Monitoring minimal residual disease in the bone marrow using next generation sequencing

Achieving minimal residual disease (MRD) negativity in the bone marrow is one of the strongest prognostic factors in multiple myeloma. Consequently, MRD testing is routinely performed in clinical trials and moving towards standard of care. This review focuses on the role of next generation sequencing (NGS) of tumor-specific immunoglobulin V(D)J sequences for MRD tracking. The immunoglobulin variable regions are ideal targets for tracking, because every tumor cell shares an identical gene sequence, which is stable over time and generally distinct from the immunoglobulin sequences of normal B-cells. Several excellent assays for NGS-based MRD testing are available, both commercial and community-based, including one that is FDA-approved. These assays can achieve the gold standard analytical sensitivity of one tumor cell per million (10⁻⁶), requiring a minimum input of 3 million bone marrow cells. On-going clinical trials will outline how MRD testing should be used to inform dynamic risk-adopted therapy.     

Emerging role for bone marrow derived mesenchymal stem cells in myocardial regenerative therapy

Current treatments for ischemic cardiomyopathy are aimed toward minimizing the deleterious consequences of diseased myocardium. The possibility of treating heart failure by generating new myocardium and vascular tissue has been an impetus toward recent stem cell research. Mesenchymal stem cells (MSC), also referred to as marrow stromal cells, differentiate into a wide variety of lineages, including myocardial and endothelial cells. The multi–lineage potential of MSCs, their ability to elude detection by the host immune system, and their relative ease of expansion in culture make MSCs a very promising source of stem cells for transplantation. In addition, emerging experimental results with MSCs offer novel mechanistic insights into cardiac regenerative therapy in general. Here we review the characterization of MSCs, animal and human trials studying MSCs in cardiomyogenesis and vasculogenesis in postinfarct myocardium, routes of delivery, and potential mechanisms of stem cell repair.     

Rapid generation of antiplasma cell activity in the bone marrow of myeloma patients by CD3-activated T cells

We have recently shown that peripheral blood T cells of multiple myeloma (MM) patients are very susceptible to stimulation of the T-cell receptor/CD3 complex with anti-CD3 monoclonal antibodies (MoAbs). CD3 stimulation is currently under clinical investigation as a nonspecific approach to boost antitumor effector mechanisms. The aim of this study was to determine whether the hyperreactivity of MM T cells to CD3 stimulation could be exploited to generate antitumor activity. Bone marrow mononuclear cells (BMMCs) from 65 MM patients were stimulated with the anti-CD3 MoAb OKT3 and the effect of this stimulation on autologous T cells and plasma cells was evaluated. The number of CD3+ CD25+ cells on day 6 was significantly higher in MM than the controls (30 normal individuals) (P = .001). Kinetic studies showed that 3H- thymidine incorporation peaked on day 3 and that the T-cell expansion peaked on days 5 and 6. In MM, T-cell activation markedly affected the survival of autologous plasma cells; their number in OKT3-treated cultures was significantly lower than in unstimulated cultures (P < .0001). T-cell activation and plasma cell decrease were not observed when T cells were removed from BMMC preparations. MM produced significantly higher levels of interferon-gamma (P = .005) and tumor necrosis factor-beta (P = .001), but lower levels of tumor necrosis factor-alpha (P < .001) than normal individuals. Interferon-gamma only was partially involved in CD3-induced plasma cell killing. Transwell cultures showed that the main mechanism by which CD3+ CD25+ cells affected plasma cells was direct cell-to-cell contact rather than cytokines. In conclusion, T cells in MM BMMCs possess distinct features in terms of susceptibility to CD3 stimulation and cytokine production compared with normal bone marrow T cells that can be exploited to generate antiplasma cell activity.     

Galectin-1-expressing stromal cells constitute a specific niche for pre-BII cell development in mouse bone marrow

In the bone marrow (BM), stromal cells constitute a supportive tissue indispensable for the generation of pro-B/pre-BI, pre-BII, and immature B lymphocytes. IL-7-producing stromal cells constitute a cellular niche for pro-B/pre-BI cells, but no specific stromal cell microenvironment was identified for pre-BII cells expressing a functional pre-B cell receptor (pre-BCR). However expression of the pre-BCR represents a crucial checkpoint during B-cell development. We recently demonstrated that the stromal cell derived-galectin1 (GAL1) is a ligand for the pre-BCR, involved in the proliferation and differentiation of normal mouse pre-BII cells. Here we show that nonhematopoietic osteoblasts and reticular cells in the BM express GAL1. We observed that pre-BII cells, unlike the other B-cell subsets, were specifically localized in close contact with GAL1(+) reticular cells. We also determined that IL-7(+) and GAL1(+) cells represent 2 distinct mesenchymal populations with different BM localization. These results demonstrate the existence of a pre-BII specific stromal cell niche and indicate that early B cells move from IL-7(+) to GAL1(+) supportive BM niches during their development.     

Functional differences between dendritic cells derived from CD34+ bone marrow and peripheral blood stem cells

BACKGROUND AND OBJECTIVE: It has been previously demonstrated that dendritic cells (DCs) are characterized by an immature stage with high antigen internalization capacity, followed by a mature stage with predominantly immunostimulatory ability. The shift from the immature to the mature state can be induced in vitro by the addition of tumor necrosis factor-a (TNFa). The aim of our study was to investigate the maturation steps of DCs obtained from CD34(+) cells from peripheral blood stem cells (PBSC) and bone marrow (BM). DESIGN AND METHODS: DCs were generated in vitro from PBSC and BM CD34(+) selected cells. The endocytic activity of the cells was measured by means of dextran-FITC uptake and alloreactivity evaluated with mixed leukocyte reactions. Immunophenotypic analysis was performed by flow cytometry. RESULTS: We observed that DCs from PBSC, in contrast to the BM derived DCs, were never able to take up soluble antigens. Mixed leukocyte reactions (MLR) performed both on PBSC and BM CD34(+) derived DCs showed an allo-stimulatory activity comparable to normal controls at day 10, but significantly higher at day 14 after the addition of TNFa. Immunophenotypic analysis showed typical dendritic markers in all the samples and, after treatment with TNFa, enhanced expression of co-stimulatory molecules. INTERPRETATION AND CONCLUSIONS: Our data seem to indicate that, in our culture conditions, BM-derived DCs could be efficiently used for pulsing with specific peptides, while PBSC-derived DCs, being functionally mature, should be more suitable for gene therapy.     

Surface expression of HLA-DM on dendritic cells derived from CD34-positive bone marrow haematopoietic stem cells

HLA-DM has been known to be largely absent from the cell surface of antigen-presenting cells, accumulating instead in the intracellular compartment. In this study, we demonstrated that a population of HLA-DM-positive (HLA-DM+) dendritic cells (DCs) can be identified in an in vitro culture of CD34+ bone marrow haematopoietic stem cells. CD34+ bone marrow cells of healthy donors were used to generate DCs with the recombinant human cytokines granulocyte-macrophage colony-stimulating factor (GM-CSF), tumour necrosis factor alpha (TNF-alpha) and stem cell factor (SCF), both with and without interleukin 4 (IL-4). Flow cytometric analysis demonstrated that HLA-DM+ cells comprised 2.5 +/- 0.9% and 1.8 +/- 0.4% of the CD34+ cell-derived progeny in the presence of GM-CSF, TNF-alpha and SCF after 7 d and 14 d of culture respectively. The number of HLA-DM molecules expressed per HLA-DM+ cell on d 7 was significantly higher than that on d 14 (1410 +/- 47 versus 370 +/- 25, P < 0.05). The addition of IL-4 to the cytokines from the commencement of culture increased the proportion of HLA-DM+ cells and increased the number of HLA-DM molecules per HLA-DM+ cell significantly (P < 0.05). Although most of the HLA-DM+ cells expressed CD1a, CD80 or CD86 antigen, only a small proportion of CD1a+, CD80+ or CD86+ cells expressed HLA-DM. About half the HLA-DM+ cells expressed CD83. The addition of IL-4 resulted in a decrease in the expression of CD83 on the HLA-DM+ cells on d 7. Microscopic evaluations of sorted HLA-DM+ cells revealed the characteristic morphological features of DCs. Primary mixed lymphocyte cultures demonstrated that the HLA-DM+ cells elicited a vigorous proliferation of allogeneic T cells. The level of antigen-specific T-cell activation induced by antigen-pulsed, chloroquine-treated HLA-DM+ cells was substantially higher than that induced by HLA-DM- cells (P < 0.05). These results show that HLA-DM can be used as a useful DC lineage-specific marker, as well as a tool for the characterization of DCs and human immunotherapy.     

CD1-reactive leukemic cells in bone marrow: presence of Langerhans cell marker on leukemic monocytic cells.

Langerhans cells originate in bone marrow and probably belong to the monocyte-macrophage lineage. CD1 is a specific marker of Langerhans cells. By immunofluorescence and immunoelectron microscopy, CD1a antigen and myeloid markers (CD11, CD13, CD14, CD15, CD33, HLA-DR) were studied in 53 cases of acute myeloid leukemias (AML) and 3 acute lymphoblastic leukemias (ALL). The 11 ANLL without monocytic component were CD1a negative. 2/5 of acute myelomonocytic leukemias (AML4) and 9/37 of acute monocytic leukemias (AML5) were positive. All 3 ALL were negative. No correlation was found between CD1a and myeloid markers. CD1a+ AML did not differ from CD1a- AML with regard to cytogenetics or response to therapy. The CD1a positive cells may originate from an abnormal proliferation of CD1a positive cells which are present in bone marrow and which may differentiate into Langerhans cell precursors.     

Cardiac cell therapies: the next generation

Although significant advances have been made in terms of pharmacological, catheter-based, and surgical palliation, heart failure remains a fatal disease. As a curative concept, regenerative medicine aims at the restoration of the physiologic cellular composition of diseased organs. So far, clinical cardiac regeneration attempts have only been moderately successful, but a better understanding of myocardial cell homeostasis and somatic as well as embryonic stem cell biology has opened the door for the development of more potent therapeutic cardiac regeneration strategies. Accumulating evidence indicates that the postnatal mammalian heart retains a pool of tissue-specific progenitor cells and is also repopulated by cells from extracardiac sources. However, this intrinsic myocardial regeneration potential clearly needs to be augmented by either manipulation of the cell cycle of differentiated cells, activation of resident cardiac progenitor cells, and/or the transplantation of exogenous cells. This review summarizes the recent developments in cardiac regenerative medicine, many of which may find their way into the clinical setting in the foreseeable future.     

Accelerated generation of CD14+ monocyte-lineage cells from the bone marrow of rheumatoid arthritis patients

Objective. To examine the capacity of bone marrow progenitor cells to generate CD14+ cells, in order to assess the role of bone marrow in the pathogenesis of rheumatoid arthritis (RA). Methods. CD14- cells purified from bone marrow specimens of 11 patients with active RA and 8 control patients (osteoarthritis or trauma) were cultured in the presence or absence of granulocyte–macrophage colony-stimulating factor (GM-CSF; 100 pg/ml). After incubation for various lengths of time, the cells were analyzed by flow cytometry for expression of CD14 and HLA-DR. Results. The spontaneous generation of CD14+ cells from bone marrow CD14- progenitor cells was accelerated in RA patients compared with control patients. Moreover, the expression of HLA–DR on the bone marrow–derived CD14+ cells was also accelerated in RA patients compared with controls. GM-CSF significantly enhanced the generation of CD14+ cells, as well as the expression of HLA–DR, on CD14+ cells of control patients, but not those of RA patients. GM-CSF levels in the culture supernatants of bone marrow CD14- cells were not significantly different between RA patients and control patients (undetectable in most cases). Conclusion. These observations strongly support the hypothesis that the accelerated generation of CD14+ cells from bone marrow progenitor cells and the accelerated maturation of such CD14+ cells into HLA–DR+ cells play an important role in the pathogenesis of RA. Moreover, the data suggest a functional alteration of RA bone marrow CD14- cells in their responsiveness to GM-CSF.     

骨髓增生异常综合征患者骨髓CD34+细胞亚群及细胞周期分析

目的 探讨骨髓增生异常综合征(MDS)患者骨髓CD34+细胞亚群及细胞周期分布异常的临床意义.方法 采用流式细胞术检测50例(17例低危、33例高危)MDS患者、8例MDS转化的急性髓系自血病(MDS-AML)及25例对照组原代骨髓CD34+CD38+、CD34+CD38-细胞亚群及G0/G1期、S期和G2/M期细胞比例.结果 高危和MDS-AML组骨髓CD34+细胞比例[(2.29±2.17)%、(18.69±17.47)%]明显高于对照组[(0.36±0.49)%,P＜0.05].低危、高危及MDS-AML组CD34+CD38+细胞相对比例[(86.09±7.79)%、(81.68±11.82)%、(82.88±2.60)%]显著低于对照组[(92.21±3.85)%,P＜0.05],而CD34+CD38-细胞比例[(13.91±7.79)%、(18.32±11.82)%、(17.13±2.60)%]显著高于对照组[(7.79±3.85)%,P＜0.05].MDS组CD34+CD38-细胞比例与国际预后积分系统(IPSS)(r=0.493,P=0.001)、WHO分型预后积分系统(WPSS)积分(r=0.586,P=0.000)均呈正相关.低危、高危及MDS-AML组骨髓单个核细胞(BMMNC)中G0/G1期细胞比例[(94.52±4.32)%,(96.07±3.88)%,(94.65±4.55)%]明显高于对照组[(88.94±7.30)%,P＜0.01],而3组S期[(4.63±3.34)%,(3.45±3.80)%,(5.12±4.55)%]和G2/M期[(0.84±1.52)%,(0.48±0.74)%,(0.22±0.34)%]细胞比例明显低于对照组[(9.06±6.50)%,(2.00±2.93)%,P值均＜0.05],3组S+G2/M期细胞比例明显高于对照组(P＜0.01).CD34+CD38-细胞比例≤12.0%的MDS患者治疗有效率高于CD34+CD38-细胞比例＞12.0%的患者,但差异无统计学意义.结论 MDS患者原代骨髓CD34+细胞亚群分化异常,BMMNC存在G1期阻滞现象,提示CD34+细胞亚群和细胞周期测定可能有助于MDS患者的辅助诊断以及疗效和预后判断.     

Apoptotic bone marrow CD34+ cells in cirrhotic patients

AIM: To access the frequency and level of apoptotic CD34+ cells isolated from the marrow fluid of patients with post-hepatitis cirrhosis. METHODS: The frequency of bone marrow CD34+ cells and apoptotic bone marrow CD34+ cells in 31 inpatients with post-hepatitis cirrhosis (cirrhosis group), and 15 out-patients without liver or blood disorders (control group) was calculated by flow cytometry. Parameters were collected to evaluate liver functions of patients in cirrhosis group. RESULTS: The percentage of norm...     

Hepatocyte transplantation: potential of hepatocyte progenitor cells and bone marrow derived stem cells

The liver has a large regenerative capacity in response to injury. However, in severe cases of liver injury, its regenerative capacity may prove insufficent and the liver injury may progress to liver failure, and in such situations liver transplantation is the only treatment option. An alternative, less invasive approach may be transplantation of hepatocytes or hepatocyte precursor cells. In the adult liver two candidate progenitor cells have been identified: oval cells and small hepatocytes. The former are induced by liver injury under conditions preventing cell division of mature hepatocytes, while the latter are present in small numbers in normal liver. Both cell types have the capacity to expand and differentiate into hepatocytes. In recent years evidence has been presented that bone-marrow derived stem cells can also be expanded and differentiated into hepatocyte progenitor cells. Such cells may be a source for hepatocyte transplantation and hence have the potential to offer a novel therapy for liver failure.     

骨髓间质干细胞在心血管疾病治疗中的应用

心血管疾病是世界范围内的常见病、多发病,细胞移植是治疗心血管疾病的有效途径.而骨髓间质干细胞(BMSC)具有来源广泛、取材方便、免疫源性低、可以分化为心肌细胞、内皮细胞等特点,是治疗心血管疾病的良好种子细胞来源.国内、外学者对BMSC治疗心血管疾病进行了很多的动物实验及部分临床研究,但仍存在很多的问题.本文就BMSC治疗心血管疾病的机制、实验研究、临床研究及所面临的问题作一综述.     

骨髓干细胞移植与动员治疗心肌梗死的比较

目的对骨髓干细胞移植与粒细胞集落刺激因子(G-CSF)动员的自体骨髓来源的干细胞对大鼠急性心肌梗死动物模型的治疗作用进行比较。方法建立大鼠左冠状动脉结扎的心肌梗死模型,随机分为对照组,细胞移植组,动员剂组,移植组模型建立1w后再次开胸,于梗死区内注射经BrdU标记的骨髓基质干细胞。4w后观察移植细胞分化情况和促血管生成作用,并用超声检测心脏功能改变。结果细胞移植4w后,可以在坏死区内找到增殖的BrdU标记的移植细胞,另外Ⅷ因子染色可见移植组和动员剂组坏死区内有大量的血管新生,超声检查显示移植组及动员组心脏功能显著改善,两组均与对照组有显著性差异(P<0.05),且两者间又有显著性差异(P<0.01)。结论细胞移植和动员剂注射治疗,均能促进大鼠急性心肌梗死缺血区及其周边区域的毛细血管新生、改善心脏功能,而细胞移植效果更明显。     

骨髓来源肝细胞的初步研究

目的 验证骨髓细胞是否可以转化为肝细胞。方法 通过放射致死剂量照射的BALB/C雌性小鼠接受周龄相配的同系雄性小鼠的全骨髓移植后，分别在移植后1，2，4周和2个月分批处死移植存活的小鼠。分别在游离的肝细胞和肝脏的石蜡切片上用荧光原位杂交法检测Y染色体阳性肝细胞。结果 在移植后2个月的小鼠肝脏游离细胞和石蜡切片上均发现有Y染色体阳性肝细胞，数量极少，但确实存在。结论 在接受放射致死剂量照射但没有导致严重的急性肝脏损伤情况下，骨髓细胞可以转化为成熟的肝细胞。