Adherent cells in granulocyte-macrophage colony-stimulating factor-induced bone marrow-derived dendritic cell culture system are qualified dendritic cells

A widely-used method for generating dendritic cell (DC) is to culture bone marrow cells in granulocyte-macrophage colony-stimulating factor (GM-CSF)-containing medium for 6-10 days. Usually, non-adherent cells are used as qualified dendritic cells while the adherent ones are discarded as “non-dendritic cells” or macrophages. In this study, we show that the adherent cells are nearly identical to the non-adherent cells in both dendritic cell surface markers expression and main dendritic cell-related functions, hence to prove that these “junk cells” are actually qualified dendritic cells.     

负载供者抗原的第三方树突状细胞延长大鼠移植心脏存活

目的观察负载供者抗原第三方未成熟DC对大鼠同种异体移植心脏存活期的影响。方法培养骨髓来源第三方大鼠未成熟DC,负载供者抗原,CTLA-4 Ig致耐受处理。建立大鼠心脏腹部移植模型,A组：心脏移植;B组：心脏移植,术前输注供者源未成熟DC;C组：心脏移植,术前输注第三方未成熟DC;D组：心脏移植,术前输注负载供者抗原致耐受第三方未成熟DC。分别行移植心病理、IFNγmRNA表达和移植心存活时间观察。结果D组的移植心病理改变轻,IFNγmRNA表达下调,移植心脏存活时间显著延长。结论负载供者抗原第三方致耐受未成熟DC能够诱导供者特异性免疫耐受,明显延长大鼠移植心脏存活时间。     

多能干细胞分化来源视网膜色素上皮细胞移植治疗视网膜变性研究进展

视网膜色素上皮（RPE）对视觉功能的维持起着至关重要的作用。视网膜变性是全球不可治愈性致盲疾病的重要原因,它由视网膜色素上皮功能失常所引起。因此,视网膜色素上皮移植是视网膜变性患者恢复视力的一种最有前景的手段之一。随着干细胞技术的快速发展,从多能干细胞（PSC）到有功能的视网膜色素上皮细胞的体外分化诱导技术已经成熟,其中包括胚胎干细胞（ESCs）和诱导多能干细胞（iPSCs）等。此外,从患者特异性iPSCs分化而来的RPE更能用于阐明发病机理并有针对性地个体治疗。更值得一提的是,经诱导得到RPE的移植不论在动物模型中,还是在临床试验里都已经得到了可喜的治疗效果。本文回顾PSC来源RPE干预治疗视网膜变性的最新研究进展。     

The effect of anti-VEGF therapy on immature myeloid cell and dendritic cells in cancer patients

Impairment of dendritic cells (DC), the most effective activators of anticancer immune responses, is one mechanism for defective antitumor immunity, but the causes of DC impairment are incompletely understood. We evaluated the association of impaired DC differentiation with angiogenesis-associated molecules D-dimer, vascular endothelial growth factor (VEGF), urokinase plasminogen activator (uPA), and plasminogen activator inhibitor (PAI-1) in peripheral blood from 41 patients with lung, breast, and colorectal carcinoma. Subsequently, we studied the effect of administration of the anti-VEGF antibody (bevacizumab) on DC maturation and function in vivo. Compared with healthy volunteers, cancer patients had a bias toward the immunoregulatory DC2, had deficits in DC maturation after overnight in vitro culture, and had a significant increase in immature myeloid cell progenitors of DC (0.50 +/- 0.31% vs. 0.32 +/- 0.16% of peripheral blood mononuclear cells, respectively, P = 0.011). A positive correlation was found between the percentage of DC2 and PAI-1 (R = 0.50) and between immature myeloid cells and VEGF (R = 0.52). Bevacizumab administration to cancer patients was associated with a decrease in the accumulation of immature progenitor cells (0.39 +/- 0.30% vs. 0.27 +/- 0.24%, P = 0.012) and induced a modest increase in the DC population in peripheral blood (0.47 +/- 0.23% vs. 0.53 +/- 0.30%). Moreover, anti-VEGF antibody treatment enhanced allo-stimulatory capacity of DC and T cell proliferation against recall antigens. These data suggest that DC differentiation is negatively associated with VEGF levels and may be one explanation for impaired anticancer immunity, especially in patients with advanced malignancies.     

Tumor cells prevent mouse dendritic cell maturation induced by TLR ligands

Tumor cells can evade the immune system through several mechanisms, one of which is to block DC maturation. It has been suggested that signaling via Toll-like receptors (TLR) may be involved in the induction of prophylactic anti-cancer immunity and in the treatment of established tumors. In the present study we found that high numbers of tumor cells interfere with BMDC activation induced by the TLR ligands LPS and poly IC. Tumor cells blocked TLR3- and TLR4-mediated induction of MHCII and the co-stimulatory molecules CD40 and CD86, as well as the cytokines IL-12, TNF-α and IL-6. Importantly, tumor cells induced inhibitory molecules (B7-DC, B7-H1 and CD80) on spleen DC in vivo and on BMDC, even in the presence of TLR ligands. Moreover, after a long exposure with tumor cells, purified BMDC were unable to respond to a second challenge with TLR ligands. The failure of tumor exposed-BMDC to express co-stimulatory molecules and cytokines in the presence of TLR ligands has implications for the future development of DC-based cancer immune therapies using TLR ligands as adjuvants for the activation of DC.     

EPO修饰增强Muller细胞对RCS大鼠视网膜变性的干预效果

目的：研究人源促红细胞生成素（hEPO）修饰的Müller（hEPO-Müller）细胞对视网膜退行性病变大鼠的干预作用。方法通过质粒转染法构建hEPO和GFP的Müller细胞稳转株（hEPO-Müller和GFP-Müller）;以体外共培养和体内细胞移植为研究体系,利用RT-PCR和冰冻切片及免疫荧光染色的方法检测hEPO-Müller对RCS大鼠视网膜退行性病变的干预作用。内核层与外核层厚度比较采用t检验。结果本实验成功构建了hEPO-Müller和GFP-Müller细胞系。将RCS大鼠的视网膜组织剥离并在体外不同条件下培养两周后测定视网膜各核层厚度发现,与对照细胞裂解液共培养组的内核层（15.94±1.77）μm和外核层（24.81±3.03）μm的厚度相比较,两核层的厚度分别在hEPO组为（23.03±3.29）μm,（33.92±7.59）μm（P〈0.05）;Müller 组为（24.81±2.02）μm,（32.15±3.03）μm（P〈0.05）;hEPO-Müller组为（32.40±8.35）μm,（40.25±3.29）μm（n=3, P〈0.01）;以hEPO-Müller组厚度增加最为显著（P〈0.05）。提示EPO和Müller细胞对视网膜变性都有干预作用且两者可以叠加。将hEPO-Müller和GFP-Müller分别移植到RCS大鼠的视网膜下腔,四周后取视网膜进行冰冻切片检测,染色结果显示,细胞移植后有更多的外核层细胞存活,且同样也是hEPO-Müller组的外核层细胞更多。此外,Müller移植并不会促进视网膜的胶质化。结论移植Müller细胞可以减缓RCS大鼠视网膜变性,而经hEPO修饰的Müller细胞对视网膜变性有更好的干预作用。因此,Müller细胞可以作为一种供体细胞兼携带hEPO等营养因子的载体用于视网膜变性的治疗。     

HuBMSC-MCP, a novel member of mitochondrial carrier superfamily, enhances dendritic cell endocytosis

A novel member of mitochondrial carrier superfamily has been identified from human bone marrow stromal cells (BMSC) and designated as human BMSC-derived mitochondrial carrier protein (HuBMSC-MCP). It encodes a 321 amino-acid protein with three tandem related domains of about 100 amino acids. Each domain contains two hydrophobic stretches, which are thought to span the membrane as alpha-helices. Distant relationship analysis indicates that the protein is highly conserved between species from Caenorhabditis elegans to human. HuBMSC-MCP gene is mapped to chromosome 11p11. HuBMSC-MCP mRNA expression is detectable in various human tissues and cell lines. By confocal imaging, HuBMSC-MCP is localized to mitochondria and also detected in the pseudopodial protrusion of human breast adenocarcinoma MCF-7 cells. When transfected into dendritic cells (DC), HuBMSC-MCP could enhance DCs endocytotic capacity. Thus, HuBMSC-MCP is a phylogenetically conserved and widely expressed mitochondrial carrier protein which perhaps associates with mitochondrial oxidative phosphorylation.     

诱导人脐带间充质干细胞分化为视网膜色素上皮样细胞的研究

目的：探讨用猪视网膜色素上皮细胞（RPE）条件培养基诱导hUCMSCs分化为RPE样细胞的方法。方法通过流式细胞技术鉴定hUCMSCs的表面标记分子;通过诱导hUCMSCs分化成为脂肪、骨和软骨细胞确定其多系分化能力;将hUCMSCs培养在猪RPE的条件培养液中并添加诱导因子来诱导hUCMSCs向RPE细胞分化。对照组与处理组Q-PCR结果采用t检验比较。结果 hUCMSCs表达CD105、CD90、CD73、CD44和CD29,但不表达CD34,CD45和MHCII等分子标记,在成脂、成骨、成软骨分化培养基中可分化为脂肪、骨和软骨细胞。单独使用猪RPE条件培养液不能有效诱导hUCMSCs向RPE细胞分化,但联合应用猪RPE条件培养液和诱导因子（视黄酸,activin-A和人重组骨形成蛋白-7）可有效诱导hUCMSCs分化为RPE样细胞,RPE细胞标记分子RPE65、Mitf和Ck8/18的基因表达量分别提高了2.1±0.4、6.8±1.3和2.5±0.3倍（P〈0.05）。诱导产生的RPE样细胞呈多边形,但不含色素颗粒。结论猪RPE条件培养液联合诱导因子可有效诱导hUCMSCs分化为RPE样细胞,可能会为治疗视网膜变性疾病提供合适的种子细胞。     

Larger numbers of immature dendritic cells augment an anti-tumor effect against established murine melanoma cells

The dendritic cell (DC) is a potentially promising tool for cancer immunotherapy. To date, however, DC-based immunotherapy has not yielded data with which firm conclusions can be drawn. In the present study, we tested the dose-dependant enhancement of the anti-tumor effect induced by DCs. When large numbers of DCs were used, tumor growth was suppressed up to 41% when compared to control mice. Survival of the animals was prolonged to 54 days compared to the 33-day survival the control mice. The delayed-type hypersensitivity (DTH) response induced was 26-fold higher than in the controls. Larger numbers of DCs also led to higher expansion of IFN-γ-secreting-CD8⁺ T cells. Furthermore, the secretion of IL-12p70 and IFN-γ by spleen cells were enhanced in proportion to the dosage. However, the level of IL-4 secreted from spleen cells was negligible compared to the level of IFN-γ that was released. These results indicate that DCs induce Th1-dominant immune response and that more DCs could lead to better immunological results, a finding which was consistent with our therapeutic results.     

胸腺内注射供体BMSCs对同种异体腹部皮瓣移植排斥的影响

目的:将供体骨髓间充质干细胞(bone marrow mesenchymal stem cells,BMSCs)胸腺内注射(intrathymic injection,IT)至受体胸腺,探讨其对同种异体腹部皮瓣移植排斥的影响及机制。方法:全骨髓贴壁培养法培养并纯化BN大鼠BMSCs,流式细胞术对其表型进行鉴定。受体Lewis鼠随机分为A组(空白对照组)、B组(BMSCs组)、C组(60Coγ射线4Gy全身照射组)、D组(全身照射+BMSCs组),每组6只。各组大鼠第0天进行同种异体腹部皮瓣移植,A组移植前14天IT PBS,B组移植前14天IT供体BMSCs,C组移植前15天给予60Coγ射线4Gy全身照射,移植前14天IT PBS,D组除移植前15天4Gy全身照射外,移植前14天IT供体BMSCs。大体观察移植皮瓣存活情况并绘制生存曲线,排斥终点流式检测脾细胞调节性T细胞(Treg)比例变化,体外混合淋巴细胞反应检测受体脾淋巴细胞对供体抗原反应性变化。结果:全骨髓贴壁培养法能够很好培养出BMSCs,其P3代流式细胞术表型鉴定结果为CD11b/c、CD45阴性,CD29、CD90阳性。B组的移植皮瓣存活时间与A组相比无明显差异(P>0.05),而D组的移植皮瓣平均存活时间较C组延长3.4天,差异具有统计学意义(P<0.01),脾细胞Treg比例显著增高(P<0.01),脾淋巴细胞对供体抗原反应性显著降低(P<0.05)。结论:IT供体BMSCs联合60Coγ射线4Gy全身照射通过上调受体脾细胞Treg比例能有效降低受体脾淋巴细胞对供体抗原的反应性,显著延长同种异体腹部皮瓣移植物存活时间。     

The anti-tumor effect of human monocyte-derived dendritic cells loaded with HSV-TK/GCV induced dying cells

Herpes simplex virus thymidine kinase (HSV-TK) gene and dendritic cells (DC) have been used as the pioneering in cancer therapy. HSV-TK gene can induce apoptosis and necrosis in tumor cells in the presence of the non-toxic prodrug ganciclovir (GCV). We investigated the anti-tumor effect of DC vaccination by introducing dying cells from HSV-TK gene treatment as an adjuvant. HepG₂-TK cell line was established by transfecting human hepatoma cell line HepG₂ (HLA-A₂ positive) with HSV-TK gene. Dying tumor cells were generated by culturing HepG₂-TK cells with GCV. After engulfed dying cells efficiently, immature DCs (imDC) derived from human monocytes were fully matured and elicited marked proliferation and cytotoxicity against HLA matched HepG₂ cells in autologous peripheral blood mononuclear cells (PBMC). It also implied that HepG₂ specific CTLs played an important role in the cytotoxicity which was primarily depended on Th1 responses. Given the feasibility of inducing dying cells by HSV-TK/GCV in vivo, our results suggest an effective method in clinical human hepatocellular carcinoma (HCC) treatment by an in vitro model of applying HSV-TK gene modified human tumor cells integrated with DC vaccination.     

Stem cell therapy for retinal diseases

In this review, we discuss about current knowledge about stem cell(SC) therapy in the treatment of retinal degeneration. Both human embryonic stem cell and induced pluripotent stem cell has been growth in culture for a long time, and started to be explored in the treatment of blinding conditions. The Food and Drug Administration, recently, has granted clinical trials using SC retinal therapy to treat complex disorders, as Stargardt’s dystrophy, and patients with geographic atrophy, providing good outcomes. This study ’s intent is to overview the critical regeneration of the subretinal anatomy through retinal pigment epithelium transplantation, with the goal of reestablish important pathways from the retina to the occipital cortex of the brain, as well as the differentiation from pluripotent quiescent SC to adult retina, and its relationship with a primary retinal injury, different techniques of transplantation, management of immune rejection and tumorigenicity, its potential application in improving patients’ vision, and, finally, approaching future directions and challenges for the treatment of several conditions.     

A novel in vitro retinal differentiation model by co-culturing adult human bone marrow stem cells with retinal pigmented epithelium cells

Human retinal pigment epithelium (HRPE) cells are important in maintaining the normal physiology within the neurosensory retina and photoreceptors. Recently, transplantation of HRPE has become a possible therapeutic approach for retinal degeneration. By negative immunoselection (CD45 and glycophorin A), in this study, we have isolated and cultivated adult human bone marrow stem cells (BMSCs) with multilineage differentiation potential. After a 2- to 4-week culture under chondrogenic, osteogenic, adipogenic, and hepatogenic induction medium, these BMSCs were found to differentiate into cartilage, bone, adipocyte, and hepatocyte-like cells, respectively. We also showed that these BMSCs could differentiate into neural precursor cells (nestin-positive) and mature neurons (MAP-2 and Tuj1-positive) following treatment of neural selection and induction medium for 1 month. Furthermore, the plasticity of BMSCs was confirmed by initiating their differentiation into retinal cells and photoreceptor lineages by co-culturing with HRPE cells. The latter system provides an ex vivo expansion model of culturing photoreceptors for the treatment of retinal degeneration diseases.     

Fate and protective effect of marrow stromal cells after subretinal transplantation

Engraftment of marrow stromal cells (MSCs) has been proposed as a therapeutic approach for degenerative diseases. In this study we investigated the fate and dynamic progress of grafted MSCs in living retina with the aim of evaluating the use of transplanted MSCs to treat retinal degeneration. Approximately 1×10⁵ gfp -MSCs in 2 μl phosphate-buffered saline were injected into the subretinal space of adult Sprague-Dawley rats. Two weeks later, approximately 0.174%±0.082% of the transplanted cells had survived and diffused into the subretinal space. Nine weeks after transplantation the surviving gfp -MSCs accounted for 0.049%±0.023% of the number of cells injected and were mainly located at the injection site. The same number of MSCs were transplanted into the left eye subretinal space of 3-week-old hereditary retinal degenerative Royal College of Surgeons rats, and phosphate-buffered saline was injected into their right eyes as a control. Five weeks after transplantation, the amount of rudimentary photo-receptors was more significantly increased in grafted eyes than in control eyes. The results indicated that grafted MSCs could survive and rescue retinal degeneration.     

Effects of bone marrow stromal cell injection in an experimental glaucoma model

We investigated if bone marrow stromal cells (BMSCs) transplanted into the vitreous body of a glaucoma model eye could be integrated in the host retina and also whether they could rescue the retinal ganglion cells (RGCs) from death induced by the elevated intraocular pressure. Glaucoma was induced in the right eye of adult Wistar rats by ligating the episcleral veins. The GFP-expressing BMSCs (GFP-BMSCs) were injected into the vitreous body of both the control and the glaucomatous eyes. After transplantation, GFP-BMSCs were mostly present along with the inner limiting membrane and only a few cells were integrated into the ganglion cell layer. At 2 or 4 weeks after transplantation, GFP-BMSCs were observed to express various trophic factors. The BMSCs injected glaucoma model eyes showed less reduction in the number of RGCs compared to the glaucomatous eyes with PBS injection. This study suggests that BMSC transplantation may be worthy as a neuroprotective tool to treat glaucoma.     

人骨髓间充质干细胞脑内移植对食蟹猴脑出血的治疗作用

目的评价人骨髓间充质干细胞脑内移植对食蟹猴脑出血模型的治疗作用。方法符合普通级标准的成年食蟹猴12只,用自体股动脉抗凝血脑内注射方法建模后1周,用脑立体定位法在血肿周围植入人骨髓间充质干细胞,细胞数分别为高剂量5×106、低剂量1×106、对照组等体积生理盐水。利用MRI、PET、神经功能缺损评分和组织病理学对干细胞移植效果进行评价。结果神经功能评分显示干细胞移植1周后动物神经功能明显改善。PET结果显示干细胞移植后2周高剂量组血肿周围皮层、基底节核团的SUV%值与对照组间存在显著性差异(P=0.02)。移植后3周高、低剂量组血肿周围皮层、基底节核团的SUV%值与对照组间差异存在显著性(P值分别为0.03和0.04)。MRI显示剂量组血肿吸收速度大于对照组。病理检查可见剂量组坏死灶面积小于对照组,出血灶周围有大量新生血管生成,剂量组与对照组间差异存在显著性(P<0.01)。结论在损伤脑组织周围移植hBMSC可促进食蟹猴损伤神经组织的恢复,为hBMSC治疗脑出血的临床应用提供了重要实验依据。     

树突细胞上Toll样受体的介导作用

树突状细胞是体内最重要的抗原提呈细胞,它表面表达多种Toll样受体。Toll样受体可通过多条途径来激活树突细胞,介导树突细胞对抗原的摄取,递呈及生存与凋亡,促进T细胞增值和分化并参与免疫反应。     

Tolerance induction between two different strains of parental mice prevents graft-versus-host disease in haploidentical hematopoietic stem cell transplantation to F1 mice

Haploidentical hematopoietic stem cell transplantation (Haplo-HSCT) has been employed worldwide in recent years and led to favorable outcome in a group of patients who do not have human leukocyte antigen (HLA)-matched donors. However, the high incidence of severe graft-versus-host disease (GVHD) is a major problem for Haplo-HSCT. In the current study, we performed a proof of concept mouse study to test whether induction of allogeneic tolerance between two different parental strains was able to attenuate GVHD in Haplo-HSCT to the F1 mice. We induced alloantigen tolerance in C3H mice (H-2k) using ultraviolet B (UVB) irradiated immature dendritic cells (iDCs) derived from the cultures of Balb/c bone marrow cells. Then, we performed Haplo-HSCT using tolerant C3H mice as donors to F1 mice (C3H × Balb/c). The results demonstrated that this approach markedly reduced GVHD-associated death and significantly prolonged the survival of recipient mice in contrast to the groups with donors (C3H mice) that received infusion of non-UVB-irradiated DCs. Further studies showed that there were enhanced Tregs in the tolerant mice and alloantigen-specific T cell response was skewed to more IL-10-producing T cells, suggesting that these regulatory T cells might have contributed to the attenuation of GVHD. This study suggests that it is a feasible approach to preventing GVHD in Haplo-HSCT in children by pre-induction of alloantigen tolerance between the two parents. This concept may also lead to more opportunities in cell-based immunotherapy for GVHD post Haplo-HSCT.     

Cyclophosphamide induces bone marrow to yield higher numbers of precursor dendritic cells in vitro capable of functional antigen presentation to T cells in vivo

We have shown recently that cyclophosphamide (CTX) treatment induced a marked increase in the numbers of immature dendritic cells (DCs) in blood, coinciding with enhanced antigen-specific responses of the adoptively transferred CD8⁺ T cells. Because this DC expansion was preceded by DC proliferation in bone marrow (BM), we tested whether BM post CTX treatment can generate higher numbers of functional DCs. BM was harvested three days after treatment of C57BL/6 mice with PBS or CTX and cultured with GM-CSF/IL-4 in vitro. Compared with control, BM from CTX-treated mice showed faster generation and yielded higher numbers of DCs with superior activation in response to toll-like receptor (TLR) agonists. Vaccination with peptide-pulsed DCs generated from BM from CTX-treated mice induced comparable adjuvant effects to those induced by control DCs. Taken together, post CTX BM harbors higher numbers of DC precursors capable of differentiating into functional DCs, which be targeted to create host microenvironment riches in activated DCs upon treatment with TLR agonists.