Expansion of alpha-galactosylceramide-stimulated Valpha24+ NKT cells cultured in the absence of animal materials

Valpha24+ NKT is an innate lymphocyte with potential antitumor activity. Clinical applications of Valpha24+ natural killer (NK) T cells, which are innate lymphocytes with potential antitumor activity, require their in vitro expansion. To avoid the potential dangers posed to patients by fetal bovine serum (FBS), the authors evaluated non-FBS culture conditions for the selective and efficient expansion of human Valpha24+ NKT cells. Mononuclear cells (MNCs) and plasma from the peripheral blood of normal healthy donors were used before and after G-CSF mobilization. MNCs and plasma separated from apheresis products were also used. MNCs were cultured for 12 days in AIM-V medium containing alpha-galactosylceramide (alpha-GalCer) (100 ng/mL) and IL-2 (100 U/mL) supplemented with FBS, autologous plasma, or autologous serum. The cultured cells were collected and their surface markers, intracellular cytokines, and cytotoxicity were evaluated. The highest expansion ratio for Valpha24+ NKT cells was obtained from G-CSF-mobilized MNCs cultured in medium containing 5% autologous plasma. Cultures containing MNCs and autologous plasma obtained before and after G-CSF mobilization had approximately 350-fold and 2,000-fold expansion ratios, respectively. These results suggest that G-CSF mobilization conferred a proliferative advantage to Valpha24+ NKT cells by modifying the biology of cells and plasma factors. Expanded Valpha24+ NKT cells retained their surface antigen expression and production of IFN-gamma and exhibited CD1d-independent cytotoxicity against tumor cells. Valpha24+ NKT cells can be efficiently expanded from G-CSF-mobilized peripheral blood MNCs in non-FBS culture conditions with alpha-GalCer and IL-2.     

脐血CD34+细胞与单个核细胞的体外扩增特性研究

目的　探讨CD34+ 富集细胞和单个核细胞 (MNC)的体外扩增特性。方法　利用Min iMACS系统富集CD34+ 细胞 ,在相同条件下与同批MNC进行对照培养 ;观察了再次富选和MNC培养上清 (MNC SN)对CD34+ 富集细胞扩增的影响 ;并尝试了MNCCD34- 细胞的培养。结果　虽然CD34+ 富集细胞具有很高的扩增潜力 ,但在培养过程中 ,其集落密度和CD34 + 细胞含量却始终呈下降趋势 ,而MNC在培养中却出现了一个上升的趋势 ,集落密度和CD34+ 细胞含量分别由第 0天的 (4 12± 16 7) 10 5细胞和 (1.12± 0 .4 2 ) %增至第 7天的 (116 2± 5 6 6 ) 10 5细胞和 (4 .17± 1.4 4 ) % ;再次富选可以使培养过的CD34+ 富集细胞的总细胞和CD34+ 细胞扩增能力大大提高 ;MNCCD34- 细胞具有集落形成和转化为CD34+ 细胞的能力 ;MNC SN对CD34+ 富集细胞的集落形成有促进作用 ,而同时又对CD34+ 细胞有促分化作用。结论　CD34+ 富集细胞在体外大量扩增的同时存在大量分化 ,其在培养过程中产生的CD34-细胞对CD34+ 细胞的扩增有抑制作用 ;脐血MNC中大量的CD34- 细胞含有造血干 祖细胞 ,其分泌的细胞因子有促进CD34+ 细胞向较为成熟的集落形成祖细胞分化的作用。     

Large ex vivo expansion of human umbilical cord blood CD4+ and CD8+ T cells.

The use of human umbilical cord (UC) blood as a source of transplantable hematopoietic stem cells and progenitor cells may present some advantages over the use of BM. For example, it has been suggested that the degree of HLA matching may be less stringent, and the risk of GvHD may be lower. We have been studying the ex vivo expansion of UC blood T lymphocytes with a view to their use in the adoptive immunotherapy of cancer, autoimmunity, and infectious disease. We have developed a new method involving the use of a conditioned medium (XLCM) that consistently results in levels of UC blood T cell expansion not hitherto possible. Primary cultures of unfractionated low-density MNC (LDMNC) derived from UC blood treated with 5% XLCM routinely show expansions greater than 10,000-fold within 4 weeks. By contrast, similar FBS-free cultures treated with IL-2 expand less than 10-fold and not after 1 week, and cultures treated with IL-2 and concanavalin A (ConA) expand to a maximum of only 300-500-fold over 2 weeks and fail to continue to proliferate thereafter. The MAb, OKT3, which, when combined with IL-2 and FBS, is known to stimulate proliferation of adult peripheral blood lymphocytes, permitted only a 17-fold expansion of UC blood lymphocytes under the same conditions. Thus, XLCM, which can also stimulate adult peripheral blood lymphocyte expansion to levels exceeding 100,000-fold in 3-4 weeks, is uniquely able to stimulate proliferation of UC blood lymphocytes to high levels. From initiation of the UC blood or adult peripheral blood LDMNC/XLCM cultures up to approximately 2 weeks, the cultures are dominated by CD4+ T lymphocytes. By 4 weeks, >80% of the cultured cells bear the CD8+ phenotype, whereas UC blood T lymphocytes cultured in the presence of IL-2 are predominantly CD8+. Thus, XLCM not only allows high levels of expansion of UC blood T lymphocytes not heretofore possible but also permits the selective expansion of different T lymphocyte subsets from a single source.     

脐血CD34+细胞迁移能力在体外扩增过程中的变化

目的　比较扩增前、后脐血 (CB)CD34 细胞在体外的迁移能力及细胞表面趋化因子CXCR4的表达情况。方法　将从新鲜CB标本中纯化的CD34 细胞接种于已建立的扩增体系 ,分别于培养 7,10和 14d从扩增产物中再纯化CD34 细胞 ,检测培养不同时间CD34 细胞的自发迁移率和SDF 1诱导迁移率以及CD34 细胞表面CXCR4的表达。结果　①原代和扩增不同时间CD34 细胞的SDF 1诱导迁移率均高于自发迁移率 ;②扩增 7d时CD34 细胞的自发迁移率和SDF 1诱导迁移率与原代CD34 细胞相当 ,但在第 2周的培养中 ,CD34 细胞的两种迁移率均明显下降 (P值均 <0 .0 5 ) ;③扩增后CD34 CXCR4 细胞的数量明显增加 ,但CXCR4在CD34 细胞上的表达呈下降趋势 ,14d时显著低于原代细胞的表达水平 (P <0 .0 5 )。结论　CB造血干 祖细胞 (HSPC)在已建立的短期培养体系中扩增 1周可保持原有的迁移功能 ,但持续扩增则可能对HSPC的归巢潜能产生不利影响。     

脐带间充质干细胞对脐血CD34＋细胞体外扩增的影响

背景:体外扩增是目前解决脐带血干细胞移植所面临的单份脐血造血干祖细胞数不足问题的丰要手段.已有许多关于不同来源的间充质干细胞联合不同细胞因子支持脐血造血干祖细胞体外扩增的报道,而单独应用间充质干细胞对人脐血CD34+细胞体外扩增的报道仍很少.目的:观察应用脐带源间充质干细胞作基质层的体外培养体系对脐血CD34+细胞体外扩增的支持作用.设计、时间及地点:对比观察实验,于2006-03/2007-05在中国医学科学院中国协和医科大学血液学研究所、实验血液学国家重点实验室完成.材料:经产妇知情同意,采集健康足月分娩胎儿脐带9份.方法:应用贴壁培养的方法从正常足月出生儿脐带中分离培养间充质干细胞,通过细胞形态学、免疫表型、分化实验进行鉴定.利用免疫磁珠分离法从正常足月出生儿脐带血中分离CD34+细胞.应用3种不同培养体系进行脐血CD34+细胞的体外扩增:单独应用脐带源间充质干细胞作基质层、细胞因子培养体系和间充质干细胞联合细胞因子培养体系.主要观察指标:应用细胞计数法、集落培养计数法和流式细胞学检测法对扩增后细胞数量、集落形成能力和免疫表型进行分析比较.RT-PCR检测间充质干细胞中细胞因子的表达情况.结果:培养第14天后,间充质干细胞组的CD34+细胞比例明显高于细胞因子联合间充质干细胞组;CD34+细胞总数为培养前的(4.19±1.37)倍,明显高于细胞因子组.培养第7天和第14天,间充质干细胞组的CD34+CD38-细胞亚群比例均高于另两组.RT-PCR结果显示,脐带源间充质干细胞体外可表达干细胞因子和血小板生成素早期干细胞效应因子.结论:单独应用脐带源间危质干细胞可有效地对脐血CD34+细胞进行体外扩增,更有利于保持较早期干、祖细胞的扩增.     

混合脐血血浆对脐血CD34^＋细胞体外扩增的作用

采用两步法分离出脐血CD34~ 细胞,比较研究了混合脐血血浆联合IL-3,IL-6,GM-CSF,Epo 4种中、晚期造血因子和单纯的4种造血因子情况下脐血CD34~ 细胞的体外扩增。结果表明,混合脐血血浆联合造血因子对粒-巨噬细胞集落形成单位(granulocyte-macrophage colony-forming unit,CFU-GM),红系爆式集落形成单位(burst-forming unit of erythriod,BFU-E),混合集落形成单位(minxed colony-forming unit,CFU-mix)3种集落的扩增效果明显优于单纯的4种造血因子联合组,差异具有统计学意义(P<0.01),但单纯混合脐血血浆扩增效果较差。脐血造血细胞扩增对子成人脐血移植有重要意义。上述结果提示,混合脐血血浆的扩增成功,可代替或弥补早期造血生长因子的作用,用于脐血造血细胞的体外扩增。     

Thrombopoietin to replace megakaryocyte‐derived growth factor: impact on stem and progenitor cells during ex vivo expansion of CD34+ cells mobilized in peripheral blood

BACKGROUND: The first protocol of ex vivo expansion that enabled almost total abrogation of postmyeloablative chemotherapy neutropenia was based on a three‐cytokine cocktail (stem cell factor [SCF], granulocyte–colony‐stimulating factor [G‐CSF], pegylated‐megakaryocyte growth and development factor [PEG‐MGDF]) in a serum‐free medium. Since the clinical‐grade molecule MGDF is no longer available on the market, we evaluated its substitution by thrombopoietin (TPO). STUDY DESIGN AND METHODS: CD34+ cells of myeloma patients were expanded for 10 days in serum‐free cultures with SCF, G‐CSF, or MGDF (100 ng/mL) or with TPO (2.5, 10, 20, 50, and 100 ng/mL) instead of MGDF. Day 10 amplifications of total nucleated cells, CD34+ cells, committed progenitors (CFCs), the capacity of engraftment of NOD/SCID mice (SCID repopulating cells [SRCs]), and the immunophenotype of cells in expansion product (CD13, CD14, CD33, CD41, CD61) were analyzed. RESULTS: TPO in doses of 2.5 and 10 ng/mL exhibits an effect comparable to that of MGDF (100 ng/mL) on total, CD34+, and CFCs amplification. Compared to MGDF, TPO (starting at 10 ng/mL) enhances two‐ to threefold the percentage of megakaryocyte lineage cells (CD41+ and CD61+). Finally, TPO maintains or even enhances (depending on dose) SRC activity. CONCLUSIONS: The use of TPO instead of MGDF in our protocol is feasible without any negative effect on progenitor cell expansion. Furthermore, applied in dose of 10 or 100 ng/mL it could enhance both the stem cell activity and the percentage of megakaryocyte lineage cells in expansion product.     

两步法脐血巨核细胞体外扩增的研究

目的探寻一种通过脐血单个核细胞体外培养获得大量巨核细胞的方法。方法首先将脐血单个核细胞在无血清培养液中加入TPO、SCF、IL-6、IL-3培养至14d行巨核祖细胞体外扩增,然后单纯加入TPO、IL-6再培养4d诱导巨核细胞成熟。结果单个核细胞数扩增了约4.8倍,CD41+细胞扩增了44倍,有核细胞形态学分析50%~74%为巨核细胞,巨核细胞中94%~96%为颗粒及产板型巨核细胞,绝大部分呈“核浆发育不平衡、胞核发育延迟”现象。结论使用这种两步培养法在体外可获取大量的脐血来源的巨核细胞以供研究使用。     

Direct immunomagnetic method for CD34+ cell selection from cryopreserved cord blood grafts for ex vivo expansion protocols

BACKGROUND: Cord blood is a useful source of HPCs for allogeneic transplantation. HPC ex vivo expansion of a cord blood graft has been proposed as a way to increase the speed of engraftment and thus to reduce the occurrence of transplantation-related complications. OBJECTIVE: The purpose of this study was to optimize a method for CD34+ cell selection of thawed cord blood grafts under clinical grade conditions, intended for application in a static, serum-free expansion culture. MATERIAL AND METHODS: Twelve samples were thawed and washed with dextran, albumin, and rHu-deoxyribo-nuclease I (RHu-DNase) to avoid clumping. CD34+ cells were selected by using a sensitized immunomagnetic bead and 9C5 MoAb complex. A buffer containing rHu-DNase, citrate, albumin, and immunoglobulin in PBS was used during the procedure. CD34+ cells were eluted and detached by using an immunomagnetic cell selection device. Cells from the enriched fraction were cultured for 6 days in serum-free medium supplemented with rHu-SCF, rHu-IL-3, rHu fetal liver tyrosine kinase 3 ligand, and rHu thrombopoietin (50 ng/mL each). Cells were expanded in well plates and in two semipermeable bags. RESULTS: A mean of 1.94 x 10(6) (+/- 1.55) CD34+ cells was obtained, yielding a CD34+ cell recovery of 52 +/- 12 percent. Nonspecific loss of CD34+ cells was 32 +/- 10 percent. CFU-GM and BFU-E/CFU-Mixed recoveries were 33 +/- 15 percent and 27 +/- 12 percent, respectively. CD34+ cells obtained were functionally comparable with fresh CD34+ cells selected for clonogenic potential. The capacity for expansion was not significantly different in the two types of bags studied. HPCs in wells were expanded 33 +/- 14-fold for CD34+ cells and 42 +/- 19-fold for overall colonies. The expansion rates observed in wells were significantly superior to those obtained in bags. CONCLUSION: The feasibility of a clinical-scale cord blood selection procedure based on a direct immunomagnetic method after thawing, followed by an ex vivo expansion culture using semipermeable bags, is shown. After 6 days of expansion, it was possible to generate a 9-fold increase in CD34+ cells, a 6-fold increase in CFU-GM and a 13-fold increase in BFU-E/CFU-Mixed colonies.     

Umbilical cord blood progeny cells that retain a CD34+ phenotype after ex vivo expansion have less engraftment potential than unexpanded CD34+ cells

BACKGROUND: Because of the limitation of cell numbers associated with cord blood harvests, there is a need to determine the efficacy of using ex vivo-expanded cord blood cells in a transplantation setting. In this study, limiting-dilution analysis was used in nonobese diabetic mice with severe combined immunodeficiency (NOD/SCID) to compare the engraftment potential of progeny cells expressing the CD34+ phenotype after expansion with that of uncultured CD34+ cells. STUDY DESIGN AND METHODS: Cord blood CD34+ cells were cultured in Iscove's modified Dulbecco medium supplemented with 10-percent fetal calf serum (FCS) and IL-6, SCF, megakaryocyte growth and development factor, and Flt3 ligand. The resulting ex vivo-expanded products were assessed for total numbers of nucleated cells, CD34+ cells, and CFUs and long-term culture-initiating cell activity. The engraftment potentials of cultured progeny CD34+ cells and uncultured CD34+ cells were determined by using NOD/SCID mice. RESULTS: After 14 days of culture, total nucleated cell counts increased over input values by 180 +/- 59-fold, CD34+ cell numbers by 44 +/- 13-fold, CFU activity by 23 +/- 5-fold, and long-term culture-initiating cell activity by 20 +/- 6-fold (mean +/- SD; n = 6). The frequency of SCID-repopulating cells (SRC) in mice transplanted with uncultured products was 1 per 20,000 CD34+ cells (95% CI, 1:10,000-1:38,000) and that in mice receiving ex vivo-expanded products was 1 per 418,000 progeny CD34+ cells (95% CI, 1:158,000-1:1,100,000). Taken together, these data indicated that, after 2 weeks of culture, there was a modest twofold increase in the total number of SRCs. However, the levels of human CD45 cell engraftment in NOD/SCID recipients of progeny CD34+ cells were significantly lower than those in mice receiving equivalent numbers of uncultured CD34+ cells (p<0.05). CONCLUSION: Umbilical cord blood progeny cells retaining a CD34+ phenotype after ex vivo expansion have less engraftment potential than do unexpanded CD34+ cells.     

体外扩增脐血CD34+细胞的实验研究

目的 探讨体外扩增脐血干／祖细胞用于成人脐血移植的可能性。方法 从１０份新鲜的脐血标本中纯化的ＣＤ３４＾＋细胞接种于含体积分数为２０％的胎牛血清（ＦＢＳ）的ＩＭＤＭ培养基的悬 培养体系中,分别加入由ＳＣＦ、Ｆｌｔ－３Ｌｉｇａｎｄ（ＦＬ）与ＩＬ－１β、ＩＬ－３、ＩＬ－６、Ｇ－ＣＳＦ、Ｅｐｏ（合称１３６ＧＥ）组成的３组细胞因子（Ａ组：１３６ＧＥ＋ＦＬ;Ｂ组：ＳＣＦ＋１３６ＧＥ;Ｃ组：ＦＬ＋ＳＣＦ＋１３     

人外周血Vα24 NKT细胞和CD3+CD56+CIK 细胞生物学特性的比较研究

目的进一步认识Vα24 NKT细胞和CIK细胞在生物学特性的差异。方法从人外周血单个核细胞扩增NKT细胞和CIK细胞;经免疫磁珠纯化获得高纯度的TCRVα24 NKT细胞和CD3 CD56 CIK细胞。运用流式细胞术测定纯化后的NKT细胞和CIK细胞的表型、细胞因子和细胞坏死相关因子的表达情况,并用DIOC18染色及流式细胞术测定纯化后的NKT细胞和CIK细胞的细胞杀伤活性。结果经纯化TCRVα24 Vβ11 NKT细胞和CD3 CD56 CIK细胞的纯度均达到>90%;纯化后的Vα24 NKT细胞多数为CD4 和DN NKT细胞,高表达TCRVα24、Vβ11、CD3、CD161,低表达CD56;而纯化后的CIK细胞则以CD8 T细胞为主,高表达CD3、CD56,低表达CD161,几乎不表达TCRVα24和Vβ11。在抗原刺激下,CD3 CD56 CIK细胞的IFN-γ、TNF-α、Perforin、FasL、TRAIL表达水平均高于NKT细胞,但CD3 CD56 CIK细胞几乎不分泌IL-4,而NKT细胞则分泌高水平的IL-4;CD3 CD56 CIK细胞对肿瘤细胞株K562、U937、Jurkat的杀伤率均远远高于NKT细胞。结论TCRVα24 NKT细胞和CD3 CD56 CIK细胞是两类完全不同的细胞群,在抗肿瘤免疫和免疫调节中可能起着不同的作用。     

Efficient transduction and engraftment of G-CSF-mobilized peripheral blood CD34+ cells in nonhuman primates using GALV-pseudotyped gammaretroviral vectors.

The optimal stem cell source for stem cell gene therapy has yet to be determined. Most large-animal studies have utilized peripheral blood or marrow-derived cells collected after administration of granulocyte colony-stimulating factor (G-SCF) and stem cell factor (SCF); however, SCF is unavailable for clinical use in the United States and the European Union. A recent study in a competitive repopulation assay in the rhesus macaque showed very inefficient marking of G-CSF-mobilized (G/only) peripheral blood (G-PBSC) CD34(+) cells relative to G-CSF and SCF-mobilized cells using vectors with an amphotropic pseudotype. Because G-PBSC would be the preferred target cell population for most clinical stem cell gene therapy applications, we asked whether we could achieve efficient transduction and engraftment of G-PBSC using Phoenix-GALV-pseudotyped vectors. We transplanted three baboons with G/only mobilized CD34(+) cells transduced with GALV-pseudotyped retroviral vectors. We observed high-level, persistent engraftment of gene-modified G-PBSC in all animals with gene marking levels in granulocytes up to 60%. We analyzed amphotropic (PIT2) and GALV (PIT1) receptor expression in G/only cells and found preferential expression of PIT1 after G/only, which may explain the inferior results with amphotropic pseudotypes. These findings demonstrate that high stem cell gene transfer levels can be achieved using G-CSF-mobilized PBSC with Phoenix-GALV-pseudotyped vectors.     

人骨髓基质细胞促进脐血CD34+细胞的体外扩增和对NOD/SCID小鼠的植入

目的 研究人骨髓基质细胞(MSC)促进脐血CD34+细胞体外扩增及植入能力的作用.方法 分离、培养正常人的MSC作为滋养层细胞.在TPO、SCF、FL和G-CSF刺激下,比较有、无MSC滋养层细胞对扩增脐血CD34+细胞后,CD34+细胞和CFU数的增加倍数,以及植入非肥胖性糖尿病/重症联合免疫缺陷(NOD/SCID)小鼠的能力.结果 以骨髓MSC为滋养层细胞的培养体系可以更加有效地扩增脐血CD34+细胞.体外扩增1周总细胞数(TNC)、CD34+细胞和CFU的均数分别增加111.6、19.3和58.0倍;体外扩增2周后TNC、CD34+细胞和CFU的均数分别增加532.8、41.3和563.5倍.脐血细胞输入NOD/SCID小鼠6周后,移植未扩增脐血细胞的对照组小鼠骨髓细胞中人CD45+细胞比例仅为1.2%～3.7%;移植单纯细胞因子刺激扩增组小鼠骨髓中,人CD45+细胞比例为7.6%～12.1%;以MSC为滋养层扩增的脐血细胞移植组,人CD45+细胞比例达到45.3%～59.1%.结论 以人骨髓MSC为作为饲养层细胞,不但可以更加有效扩增脐血CD34+细胞,而且可以促进脐血细胞植入NOD/SCID小鼠的能力,有潜在的临床应用价值.     

Effect of ex vivo culture duration on phenotype and cytokine production by mature dendritic cells derived from peripheral blood monocytes

BACKGROUND: To generate clinical-grade dendritic cells (DCs) ex vivo for immunotherapy trials, peripheral blood monocytes are typically cultured in granulocyte-macrophage–colony-stimulating factor (GM-CSF) and interleukin (IL)-4 and then matured using one or more agents. Duration of the initial DC culture is one important variable that has not been systematically evaluated for its effect on the characteristics of the final mature DC product.
STUDY DESIGN: DCs were generated from elutriated peripheral blood monocytes by incubation in medium containing 2000 units per mL each of GM-CSF and IL-4 for 3 to 7 days, followed by maturation with lipopolysaccharide and interferon-γ (IFN-γ). DC yield, viability, flow cytometric phenotype, and cytokine production were evaluated.
RESULTS: The percentage yield and viability of mature DCs were similar after GM-CSF/IL-4 culture for 3 or 7 days. In either case, mature DCs expressed abundant CD80, CD86, CD83, and CCR7, but 3-day DCs expressed these antigens in a more consistent and homogeneous manner. Mature 3-day DCs produced much more IL-12 and less IL-10 after restimulation with CD40L-LTK than 7-day DCs. The former were also more effective in presenting immunogenic peptides to CD8 T cells. Analogous changes in cytokine production were observed in mature DCs prepared using lower concentrations of GM-CSF/IL-4 or when the alternative maturation cocktails poly(I:C)/IFN-γ and soluble CD40L/IFN-γ were used.
CONCLUSION: Extended initial culture of DCs in GM-CSF/IL-4 does not affect yield or viability of subsequently matured DCs, but can adversely affect their ability to homogeneously express high levels of functionally important surface molecules such as CD83 and CCR7 and to produce IL-12.     

人外周血Vα24 NKT细胞和CD3~+CD56~+CIK细胞生物学特性的比较研究

目的进一步认识Vα24 NKT细胞和CIK细胞在生物学特性的差异。方法从人外周血单个核细胞扩增NKT细胞和CIK细胞;经免疫磁珠纯化获得高纯度的TCRVα24+NKT细胞和CD3+CD56+CIK细胞。运用流式细胞术测定纯化后的NKT细胞和CIK细胞的表型、细胞因子和细胞坏死相关因子的表达情况,并用DIOC18染色及流式细胞术测定纯化后的NKT细胞和CIK细胞的细胞杀伤活性。结果经纯化TCRVα24+Vβ11+NKT细胞和CD3+CD56+CIK细胞的纯度均达到>90%;纯化后的Vα24 NKT细胞多数为CD4+和DN NKT细胞,高表达TCRVα24、Vβ11、CD3、CD161,低表达CD56;而纯化后的CIK细胞则以CD8+T细胞为主,高表达CD3、CD56,低表达CD161,几乎不表达TCRVα24和Vβ11。在抗原刺激下,CD3+CD56+CIK细胞的IFN-γ、TNF-α、Perforin、FasL、TRAIL表达水平均高于NKT细胞,但CD3+CD56+CIK细胞几乎不分泌IL-4,而NKT细胞则分泌高水平的IL-4;CD3+CD56+CIK细胞对肿瘤细胞株K562、U937、Jurkat的杀伤率均远远高于NKT细胞。结论TCRVα24+NKT细胞和CD3+CD56+CIK细胞是两类完全不同的细胞群,在抗肿瘤免疫和免疫调节中可能起着不同的作用。     

脐血间充质干细胞的生物学特征及其对造血干/祖细胞体外扩增的支持作用

目的探讨脐血间充质干细胞(MSC)的生物学特征及其对造血干/祖细胞体外扩增的支持作用。方法用液体培养法分离脐血贴壁细胞,采用ELISA方法检测贴壁细胞条件培养液中细胞因子的表达;用流式细胞术分析其免疫表型特征;在成软骨细胞诱导培养条件下诱导细胞分化,并用RTPCR方法检测分化后细胞原胶原Ⅱ型基因的表达。采用分阶段共培养方法观察脐血贴壁细胞对CD34+细胞体外扩增的支持作用。结果脐血单个核细胞纤维样细胞集落形成率为(3.5±0.7)/106。脐血MSC体外至少可以扩增15代。没有分化的脐血MSC表型为CD13、CD29、CD90、CD105、CD166、SH2、SH3和SH4阳性,CD45、CD34和CD14阴性;脐血MSC培养上清中干细胞因子、IL6和肿瘤坏死因子α检测阳性。在成软骨细胞诱导培养基培养条件下,脐血MSC原胶原Ⅱ型基因mRNA表达阳性。脐血MSC与CD34+细胞共掊养14d,CD34+细胞扩增率高于未共培养组4倍。结论脐血MSC具有类似于成体骨髓MSC的特征,对造血干细胞增殖有明显的支持作用。     

脐血CD34^＋细胞向肝细胞分化的体内外实验

目的:以脐血CD34 细胞为起始细胞,分别在人体外和肝受损的重度联合免疫缺陷小鼠体内诱导CD34 细胞向肝细胞转化。方法:实验于2004-09/2005-06在反应器工程国家重点实验室进行。取健康足月产妇的新鲜脐血,产妇知情同意。采用密度梯度离心法分离脐血单个核细胞。将单个核细胞悬浮于免疫磁珠法缓冲液中,获取CD34 细胞。将CD34 细胞在干细胞因子 白细胞介素3 白细胞介素6细胞因子组合中培养1周,然后在肿瘤抑制素 成纤维细胞因子1 成纤维细胞因子2 白血病抑制因子 肝细胞生长因子 表皮生长因子组合中诱导其向肝细胞分化。将2-乙酰氟氨以0.4mg/只的剂量通过腹腔注射输入到重度联合免疫缺陷小鼠体内。7d后再腹腔注射入0.4mL/kg的CCl4,同时向实验组小鼠尾部静脉注射CD34 细胞,对照组小鼠则仅输注2-乙酰氨芴和CCl4。分别于4,6周后采用流式细胞术检测小鼠肝脏中的人源细胞,并用RT-PCR和免疫组化方法检测人源血清白蛋白基因和抗原的表达。结果:①CD34 细胞体外培养过程中,细胞总数扩增了近30倍,并且在培养21d收获的细胞中可检测到人血清白蛋白基因和抗原的表达,CD34 在体外被诱导成肝样细胞。②采用流式细胞术检测重度联合免疫缺陷小鼠肝脏中的人源细胞,并用RT-PCR和免疫组化的方法检测人源血清白蛋白基因和抗原的表达,4周时发现小鼠肝脏中含有7.66%的人源细胞,但人源细胞不表达血清白蛋白基因和抗原。6周时重度联合免疫缺陷小鼠肝脏中的人源细胞的比例增加至31.10%,并且人源细胞开始表达血清白蛋白基因和抗原。结论:CD34 细胞无论在体外培养还是在肝脏受损的重度联合免疫缺陷小鼠体内均能成功转化为肝实质细胞。