成骨诱导后的骨髓间充质干细胞对外周血单个核细胞增殖的免疫调节作用

目的:探索骨髓间充质干细胞(BMSCs)及成骨诱导后的骨髓间充质干细胞(OM-BMSCs)对同种异体的外周血单个核细胞(PBMCs)的免疫调节作用。方法:分离比格犬BMSCs,成骨诱导培养基(ost eogenic medium,OM)进行成骨诱导,建立BMSCs、OM-BMSCs与同种异体PBMCs的共培养体系,分三种实验条件,共9组。A组:5×104受体PBMCs加入5×104供体PBMCs共培养;B组:A组组分加入已铺被1×104/孔BMSCs的96孔板;C组:A组组分加入已铺被1×104/孔OM-BMSCs的96孔板;D组:5×104受体PBMCs加入植物血凝素A(PHA)刺激物;E组、F组:将D组组分按B、C组方式处理;G组:5×104受体PBMCs加入IL-2炎症因子;H组、I组:G组组分按B、C组方式处理。A、D、G组分别为三个实验条件的对照组,单独接种1×104/孔BMSCs、OM-BMSCs作为空白对照组Bl ank1组、Bl ank2组。以上各组分别培养120h后,应用Cell Titer 96 Aqueous检测各组PBMCs的增殖情况。结果:在各实验条件下与相应对照组相比较,BMSCs与OM-BMSCs均能抑制双向混合淋巴细胞反应(MLR)中PBMCs的增殖,均能抑制经PHA刺激后PBMCs的增殖,均能抑制经IL-2刺激后PBMCs的增殖(P<0.01)。结论:BMSCs及成骨分化的BMSCs对刺激细胞、PHA、IL-2刺激的同种异体PBMSs的增殖均表现为抑制效应,成骨分化后的骨髓间充质干细胞对同种异体免疫反应仍具有免疫调节作用。     

扁桃体间充质干细胞免疫学特性的初步研究

目的 探讨扁桃体间充质干细胞(tonsil mesenchymal stem cells,TMSCs)的免疫学特性及机制.方法 取慢性扁桃体炎患儿的扁桃体组织,分离、培养TMSCs,通过流式细胞术检测HLA-Ⅰ、HLA-Ⅱ、CD80、CD86等免疫分子的表达情况.以牙周膜干细胞作为对照,观察TMSCs能否引起同种异体外周血单个核细胞(peripheral blood mononuclear cells,PBMCs)的增殖,以及TMSCs对混合淋巴细胞反应(mixed lymphocyte reaction,MLR)和植物血凝素(phytohemagglutinin,PHA)引起的淋巴细胞增殖的影响.建立TMSCs+PHA+异体PBMCs、TMSCs+MLR的培养体系,测定细胞上清液中的犬尿氨酸浓度.在上述反应体系进行中和实验,观察被TMSCs抑制了的淋巴细胞重新发生增殖的情况.每个实验重复3次,每组6个佯本.统计学方法采用方差分析,P ＜0.05为差异有统计学意义.结果 TMSCs表达HLA-Ⅰ,但不表达HLA-Ⅱ和共刺激分子CD80、CD86.TMSCs与异体PBMCs共培养5d后,刺激指数为1.38±0.26,而单纯PBMCs培养5d后的刺激指数为1.22±0.28,2组差异无统计学意义(P＞0.05),证实TMSCs不会引起异体PBMCs增殖.TMSCs与异体PBMCs、PHA共培养5d后,刺激指数分别为1.49±0.29(TMSCs∶ PBMCs为0.5∶1)和1.23±0.22(TMSCs∶ PBMCs为1∶1),而PBMCs+PHA组培养5d后的刺激指数为4.60±0.81,2组之间的差异均有统计学意义(P＜0.05),说明TMSCs能够抑制PHA引起的淋巴细胞增殖.TMSCs与MLR共培养5d后,刺激指数分别为1.29±0.23(TMSCs∶ PBMCs为0.5∶1)和1.26±0.27(TMSCs∶ PBMCs为1∶1),而MLR培养5d后的刺激指数为3.04±0.66,2组之间的差异均有统计学意义(P＜0.05),说明TMSCs能够抑制MLR引起的淋巴细胞增殖.在TMSCs+PHA+异体PBMCs、TMSCs+MLR的培养体系中,犬尿氨酸浓度显著升高,分别为(26.0±2.3) μmol/L和(23.5±4.5)μmol/L.中和实验发现,1-甲基-L-色氨酸基本恢复了被TMSCs抑制的淋巴细胞增殖.结论 TMSCs具有低免疫原性和免疫抑制特性,有望进行同种异体移植.     

强直性脊柱炎骨髓间充质干细胞诱导Th17/Treg失衡

目的观察强直性脊柱炎(AS)患者外周血白介素(IL)-17A、IL-23水平及Th17/Treg比例,探讨骨髓间充质干细胞(BMSCs)与Th17/Treg体外相互作用,为研究AS发生机制提供理论依据。方法研究对象为48例活动期AS患者[实验组,男43例、女5例,年龄(26.2±5.2)岁,均为HLA-B27~+]和49例健康志愿者[对照组,男44例、女5例,年龄(25.9±4.8)岁,HLA-B27~+43例、HLA-B27~-6例]。ELISA检测外周血清中IL-17A及IL-23水平,流式细胞术检测外周血单个核细胞(PBMCs)中的CCR4~+CCR6~+Th细胞(Th17)及Treg细胞数量。分离健康志愿者的PBMCs,将PBMCs分别与AS患者及健康志愿者的BMSCs体外共培养72 h,收集PBMCs行流式细胞术检测,评价BMSCs与Th17/Treg体外的相互作用。结果实验组与对照组血清IL-17A及IL-23的表达水平相近(P0.05);实验组Th17细胞明显高于对照组(P0.05),而Treg细胞明显低于对照组(P0.05)。与健康志愿者BMSCs共培养72 h后的PBMCs中Th17较培养前轻度下降,Treg轻度上升,差异无统计学意义(P0.05);而与AS患者BMSCs共培养72 h的PBMCs中Th17较培养前及对照组均明显上升,Treg均明显下降,差异均有统计学意义(P0.05)。结论 AS患者PBMCs中Th17/Treg细胞亚群失衡。免疫抑制能力明显下降的BMSCs极可能通过诱导Th17/Treg失衡而在AS免疫发生机制中发挥重要作用。     

地塞米松对骨髓间充质细胞增殖及成骨、成脂分化的效应

目的 探讨不同浓度地塞米松(dexamethasone,DEX)作用不同时间对骨髓间充质干细胞(bone marrow mesenchymal stem cells,BMSCs)的增殖及成骨、成脂分化的影响.方法 体外分离培养大鼠BMSCs,将状态良好的第三代细胞接种于96孔板中,随机分组为对照组(不加入DEX)及不同浓度(1 nmol/L、10 nmol/L、0.1μmol/L、1μmol/L)DEX作用组,培养1、3、5、7、9 d后,分别用细胞增殖检测(CCK-8)法检测细胞增殖状况.将BMSCs接种于6孔板中,随机分为对照组及不同浓度(1 nmol/L、10 nmol/L、0.1μmol/L、1μmol/L)DEX作用组,培养7、14 d后分别用荧光定量PCR方法检测成骨、成脂相关基因的表达,培养14 d后用Western blot检测成骨、成脂相关蛋白的表达.培养5 d后进行碱性磷酸酶(alkaline phosphatase,ALP)染色,培养14 d后进行油红"O"染色、茜素红染色.结果 较低浓度的DEX促进BMSCs增殖,而较高浓度DEX抑制BMSCs增殖.干预早期,较低浓度的DEX促进BMSCs成骨分化而高浓度DEX抑制其成骨分化;干预晚期,各浓度DEX均促进BMSCs成骨指标的表达,但是不能诱导BMSCs钙质沉积.DEX浓度依赖性地促进BMSCs成脂相关指标基因和蛋白的表达,并诱导BMSCs细胞内脂质沉积.结论 DEX可直接影响BMSCs增殖及向成骨、成脂方向分化,这种效应存在浓度和干预时间依赖性.     

绵羊BMSCs与光接枝改性前后聚羟基丁酸-羟基异戊酯共培养的对比研究

目的 评价光接枝改性对聚羟基丁酸-羟基异戊酯(copolymers of 3-hydroxybutyrate and 3-hy-droxyvalerate,PHBV)与绵羊BMSCs相容性的影响. 方法 取6月龄雄性绵羊1只,体重17 kg,髂后棘穿刺抽取骨髓,全骨髓贴壁培养法分离培养BMSCs.制备PHBV膜、光接枝PHBV膜、PHBV支架及光接枝PHBV支架.取第3代BMSCs以1 ×105/mL接种至培养板,分别与PHBV膜和光接枝PHBV膜复合培养,接种后1、2、6 h计算细胞在两种膜上的黏附率;另将BMSCs以1×104/孔接种于两种膜上,接种后6 h、3 d及1、3周取材,扫描电镜观察细胞在两种膜上的生长情况;另将BMSCs以2×105/孔接种于两种支架上,接种后3 d及1、3周取材,扫描电镜观察细胞在两种支架上的生长情况;再将BMSCs以2 × 104/孔接种于两种膜上,5 d后收集细胞,流式细胞仪分析细胞周期;再将BMSCs以1 ×107/孔接种于两种支架上,接种后4、8、12d测定细胞内蛋白质和DNA含量. 结果 接种后1 h,PHBV膜上的细胞黏附率为37.5%±5.3%,光接枝PHBV膜为52.7%±6.0%,二者比较差异有统计学意义(P＜0.05);接种后2、6 h,两种支架上的细胞黏附率比较差异无统计学意义(P＞0.05).扫描电镜观察光接枝PHBV膜以及光接枝PHBV支架上的细胞黏附较早,接种后1周两种材料上的细胞数较多,且细胞分泌物亦较多.流式细胞仪检测见两种膜上的BMSCs均为正常二倍体细胞,未见异倍体细胞,细胞周期和增殖指数比较差异均无统计学意义(P＞0.05).BMSCs接种至两种支架上4、8、12 d,细胞内DNA、蛋白质含量比较差异均无统计学意义(P＞0.05). 结论 光接枝表面改性增强了PHBV对绵羊BMSCs的早期吸附,改善了其生物相容性.     

胃癌根治术病人围术期异体输血后外周血单核细胞CD40L表达的变化

目的 研究胃癌根治术病人围手术期异体输血外周血单核细胞(PBMCs)白细胞分化抗原40配体(CD40L)表达的变化。方法 胃癌根治术病人30例,随机分为3组,每组10例。A组围术期不输血,B组围术期输入去白细胞的全血,C组围术期输入异体全血。另选10例健康人作为对照。分别在手术前、术后2、5、10 d采外周静脉血5 ml,用Ficoll分离液梯度离心法分离出PBMCs和血浆,将PBMCs置于自身血浆环境中,并在植物血凝素(PHA,20 mg/L)的刺激下进行培养,48 h后收获细胞,用流式细胞术检测CD40L表达。结果 健康人外周血未受PHA刺激时检测不到CD40L的表达,经PHA刺激后CD40L 细胞占CD4 T细胞的百分数为1.7％±0.4％,与三组胃癌病人术前比较差异无显著性(P>0.05)。与术前比较,B组术后2 d PBMCs CD40L表达升高(P<0.05),C组术后各时点升高(P<0.05);与A组比较,B组术后2 d升高(P<0.05),C组术后各时点升高(P<0.05);与B组比较,C组术后各时点升高(P<0.05)。结论 围手术期异体输血可造成免疫抑制,输异体血后CD40L表达增加,且输全血比输去白细胞的全血更明显。围手术期成分输血优于输注全血。     

成人骨髓间充质干细胞抑制异体淋巴细胞增殖的实验研究

目的研究成人骨髓间充质干细胞（BMMSCs）的免疫调节作用。方法从成人骨髓中分离和培养间充质干细胞，并通过形态的均一性及流式细胞术检测其表面标志以鉴定纯度。将分离培养的间充质干细胞接种于96孔板中，经丝裂霉素处理后，与异体淋巴细胞共同培养3d；并以单独培养的异体淋巴细胞作为对照组。各组经培养后加入植物血凝素（PHA）刺激72h，用MTT还原法测定细胞增殖率，观察成人骨髓BMMSCs对异体淋巴细胞增殖转化的影响。结果成人BMMSCs与PHA诱导的异体淋巴细胞共同培养组抑制了细胞增殖，其增殖转化抑制率为对照组的60．68％，配对t检验结果显示，两组差异有统计学意义（P〈0．01）。结论成人BMMSCs可以抑制PHA诱导的异体淋巴细胞增殖转化，对同种异体免疫反应具有负调节作用。     

不成熟树突状细胞体外诱导T细胞表达转录因子Foxp3

目的探讨不成熟树突状细胞（imDCs）能否在体外诱导T细胞高表达转录因子Foxp3。方法体外无菌培养BALB／c小鼠骨髓来源的不成熟树突状细胞，并通过脂多糖（LPS）刺激诱导其分化为成熟树突状细胞（mDCs）。在96孔细胞培养板中分别以不成熟树突状细胞（imDCs）2×10^4／孔和成熟树突状细胞（mDCs）2×10^4／孔与C57BL／6小鼠的脾淋巴细胞以1：5、1：10、1：50、1：100的比例共同培养6d。流式细胞术检测混合培养6d后的淋巴细胞CD4、CD25及转录因子Foxp3的表达。结果imDCs及mDCs和淋巴细胞混合培养6d后，淋巴细胞表面CD25的表达水平较正常淋巴细胞明显升高（P〈0．05）；mDCs与淋巴细胞混和培养6d后，淋巴细胞表达Foxp3的水平与正常淋巴细胞差异无统计学意义（P〉0．05），而用imDCs诱导则可使淋巴细胞表达Foxp3显著升高（P〈0．05）。结论imDCs可以在体外诱导T细胞上调转录因子Foxp3的表达。     

胎盘间充质干细胞与骨髓间充质干细胞分离培养和生物学特性研究

目的探讨兔胎盘间充质干细胞(placenta-derived mesenchymal stem cells,PMSCs)和兔骨髓间充质干细胞(bone marrow-derived MSCs,BMSCs)体外分离培养、增殖,对其生物学性状进行比较观察。方法取足月待产新西兰大耳白兔1只,采用密度梯度离心法及贴壁培养技术从兔胎盘对PMSCs进行分离、纯化和传代培养。取2周龄新西兰大耳白兔1只,采用直接贴壁法从后肢骨髓中对BMSCs进行分离、纯化和传代培养。用倒置相差显微镜观察两种细胞形态。免疫组织化学染色对第3代细胞表面标志(CD44、CD105、CD34、CD40L)进行鉴定。将BMSCs与PMSCs第2代细胞分别与生物衍生骨进行复合培养5d,每条材料接种(1.0~1.5)×106个细胞,苏木素染色观察细胞与材料复合培养情况。扫描电镜观察两种细胞分别与材料复合培养3d和8d的情况。结果在倒置相差显微镜下观察,两种细胞均为贴壁生长,形态为均一成纤维细胞样。PMSCs增殖力强,细胞的增殖能力随传代次数的增加而有所下降,细胞体外培养10代后,生长速度减慢。两种细胞均表达CD44、CD105,不表达CD34、CD40L。复合培养5d,PMSCs和BMSCs在生物衍生骨表面生长,大量黏附,细胞积聚成团,相互连接成网状,孔隙内也可见细胞生长和增殖,并分泌基质。扫描电镜观察:复合培养3d,可见较多量的细胞在生物衍生骨上黏附,呈梭形或多角形;8d两种细胞均已大量增长,呈层状排列,细胞连接紧密,分泌大量基质,细胞周围有较多的网状胶原形成。结论PMSCs与BMSCs有相似的生物学特性,可作为组织工程的另一成体干细胞来源。     

聚羟基烷酸酯与绵羊骨髓基质干细胞相容性的研究

目的评价聚羟基烷酸酯(PHBV)作为组织工程支架与绵羊骨髓基质干细胞(BMSCs)的生物相容性。方法原代培养绵羊BMSCs,传至2～3代后,接种至PHBV膜和泡沫样三维支架上,光镜和扫描电镜观察细胞形态,计数1、2、6 h时的细胞黏附率;并以接种至培养板上细胞为对照组,每日细胞计数,绘制生长曲线;按培养液量与支架体积10 mL／cm3为标准浓度制备浸提液,并制备标准浓度1／16～16倍的浸提液,以MTT法检测细胞毒性;流式细胞仪分析接种到材料上的细胞周期,计算增殖指数;BMSCs接种于PHBV三维支架上4、8、12 d,以Hoechst33258荧光法定量测定细胞内DNA含量, BCA法测定蛋白质含量。结果第3代BMSCs接种至PHBV膜上2 h后即大部黏附,黏附率75．6％,与对照组相比差异无统计学意义,绘制生长曲线见细胞生长与对照组无差异;MTT法检测见9个浓度梯度的浸提液毒性均为0级;光镜和扫描电镜观察见细胞接种于PHBV膜上2 h后大部分黏附,3 d后伸展良好,呈纺锤形或梭形,在三维支架的孔隙内立体生长,1周开始细胞间连接,3周广泛连接,分泌大量基质;流式细胞分析见接种于材料上的细胞周期无变化;接种至PHBV三维支架上的细胞内DNA、蛋白质浓度与对照组比较无差异。结论PHBV作为BMSCs的组织工程支架材料,具有良好的生物相容性。     

Atorvastatin down-regulates the primate cellular response to porcine aortic endothelial cells in vitro

Using mixed lymphocyte reaction (MLR), the effect of atorvastatin on proliferation of human and baboon peripheral blood mononuclear cells (PBMCs) and human CD4+ T cells in response to wild-type (WT) and alpha-1,3-galactosyltransferase gene-knockout (GTKO) porcine aortic endothelial cells (pAECs) was investigated. swine leukocyte antigen class-II (SLA II) expression on pAEC before and after porcine interferon gamma (pIFN-gamma) stimulation, and the effect of atorvastatin on this expression was assessed. Added to the MLR, atorvastatin reduced (i) the human PBMC response to unstimulated (P<0.05) and (ii) the human and baboon PBMC responses to stimulated (P<0.05) WT and GTKO pAEC. Atorvastatin treatment of human PBMC before MLR reduced their response to stimulated WT (P<0.05) and GTKO (P<0.05) pAEC. Stimulation of pAEC with pIFN-gamma increased SLA II expression 20- to 60-fold, which was down-regulated by atorvastatin. Atorvastatin treatment of stimulated pAEC before MLR reduced proliferation of human PBMC (P<0.05) and CD4+ T cells (P<0.05). Atorvastatin down-regulates the primate cellular xenoresponse, possibly through its antiproliferative effect on PBMCs and the reduction of SLA II on pAECs.     

Direct anti-proliferative effect of adipose-derived mesenchymal stem cells of ankylosing spondylitis patients on allogenic CD4+ cells

ObjectivesT-cell-mediated adaptive immunity contributes to the development and persistence of ankylosing spondylitis (AS). Mesenchymal stromal/stem cells (MSCs) have immunomodulatory potential and are able to inhibit T-cell proliferation, but their functionality in AS patients is relatively unknown. The aim of the study was to assess the direct anti-proliferative effects of MSCs isolated from subcutaneous abdominal adipose tissue of AS patients (AS/ASCs) on allogeneic T lymphocytes, using commercially available ASC lines from healthy donors (HD/ASCs) as a control.Material and methodsCD3+CD4+ T-cells were isolated from peripheral blood of healthy blood donors, activated with anti-CD3/CD28 beads, and co-cultured for 5 days with untreated and TNF+IFN-γ pre-stimulated HD/ASCs (5 cell lines) and AS/ASCs, obtained from 11 patients (6F/5M). The proliferative response of T-cells was analysed by flow cytometry, while the concentrations of kynurenines, prostaglandin E2 (PGE-2), interleukin 10 (IL-10), and interleukin 1 receptor antagonist (IL-1Ra) were measured spectrophotometrically or using a specific enzyme-linked immunosorbent assay (ELISA).ResultsHD/ASCs and AS/ASCs similarly reduced the T-cell proliferation response, i.e. the percentage of proliferating cells, the proliferation, and replication indices, and these effects were dependent mostly on soluble factors. In the co-cultures of activated CD4+ T-cells with HD/ASCs and AS/ASCs significant increases of kynurenines, PGE-2, and IL-1Ra, but not IL-10, production were observed. The release of these factors was dependent either on cell-to-cell contact (IL-10, IL-1Ra) or soluble factors (kynurenines, PGE-2). There was a moderate to strong negative correlation between T-cell proliferative response, and the concentrations of kynurenines, PGE-2, and IL-10, but not IL-1Ra. This association was more evident in the case of TI-treated AS/ASCs than HD/ASCs.ConclusionsAS/ASCs, similar to HD/ASCs, exert a direct effective anti-proliferative impact on CD4+ T cells, acting via soluble factors that are released in cell contact-dependent (IL-10) and independent (kynurenines, PGE-2) pathways. Thus, our results suggest that AS/ASCs are potentially useful for therapeutic application.     

High permeability haemofiltration improves peripheral blood mononuclear cell proliferation in septic patients with acute renal failure.

BACKGROUND: Continuous veno-venous haemofiltration (HF) with high permeability (HP) haemofilters is a novel approach in the adjuvant therapy of septic patients. HP haemofilters are characterized by an increased pore size which facilitates the filtration of inflammatory mediators. The present study examines whether HP-HF has an impact on peripheral blood mononuclear cell (PBMC) proliferation and whether ultrafiltrate can alter PBMC function in isolates from healthy volunteers. METHODS: Twenty-eight septic patients with acute renal failure were randomly allocated to either HP-HF or conventional HF (C-HF). HP-HF was performed with a newly developed high-flux polyamide membrane (P2SH) with a nominal cut-off point of 60 kDa. For C-HF, a high-flux polyamide haemofilter (Polyflux 11S; cut-off, 30 kDa) was used. RESULTS: Septic patients demonstrated a significantly reduced proliferation of anti-CD3-stimulated PBMCs compared to healthy controls (P = 0.016). Initiating HF led to a restoration of the PBMC proliferation in HP-HF but not in C-HF. Exposing PBMCs isolated from healthy donors to ultrafiltrates from patients with sepsis demonstrated a significant suppressive effect of HP ultrafiltrates on the anti-CD3-stimulated PBMC proliferation (P = 0.011). Ultrafiltrate from patients with sepsis who received C-HF had no impact on PBMC proliferation. CONCLUSION: HP-HF restores PBMC proliferation in septic patients probably by eliminating immunomodulatory mediators. HP-HF may represent a new renal replacement therapy able to modulate PBMC function in sepsis.     

The role of prostaglandin E2 in immune suppression following injury.

It has been thought for some time that prostaglandin E2 (PGE2) released from activated monocytes/macrophages may contribute to the suppression of immunity seen after burns and major injury because PGE2 inhibits the activation of T lymphocytes. To clarify this issue, we studied 15 patients with total body surface area burns of 20% to 90% (mean, 48%). Peripheral blood mononuclear cells (PBMC) were obtained from these patients one to two times each week for 1 month after burn and were stimulated with the T-cell mitogen phytohemagglutinin (PHA). On 14 occasions the PBMCs from eight patients were significantly suppressed (30% or more) in their response to PHA (suppressed [sup] burn) as compared with PBMCs from normal controls. In 38 instances PBMCs from 12 patients were not significantly suppressed in PHA (nonsuppressed [nonsup] burn). Sup burn PBMCs and control PBMCs were cultured with or without the addition of the cyclooxygenase (CO) inhibitor indomethacin (Indo, 1 microgram/mL) and studied for PHA response and the production of the stimulatory cytokine interleukin-2 (IL-2). Indo partially restored the PHA response of sup burn PBMCs to normal. Sup burn PBMCs also were deficient in production of IL-2. Indo increased IL-2 production by sup burn PBMCs significantly more (160% +/- 20%, p less than 0.005) than control (57% +/- 5%) and nonsup PBMCs (67% +/- 8%). Next inhibition of the PHA response of PBMCs from 12 burn patients and 17 controls was studied by exogenous PGE2. At all time periods after burn injury, patients' PBMCs were significantly more sensitive to inhibition by PGE2 (50% inhibition at 10(-8) mol/L [molar] PGE2) than PBMCs from normal controls (50% inhibition at 10(-6) mol/L PGE2) with maximum sensitivity occurring 8 to 14 days after injury. Peripheral blood mononuclear cells from patients with more than 40% burns were significantly (p less than 0.05) more sensitive to PGE2 than those from patients with lesser burns. Interleukin-2 was added to cultures of sup burn PBMC, nonsup burn PBMC, and controls containing 10(-7) mol/L PGE2. Interleukin-2 totally reversed PGE2 inhibition of the PHA response in PBMC from both controls and burn patients. Because endotoxin leak from the gut has been implicated as a trigger for a number of the metabolic and immunologic abnormalities following injury, the authors looked for the effect of a bolus infusion of Escherichia coli endotoxin (Endo, 4 ng/kg) in seven normal healthy volunteers on the response of PBMC to PHA and on the production of PGE2 and IL-2.(ABSTRACT TRUNCATED AT 400 WORDS)     

A comparison of the sensitivity of pig and human peripheral blood mononuclear cells to the antiproliferative effects of traditional and newer immunosuppressive agents

Difficulty in preventing rejection of fetal pig islet-like cell clusters (ICCs) transplanted into pigs using traditional forms of immunotherapy has been reported. An in vitro study of the efficacy of seven different immunosuppressive agents to inhibit proliferation of pig peripheral blood mononuclear cells (PBMC) was performed, and a comparison was made between the human and pig to determine if the efficacy of these agents differed between species. The efficacy of cyclosporine (CsA), azathioprine (Aza), methylprednisolone (MP), FK506, rapamycin (RAP), mycophenolate mofetil (MMF) and deoxymethylspergualin (MeDSG) to inhibit pig and human PBMC proliferation in mitogenic experiments using phytohaemagglutinin (PHA) as a stimulus was performed. Further, allogeneic pig mixed lymphocyte reactions (MLR) were used to determine the activity of these agents in a model more comparable to the allograft rejection process. It was found that pig PBMC stimulated with PHA or in a MLR were inhibited by the agents tested, with the exception of MeDSG that was ineffective in mitogenic experiments. The inhibitory effects of these agents differed between PHA and MLR, the respective (50% inhibitory concentration) IC50 values for pig PBMC being 1.7 and 0.08 microg/ml for CsA, 1.4 and 4.4 microg/ml for Aza, 0.11 and 0.002 microg/ml for MP, 3.0 and 2.8 ng/ml for FK506, 2.1 and 0.3 ng/ml for RAP and 10.8 and 454 ng/ml for MME Pig PBMC were less sensitive than human PBMC to the antiproliferative effects of CsA, Aza, FK506, RAP and MMF, but not MP on PHA stimulation, the ratio of the pig to human IC50 values being 19, 11, 13, 2.3, 1.4, and 0.4, respectively. These data suggest that the doses of most immunosuppressive agents administered to prevent rejection in pigs need to be higher than those used to achieve therapeutic benefit in humans.     

Functional characterization of the immunomodulatory properties of human urine-derived stem cells

BackgroundUrine-derived stem cells (USCs) have been widely researched as a novel cell source for stem cell therapy, but their immunomodulatory characteristics remain to be investigated. This study aimed to characterize the immunomodulatory properties of human USCs.MethodsHuman USCs were isolated from fresh voiding urine samples from healthy male donors and expanded. Their cell surface markers were characterized by flow cytometry analysis and the telomerase activities for several USCs clones were determined. The immunosuppressive potential of USCs was evaluated by the performing the mixed lymphocyte reaction (MLR) [co-culture with peripheral blood mononuclear cells (PBMNCs)] and natural killer cells (NK) cytotoxicity assay. USCs cytokines release profile was determined by using human cytokine proteome array.ResultsUSCs exhibited high cell surface expression of embryonic/mesenchymal stem cells (MSCs) markers CD29, CD44, CD54, CD73, CD90, CD146, and CD166, while lacked expression of hematopoietic stem cell markers CD11, CD14, CD19, CD31, CD34, CD45, B cell marker CD79, and co-stimulatory factors CD80 and CD86, thus, exhibiting the phenotype of MSCs. MLR indicated that USCs significantly inhibited the proliferation of PBMNCs, as compared to that of the human smooth muscle cells (SMCs). In cell cytotoxicity assays, NK cells displayed less cytotoxicity against USCs than against bone marrow mesenchymal stem cells (BMSCs) and SMCs. Furthermore, upon PBMNCs stimulation, USCs secreted higher levels of immunomodulatory cytokines, including IL-6, IL-8, MCP-1, RANTES, GROα, and GM-CSF, compared to those of BMSCs, especially when directly contact mix-culture with PBMNCs.ConclusionsUSCs secreted immunoregulatory cytokines and possessed immunomodulatory properties, comparable to those of BMSCs.     

The role of increased frequency of treg cells in patients with chronic osteomyelitis

The aim of this study is to determine whether regulatory T cells (Treg cells) are increased in patients with chronic osteomyelitis and whether they suppress cellular immune responses to the bacteria. The frequency of circulating CD4(+)CD25(+) and CD4(+)CD25(+)FoxP3(+) T cells in 30 chronic osteomyelitis patients were compared with 30 healthy donors. Treg-depleted PBMCs from the patients were cultured together with autologous antigen, unfractioned PBMCs used as the control. The cell proliferation and production of IL-10 and IFN-γ were compared with those of the control. The results demonstrated that frequencies of CD4(+)CD25(+) (10.85±2.82% vs 6.08±1.62%, P<.001) and CD4(+)CD25(+)FoxP3(+) T cells (2.06±0.83% vs 1.43%±0.51%, P<.001) in blood from chronic osteomyelitis patients were significantly higher than in healthy donors. The level of IL-10 (117±91 pg/ml vs 323±189 pg/ml, P<.001) in supernatants of Treg-depleted PBMCs was decreased. Cell proliferation (4489±11876 cpm vs 3547±1517 cpm, P<.05) and IFN-γ (875±203 pg/ml vs 405±129 pg/ml, P<.001) production by CD4(+)CD25(+) T cell in response to antigen was significantly inhibited by CD4(+)CD25(+) T cells. These results indicate that specific Tregs can depress the T cell mediated immune responses to bacteria in chronic osteomyelitis, and may play an important role in the persistence of bacteria.     

Apoptotic markers on lymphocytes and monocytes are unchanged during single hemodialysis sessions using either regenerated cellulose or polysulfone membranes

BACKGROUND: There is an increased rate of apoptosis of peripheral blood mononuclear cells (PBMCs) in patients undergoing hemodialysis (HD), but little is known about how different dialysis membranes may contribute to the process. We, therefore, studied the influence of two different dialysis membranes on apoptotic markers during HD. METHODS: 8 healthy controls and 8 patients on regular HD 3 times per week were enrolled in this cross-controlled study. Patients received HD using polysulfone and then regenerated cellulose dialysis membranes for one week each, sequentially. Serum was collected for C-reactive protein (CRP) detection; flow cytometry with dual antibody staining was used to measure the apoptotic markers Fas (CD95), FasL (CD 178) and TNF-R2 (CD120b) in T cells (CD3+), B cells (CD19+), and monocytes (CD14+) at 0, 15, 120 and 240 min after starting HD. We also measured total leukocyte numbers and differential white cell counts. RESULTS: Hemodialysis patients revealed lymphocytopenia, monocytopenia, higher CRP levels and higher Fas and TNF-R2 expression on lymphocytes and monocytes at baseline when compared with normal controls. Leukocyte numbers, including neutrophils, lymphocytes and monocytes, dropped significantly after 15 min of dialysis. There were no significant differences in Fas levels during hemodialysis on T and B lymphocytes or on monocytes. T lymphocyte FasL (CD 178) levels remained unchanged throughout the process. There was a significantly lower overall level of CD120b at 15 min of HD, whereas this marker was higher on monocytes after dialysis. There were no significant differences in the levels of apoptotic markers between the two membranes. CONCLUSION: Our results suggest that uremia itself contributes to PBMC apoptosis. The two different dialysis membranes used in this study did not influence apoptotic markers on PBMCs significantly, but increased TNF-R2 expression on monocytes during a single dialysis session.