Effects of flt-3 ligand in combination with TPO on the expansion of megakaryocytic progenitors

As an early acting growth factor, flt-3 ligand (FL) promotes the ex vivo expansion of hematopoietic stem and progenitor cells. The effect and mechanism of FL on the development of the megakaryocytic lineage remain unclear. In this study, we compared the effects of FL and stem cell factor (SCF) in combination with other megakaryocyte-promoting cytokines on the differentiation and proliferation of megakaryocytic progenitors and investigated the expression of flt-3 receptors on megakaryocytic cell lines. In liquid cultures of enriched CD34+ cells from human umbilical cord blood for 14 days, FL plus thrombopoietin (TPO), interleukin-3 (IL-3), and IL-6 promoted the expansion of nucleated cells, CD34+ cells, CD34+ CD38- cells, and megakaryocyte colony-forming units (CFU-MK) by 300 +/- 115-, 23.8 +/- 11.3-, 33.9 +/- 28.6-, and 584 +/- 220-fold, respectively. Replacing FL with SCF significantly decreased the yield of all cell types. Using murine bone marrow (BM) cells, we demonstrated that FL at a range of 0-100 ng/ml had no significant mitogenic effect on CFU-MK formation. TPO increased CFU-MK (p < 0.001) but the effect was not significantly modified by FL. While one human acute lymphoblastic leukemia sample expressed high levels of flt-3 receptor, the four megakaryocytic cell lines (Meg-01, CHRF-288-11, M-07e, and Dami) did not show any positive expression. Our data suggest that the present cytokine combination and expansion conditions provide an effective and potentially useful system for the clinical expansion of cord blood for bone marrow transplantation (BMT). FL alone did not stimulate megakaryocytopoiesis, possibly due to the lack of receptor expression on megakaryocytes. The effect of FL in augmenting the expansion of CFU-MK in liquid culture might be due to the early action of FL at the pluripotent stem cell stage.     

小鼠不成熟CD8α+树突状细胞的免疫抑制功能的体外实验

目的 观察不成熟CD8α+树突状细胞(DC)的体外免疫抑制功能.方法 取C57BL/6(H-2b)小鼠和Balb/c(H-2d)小鼠的骨髓和脾脏,制备不成熟CD8α+DC和脾淋巴细胞,并经丝裂霉素处理.采用甲基噻唑基四唑(MTT)法,实验设混合淋巴细胞反应(MLR)组(阳性对照组)、MLR加不同密度的同系CD8α+DC组、MLR加不同密度同种异型CD8α+DC组、MLR加不同密度CD8α+DC的培养上清组、CD8α+DC加同系T淋巴细胞组及阴性对照组.MLR组按刺激细胞/反应细胞10∶1建立.CD8α+DC按与反应细胞比例0.2∶1、0.5∶1、0.8∶1和1∶1的梯度加入MLR中分别建立同系CD8α+D组和同种异型CD8α+D组;MLR中加入不同密度(1×105/ml～5×106/ml)CD8α+DC的培养上清液建立CD8α+DC上清组;CD8α+DC与同系淋巴细胞共培养建立CD8α+DC加同系T淋巴细胞组;以反应细胞2×105/孔作为阴性对照.采用酶联免疫吸附试验法检测MLR加同系CD8α+DC组(1∶1)上清液中γ干扰素(IF-γ)和白细胞介素10(IL-10)的浓度.结果 同系和同种异型不成熟CD8α+DC对MLR均有抑制作用(P＜0.05),二者间差异无统计学意义(P＞0.05).抑制作用随DC比例的增加而增强,当CD8α+DC/反应细胞比例大于0.2时显示抑制作用(P＜0.05),比例为1时抑制作用最强.CD8α+DC体外刺激同系淋巴细胞增殖的能力较弱,当DC与T淋巴细胞的比值大于2时,显示出一定的刺激作用(P＜0.05),其培养上清液对MLR也有抑制作用(P＜0.05),其中密度5×105/ml的细胞培养上清液抑制作用最强.MLR加同系CD8α+DC组(1∶1)上清液中IL-10的含量为(451.9±12.2)pg/ml,IFN-γ的含量为(1.0±1.2)pg/ml.结论 不成熟CD8α+DC体外具有免疫抑制或诱导免疫耐受的功能,可产生较高水平的IL-10,CD8α+DC及其培养上清液均可抑制MLR.

Abstract：

Objective To observe the function of immature CD8α+ dentritic cells (DCs) in vitro. Methods The bone marrow and spleen of C57BL/6(H-2b) and Balb/c (H-2d) mice were got to prepare immature CD8α+ DCs and spleen lymphocytes,and treated by mytomycin. MTT test was used.MLR group, MLR plus variable density syngeneic CD8α+ DC group, MLR plus variable density allogeneic CD8α+ DC group,MLR plus variable density CD8α+ DC supernatant group,CD8α+ DC plus syngeneic T cell group and negative control group were established. MLR group was set up by responder cell ratio of 0.2,0.5,0.8,1.0,to build the MLR plus syngeneic and allogeneic CD8α+ DC experimental groups. Culture supernatant from different density (1 × 105/ml - 5 × 106/ml) of CD8α+DCs was added into MLR to build CD8α+ DC supernatant group. CD8α+ DCs were co-cultured with syngeneic T cells to build CD8α+ DCs plus syngeneic T cells group. 2 × 105/well responder cells served as the negative control group. ELISA was used to detect the concentrations of IFN-γ and IL-10 in the DCs could both suppress MLR (P＜0. 05), and the difference was not statistically significant (P＞0. 05). When CD8α+ DCs were increased, the suppressive effect was enhanced. When CD8α+ DC/responder cell ratio ＞0. 2, the inhibitory effect could be observed, and this effect reached the peak when the ratio was 1.0. The CD8α+ DCs had weak ability to stimulate syngeneic lymphocyte proliferation in vitro, and certain stimulating effect could be seen only when CD8α+ DC/responder cell ratio ＞2 (P＜0. 05). Its culture supernatant also showed suppressive effect (P＜0. 05), and the supernatant with a cell density of 5 × 105/ml showed the maximum effect. IL-10 concentration in the concentration was 1.0 ± 1.2 pg/ml. Conclusion The in vitro function of immature CD8α+ DCs was immunosuppression/tolerance,and they could secret high level of IL-10. The CD8α+ DCs and their culture supernatant could suppress MLR in vitro.     

Induction of tolerance-inducing antigen-presenting cells in bone marrow cultures in vitro using monoclonal antibodies to CD200R

CD200 to CD200R interactions produce immunoregulation. We investigated whether the expression of CD200R on dendritic cell (DC) precursors affects their developmental fate. C57BL/6 bone marrow (BM) cells were cultured in vitro in the presence of (interleukin-4 + granulocyte-macrophage colony-stimulating activity) to generate allostimulatory DCs, which were in turn used to induce cytotoxic T-lymphocyte and cytokine production after culture with C3H responder spleen cells. Some marrow cultures included anti-CD200R antibodies. The inclusion of monoclonal antibodies in different isoforms of CD200R in the BM culture led to a generation of cells (tolerogenic DCs) that were unable to produce allostimulation in vitro with responder cells. Cells taken from these latter mixed leukocyte cultures (MLCs) now contained CD4(+)CD25(+) cells able to inhibit the antigen-specific MLC response of fresh C3H responder cells to stimulation with C57BL/6 cells, but not stimulation with BALB/c cells. Tolerogenic DCs, infused in vivo into mice receiving C57BL/6 skin grafts, produced antigen-specific decreased rejection of BL/6 allografts, not BALB/c allografts, compared with mice receiving control DCs (generated from BM in the absence of anti-CD200R). The induction of CD4(+)CD25(+) suppressor cells in MLCs using tolerogenic DCs from the initial BM cultures could be overcome by using limiting numbers of tolerogenic DCs and an excess of allostimulatory DCs derived from BM cultures maintained in the absence of anti-CD200R. These data indicate that anti-CD200R biases stem cells in BM toward the development of suppressive antigen-presenting cells, which can induce CD4(+)CD25(+) regulatory T cells. Tolerogenic DCs have the potential to modify graft acceptance in vivo.     

Quantitative and qualitative differences in thrombopoietin-dependent hematopoietic progenitor development between cord blood and bone marrow

BACKGROUND: To assess the clinical application of thrombopoietin (TPO) for thrombocytopenia of patients receiving cord blood (CB) or bone marrow (BM) transplants, we examined whether various types of hematopoietic progenitors including megakaryocyte (MK) progenitors from CB and BM exerted different proliferative and differentiative potential in the presence of TPO. METHODS: The development of MK, granulocyte-macrophage, and erythroid/mixed erythroid (E/Mix) progenitors in a serum-deprived liquid culture medium supplemented with TPO was compared between CD34+ CB and BM cells. RESULTS: The CD34+ CB cells generated 30-fold more MKs than the CD34+ BM cells, but the CB-derived MKs were more immature. A single-cell culture study showed that CB CD34+CD38- cells as well as CD34+CD38+ cells proliferated in response to TPO, whereas the two subpopulations of CD34+ BM cells showed little multiplication. In short-term liquid cultures containing CD34+ CB or BM cells, TPO significantly increased the absolute numbers of various types of colony-forming cells, compared with the input values. In particular, MK progenitors and E/Mix progenitors in CB were amplified to a substantially greater extent than in BM. The superior response of CD34+ CB cells to TPO observed in this study may be due in part to the use of cryopreserved cells. CONCLUSIONS: Our results suggest that TPO alone cannot only stimulate megakaryocytopoiesis but also increase the numbers of various types of hematopoietic progenitors, and that quantitative and qualitative differences in TPO-dependent hematopoietic progenitor development exist between CB and BM.     

Successful generation of donor specific hematopoietic stem cell lines from co-cultured bone marrow with human embryonic stem cell line: a new methodology

We report the generation of 30 healthy human embryonic stem cell (h-ESC) lines from 33 voluntary oocyte donors using a donor somatic cell nuclear transfer (SCNT) technique on 190 oocytes. Our aim was to coculture them with their own bone marrow (BM) to generate hematopoietic progenitor cells for therapeutic purposes. Pluripotency and undifferentiated stage were confirmed using molecular cell surface markers. Normal karyotype of these cell lines was confirmed. Here we demonstrate that SCNT-h-ESCs differentiate to hematopoietic precursors when cocultured with unmodified, nonirradiated donor BM. We did not use any xenogeneic material for this hematopoietic differentiation. Hematopoietic precursors derived from them expressed cell surface antigens CD45/34. When further cultured with hematopoietic growth factors these hematopoietic precursors formed characteristic myeloid, erythroid, and megakaryocyte lineages. Phenotypic CD34+ cells derived from NT-h-ESCs were functionally similar to their counterparts in primary hematopoietic tissues like BM, umbilical cord, and blood. More terminally differentiated hematopoietic cells derived from h-ESCs under these culture conditions also expressed normal surface antigens like glycophorin A on erythroid cells, CD15 on myeloid cells, and CD41 on megakaryocytes. We report generation of hematopoietic progenitor cells from h-ESC lines by a SCNT technique, with differentiation into further lineages with structural and functional similarities to their adult counterparts in vivo. This novel alternative source of CD34+ stem cells from h-ESC lines generated without any xenogeneic material might be used to create transplantation tolerance, to implement regenerative medicine, and to treat autoimmune disorders.     

慢性粒细胞白血病患者的骨髓间充质干细胞对树突状细胞功能的调控

目的 探讨慢性粒细胞白血病(CML)患者骨髓间充质干细胞(MSC)对单个核细胞来源的树突状细胞(DC)的功能的调控及其机制.方法 采用细胞贴壁法获取CML患者骨髓MSC,在低血清培养液中培养和扩增.获取正常成人志愿者外周血单个核细胞,直接在体外诱导生成DC(正常DC组),另加入正常志愿者MSC(正常诱导组)或CML患者骨髓MSC(CML诱导组)以诱导生成DC.用流式细胞仪检测各组收获DC的免疫表型及MSC对DC吞噬功能的影响;用酶联免疫吸附试验检测各组DC白细胞介素12(IL-12)的分泌;混合淋巴细胞反应检测MSC对DC介导的异体T淋巴细胞增殖能力的抑制作用.结果与正常DC组相比较,正常诱导组和MSC诱导组培养7 d后未成熟DC的共刺激分子CD1a、CD80、CD83、CD86、CD40和HLA-DR的表达量较低(P＜0.05);与正常DC组相比较,诱导9 d后,正常诱导组和MSC诱导组成熟DC的CD40、CD86和CD83的表达量较低(P＜0.05).与正常DC组相比较,CML诱导组的不成熟DC的吞噬功能显著降低(P＜0.05),CML诱导组DC IL-12的分泌量显著下降(P＜0.05).CML诱导组的DC对T淋巴细胞增殖的刺激作用有所下降(P＜0.05).结论 CML患者骨髓MSC对DC的分化成熟以及其免疫调控能力有一定的抑制作用.

Abstract：

Objective To study the effects and mechanisms of mesenthymal stem cells (MSCs)derived bone marrow of patients with chronic myelogenous leukemia (CML) on function of monocytederived dendritic cells in vitro. Methods Bone marrow mononuclear cells from CML patients were obtained and cultured. Peripheral blood mononuclear cells (PBMCs) derived from normal volunteers were isolated and cultured in DC differentiational condition. Moreover, PBMCs were co-cultured with CML bone marrow-derived MSCs (CML-MSC) or normal volunteers' bone marrow-derived MSC (normal-MSC) in DC differentiational condition. Immunophenotype and the endocytosis of monocytederived DCs were investigated by FACS. The level of IL-12 was evaluated by enzyme linked immunosorbant assay (ELISA). The immunoregulatory ability was detected by mixed lymphocyte culture assay. Results CML-MSCs or normal-MSC inhibited the up-regulation of CD1a,CD40,CD80,CD86,and HLA-DR during DC differentiation and reduced CD40,CD86,and CD83 expression during DC maturation. CML-MSCs inhibited the endocytosis of DCs and decreased their capacity to secret IL-12. CML-MSC could significantly suppress the function of DCs stimulating proliferation of T lymphocytes. Conclusion CML-derived MSCs harbored effect on the differentiation and maturation of DCs in vitro ; CML-MSC could inhibit the immunregulation of DCs.     

树突状细胞在肾小管间质炎症病变中的作用及抗黏附干预调节的研究

目的 探讨树突状细胞(DC)在肾小管间质炎症损伤中的作用，以及抗P-选择素功能域单抗(PsL-EGFmAb)对DC浸润及体外成熟与功能的干预调节。 方法 (1)建立大鼠单侧输尿管梗阻(UUO)模型。分别采用免疫组化和免疫双染与图像分析，观察P-选择素及CD1a+CD80+DC在肾组织表达和分布变化。(2)从脐血CD34+造血干细胞中诱导扩增DC，并于成熟过程中采用流式细胞仪分析细胞表面分子表达；RT-PCR检测细胞NF-κB P50、P65 mRNA表达；混合淋巴细胞反应(MLR)检测DC对T细胞刺激能力；以及ELISA测定MLR上清液IL-12 p70分泌含量。 结果 (1)与假手术组比较，UUO大鼠从第1天起，随着P-选择素以肾小管上皮细胞为主的小管间质表达，CD1a+CD80+DC以肾间质为主浸润；至第7天P-选择素上调且CD1a+CD80+DC显著聚集，两者明显相关且与肾小管间质病变程度显著相关。经PsL-EGFmAb处理后，大鼠肾组织P-选择素表达下调，CD1a+CD80+DC浸润减少，且肾小管间质损害程度减轻。(2)经TNF-α刺激炎性状态下，培养人DC成熟过程中基本不表达或低表达P-选择素，但持续高表达与P-选择素同属C型凝集素的DC-SIGN。经PsL-EGFmAb处理后，可明显抑制DC-SIGN及细胞内NF-κB基因表达，并相应抑制DC黏附共刺激分子表达、IL-12分泌及刺激T细胞增殖能力。 结论 DC也是肾小管间质炎症病变启动因素，针对P-选择素功能域的单抗对其浸润具抑制作用。此外，该单抗对人DC成熟与功能有调节效应，提示与抑制作为DC模式识别及黏附受体的DC-SIGN有关，并可能通过影响NF-κB途径起作用。     

白细胞介素-12基因修饰对树突状细胞表面分子表达及细胞因子分泌的影响

目的 观察白细胞介素(IL)-12基因修饰对树突状细胞(DC)表面分子及细胞因子分泌的影响.方法 采用重组逆转录病毒介导IL-12基因修饰人外周血单个核细胞(PBMC)来源的Dc;ELISA法检测各组DCs和各组T细胞上清中IL-12、IL-10、IFN-γ因子的分泌水平;流式细胞仪(FACS)分析各组DC表面CD83、CD86的表达;MTT法检测DC刺激同源T淋巴细胞增殖的能力;统计学分析比较各组间的差异.结果 IL-12基因修饰使得DC高表达CD83和CD86分子,分泌高水平IL-12及IFN-γ,但对IL-10因子的分泌无明显影响,刺激同源T淋巴细胞增殖明显,诱导激活的T细胞上清中IFN-γ水平显著增高、IL-10分泌水平显著降低.结论 经IL-12基因修饰后的DC表型成熟,分泌IL-12及IFN-γ的能力增强,对IL-10因子的分泌无影响,能抑制T细胞分泌IL-10因子,优化抗原提呈的微环境.     

CD34+细胞在干细胞旁分泌下向内皮细胞分化的研究

目的 探讨人脐血CD34+细胞在脐带间充质干细胞(UC-MSCs)旁分泌作用下向内皮细胞诱导分化的可行性.方法 收集20份脐血,体积(103.80±19.77)ml.免疫磁珠(MACS)分选CD34+细胞;取脐带用消化贴壁法获得UC-MSC.流式鉴定干细胞表型.实验分单纯培养组、诱导组、共培养组.结果 流式鉴定CD34+细胞纯度(95.02±3.81)%.培养14 d流式检测共培养组表达CD31、CD144、VWF分别为(65.43±5.61)%、(54.40±4.13)%、(47.53±3.96)%(与单纯培养组比较P＜0.05),部分表达CD34,阴性表达CD45,这与诱导组及成熟脐静脉内皮细胞表达率一致.结论 UC-MSCs旁分泌作用与外源性细胞因子都具有促分化作用,均能使脐血CD34+细胞向内皮细胞分化.

Abstract：

Objective To study whether the paracrine action of umbilical cord-derived mesenchymal stem cells (UC-MSC) can induce differentiation of human umbilical cord blood-derived CD34+ cells into endothelial cells in vitro. Methods The 20 fresh umbilical cord blood samples were collected with volume of (103. 80 ± 19. 77) ml. CD34+ cells were isolated from the mononuclear cells by magnetic activated cell sorting system (MACS) , and mesenchymal stem cells (MSCs) were isolated from umbilical cord by collagenase and trypsin digestion. Three groups were set up: CD34+ cells pure culture group, cytokineinduced group and two stem cells co-culture group with noncontact. Results The average purity of enriched CD34+ cells as assessed by FACS was (95. 02 ± 3. 81) %. Freshly isolated CD34+ cells were small and round which suspended in culture medium. Attached cord-like structure cells of CD34+ cells appeared after 7 days coculture with noncontacted MSC, and when the CD34+ cells grew into large number, they formed colonies. These cells expressed endothelial specific markers, including CD144 (54. 40 ±4. 13)% ,vWF (47. 53 ± 3. 96) % , CD31 (65. 43 ± 5. 61) % ( P ＜ 0. 05, as compared with CD34+ cells pure culture group) , partially expressed CD34 and, the leukocyte common antigen CD45 was negatively expressed.Conclusion Human umbilical cord blood-derived CD34+ cells could be induced into endothelial cells under the paracrine action of umbilical cord-derive mesenchymal stem cells which has the same effect of cytokines.     

Sequential delivery of maturation stimuli increases human dendritic cell IL-12 production and enhances tumor antigen-specific immunogenicity

BACKGROUND: Despite the increasing use of dendritic cells (DCs) in clinical trials, questions regarding the optimal means of DC preparation, in particular how to achieve optimal maturation, remain unanswered. We hypothesized that delivering two separate sequential maturation signals to DC in vitro, mimicking the process of DC maturation that occurs in vivo, would enhance the ability of DCs to generate antigen-specific effector T cells in an experimental in vitro antimelanoma model. MATERIALS AND METHODS: Human monocyte-derived DCs were transfected with mRNA encoding melanoma-associated antigen Mart-1 (MART) or influenza M1 matrix protein (M1). After mRNA transfection, DCs were left untreated or exposed to different maturation stimuli either added simultaneously or delivered sequentially 18 h after first stimulation. Phenotypic DC cell-surface marker changes and IL-12 secretion were analyzed. Specific antigen presentation by DCs was measured by IFN-gamma release Elispot assay using a CD8(+) MART peptide-specific T cell clone. RNA-transfected and treated DCs were cultured with autologous naive T cells and the induction of antigen-specific effector T cells were assessed by IFN-gamma release Elispot assay. RESULTS: DCs transfected and matured had increased cell-surface expression of CD40 and costimulatory molecules CD80, and CD86. DCs matured and further treated by soluble CD40 ligand (sCD40L) had a 10- and 2-fold increase in MART antigen presentation compared to untreated (immature) DCs and DCs treated only with a first maturation signal, respectively (Elispot P = 0.02). Delivery of sequential maturation stimuli resulted in maximal DC IL-12 secretion compared to simultaneous stimuli. Last, generation of antigen-specific effector T cells more than doubled with the sequential addition of sCD40L to mature DC stimulators (Elispot P = 0.009). CONCLUSIONS: Maturation of DCs following mRNA transfection increases expression of cell-surface costimulatory molecules. Delivery of a second sequential maturation stimulus enhances antigen presentation, increases IL-12 secretion, and augments immunogenicity as evidenced by generation of tumor antigen-specific effector T cells. This strategy should be considered in the future development of RNA-based DC vaccine strategies for the treatment of cancer.     

Effects of cyclophilin A on myeloblastic cell line KG-1 derived dendritic like cells (DLC) through p38 MAP kinase activation

BACKGROUND: Cyclophilin A (CypA) is a ubiquitously distributed intracellular protein as well as a secreted protein and has recently been reported to be an immunomodulatory molecule. The objective of this study was to determine the effect of CypA on dendritic cell (DC) differentiation, activation, and functional maturation. The role of p38 MAP kinase in DC functions was also investigated. MATERIALS AND METHODS: KG1 cells (CD34+ human myeloblastic cell line) were treated with cytokines (GM-CSF+IL-4) and/or CypA and expression of cell surface markers was analyzed by FACS analysis. The antigen-uptake capacity of different DCs was determined by FITC-dextran uptake assay. Antigen-presentation capacity of DCs was determined by allogeneic mixed lymphocyte reaction (MLR) by [3H] thymidine incorporation assay. To assess the T cell polarization stimulated by KG1 derived DCs, various Th1 and Th2 cytokines secreted by allostimulated CD4+ and CD8+ T cells were determined by Bioplex cytokine assay. Total and phosphorylated p38 MAPK activity in CypA treated DCs was detected by Bioplex p38 total and phosphoprotein assay. RESULTS: During the differentiation of KG1 cells to immature DCs, cell surface expression of CD11b was increased by 30.6% for CypA alone, 55% for CypA plus cytokines, and 44% for cytokines alone. Similarly, CypA alone increased the cell surface expression of CD11c by 59% as compared to CypA plus cytokines (68%) and cytokines alone (50%). CypA up-regulated the antigen uptake capacity of the immature DCs to a greater extent (5 times) as compared to cytokines alone (2.5 times). Moreover, CypA augmented the capacity of DCs to present antigens to allogenic CD8+ T cells, and also increased the secretion of Th1 type cytokines TNF-alpha and IFN-gamma from the allogenic CD4+ T cells. Furthermore, CypA induced the phosphorylation and hence activation of MAP kinase p38. Pre-treatment with SB-203580, a p38 inhibitor, significantly reduced MLR stimulatory capacity of CypA-induced DCs in both CD8+ and CD4+ T cells (P < 0.05). CONCLUSIONS: CypA enhances DC differentiation and maturation by up-regulating CD11b and CD11c expression. CypA can also augment DC antigen uptake and antigen presentation, which may be mediated by the p38 signaling pathway.     

乳腺癌细胞抗原负载的自体树突状细胞体内诱导特异性T细胞应答

目的 以乳腺癌细胞抗原体外负载自体树突状细胞(DCs)对24例乳腺癌患者进行自身免疫,探讨其体内诱导特异性T细胞免疫应答的能力.方法 新鲜癌组织制备成热休克凋亡细胞抗原负载外周单核细胞来源DC,分别在采血后第1、2、4、6周于患者腹股沟淋巴结富集区进行皮内注射,细胞剂量为4×10+～6×106/次.结果 DC免疫治疗后患者血清抗瘤免疫因子水平明显上升:白细胞介素(IL)-2治疗前为(33.8±7.2)ng/L,治疗后为(68.5±12.4)ng/L;IL-12治疗前为(48.5±10.9)ng/L,治疗后为(118.2±31.5)ng/L;肿瘤坏死因子(TNF)-α治疗前为(18.7±5.3)ng/L,治疗后为(78.3±11.5)ng/L;干扰素(IFN)-γ治疗前为(20.5±6.3)ng/L,治疗后为(92.6±14.9)ng/L,治疗前后比较差异有统计学意义(P<0.01);DTH试验阳性率为7/10;4/10例IFN-γ+CD8+T细胞频率较治疗前明显增加.随访发现:除1例患者在治疗后3个月内疾病进展(PD),其余患者病情稳定无复发与转移症状(SD).结论 以乳腺癌细胞为抗原负载自体DC免疫患者,能够有效提高患者非特异免疫水平,激发体内特异性T细胞免疫应答,是一种安全、副反应较小、有效的乳腺癌辅助治疗手段.     

供者应用粒细胞集落刺激因子促进异基因骨髓移植受者造血重建的临床研究

目的评价供者应用粒细胞集落刺激因子（G-CSF）以增加骨髓中CD34+细胞的效果和对异基因骨髓移植造血重建的影响。方法供者采髓前应用G-CSF250μg/d,连用7d,随后对15例白血病患者进行异基因骨髓移植,观察植入物单个核细胞、CD3     

微波消融灭瘤联合瘤内接种树突状细胞诱导特异性抗肝癌免疫

目的 探讨微波消融(MWA)灭瘤联合瘤内接种树突状细胞(DCs)诱导特异性抗肝癌免疫的效能.方法 采用GM-CSF联合IL-4体外培养C57BL/6小鼠骨髓来源的DCs,于第6天收集使用.建立C57BL/6小鼠皮下Hepa1-6肝癌模型,随机分为对照组、瘤内接种DCs组(DC组)、肿瘤微波消融组(MWA组)及肿瘤微波消融+瘤内接种DCs组(MWA+DC组).免疫组织化学法检测肿瘤组织内CD4+和CD8+T细胞的浸润,MTT法检测小鼠脾脏细胞对Hepa1-6的特异性杀伤活性,观测各组小鼠肿瘤生长情况.结果 免疫组织化学法检测显示MWA+DC组肿瘤组织内有大量的CD4+和CD8+T淋巴细胞浸润,显著高于其它组(P<0.05).MwA+DC组脾细胞对Hepa1-6细胞有特异性杀伤效能,在E/T=40和100时,MWA+DC组脾细胞对Hepa1-6细胞的特异性杀伤力显著高于对照组、DC组及MWA组(P<0.05).MWA+DC组小鼠肿瘤完全消退率显著高于其它各组(P<0.05).结论 MWA联合瘤内接种DCs可有效诱导机体产生特异性抗肝癌免疫,是预防MwA治疗后肝瘤复发的一种有效方法 .     

Rapamycin-conditioned, alloantigen-pulsed dendritic cells promote indefinite survival of vascularized skin allografts in association with T regulatory cell expansion

Clinically-applicable protocols that promote tolerance to vascularized skin grafts may contribute to more widespread use of composite tissue transplantation. We compared the properties of alloantigen (Ag)-pulsed, rapamycin (Rapa)-conditioned and control bone marrow-derived host myeloid dendritic cells (DCs) and their potential, together with transient immunosuppression (anti-lymphocyte serum+cyclosporine), to promote long-term, vascularized skin graft survival in Lewis rats across a full MHC barrier. Both types of DCs expressed low levels of CD86, but Rapa DC expressed lower levels of MHC II and CD40 and were less stimulatory in MLR. While both Rapa and control DCs produced low levels of IL-12p70 and moderate levels of IL-6 and IL-10 following TLR ligation, Rapa DC secreted significantly lower levels of IL-6 and IL-10 in response to LPS. Donor Ag-pulsed Rapa DC, but not control DC, induced long-term skin graft survival (median survival time >133 days) when administered 7 and 14 days post-transplant. Circulating T cells in hosts with long-surviving grafts were hyporesponsive to donor alloAg stimulation, but proliferated in response to third-party stimulation and produced IFN-gamma and IL-10. When recipients of long-surviving grafts were challenged with skin grafts, donor but not third-party grafts were prolonged, suggesting underlying regulatory mechanisms. Both flow cytometry and immunohistochemical analysis revealed that donor Ag-pulsed Rapa DC infusion expanded CD4+ Foxp3+ Treg in recipients' spleens, graft-associated lymph nodes and the graft. These data demonstrate for the first time that pharmacologically-modified, donor Ag-pulsed host DC administered post-transplant can promote indefinite vascularized skin graft survival, associated with Treg expansion.     

Autoimmune diabetes is suppressed by transfer of proinsulin-encoding Gr-1+ myeloid progenitor cells that differentiate in vivo into resting dendritic cells

The nature of the T-cell response to antigen is governed by the activation state of the antigen-presenting dendritic cell (DC). Immature or resting DCs have been shown to induce T-cell responses that may protect against the development of autoimmune disease. Effectively harnessing this "tolerogenic" effect of resting DCs requires that it be disease-specific and that activation of DCs by manipulation ex vivo is avoided. We reasoned that this could be achieved by transferring in vivo partially differentiated myeloid progenitor cells encoding a disease-specific autoantigen. With the aim of preventing autoimmune diabetes, we transferred myeloid progenitor cells encoding proinsulin into NOD mice. Bone marrow (BM) was cultured in granulocyte macrophage colony-stimulating factor (GM-CSF) and transforming growth factor-beta1, a cytokine combination that expands myeloid cells but inhibits terminal DC differentiation, to yield Gr-1(+)/CD11b(+)/CD11c(-) myeloid progenitor cells and a minor population of CD11c(+)/CD11b(+)/CD86(lo) immature DCs. After transfer, Gr-1(+) myeloid cells acquired the characteristics of resting DCs (CD11c(+)/MHC classII(int)/CD86(lo)/CD40(lo)). Gr-1(+) myeloid cells generated from transgenic NOD mice that expressed proinsulin controlled by a major histocompatibility complex (MHC) class II promoter, but not from wild-type NOD mice, transferred into 4-week-old female NOD mice significantly suppressed diabetes development. The transfer of DC progenitors encoding a disease-specific autoantigen is, therefore, an effective immunotherapeutic strategy that could be applied to humans.     

Immunotherapy of NOD mice with bone marrow-derived dendritic cells

We evaluated two bone marrow-derived dendritic cell (DC) populations from NOD mice, the murine model for type 1 human diabetes. DCs derived from GM-CSF [granulocyte/macrophage colony-stimulating factor] + interleukin (IL)-4 cultures expressed high levels of major histocompatibility complex (MHC) class II, CD40, CD80, and CD86 molecules and were efficient stimulators of naive allogeneic T-cells. In contrast, DCs derived from GM-CSF cultures had low levels of MHC class II costimulation/activation molecules, were able to take up mannosylated bovine serum albumin more efficiently than GM + IL-4 DCs, and were poor T-cell stimulators. The two DC populations migrated to the spleen and pancreas after intravenous injection. To determine the ability of the two DC populations to modulate diabetes development, DCs were pulsed with a mixture of three islet antigen-derived peptides or with medium before injection into prediabetic NOD mice. Despite phenotypic and functional differences in vitro, both populations prevented in vivo diabetes development. Pulsing of the DCs with peptide in vitro did not significantly improve the ability of DCs to prevent disease, which suggests that DCs may process and present antigen to T-cells in vivo. In addition, we detected GAD65 peptide-specific IgG1 antibody responses in DC-treated mice. Overall, these results suggest that a Th2 response was generated in DC-treated mice. This response was optimal when using GM + IL-4 DCs, which suggests that the balance between regulatory Th2 and effector Th1 cells may have been altered in these mice.     

High-avidity antitumor T-cell generation by toll receptor 8-primed, myeloid- derived dendritic cells is mediated by IL-12 production

BACKGROUND: High-level production of heterodimeric p70 interleukin (IL)-12 by myeloid-derived dendritic cells (DCs) requires 2 signals: interferon gamma (IFN-gamma) and a maturation signal provided by CD40 ligation (CD40L) or lipopolysaccharide (LPS). METHODS: In the current study we demonstrate that signaling through toll-like receptor (TLR) 8, but not TLR3, TLR2, or TLR4, provides a priming signal to myeloid-derived DC for high IL-12 p70 heterodimer production. RESULTS: All the TLR agonists induced maturation of DC as evidenced by increased expression of CD83, CD80, and CD86. Both IFN-gamma and TLR7/8 agonist R848 increased expression of TLR8 in immature monocyte-derived DCs. The combination of TLR7/8 agonist R848 and maturation signals LPS or CD40L induced high-level expression of IL-12p35 and p40 similar to that induced by IFN-gamma plus LPS. In contrast, receptor agonists specific for TLR7 did not prime for IL-12 production. The p70 IL-12 produced by the TLR8-primed DC polarized CD4+ T for Th1 cytokine production and induced CD8+ T cells, displaying high functional avidity with enhanced tumor cell recognition. CONCLUSIONS: The data suggest that toll 8 receptor agonists are useful for inducing type-1 polarized DCs for vaccine design in treating cancer and infectious disease.     

Ex vivo expansion of canine dendritic cells from CD34+ bone marrow progenitor cells

BACKGROUND: The aims of this study were to ex vivo expand canine dendritic cells and determine their phenotype and functional characteristics. METHODS: CD34+-selected cells and CD34+-depleted canine bone marrow (BM) cells were cultured in Iscove's modified medium for 14 days. Cytokines added to the cultures included human granylocyte/macrophage colony-stimulating factor 5 ng/ml, hFlt3 ligand 200 ng/ml, and human tumor necrosis factor-alpha 10 ng/ml. Cultured cells and purified subpopulations were assessed for cell surface antigen expression, morphology, and function by flow cytometric analysis, electron microscopy, and an allogeneic mixed lymphocyte reaction at day 14. RESULTS: Two main cell populations were identified, DR++(bright)/CD14- and DR+(dim)/CD14+. Ex vivo expanded CD34+-selected cells showed increased allostimulatory activity compared to both cultured CD34+-depleted cells and mononuclear cells. In contrast, ex vivo expansion from CD34+-depleted cells was unsuccessful. After sorting cells from the ex vivo expanded CD34+-selected bone marrow to enrich for DR++/CD14- cells, a 42-fold increase (median) of allostimulatory activity was observed as compared with sorted DR+/CD14+ cells (P=0.02). CONCLUSIONS: Cells with dentric cell-like phenotypes and functions can be cultured from canine CD34+-selected bone marrow cells. Future studies will address the roles of these cells in engraftment, graft versus host reactions and graft-host tolerance in a canine hematogoietic stem cell transplantaton model.     

乳腺癌树突状细胞瘤苗对自体CIK细胞生物活性的影响

目的探讨乳腺癌树突状细胞瘤苗（DCs）对自体CIK细胞生物活性的影响。方法取诱导7d的活化DCs瘤苗和诱导7d的自体CIK细胞混合培养（DC—CIK细胞）,同期自体CIK细胞为对照组。检测2、8、14d的DC—CIK细胞CD3与CD56表型、培养上清液IL．12的水平及测定混合培养8d时对乳腺癌细胞MCF．7的细胞毒效应。结果混合培养14d的DC-CIK细胞增殖率显著高于CIK细胞（P〈0．01）,但CD3和CD56表型无显著变化（P〉0．05）。DC—CIK细胞对MCF-7乳腺癌细胞的特异性溶解率和细胞毒活性均高于CIK细胞（P〈0．01）：CIK细胞强烈刺激DCs分泌IL-12．混合培养2d时,DCs的IL-12p40分泌水平达到高峰。结论乳腺癌DCs瘤苗与自体CIK细胞混合培养后（DC—CIK细胞）,进一步促进了DCs的成熟并增强了CIK细胞的细胞毒活性。