Ex vivo cytokine activation of peripheral blood stem cells: a potential role for adoptive cellular immunotherapy

Ex vivo activation of peripheral blood stem cells (PBSC) using interleukin-2 (IL-2) results in cytotoxic effector cells that may possess beneficial in vivo effects. We proposed to evaluate ex vivo stimulation of PBSC using various cytokines alone or in combination to optimize their function. Cytokine-activated PBSC were analyzed for tumor-directed cytotoxicity and their ability to remove tumor cells from long-term clonogenic assays. Mononuclear cells were obtained from the apheresis products of normal donors and cultured with IL-2 (1000 U/ml), interferon-alpha (IFN-alpha) (1000 U/ml), or IL-12 (50 U/ml) either alone or in combinations at 37 degrees C and 5% CO(2) for 24 h. Colony-forming unit-tumor (CFUT) assays were initiated using cytokine-activated PBSC with varying concentrations of MCF-7 or SKBR-3 human breast cancer cells. Standard 4-h (51)Cr-release assays were performed with cytokine-activated PBSC using MCF-7 or SKBR-3 cells as targets. Activation of PBSC with IL-2, IFN-alpha, or IL-12 resulted in enhanced cytotoxicity against the two breast cancer cell lines when compared to controls. PBSC activated with IL-2 and IFN-alpha or IL-2 and IL-12 were more cytotoxic than PBSC activated with single cytokines (p = 0.0004 for MCF-7 cells and p < 0.001 for SKBR-3 cells). Using clonogenic assays, IL-2-activated PBSC reduced the number of CFU-T to a greater extent than did IL-12 or IFN-alpha-activated PBSC (p = 0.0006). However, PBSC activated with a combination of IL-2 and IFN-alpha or IL-2 and IL-12 demonstrated 95% and 90% reductions, respectively, compared to 79% reduction using IL-2-activated PBSC (p < 0.0001). The greatest reduction in cytotoxicity occurred in the cell populations depleted of CD56(+) cells (p = 0.016) and CD8(+) CD56(+) cells (p = 0.002), suggesting that the effector cell population includes a combination of cytotoxic CD8(+) T cells and CD56(+) natural killer cells. These results demonstrate that the ex vivo activation of PBSC with cytokines, either alone or in combination, enhances cytotoxicity against, and removal of two human breast cancer cells. The combinations of IL-2 with IFN-alpha or IL-12 are most beneficial in cytotoxicity and purging assays. These results could play an important role in designing adoptive cellular immunotherapy clinical trials in the autologous hematopoietic stem cell transplant setting.     

低剂量rhG-CSF对56例非血缘供者外周造血干细胞动员

本研究观察低剂量人重组粒细胞集落刺激因子(rhG-CSF)对非血缘健康供者的影响,探讨用于中华造血干细胞捐赠者资料库提供的非血缘健康供者外周造血干细胞动员方案。56例非血缘健康供者接受rhG-CSF 5μg/(kg.d)皮下注射,在动员第4、5两天或第5、6两天采集干细胞,观察动员效果及不良反应,检测动员前后血常规指标、CD3+、CD4+、CD8+和CD20+细胞比例;对采集物进行单个核细胞(MNC)和CD34+细胞计数;对所有供者随访至2006年5月31日。结果显示:在rhG-CSF动员过程中出现1级毒副作用(按WHO分级标准):腰背酸痛17.9%(10/56)、焦虑失眠8.9%(5/56)、疲乏4.5%(3/56)等,无需特殊处理,无需终止动员。第4、5两天采集和第5、6两天采集所得的MNC分别是(5.95±1.52)×108/kg和(7.19±2.12)×108/kg;CD34+细胞分别是(3.03±1.09)×106/kg和(7.92±2.50)×106/kg。血红蛋白水平、血小板量、CD3、CD4、CD8、CD20百分比动员前后无变化。结论:5μg/(kg.d)rhG-CSF用于非血缘健康供者的动员是安全而有效的。     

Leukapheresis after high-dose chemotherapy and autologous peripheral blood progenitor cell transplantation: a novel approach to harvest a second autograft

BACKGROUND: Autologous peripheral blood progenitor cells (PBPCs) are usually collected after the administration of conventional-dose chemotherapy (CDCT) and growth factors. However, there are no data available concerning the collection of PBPCs after high-dose chemotherapy (HDCT) and autologous hematopoietic transplantation in a larger series. STUDY DESIGN AND METHODS: Patients (n = 30) underwent leukapheresis for PBPC harvest after CDCT. After HDCT and autografting, the collection of a second PBPC autograft was attempted. RESULTS: Leukapheresis was performed after CDCT in all cases at a median of 118 CD34+ cells per microL (range, 18-589) and resulted in 6.4 x 10(6) CD34+ cells per kg (range, 1.7-29.0). After HDCT and autografting, 24 patients (80%) underwent secondary leukapheresis, although they had a significantly lower median of peripheral blood (PB) CD34+ cells (30/microL; range, 10-171; p < 0.001). In these patients a median of 3.6 x 10(6) CD34+ cells per kg (range, 1.6-10.1) was collected in the post-transplantation course. In the remaining six patients (20%) with PB CD34+ cells < 10 per microL, no PBPC harvesting was performed. These so-called poor mobilizers had received significantly less CD34+ cells for autologous transplantation than patients with successful post-HDCT mobilization (median, 2.5 x 10(6)/kg [range, 1.7-3.0] vs. 6.5 x 10(6)/kg [range, 3.2-19.6]; p < 0.001). CONCLUSION: Collection of PBPCs is possible in most patients during the recovery phase of hematopoiesis after HDCT plus autografting, and the number of circulating PBPCs may be related to the CD34+ cell dose transfused by the preceding autograft.     

细胞因子联合激活人骨髓和外周血免疫细胞的比较研究

在本研究中比较了某些细胞因子在体外联合激活骨髓和外周血免疫细胞后二免疫细胞数量、形态、细胞化学染色、免疫表型和细胞毒变化的差异。在体外加入INF－γ，rIL-1，rIL-2和McAb-CD3分别激培养骨髓笔外周血单个核细胞，培养过程中观察两组免疫细胞增数量及形态的变化，培养前后两组取样进行细胞化学染色和有型检测，用MTT法检测培养后两组的细胞毒情况。研究结果发现，两组的细胞数量在激活培养后均较培养前明显增加，但外周血组增加倍数更多（P＜0．05）；细胞化学染色可见两组培养以后髓过氧化物酶积分均较培养前减少，过碘酸雪夫染色见两组含较多粗颗粒的淋巴样细胞明显较培养前多，两组CD3^ ，CD56^＋和CD38^ 细胞较培养前明显增加（P＜0．05），但两组增殖无明显差别；骨髓组培养后CD3^ CD56^ 细胞无明显增加，而外周血组培养后激活增加显（P＜0．05）；两组激活培养后细胞的细胞毒无明显差异，结论：rIL-γ，rIL-1，rIL-2和CD3单抗联合激活骨髓和外周血单个核细胞可使二细胞数量和细胞毒明显增加，在临床上可利用激活的不同来源的细胞因子诱导的杀伤细胞进行细胞免疫治疗。     

Transfusion-associated iron overload as a predictive factor for poor stem cell mobilization in patients with haematological malignancies

Transfusion-associated iron overload is often observed in patients with haematological malignancies. We analysed the effect of iron overload, indicated by high serum ferritin level, on the mobilization of CD34(+) peripheral blood stem cells (PBSCs). We evaluated the association between the serum ferritin level prior to PBSC collection and the number of CD34(+) cells collected through leukapheresis in 51 patients with various haematological malignancies. Patients with serum ferritin level over 1000 ng mL(-1) were defined as high-ferritin group. Comparing the good (> or =1 x 10(6) per kg CD34(+) cells) and poor (<1 x 10(6) per kg CD34(+) cells) mobilizing groups, there was no difference in disease status, previous chemotherapies and white blood cell count at the first day of apheresis. However, there was a significant difference in the median units of red blood cell transfused between the good and poor mobilizer (2 vs. 8 units; P = 0.012). Serum ferritin level was notably higher in the poor mobilizer (1670 +/- 1320 ng mL(-1)) compared with the good mobilizer (965 +/- 705 ng mL(-1), P = 0.035). The cumulative number of CD34(+) cells per kg collected during the whole procedure was significantly lower in the high-ferritin group (5.5 +/- 4.7 x 10(6) per kg vs. 13.1 +/- 9.1 x 10(6) per kg, P = 0.01). Multivariate analysis revealed that serum ferritin level remained as an independent predictive factor for poor PBSC mobilization. Our study indicated that transfusion-associated iron overload is a predictive factor for poor PBSC mobilization. Iron chelation therapy prior to apheresis may be required to collect sufficient numbers of PBSCs in the iron overload patients.     

Ex vivo expansion of early and late megakaryocyte progenitors

Our goal is to produce ex vivo-expanded human megakaryocytes (MK) cells from peripheral blood progenitor cell (PBPC) harvests for use in supplementing conventional autografts. In this paper we show the megakaryocytopoietic productivity of small-scale in vitro serum-free cultures of human CD34+ cells containing MK growth and development factor (MGDF) and stem cell factor (Kit ligand; SCF) +/- granulocyte colony-stimulating factor (G-CSF). Cultures were characterized after 3, 6, 9, and 13 days by flow cytometry and clonogenic assays. CD34+ cells expanded 5.2- and 3.4-fold, and produced 2.2 and 2.4 CD34+/41(+) cells per seeded CD34+ cell after 6 and 9 days in culture, respectively. None were detected at day 13. CD41+ cells expanded exponentially over 13 days. Colony-forming unit-megakaryocyte (CFU-MK) also expanded exponentially, but the proportion of the most primitive CFU-MK dropped from 45% to 1.5% and to <1% after 6 and 9 days, respectively. G-CSF increased total cell expansion, but decreased CD41+ frequency, yielding no gain in MK production. We also found that PB CD34+ cells cultured for 3-6 days are richer in primitive MK progenitors, while those cultured for 9-13 days have greater numbers of more differentiated MKs. Overall, the combination of MGDF+SCF proved sufficient for expanding CD34+/CD41+ cells. As the stage of ex vivo MK differentiation most conducive to optimal platelet production in vivo is not known, we are planning a clinical trial to determine the efficacy of ex vivo-expanded MKs on platelet recovery in relation to MK maturity.     

Ex vivo expansion of human umbilical cord blood-derived T-lymphocytes with homologous cord blood plasma

This study was designed to establish a more effective and safe culture system for adoptive immunotherapy by investigating the use of homologous cord blood plasma (HCBP) instead of fetal bovine serum (FBS), which has various limitations including ethical problems for the ex vivo expansion of human umbilical T lymphocytes. Fresh human umbilical mononuclear cell fractions were isolated by Ficoll-Hypaque density centrifugation. Nonadherent mononuclear cell fractions were cultured with anti-CD3 antibody (5 microg/ml), IL-2 (175 U/ml), and either 10% FBS or 10% HCBP. On day 8, the cellular proliferation rate and cell surface markers were assessed. There was no significant difference in proliferation when human umbilical cord blood T lymphocytes were grown in medium supplemented with FBS or HCBP (p > 0.05). In medium containing FBS, the proportion of CD3(+)CD4(+) (markers for helper T cell), CD3(+)CD8(+) (cytotoxic T cell), CD3(+)CD25(+) (activated T cell), CD3(+)CD38(+) (immature T cell), and CD3(+)CD45RO(+) (memory T cell) cells was significantly increased (p < 0.05), whereas proportion of CD3(+)CD45RA(+) (naive T cell) and CD16(+)CD56(+) (NK cell) cells was significantly decreased (p < 0.05). In HCBP supplemented medium, the proportion of CD3(+)CD8(+), CD3(+)CD25(+), CD3(+)CD45RA(+), and CD3(+)CD45RO(+) cells was significantly increased (p < 0.05). The proportion of CD3(+)CD4(+), CD3(+)CD45RO(+) and CD3(+)CD38(+) cells was significantly higher, but proportion of CD3(+)CD45RA(+) and CD3(+)CD8(+) cells was significantly lower in FBS compared with HCBP supplemented medium (p < 0.05). Our results support the feasibility of ex vivo expansion of human umbilical cord blood T lymphocytes in medium supplemented with HCBP for future adoptive cellular immunotherapy.     

异基因造血干细胞移植后免疫重建临床研究

为探讨异基因外周血造血干细胞移植（allo—PBSCT）后12个月内患者免疫重建特点及其与供受者年龄、供受者间HLA相容性、移植物抗宿主病（GVHD）及病毒感染的关系，随访37例异基因造血干细胞移植患者，用流式细胞术测定移植后1、3、6及12个月的T细胞亚群（CD3^＋、CD4^＋、CD8^＋）、B细胞（CD19^＋）及NK（CD16^＋CD56^＋）细胞，用散射比浊法检测免疫球蛋白IgG、IgA及IgM水平。结果显示，移植后1个月CD3^＋细胞的百分比为（47．5±23．2）％，3个月为（75．1±6．4）％，6个月为（69．7±12）％，12个月为（71．7±4．2）％。移植后1个月CD4^＋细胞百分比为（13．3±6．4）％，3个月为（20．2±11．4）％，6个月为（18．4±9．3）％，12个月为（29．1±8．7）％；移植后1个月CD8^＋细胞百分比为（43．1±17．4）％，3个月为（42．6±16．9）％，6个月为（46．9±10．3）％，12个月为（47±5．6）％；移植后1个月CD16^＋CD56^＋细胞百分比为（14．4±8．4）％，3个月为（15．9±7．6）％，6个月为（14．7±6．6）％，12个月为（13．6±3．4）％；移植后1个月CD19^＋细胞百分比为（6．4±5．6）％；3个月为（11．7±2．4）％，6个月为（13．3±7．3）％，12个月为（16．7±5．7）％。血清免疫球蛋白检测结果显示：移植后1个月IgA为（0．37±0．14）g／L，3个月为（0．28±0．21）g／L，6个月为（0．42±0．18）g／L，12个月为（0．53±0．34）g／L；移植后1个月IgG为（12．7±3．8）g/L，3个月为（16．3±5．2）g／L，6个月为（14．3±6．2）g/L，12个月为（15．4±6．9）g／L。移植后1个月IgM为（0．56±0．24）g／L，3个月为（0．64±0．16）g／L，6个月为（1．1±0．35）g／L，12个月为（1．2±0．28）g／L。大于等于45岁的患者T细胞亚群检测和血清免疫球蛋白与小于45岁患者比较无差异。发生慢性GVHD的患者移植后12?     

体外扩增高纯度的人外周血来源的NK细胞的研究

本研究探讨从人外周血中分选及扩增高纯度NK细胞的优化技术。先用miniMACS及阴性免疫磁珠分选方法,从外周血单个核细胞(PBMNC)得到纯化的NK细胞,随后在干细胞培液基条件下,通过IL-2、IL-12和IL-15等细胞因子的不同组合将培养体系分为IL-2组、IL2+IL12组、IL2+IL15组、IL2+IL15+IL12组和对照组(不加任何细胞因子),分别培养15天,每3天半量换液并补充细胞因子;检测分选及扩增前后(CD3-CD56+)NK细胞含量、扩增倍数及扩增前后各组在不同效靶比下的杀伤率。结果显示经:miniMACS阴性免疫磁珠分选后(CD3-CD56+)NK细胞含量由分选前的11.19±5.25%提高到94.23±3.50%。培养15天后除对照组(CD3-CD56+)NK细胞纯度略下降外,其余4组与扩增前无显著性差异(P>0.05)。在IL-2、IL2+IL12、IL2+IL15、IL2+IL15+IL12培养体系中,NK细胞扩增倍数分别为15.43±1.08,19.87±3.87,50.46±4.31和52.35±6.72,均显著高于对照组6.14±1.0(P<0.01),但IL2+IL15与IL2+IL15+IL12组间未见显著差异(P>0.05)。各组扩增的NK细胞对K562细胞的杀伤率均较扩增前增强,在不同效靶比下IL2+IL15、IL2+IL15+IL12组对K562细胞的杀伤率显著高于其他组,但两组间无显著性差异(P>0.05)。结论:经miniMACS免疫磁珠阴性分选得少量NK细胞后,应用IL2+IL15培养条件是获得高纯度NK细胞的简单有效方法。     

CD34+ progenitors and colony-forming units-granulocyte macrophage are recruited during large-volume leukapheresis and concentrated by counterflow centrifugal elutriation

The recruitment of mononuclear cells (MNCs), colony-forming units- granulocyte macrophage (CFU-GM), lymphocyte subpopulations, and CD34+ progenitor cells was studied during large-volume (15-25 L blood processed) peripheral blood stem cell (PBSC) harvests. Normal donors (n = 13) underwent a 4-hour leukapheresis designed to maximize PBSC yield (blood flow rate, 85 mL/min). Mean (+/− SD) volume processed was 17.7 +/− 0.4 L, and yield was 2.4 +/− 0.7 × 10(10) white cells containing 99 percent MNCs and 1.3 mL red cells per L of blood processed. Postapheresis hematocrit, platelets, and MNCs were reduced from preapheresis values by 7, 35, and 23 percent, respectively (p < 0.05). In nine donors, the component was collected as four 1-hour samples, and culturing of CFU-GM and flow cytometric analysis of lymphocyte subpopulations and CD34+/HLA-DR+ cells were done in individual samples. Total CFU-GM were 2.4 +/− 1.4 × 10(6) (3.0 +/− 1.8 × 10(4) CFU-GM/kg) and lymphocytes were 20.8 × 10(9), with 75 percent CD3+ T cells, 10 percent CD19/CD20+ B cells, and 17 percent natural killer cells. A more than twofold increase in CFU-GM and CD34+ cells was noted over the course of the 4-hour procedure (p < 0.05). In four donors, the leukapheresis component underwent counterflow centrifugal elutriation (CCE), which separated it into four fractions in an attempt to concentrate CD34+ and CFU-GM progenitors and to deplete T-lymphocytes on a large scale. There was a 1.8-, 4.6-, 3.9-, and 0.32-fold increase in CFU-GM in the four fractions relative to the unseparated component.(ABSTRACT TRUNCATED AT 250 WORDS)     

联合使用干细胞因子、FLT3配基与白介素2,7,15体外扩增人脐血来源CIK/NK细胞

通过干细胞因子 (SCF)、FLT3配基 (FL)联合白介素 (IL) 2 ,7,15等的不同组合体系体外扩增人脐血来源的CIK NK细胞 (CB CIK NK) ,探讨不同培养方式对CB CIK NK细胞诱导、扩增产率的影响。按诱导扩增体系的不同分 3组 :A组 (SCF IL2 IL7 IL15 ) ,B组 (SCF FL IL2 IL7 IL15 )和C组 (IL2 IL7 IL15 ,对照组 ) ,培养 2 1天 ,检测CD3 CD5 6 CIK细胞、CD3- CD5 6 NK细胞比例和扩增倍数。结果表明 :经 2 1天培养 ,A ,B及C组CIK细胞比例分别为 (19.84± 2 .93) %、(2 6 .2 0± 4 .0 5 ) %及 (2 4 .0 3± 4 .99) % ;而NK细胞的比例A、B及C组比例分别为 (4 9.6 0± 1.4 0 ) %、(5 1.16± 6 .4 5 ) %及 (30 .85± 8.12 ) %。含SCF FL的B组扩增效率最高 ,其中CIK细胞的扩增倍数由对照组 (C组 )的 (5 75 81± 2 2 1.72 )倍增加至 (796 .0 9± 2 78.4 7)倍 (最高为 1313倍 ) ;NK细胞由对照组 (C组 )的 (30 .39± 14 .4 7)倍增加至 (6 5 .85± 30 .83)倍 (最高为 12 1.0 6倍 )。结论 :通过合适的细胞因子组合可以同时扩增CB来源的CIK NK细胞 ;联合诱导、扩增CB CIK NK细胞以采用含SCF FL IL2 IL7 IL15的培养体系为佳。     

Differential effects of IL-2 incubation on hematopoietic potential of autologous bone marrow and mobilized PBSC from patients with hematologic malignancies

Culturing of hematopoietic progenitor cells for 24 h with IL-2 generates cytotoxic effector cells that mediate in vitro and possibly in vivo antitumor activity. We examined the effect of IL-2 incubation on progenitor cells from 24 patients with hematologic malignancies using paired autologous bone marrow (ABM) and PBSC to determine differences in hematopoietic potential. Cells were cryopreserved and stored in liquid nitrogen until conditioning therapy was completed. After thawing, cells were incubated with IL-2 for 24 h at 37 degrees C. Paired samples of ABM and PBSC from the same patient were analyzed for nucleated and mononuclear cell number, CD34 antigen expression, and colony-forming unit (CFU) activity before and after IL-2 incubation. There was a significant decrease in the average number of mononuclear cells (MNC) (x10(8)/kg) (<0.001) and CD34+ cells (x10(6)/kg) (0.006) from both ABM and PBSC after 24 h IL-2 culture (ABM MNC: 0.6+/-0.1 vs. 0.4+/-0.0, p = <0.001; PBSC MNC: 4.4+/-0.5 vs. 3.7+/-0.4, p = 0.03; ABM CD34+: 2.4+/-0.5 vs. 1.3+/-0.3, p = <0.001; PBSC CD34+: 6.6+/-1.8 vs. 5.0+/-1.2, p = 0.05). However, whereas ABM CFU/10(5) MNC plated (269.3+/-47.2 vs. 385.6+/-70.6) were significantly increased (p = 0.005), there was no change in PBSC CFU (271.0+/-47.2 vs. 257.3+/-48.5). The mean plating efficiency (%) of ABM CD34+ cells was markedly increased after IL-2 incubation (10.1+/-3.3 vs. 19.0+/-7.2, p = 0.04), although it was lower than that of PBSC CD34+ cells, which did not change significantly in culture (29.4+/-5.5 vs. 36.0+/-6.5). Additional work is in progress to determine the cause and significance of the enhanced plating efficiency of the ABM progenitor cells.     

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.     

脐血CD133^＋细胞体外扩增巨核系祖细胞的研究

本研究探讨脐血CD133^＋（UCB—CD133^＋）细胞体外扩增巨核系祖细胞的能力和最佳收获时间。采用免疫磁珠激活细胞分选系统（MACS）分选UCB—CD133^＋细胞，将纯化的UCB—CD133^＋细胞接种于含TPO、IL-3和SCF的无血清液体培养体系中体外扩增巨核系祖细胞，在培养第7、10和14天进行细胞计数，流式细胞仪检测扩增过程中CD133、CD34、CD41抗原表达的动态变化，并采用半固体法对不同扩增阶段的细胞进行巨核祖细胞集落形成单位（CFU—MK）培养。结果表明：培养至第7天时，UCB—CD133^＋细胞扩增效果最佳，扩增了8、2-1-2．2倍；培养至第14天，细胞总数扩增了116倍；培养至10天时，平均1个CD133^＋细胞所产生的CD133^＋CD41^＋和CD34^＋CD41^＋细胞数最多，分剐为2．5±0．9和2．6±0.5个，所产生的CD41^＋细胞为20．3±5、9个；扩增前后的UCB—CD133^＋细胞均能形成CFU—MK，扩增第10天的UCB—CD133^＋细胞所形成的CFU—MK总数最多，CFU—MK扩增倍数为59．5±11．8倍。巨核细胞免疫组织化学染色显示，扩增后的巨核系细胞多呈幼稚状态，未见血小板形成。结论：UCB—CD133^＋细胞具有较强的体外扩增巨核系祖细胞的能力，培养第10天扩增效能最佳。     

Rapid generation of CMV pp65-specific T cells for immunotherapy

Adoptive immunotherapy with cytomegalovirus (CMV)-specific cytotoxic T lymphocytes (CTL) has been shown to be an effective means of restoring cellular immunity to this virus and preventing CMV infection after allogeneic stem cell transplantation. Problems with current strategies include requirements for generating dendritic cells or other antigen presenting cells for stimulating CTL and the time needed for cell culture. The adherent cell fraction of peripheral blood mononuclear cells from 6 CMV seropositive donors were pulsed with pooled CMV pp65 peptides and incubated with nonadherent peripheral blood lymphocytes. CTL lacking specific cytotoxicity to pp65 were restimulated at day 10 of culture using peptide pulsed adherent cells. Of the 6 CMV seropositive donors tested, 5 had specific cytotoxicity to CMV pp65 (range 31% to 75%), with no alloreactivity. The resulting pp65-specific CTL consisted of a mixture of CD4 and CD8 cells, with 1% to 29% of CD8 cells and 0.5% to 10% CD4 cells making interferon-gamma (IFN-gamma) in response to pp65. The donor from whom we could not detect CMV-specific cytotoxicity had detectable CD4 and CD8 CMV pp65 CTL by intracellular cytokine analysis for IFN-gamma. Using this simplified strategy for expanding CMV pp65 CTL, adoptive immunotherapy with pp65-specific CTL could be made available in a more timely manner for patients who have persistent or therapy refractory CMV infections.     

Mobilization of peripheral blood stem cells with paclitaxel and rhG-CSF in high-risk breast cancer patients

Preclinical studies have demonstrated the rapid and efficient mobilization of hematopoietic peripheral blood stem cells (PBSC) in a mouse model using the combination of paclitaxel with recombinant human granulocyte colony-stimulating factor (rhG-CSF). On the basis of these results, a clinical trial was initiated using rhG-CSF with paclitaxel for PBSC mobilization in high-risk breast cancer patients. The mobilized PBSC were evaluated for CD34(+) cell number, mononuclear cell content, and clonogenic potential. One-hundred and seventeen breast cancer patients received paclitaxel (300 mg/m(2)) administered as a 24-h continuous intravenous infusion. Forty-eight hours after completing paclitaxel, rhG-CSF (5 microg/kg) was initiated and continued until completion of PBSC collection. Leukapheresis was initiated once the white blood cell count reached 1.0 x 10(9)/L. Each collection was evaluated for the numbers of mononuclear cells (MNC) and CD34(+) cells. Clonogenic potential was enumerated using colony-forming units-granulocyte-macrophage (CFU-GM) and burst-forming units-erythroid (BFU-E). Patients receiving paclitaxel with rhG-CSF mobilized a large number of mononuclear cells/apheresis (mean, 3.7 x 10(8); range, 3.3-4.1) and CD34(+) cells/apheresis (mean, 7.2 x 10(6); range, 6.1-8.4). The average number of leukophereses needed was 1.8 (mean, range 1.6-2.0). Colony growth was normal with 178.9 x 10(5) and 214.8 x 10(5) colonies counted in CFU-GM and BFU-E assays, respectively. Patients engrafted platelets and neutrophils on day 10 following transplantation. In conclusion, PBSC mobilization with paclitaxel and rhG-CSF results in a large number of mononuclear cells and CD34(+) cells with normal clonogenic potential. The cells engraft normally following high-dose chemotherapy and autologous stem cell transplantation in high-risk breast cancer patients. These results demonstrate that paclitaxel with rhG-CSF is an efficient mobilizing agent in high-risk breast cancer patients.     

Harvesting of CD34 antigen-expressing cells with a new programme for the collection of mononuclear cells with use of the Amicus (Baxter) blood cell separator

A study was performed to evaluate a new programme for peripheral blood stem cell (PBSC) collection with the use of the Amicus (Baxter) blood cell separator. Healthy donors (n = 9) and oncology patients (n = 21) scheduled for PBSC transplant were studied. Ten PBSC harvests were performed in the donors and 30 in the patients. A median of 6.37 x 106 CD34+ cells per kg recipient body weight (range 3.08-11.06 x 106) were collected from the donors in a product weight of 169.5 g (118-186). From the patients, 6.26 x 106 CD34+ cells per kg body weight (range 0.2-53.6 x 106) were harvested in a product weighing 121.5 g (range 92-190). The median platelet contamination was 0.93 x 1011 (range 0.45-1.23 x 1011) per donor product and 0.2 x 1011 (range 0.05-0.86 x 1011) per patient product. No severe side effects were observed during or after the PBSC collection procedures.     

Adoptive transfer of effector CD8+ T cells derived from central memory cells establishes persistent T cell memory in primates

The adoptive transfer of antigen-specific T cells that have been expanded ex vivo is being actively pursued to treat infections and malignancy in humans. The T cell populations that are available for adoptive immunotherapy include both effector memory and central memory cells, and these differ in phenotype, function, and homing. The efficacy of adoptive immunotherapy requires that transferred T cells persist in vivo, but identifying T cells that can reproducibly survive in vivo after they have been numerically expanded by in vitro culture has proven difficult. Here we show that in macaques, antigen-specific CD8(+) T cell clones derived from central memory T cells, but not effector memory T cells, persisted long-term in vivo, reacquired phenotypic and functional properties of memory T cells, and occupied memory T cell niches. These results demonstrate that clonally derived CD8+ T cells isolated from central memory T cells are distinct from those derived from effector memory T cells and retain an intrinsic capacity that enables them to survive after adoptive transfer and revert to the memory cell pool. These results could have significant implications for the selection of T cells to expand or to engineer for adoptive immunotherapy of human infections or malignancy.     

Abrogating Cbl-b in effector CD8(+) T cells improves the efficacy of adoptive therapy of leukemia in mice

The clinical use of adoptive immunotherapy with tumor-reactive T cells to treat established cancers is limited in part by the poor in vivo survival and function of the transferred T cells. Although administration of exogenous cytokines such as IL-2 can promote T cell survival, such strategies have many nonspecific activities and are often associated with toxicity. We show here that abrogating expression of Casitas B-lineage lymphoma b (Cbl-b), a negative regulator of lymphocyte activation, in tumor-reactive CD8(+) T cells expanded ex vivo increased the efficacy of adoptive immunotherapy of disseminated leukemia in mice. Mechanistically, Cbl-b abrogation bypassed the requirement for exogenous IL-2 administration for tumor eradication in vivo. In addition, CD8(+) T cells lacking Cbl-b demonstrated a lower threshold for activation, better survival following target recognition and stimulation, and enhanced proliferative responses as a result of both IL-2-dependent and -independent pathways. Importantly, siRNA knockdown of Cbl-b in human CD8(+)CD28- effector T cell clones similarly restored IL-2 production and proliferation following target recognition independent of exogenous IL-2, enhanced IFN-γ production, and increased target avidity. Thus, abrogating Cbl-b expression in effector T cells may improve the efficacy of adoptive therapy of some human malignancies.