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.     

人骨髓来源内皮祖细胞的分离培养及生物学特性的鉴定

目的建立人骨髓来源的内皮祖细胞（EPCs）分离、培养、诱导分化与鉴定的方法,并探讨其生物学特性。方法收集腰椎间盘退变性疾病患者的髂骨骨髓24例,密度梯度离心法分离的单个核细胞接种于纤维连接蛋白包被的培养瓶,贴壁培养,EGM-2培养基诱导扩增EPCs。Dil-ac-LDL、FITC．UEA—I荧光双标、流式细胞术鉴定EPCs,计算纯度。透射电镜和管腔形成实验鉴定EPCs向血管内皮细胞（ECs）分化的能力。结果培养72h换液时可见贴壁细胞形成明显细胞克隆集落,第5天集落数增加,1周后细胞融合达80％,至第14天细胞呈铺路石样排列。培养至第7天细胞Dil-ac-LDL、FITC-UEA-I双荧光染色阳性率为（95．1±4．0）％,CD133、CD34、KDR、VE。Cadherin标记阳性率分别为（18．5±4．4）％、（45．4±7．8）％、（66．7±7．2）％、（20．5±5-3）％。培养第10天细胞透射电镜显示成熟血管ECs特有的Weibel-Palade小体。管腔形成实验表明,体外ECMatrix上培养7至12d的EPCs具有较强的管腔形成能力。结论采用密度梯度离心与贴壁培养法分离、培养的人髂骨骨髓来源的单个核细胞在特定诱导条件下可分化为EPCs,纯度较高,稳定性和重复性好。EPCs培养7至12d,具有良好的管腔形成能力。     

骨髓单个核细胞和骨髓源内皮祖细胞移植促进血流重建的比较研究

目的 比较骨髓单个核细胞(MNCs)和骨髓源内皮祖细胞(EPCs)移植促进血流重建的效果,探讨非内皮祖细胞在血流重建中的作用.方法 获取Lewis大鼠骨髓MNCs,部分MNCs在体外诱导分化为EPCs.采用Lewis大鼠建立单侧后肢缺血模型.建模后3 d,将模型鼠随机分为3组:(1)对照组(n=6),将0.8 mL D-Hank's液注入对照组大鼠缺血侧后肢;(2)MNC组(n=6),将8×10~6个骨髓MNC植入MNC组大鼠缺血侧后肢;(3)EPC组(n=6),将体外培养的8 × 10~6个EPC植入EPC组大鼠缺血侧后肢.细胞移植后3周行大鼠后肢动脉造影,检测缺血侧后肢侧支血管数;切取缺血侧后肢腓肠肌,分别行CD31和α-SMA免疫组化染色,计算毛细血管密度和小动脉密度.结果 MNC组毛细血管密度与EPC组差异无统计学意义[(31.67 ± 7.87)个/HP vs.(32.83±5.38)个/HP,P＞0.05].而均高于对照组(19.67 ± 4.80个/HP)(P＜0.05);MNC组侧支血管数与EPC组差异无统计学意义[(4.17±0.75)个vs.(4.50 4±1.38)个,P＞0.05],但均高于对照组[(2.50 ± 1.5)个](P＜0.05);MNC组小动脉密度与EPC组差异无统计学意义[(4.83 ± 1.47)个vs.(5.50 ± 2.35)个,P＞0.05],亦均高于对照组[(2.17±0.98)个](P＜0.05).结论 在骨髓干细胞移植治疗肢体缺血性疾病中,非内皮祖细胞在血流重建中所起的作用与EPC相似.     

Risk of viral transmission via bone marrow progenitor cells versus umbilical cord blood hematopoietic stem cells in bone marrow transplantation

Hematopoietic stem cell transplantation (HSCT) is the treatment of choice for children and certain adults with malignant and nonmalignant hematologic disease. Since viral infections are the major problem, this study examined those that might potentially be transmitted to HSCT recipients via bone marrow (BM) versus umbilical cord blood (UCB). BM progenitor cells, peripheral blood leukocytes, and plasma samples were collected from 30 allogenic BM donors. Umbilical cord blood hematopoietic stem cells and plasma samples were also collected from 34 UCB donors. Viral DNA extracted and purified from collected specimens was processed using nested polymerase chain reactions (PCR) to detect human parvovirus B19 (HPV B19), human herpesvirus-6 (HHV-6), varicella-zoster virus (VZV), human cytomegalovirus (HCMV), and Epstein-Barr virus (EBV). The prevalences of HCMV DNA in collected BM progenitor cells versus UCB hematopoietic stem cells were 73% versus 23%, respectively. Conversely, HHV-6 DNA was not detected in any collected specimen by simple PCR. Distribution of the other investigated virus DNAs except EBV DNA was similar in specimens collected from both groups. EBV DNA was not determined in UCB hematopoietic stem cells. The results indicate that the risk of viral transmission to BM transplant recipients via UCB hematopoietic stem cells is less than that with BM progenitor cells.     

大鼠未成熟树突状细胞体外扩增及功能鉴定

摘要：目的 探讨建立大鼠体外大量扩增未成熟树突状细胞(DC) 的方法, 以及不同剂量粒细胞巨噬细胞集落刺激因子(GM CSF)对大鼠DC分化成熟的影响。方法 分离纯化并扩增大鼠骨髓细胞，用不同剂量GM CSF培养,6 d 和10 d后收集悬浮细胞进行扫描电镜观察和免疫表型鉴定,并行混合淋巴细胞反应,观察其诱导未致敏T 淋巴细胞增殖的情况。结果 小剂量GM CSF 培养获得的DC(GMlowDC) 形态上具有DC 的典型特征,在细胞表型、细胞功能试验上具有未成熟的特性,具有DC 的典型特征,细胞表面高表达CD11c,低表达CD80，CD86及MHC II类分子,与大剂量GM CSF加IL 4的联合组培养获得的DC( GMhighDC) 相比,其体外刺激未致敏T 淋巴细胞的增殖能力较弱.结论 笔者所建立的培养未成熟DC 的方法是可行的；GM CSF的剂量与细胞的成熟程度相关。     

低氧作用下肾小管上皮细胞对大鼠骨髓内皮祖细胞的影响

肾小管周毛细血管丢失和低氧是小管间质损伤及纤维化的共同通路,因此,重建间质毛细血管,改善间质低氧是治疗慢性肾脏病(CKD)的又一重要途经~([1]).内皮祖细胞(EPC)具有强大的成血管能力~([2]).研究肾小管上皮细胞(RTEC)与EPC间的相互作用,对于重建小管周毛细血管具有重要意义.本课题拟在体外研究低氧作用下的RTEC对EPC的归巢、成血管能力的影响和可能的机制.     

Immunosuppressive and trafficking properties of donor splenic and bone marrow dendritic cells

BACKGROUND: Infusion of donor dendritic cells (DC) has been shown to prolong allograft survival in a number of models. However, many regimens that utilize donor DC do not consistently produced tolerance or long-term allograft survival. We hypothesized that one factor limiting the therapeutic effect of donor DC is their relative inability to traffic to recipient peripheral lymph nodes and inhibit the function of resident alloreactive T cells. METHODS: Donor strain DC isolated from the spleens or bone marrow of Flt3L-treated mice were transferred intravenously into recipients at the time of skin grafting. Where indicated, recipients were treated with an anti-CD40L antibody and CTLA4-Ig. RESULTS: Infusion of donor DC together with costimulatory blockade promoted donor-specific prolongation of skin allograft survival in mice. Perhaps due to their more immature phenotype, bone marrow DC trafficked more effectively to the spleen, bone marrow, and thymus and were associated with significantly longer allograft survival than were splenic DC. Neither population of DC trafficked well to peripheral lymph nodes. Consistent with our hypothesis, splenic but not lymph node T cells from DC-treated recipients displayed donor-specific hyporesponsiveness in vitro. CONCLUSION: These data suggest that one factor contributing to rejection following treatment with donor DC plus costimulation blockade is the persistence of donor-reactive T cells within the recipient's secondary lymphoid structures. Strategies to improve DC trafficking to these structures may enhance their therapeutic effect.     

Long-term effects of recombinant human erythropoietin on bone marrow progenitor cells

Eleven uraemic patients were treated with recombinant humanerythropoietin (rHuEpo). Seven haemodialysis patients and fourperitoneal dialysis patients received a starting dose of 80IU/kg i.v. and 40 IU/kg s.c. respectively, thrice weekly. Thenumber of burst-forming-unit erythroid (BFU-E), colony-forming-uniterythroid (CFU-E), granulocyte-monocyte (CFU-GM) and megakaryocyte(CFU-Mk) were assayed 2 weeks before (DO), and 1 (M1) and 6months (M6) after the initiation of rHuEpo treatment by meansof a commonly applied in-vitro clonal assay. All the patientsshowed the same haematopoietic response. A significant increaseof CFU-E and CFU-Mk could be observed within 1 month of treatment.At this time, no significant modification was observed in BFU-Eand CFU-GM number. At the 6th month the increase of CFU-E wasmaintained, whereas a significant fall of BFU-E, CFU-GM andCFU-Mk was observed. These results suggest that in-vivo effects of rHuEpo are notrestricted to the erythroid lineage but that erythropoietinmight also act as a co-factor of megakar-yopoiesis. In the longterm erythropoietin might induce erythroid differentiation inmultipotent progenitor cells at the expense of the non-erythroidprogenitors.     

Potent skin allograft survival prolongation using a committed progenitor fraction of bone marrow in mice

BACKGROUND: The infusion of donor bone marrow (BM) into mice conditioned with antilymphocyte serum (ALS) and sirolimus (Sir) prolongs skin allograft survival and produces chimerism. This study identifies the BM cell(s) responsible for this effect and determines whether enrichment for these cells will improve efficacy. METHODS: Skin grafts from BALB/C mice were transplanted into C57BL/6 or C57BL/10 recipients by using ALS, Sir, and BM (or fractions). BM was fractionated by using immunomagnetic beads. Flow cytometry was used for phenotyping and detecting chimerism. RESULTS: The median graft survival in mice receiving 25 million BM cells was 61 days. Infusion of BM depleted of cells expressing CD19, CD3, CD11c, and c-kit had no effect on median graft survival, whereas infusion of fractions enriched for those cells resulted in median graft survival of 38, 48, 28, and 83 days, respectively. The administration of higher doses (4 x 10(6) and 8x10(6)) of fractions enriched for c-kit resulted in median graft survival of 124 and 197 days, respectively, without chimerism. This favorably compared with mice receiving 150 million BM cells that demonstrated transient mixed chimerism and a median graft survival of 190 days. The majority of cells in the c-kit+-enriched fraction expressed lineage markers. Removal of lineage positive cells from BM before infusion shortened median graft survival (90 days), indicating that the c-kit+ lin+ population is largely responsible for prolongation of graft survival. CONCLUSIONS: Cells enriched for C-kit+lin+ constitute approximately 5% of murine BM cells and are more potent than whole BM at prolonging skin allograft survival in mice treated with ALS and Sir.     

The mobilization and effect of endogenous bone marrow progenitor cells in diabetic wound healing

Diabetic patients suffer from impaired wound healing, characterized by only modest angiogenesis and cell proliferation. Stem cells may stimulate healing, but little is known about the kinetics of mobilization and function of bone marrow progenitor cells (BM-PCs) during diabetic wound repair. The objective of this study was to investigate the kinetics of BM-PC mobilization and their role during early diabetic wound repair in diabetic db/db mice. After wounding, circulating hematopoietic stem cells (Lin(-)c-Kit(+)Sca-1(+)) stably increased in the periphery and lymphoid tissue of db/db mice compared to unwounded controls. Peripheral endothelial progenitor cells (CD34(+)VEGFR(+)) were 2.5- and 3.5-fold increased on days 6 and 10 after wounding, respectively. Targeting the CXCR4-CXCL12 axis induced an increased release and engraftment of endogenous BM-PCs that was paralleled by an increased expression of CXCL12/SDF-1α in the wounds. Increased levels of peripheral and engrafted BM-PCs corresponded to stimulated angiogenesis and cell proliferation, while the addition of an agonist (GM-CSF) or an antagonist (ACK2) did not further modulate wound healing. Macroscopic histological correlations showed that increased levels of stem cells corresponded to higher levels of wound reepithelialization. After wounding, a natural release of endogenous BM-PCs was shown in diabetic mice, but only low levels of these cells homed in the healing tissue. Higher levels of CXCL12/SDF-1α and circulating stem cells were required to enhance their engraftment and biological effects. Despite controversial data about the functional impairment of diabetic BM-PCs, in this model our data showed a residual capacity of these cells to trigger angiogenesis and cell proliferation.     

Giant cell formation in rabbit long-term bone marrow cultures: immunological and functional studies

A method for the long-term culture of rabbit newborn bone marrow has been developed. It is characterized by the rapid appearance of an adherent, adipocyte-containing stromal layer, proliferation of mature myeloid cells, and the formation of numerous, large multinucleate giant cells. By the combined use of morphological, immunological, and functional criteria these giant cells have been characterized as macrophage polykaryons and not osteoclastic giant cells. We conclude that long-term bone marrow culture in the rabbit favors the proliferation, maturation, and fusion of macrophage, but not osteoclast, precursors--new experimental models will have to be developed to enable the developmental biology of osteoclasts to be studied in the rabbit.     

Phenotype and function of T lymphocytes infiltrating the skin during graft-versus-host disease following allogeneic bone marrow transplantation

Seven lymphocyte populations were expanded from skin samples of patients with acute or chronic GVHD following allogeneic genotypically identical BMT. After amplification without in vitro antigenic stimulation or addition of mitogens, 5 of the 7 cell lines showed a large majority of mature CD4+ T cells (in contrast to published immunopathological data). One cell line showed an equal number of CD4+ and CD8+ cells, and another a predominance of CD4+ cells along with a large number of cells with a phenotype suggestive of non-MHC-restricted CTLs. After in vitro antigenic stimulation, various cytotoxicity patterns were seen: specific antihost cytotoxicity was seen in half the cell lines, NK activity was seen in 5 of the 7 lines, and a strong LAK activity was seen in 1 of the 7 cell lines. These results point to a diversity of cytotoxic effectors involved locally in GVHD and emphasize the need for further study of these local events. The cell lines established now constitute basic functional material for the in vitro study of cellular and humoral interactions at the site of GVHD lesions.     

骨髓基质干细胞定向分化为神经细胞及分化后细胞功能特征的研究

目的 探讨骨髓基质干细胞(BMSCs)定向分化为神经细胞的潜能及分化后细胞的功能特征.方法 体外分离、扩增、纯化Sprague-Dawley大鼠BMSCs,取第6代细胞接种并随机分为4组,实验组A、B、C组开始每组加预诱导夜(含预诱导剂碱性成纤维细胞生长因子和表皮生长因子),6d后A组继续加预诱导夜,其余两组在预诱导后加定向诱导剂(音猬因子和维甲酸)时选择是否保留预诱导液分为B组(保留)和C组(去除);D组不做任何干预,为空白对照组.采用细胞免疫荧光化学法检测分化后神经样细胞的形态和功能标志.结果 接种后的细胞迅速贴壁,加预诱导液6 d细胞增殖迅速,且可以观察到有类似神经干细胞的克隆团形成.在诱导剂的特定组合和时序的诱导下,A、B、C组均出现胞体收缩和突起伸出,呈现神经元细胞样改变.D组细胞形态基本没有变化.6～12 d,B组微管相关蛋白-2(MAP-2)阳性细胞率为59.17%±1.84%,胶质酸性蛋白(GFAP)阳性细胞率为22.10%±1.03%;C组MAP-2阳性细胞率为29.35%±4.85%,GFAP为36.35%±4.85%,A组和D组均未检测到上述细胞标志物.12～18 d,A组仅出现少量GFAP阳性细胞;B组MAP-2、GFAP阳性细胞率分别为72.54%±1.02%、21.54%±1.02%;C组MAP-2、GFAP阳性细胞率分别为31.02%±2.37%、23.45%±3.74%.神经细胞的功能标志胆碱乙酰转移酶、囊泡乙酰胆碱通道只有B组表达,12～18 d后阳性细胞率分别为45.11%±3.04%、28.22%±1.72%.结论 BMSCs在体外能定向诱导为具有一定功能的神经细胞,为脊髓损伤后细胞移植治疗奠定了基础.