胸腺基质细胞支持下骨髓CD34+细胞向T细胞体外定向分化

本文研究了人骨髓CD34^＋细胞体外向T细胞定向分化的程序,为进一步研究银屑病患者骨髓CD34^＋细胞定向分化的T细胞活性方法提供理论依据.     

衰老模型骨髓基质细胞抑制造血细胞增殖分化

目的研究衰老骨髓基质细胞对骨髓造血细胞增殖分化能力的影响,为阐述机体造血微环境衰老对造血干/祖细胞增殖的影响提供实验依据。方法全骨髓贴壁法体外培养大鼠骨髓基质细胞,分为对照组和衰老组。衰老组:常规培养基内加入30 mg/m L D-半乳糖作用48 h。CCK-8法测定BMSCs增殖;流式细胞术分析细胞周期;β-半乳糖苷酶(SA-β-Gal)染色观察衰老BMSCs百分率;Western blot检测P16、P21和P53蛋白表达。骨髓造血细胞与BMSCs共培养,集落计数检测髓系多向性造血祖细胞(CFU-Mix)增殖分化。ELISA检测BMSCs培养上清液中IL-1β、GM-CSF和SCF含量;DCFH-DA流式荧光检测BMSC活性氧簇(ROS)水平;酶学法检测BMSCs内过氧化物丙二醛(MDA)含量和总超氧化物歧化酶(SOD)活性。结果与对照组相比,D-半乳糖诱导BMSCs衰老,细胞阻滞于G0/G1期(P0.01),增殖能力显著下降,SA-β-Gal染色阳性率升高(P0.01);衰老相关蛋白P16、P21和P53表达明显上调(P0.01)。与衰老BMSCs共培养的骨髓造血细胞增殖分化能力减弱。衰老BMSCs内ROS、MDA氧化损伤指标上升,SOD抗氧化指标下降(P0.01);BMSCs培养上清液IL-1β、GM-CSF和SCF含量明显下降(P0.01)。结论衰老骨髓基质细胞抑制造血细胞增殖、分化能力,其机制可能与骨髓基质细胞氧化损伤,分泌活性因子改变有关。     

人CK8&18阳性胸腺上皮细胞对脐血CD34~+细胞向T细胞分化的影响

目的:通过CK8/18阳性胸腺上皮细胞与人脐血单个核细胞在Transwell板的共培养,探讨CK8/18阳性TEC对T细胞增殖分化的影响。方法:用胶原酶消化法分离纯化胸腺上皮细胞、免疫组化鉴定分离纯化的TEC,采用密度梯度离心法分离获得脐血单个核细胞,并采用免疫磁珠分选CD34+细胞,将TEC种植培养于Transwell双层培养板上层,使其均匀平铺于上层板底部,再将分选后的细胞加入上层小室,经过48小时的共培养,流式细胞术检测进入下室细胞的表型变化。结果:分离纯化的TEC经免疫组化鉴定CK8/18阳性。TEC与脐血单个核细胞共培养后,CD3+CD4-CD8-双阴性、CD3+CD4+CD8-单阳性细胞显著增加,CD3+CD4+CD8+双阳性细胞亚群细胞减少,CD8单阳性细胞增加不明显;CD45RA阳性细胞比率无显著变化,CD45RO阳性细胞比率显著增加。结论:CK8/18阳性TEC能选择促进脐血单个核细胞CD4+T细胞和CD45RO+细胞增殖。     

脐血CD34+细胞体外定向诱导分化为T淋巴细胞的实验研究

目的：建立利用人造血干／祖细胞体外定向诱导分化为T淋巴细胞的方法，为研究T细胞生物学特性及细胞免疫提供技术平台。方法：MACS方法分离人脐带CD34^ 细胞接种到人胎儿胸腺基质单层细胞上，IMDM液体培养基含20％人AB血清并加入FL、IL-12、IL-7和IL-2细胞因子组合，于培养7、14、21、28、35、42天取非贴壁细胞利用流式细胞仪对细胞表型进行检测，并进行细胞形态学分析。结果：2周后，CD4^ CD8^ 非成熟T淋巴细胞占细胞总数的0．3％-13．3％，4-5周CD4^ CD8^ T淋巴细胞达到高峰占16．6％-26．5％，且CD3^ CD4^ CD8^ 和CD3^ CD4^-CD8^ T淋巴细胞逐渐增多，6周后达26．5％～64．9％和11．6％-38．9％。培养成熟的T淋巴细胞经PHA IL-2刺激后瑞氏染色鉴定可见大原始淋巴细胞存在。结论：利用人脐血CD34^ 在体外人胎儿胸腺基质单层细胞上加FL、IL-12、IL-7和IL-2细胞因子组合条件下，可诱导分化出T淋巴细胞，并且培养的T细胞对有丝分裂素刺激有增殖反应。     

CD8+ T 细胞活化与分化的分子机制

CD8+ T 细胞识别由MHC玉分子递呈的抗原肽,由于大多数有核细胞都表达MHCⅠ分子,因此CD8+ T 细胞在清除被病毒、胞内菌、寄生虫等感染的细胞或突变的肿瘤细胞中发挥着重要作用。识别病原微生物等抗原后,CD8+ T 细胞活化并分化形成多种类型的效应和记忆细胞,不仅能及时清除被感染的细胞,也能形成长期保护。各亚群CD8+ T 细胞的表面分子、功能和定位不同,细胞存活的时间、再次感染时的增殖能力和效应功能也有所差别。本文主要讨论CD8+ T 细胞如何受到多条信号通路和转录因子调控,活化和分化成不同类型的效应和记忆细胞,并对临床应用T 细胞抵御肿瘤和病原微生物的进展作一简单概述。     

施万细胞诱导共培养骨髓基质细胞向多巴胺能神经元分化

观察施万细胞(SCs)对骨髓基质细胞(BMSCs)的诱导分化作用。分离和体外培养SD大鼠SCs和BMSCs,分为SCs+BMSCs共培养(实验组)和BMSCs单独培养(对照组)。用流式细胞仪(FCM),S100、Brdu/nestin、Brdu/TH免疫荧光法分别鉴定BMSCs、SCs和BMSCs的分化情况。第2代SCs呈S100阳性,第3代BMSCs呈CD29和CD90阳性,CD45阴性。二者共培养3d后,可见Brdu/nestin免疫荧光双标细胞,阳性率达28.3±1.3%,与对照组比较,P<0.05。7d后,Brdu/nestin双标细胞减少,出现Brdu/TH免疫荧光双标细胞,阳性率为19.2±1.6%,与对照组比较,P<0.05。而对照组始终只见Brdu单标细胞。上述结果表明SCs可诱导共培养的BMSCs分化为DA能神经元。     

骨髓基质干细胞体外诱导分化为施旺细胞的研究进展

骨髓基质干细胞是一种具有多向分化潜能的细胞,除了分化为间充质细胞谱系外,还具有向非间充质细胞谱系如神经细胞分化的潜能,在体外适宜的条件下可以诱导分化为施旺细胞。多种抗氧化剂可以诱导骨髓基质干细胞分化为施旺细胞,分化所需时间较短;多种生长因子亦有同样的作用,诱导的施旺细胞传代时寿命延长;抗氧化剂和生长因子合用,分化施旺细胞的数量更多,传代时寿命更长。     

mTOR调节CD4~+T细胞亚群分化及功能的研究进展

哺乳动物雷帕霉素靶蛋白(mammalian target of rapamycin,mTOR)属于磷脂酰肌醇激酶相关激酶蛋白质家族成员,是一种非典型丝氨酸/苏氨酸激酶。mTOR可整合来自营养、能量、生长因子和环境压力对细胞的刺激信号,调节下游蛋白p70S6K和4E-BP1活性而影响细胞生长。CD4+T细胞是一群具有重要免疫调节功能的淋巴细胞,其中不同亚群在机体免疫应答中的作用存在明显差异。近来研究证实,mTOR信号在CD4+T细胞亚群分化发育及功能活性中发挥重要的调节作用。     

OP9-DL1细胞共培养系统在T细胞体外定向诱导分化中的应用

T细胞是一类在机体免疫应答中起核心作用的免疫活性细胞。T细胞的分化发育指来自骨髓的淋巴样祖细胞(lymph-oid pregnitors)进入胸腺增殖、分化,并从胸腺皮质迁移至髓质,成为成熟T细胞的过程。长期以来,T细胞发育的体内外研究一直依赖于胸腺。但人或鼠的胸腺组织来源有限且取材困难,加大了T细胞发育的研究难度。近年来,随着T细胞发育过程中一些关键分子的发现及其研究的不断深入,一种可高效诱导造血干/祖细胞在体外向T细胞分化的简单模型骨髓基质细胞OP9-DL1体外培养系统得以建立,这种系统的出现大大简化了T细胞分化发育的研究,本文将就其在T细胞体外定向诱导分化中的应用作一综述。     

骨髓基质细胞诱导分化为神经细胞的研究进展

骨髓基质细胞(BMSCs)在诱导剂的作用下在体外可以定向分化为神经元样细胞,但尚未在临床上广泛使用,主要的原因是神经元样细胞的数量和纯度不够。在骨髓基质细胞诱导分化为神经元样细胞的研究中,诱导剂的选择是关键,目前常见的诱导剂有β-巯基乙醇、细胞因子等。近年来发现利用中药也可以进行诱导分化。     

Human bone marrow stromal cells hamper specific interactions of CD4 and CD8 T lymphocytes with antigen-presenting cells

Bone marrow stromal cells (BMSCs) may inhibit T-cell functions in vitro and thus have been proposed as immunoregulators to control in vivo graft-versus-host disease (GVHD) in haploidentical hemopoietic stem cell transplants. To better investigate this phenomenon, we used a defined experimental system in which responding T cells are antigen-specific and devoid of alloreactivity against BMSC from a different subject. Thus, we established antigen-specific human CD4 and CD8 T-cell lines as the readout system. Antigen-dependent proliferation was reduced with both T-cell subsets cultured on confluent BMSCs, and also on confluent human skin fibroblasts (HSF) inhibited T-cell proliferation with similar efficiency. Morphological observations of the cocultures showed impairment of physical interactions between T-cell and antigen-presenting cells in the presence of BMSC, with lack of formation of antigen-dependent clusters of T cells and antigen-presenting cells (APCs). In contrast, no effects were seen with BMSC-conditioned medium. Since suppression was seen only with confluent mesenchymal cells, this phenomenon may not be relevant in vivo, where BMSCs are at low frequency. In addition, if the reported suppressive effect of BMSCs on GVHD in vivo is confirmed, a different in vitro system should be envisaged to better understand and exploit the underlying mechanism.     

黄芩甙体外诱导大鼠骨髓基质细胞成为神经细胞

目的:探讨黄芩甙体外诱导成年大鼠骨髓基质细胞(MSCs)分化为神经细胞的条件。方法:采用黄芩甙诱导6h后,继续维持诱导6d。免疫细胞化学染色评价神经细胞特异性烯醇化酶(NSE)、神经微丝(NF)、胶质纤维酸性蛋白(GFAP)和波形蛋白(vimentin)的表达率;Hoechst33258染色评价细胞存活率。结果:诱导6d后MSCs形态改变,胞体成锥形,突起交织成网。免疫细胞化学染色NSE、NF、GFAP和vimentin表达率分别为70.5%±11.6%,68.3%±13.4%,＜1%,＜1%,细胞存活率为88.4%±5.0%。结论:黄芩甙可以诱导成年大鼠MSCs在体外分化成为神经细胞,该方法将为神经系统细胞移植和基因治疗提供新的思路。     

骨髓基质细胞体外诱导分化成神经元和胶质细胞

目的　探索骨髓基质细胞 (bonemarrowstromalcells,BMSC)体外诱导分化为神经元和神经胶质细胞的可行性 ,为BMSC在神经科学领域内的应用奠定基础。方法　以成年犬BMSC为实验对象 ,利用碱性成纤维细胞生长因子 (bFGF)、表皮生长因子 (EGF)、维甲酸 (RA)、脑源性神经营养因子 (BDNF)、胶质细胞系来源神经营养因子 (GDNF)等作为增殖及分化诱导因子 ,进行增殖培养、分化诱导 ;免疫组化法进行细胞性质鉴定。结果　加入bFGF、EGF增殖培养 72h可见细胞分裂相 (成纤维细胞样细胞 )。加入RA、BDNF、GDNF诱导 3d ,部分细胞有NSE、GFAP成分表达 ;第 10d可见有神经元、神经胶质形态样细胞形成 ,经细胞成分 (NSE、GFAP)鉴定证实为神经元、神经胶质细胞。结论　BMSC在体外培养条件下 ,经过bFGF、EGF、RA、BDNF、GDNF等因子的“程序性”作用 ,可以分化成神经元和神经胶质细胞     

人骨髓间充质干细胞体外内皮细胞诱导分化的研究(英)

目的：探讨人骨髓间充质干细胞hMSCs(human mesenchymal stem cells,hMSCs)体外内皮分化基础及其诱导条件。方法：〖HTSS〗采用密度分离与贴壁筛选结合法分离hMSCs，体外联合应用生长因子VEGF165和不同细胞外基质纤维连接蛋白(FN)与Ⅰ型胶原(Col)，对其进行内皮诱导分化。通过免疫细胞化学、细胞化学、流式细胞分析法及透射电镜对其分化后细胞进行鉴定。结果：hMSCs表达早期内皮分化标志之一KDR；PAS反应阳性及超微结构显示，hMSCs胞浆内含有大量糖原形成糖原池，分化后细胞胞浆外质内糖原明显减少或消失，暗示细胞发生分化；细胞诱导后CE34、β1整合素和KDR表达均增强。结论：诱导后细胞为过渡细胞群类型(transit population,TP)，可向内皮前体细胞(endothelial progenitor cells,EPC)EPC方向分化。推测由此类型细胞再分化为内皮细胞(endothelial cells,ECs)，即hMSCs→TP→EPC→ECs。     

Human bone marrow stromal cells: In vitro expansion and differentiation for bone engineering

Stromal cells from marrow hold a great promise for bone regeneration. Even if they are already being exploited in many clinical settings, the biological basis for the source and maintenance of their proliferation/differentiation potential after in vitro isolation and expansion needs further investigation.

Most studies on osteogenic differentiation of marrow stromal cells (MSC) have been performed using bone marrow from the iliac crest. In this study, MSC were derived from spare femoral bone marrow obtained during hip replacement surgery from 20 adult donors. After in vitro isolation the cells were grown in osteogenic medium, and their proliferation and differentiation analysed during in vitro expansion. We found that MSC isolated from the femur of adult patients consistently maintain an osteogenic potential. Using biochemical signals, these cells turn to fully differentiated osteoblasts with a predictable set of molecular and phenotypic events of in vitro bone deposition. When seeded on polycaprolactone-based scaffold or surfaces, the proliferation and mineralization of femur-derived MSC were modulated by the surface chemistry/topography. Despite remarkable differences between individual colony-forming ability, alkaline phosphatase production, and mineralization ability, these cells are a potential source for bone engineering, either by direct autologous reimplantation or by ex vivo expansion and reimplantation combined to a proper scaffold.     

T cell lymphoblastic leukaemia/lymphoma associated with a microenvironment of thymic asteroid B cells in the bone marrow

Naresh K N, May P C, Reid A G, Marks A J, Macdonald D & Kanfer E
(2010) Histopathology 57, 549–554
T cell lymphoblastic leukaemia/lymphoma associated with a microenvironment of thymic asteroid B cells in the bone marrow Aims: Asteroid B cells are a component of normal thymus. It is currently unclear whether these cells are identifiable in T cell lymphoblastic leukaemia/lymphoma (T‐ALL/LBL) of the thymus. The aim of this study was to identify asteroid B cells both in thymic and extrathymic tissue involved by T‐ALL/LBL. Methods and results: Thymic, lymph node (LN) and bone marrow trephine biopsy (BMTB) samples from eight patients with T‐ALL/LBL were reviewed. All had been investigated by immunohistochemistry and one by fluorescent in situ hybridization (FISH). The BMTB samples of two of eight T‐ALL/LBLs and LN sample in one of them showed the presence of asteroid‐shaped B cells with dendritic cytoplasmic processes. These B cells also expressed CD23 and the features were akin to the unique thymic asteroid B cells. Both patients had aggressive/resistant disease. Cytogenetic analysis in one showed a complex translocation involving the T cell receptor beta (TCRB) gene at 7q35 and a distal region of 9q known to harbour the NOTCH1 gene. Conclusion: This is the first report of T‐ALL/LBL documenting the presence of an asteroid B cell‐rich microenvironment at bone marrow and LN sites. In this small subset, T‐ALL/LBL cells are possibly dependent upon asteroid B cells, and whether targeting of asteroid B cells with anti‐CD20 monoclonal antibody in such cases will result in clinical benefit remains to be determined.     

Regulation of allergen-induced bone marrow eosinophilopoiesis: role of CD4+ and CD8+ T cells

BACKGROUND: The mechanisms of the distant stimulation of the bone marrow (BM) after airway allergen exposure remain largely obscure. T cells have been implicated in allergic airway inflammation but their role in allergen-induced BM eosinophilopoiesis is poorly understood. The aim of this study was to determine the role of CD4(+) and CD8(+) T cells in allergen-induced BM eosinophilopoiesis. METHODS: Ovalbumin (OVA)-sensitized wild type (WT), CD4 knockout (CD4-/-) and CD8 knockout (CD8-/-) mice were exposed intranasally to OVA or saline. Bromo-deoxyuridine (BrdU) was used to label newly produced cells. Bone marrow, blood and bronchoalveolar lavage (BAL) were sampled 24 h after the final exposure. Immunostaining for newly produced eosinophils (i.e. BrdU(+)/MBP(+)) and BM eosinophil progenitor [CD34(+)/CD45(+)/interleukin-5 (IL-5)Ralpha(+)] cells was performed. RESULTS: The number of newly produced BM eosinophils (BrdU(+)/MBP(+) cells) was significantly reduced in allergen exposed CD4-/- or CD8-/- mice compared with allergen exposed WT mice, which was followed by a subsequent decrease in newly produced blood and airway eosinophils. Furthermore, BM eosinophil progenitors were significantly reduced in allergen exposed CD4-/- and CD8-/- mice compared with WT mice. Finally, serum IL-5 and Bronchoalveolar lavage fluid eotaxin-2 levels were abolished in allergen exposed CD4-/- mice to levels seen in saline exposed WT mice. CONCLUSIONS: These data suggests that both CD4(+) and CD8(+) T cells have a regulatory role in allergen-induced BM eosinophilopoiesis, whereas CD4(+) T cells are obligatory for allergen-induced airway eosinophilia. The subsequent traffic of eosinophils to the airways is likely to be at least partly regulated by a CD4(+) T-cell-dependent local airway eotaxin-2 production.     

体外诱导恒河猴骨髓基质细胞分化为神经细胞的分化条件

目的比较血清维甲酸(retinoic acid,RA)、胶质细胞源神经营养因子(glial cell line-derived neurotrophic factor,GDNF)及脑源性神经营养因子(brain derived neurotrophic factor,BDNF)等在不同浓度诱导条件下使恒河猴骨髓基质细胞(bone marrow stromal cells)诱导分化为神经干细胞(NSCs)及成熟神经细胞的分化条件。方法用Nestin、CD133抗体免疫细胞化学染色,鉴定NSCs;用NSE、β-tublin鉴定神经元;用GFAP鉴定神经胶质细胞,膜片钳检测分化成熟细胞的电生理特性。结果培养第8天多数细胞表现出Nestin及CD133抗原阳性,即为NSCs细胞;诱导后3天即有神经元样细胞出现,此后神经元样细胞逐渐增多,膜片钳检测发现这些细胞具有类似神经细胞的电生理特性。同时,与其他培养条件相比较,低浓度血清(2．5％) RA GDNF组诱导分化效能最高。结论应用RA GDNF及配合使用低浓度血清能够高效诱导骨髓源NSCs向成熟神经细胞分化。     

CMV-specific central memory T cells reside in bone marrow

CMV-specific CD8(+) T cell responses in peripheral blood (PB) are characterized by a preponderance of effector and effector memory T cells. CMV-specific central memory T cells (T(CM)), which are considered crucial in maintaining long-term immunity, are rarely detectable in PB. In this study we have analyzed differentiation and function of CMV pp65-specific CD8(+) T cells in paired samples of human PB and BM using intracellular cytokine and tetramer staining. Overall frequencies of CMV pp65-specific T cells were similar in PB compared to BM; however, CMV-specific CD45RA(-)CCR7(+) T(CM) were almost exclusively detectable in BM, which was not related to a general accumulation of T(CM) in BM. In vitro, CMV-specific T cells could be more efficiently expanded from BM (median 128-fold, n=6) than from PB (median 72-fold, p=0.01). Taken together, these data show that the BM is a compartment harboring CMV-specific T(CM) and underline the concept of the BM as a secondary immune organ. CMV specific BM-derived T(CM) might be a valuable source for generating T cells for adoptive transfer.