferring splenocytes of euthymic Balb/c mice depleted of CD25+ cells into athymic Balb/c nude mice bearing established macroscopic RENCA tumours. Second, we tested the anti-RENCA activity in euthymic mice bearing macroscopic RENCA tumours by neutralizing IL-2. RESULTS: The intravenous administration of CD25+ cell-depleted splenocytes of euthymic Balb/c mice initiated the retardation of macroscopic RENCA tumours subcutaneously established in athymic Balb/c mice. The tumour site showed massive lymphocyte infiltration of mainly CD4+ T cells. By eliminating either the CD4+ cells, CD8+ cells, or natural killer (NK) cells with antibodies after the adoptive transfer of CD25+ cell-depleted splenocytes of euthymic Balb/c mice, macroscopic RENCA tumour retardation was abrogated. The growth of macroscopic RENCA tumour established in euthymic Balb/c mice was also retarded with IL-2 neutralization alone by anti-IL-2 monoclonal antibody (mAb), as well as co-administration of anti-IL-2 mAb and anti-CD25 mAb compared with that of the controls given vehicle. After tumour inoculation, peri- and intratumoral infiltration of CD4+ and CD8+ T cells was very prominent in RENCA tumours in hosts given anti-IL-2 mAb, regardless of the administration of anti-CD25 mAb. Two x 10(5) units of recombinant human IL-2 reverted the retardation of RENCA tumour growth caused by the anti-IL-2 mAb. IL-2 neutralization alone in euthymic Balb/c mice with no tumour inoculation did not suppress splenic CD25+ CD4+ T cells. CONCLUSION: Both the intravenous administration of CD25+ cell-depleted splenocytes of euthymic Balb/c mice into athymic Balb/c nude mice and IL-2 blocking with anti-IL-2 mAb in euthymic Balb/c mice retarded the growth of macroscopic RENCA tumours in vivo.     

A prospective study of serum soluble CD30 in allogeneic hematopoietic stem cell transplantation

The expression of CD30 is restricted to cells of the immune system and strictly regulated under physiological conditions. However, active immune cells express CD30 and soluble CD30 (sCD30) is released. Several investigators reported the relevance for sCD30 as a predictive marker for allograft rejection following organ transplantation. We investigated the role of sCD30 in 30 patients undergoing allogeneic hematopoietic stem cell transplantation for hematologic malignancies. sCD30 was measured at different time points until day 120 post transplant. There was a great variety of sCD30 at baseline before transplantation. At time of engraftment, patients who developed no or only mild signs of acute graft-versus-host-disease (aGvHD) until day 120 had significant lower levels of sCD30 than patients who developed severe aGvHD. Moreover, all patients with aGvHD °III/IV showed a clear increase in sCD30 levels before clinical signs of aGvHD. Levels of sCD30 decreased if patients responded to aGvHD-therapy. We suggest a potential role of sCD30 serum levels in prediction of aGvHD following allogeneic stem cell transplantation.     

Liver sinusoidal endothelial cells have a capacity for inducing nonresponsiveness of T cells across major histocompatibility complex barriers

Livers transplanted across major histocompatibility complex (MHC) barriers in mice are normally accepted without recipient immune suppression. To identify the cell type that contributes to induction of such a tolerance state, we established an allogeneic mixed hepatic constituent cell-lymphocyte reaction (MHLR) assay. Hepatic constituent cells were isolated from C57BL/6 (B6) and Balb/c mice as stimulators, and splenocytes were isolated from B6 mice as responders. Irradiated hepatic constituent cells were co-cultured with fluorescent dye (CFSE)-labeled B6 splenocytes. In the allogeneic MHLR using either whole hepatic constituent cells or parenchymal hepatocytes as stimulators, a lack of T-cell proliferation was observed. Only when CD105(+) cells, which are exclusively liver sinusoidal endothelial cells (LSECs), were depleted from hepatic constituent cell stimulators, the MHLR resulted in marked proliferation of both allo-reactive CD4(+) and CD8(+) T cells. These results indicate that CD105(+) LSECs have the capacity to induce nonresponsiveness of T cells across MHC barriers.     

大鼠骨髓间充质干细胞诱导分化为表皮细胞的实验观察

目的:研究表皮生长因子(Epidermal growth factor,EGF)加条件培养基体外诱导大鼠 MSCs 向表皮细胞定向分化的可行性。方法:采用 Ficoll-Paque 淋巴细胞分离液分离扩增大鼠骨髓 MSCs,免疫细胞化学染色及流式细胞仪进行鉴定。传至第3代的大鼠 MSCs 用表皮生长因子(EGF)、条件培养基等定向诱导 MSCs 分化为表皮细胞;免疫细胞化学对细胞角蛋白 CK5/8、19(Cytokeratin5/8、19)阳性表达细胞进行检测。结果:从大鼠骨髓中分离培养的 MSCs 增殖能力强,细胞表面标志 CD34、CD45阴性,CD29、CD44阳性,流式细胞仪检测显示细胞纯度高,诱导后7d 细胞免疫化学显示角蛋白5/8、19染色阳性,具有表皮细胞特征。结论:从大鼠骨髓中分离培养出的问充质干细胞,具有自我更新和增殖能力强的特点,经诱导可定向分化表达角蛋白。     

CD4+CD25+ cells regulate CD8 cell anergy in neonatal tolerant mice

BACKGROUND: Injection of neonatal BALB/c mice with semi-allogeneic splenocytes leads to antigen-specific tolerance lasting into adulthood. Tolerant mice accept A/J skin grafts and fail to generate CD8 cytotoxic T lymphocyte (CTL) activity against A/J targets. Anergic CD8 T cells are present in tolerant mice, and CD4 regulatory cells function to maintain CD8 cell anergy. METHODS: Neonatal BALB/c mice were injected with 108 live CAF, splenocytes, and mice were deemed tolerant by accepting A/J grafts over 40 days. CD8 cell proliferation was measured by in vitro incorporation of bromodeoxyuridine coupled with fluorescence-activated cell sorter analysis. Alloantigen-specific cytotoxicity was tested using 51Cr release assays of A/J or third-party targets. RESULTS: We demonstrate that A/J-specific anergic CD8 cells are present in neonatal primed mice that develop tolerance but not in neonatal primed mice that reject A/J skin grafts. Anergic CD8 cells show decreased proliferation and no CTL activity against A/J targets. Addition of interleukin-2 (IL-2) to unfractionated cultures fails to restore CTL activity against A/J targets. However, addition of IL-2 to CD4-depleted cultures restores A/J-specific CD8 CTL activity. Removal of CD4+/CD25+ cells, but not CD4+/CD25- cells, also restores CD8 CTL activity against A/J in the presence, but not the absence, of IL-2. Moreover, when added back into cultures, purified CD4+/CD25+ cells from tolerant mice inhibit the generation of CD8 CTL against A/J targets. CONCLUSION: These data indicate that CD8 anergy is associated with the state of tolerance, and that CD4+CD25+ cells from tolerant mice function to maintain A/J-specific CD8 cell anergy in vitro.     

Liver sinusoidal endothelial cells contribute to alloreactive T-cell tolerance induced by portal venous injection of donor splenocytes

We demonstrated that an indirect pathway of alloantigen presentation via liver sinusoidal endothelial cells (LSEC) is involved in alloreactive T-cell tolerance induced by portal venous injection (PI) of donor cells. Thirty million C57BL/6 (B6) splenocytes that were either untreated or treated with 30-Gy irradiation were injected via the portal vein into Balb/c mice. Host LSEC expressing major histocompatibility complex class II actively endocytosed the allogeneic naive splenocytes as well as irradiated splenocytes after PI. Using a transendothelial migration assay, it was demonstrated that host-type Balb/c CD4(+) T cells that transmigrated across LSEC that had captured irradiated B6 splenocytes were rendered tolerant to subsequent alloantigen presentation by host professional antigen-presenting cells. Consistently, PI of irradiated donor-type splenocytes led to remarkable prolongation of the survival of subsequently transplanted heart allografts. These results indicate that indirect antigen presentation by LSEC significantly contributes to alloreactive T-cell tolerance induced by PI of irradiated donor splenocytes.