Agranulocytosis induced by macrolide antibiotics

Expansion of the natural killer (NK) subset of lymphocytes represents a rare leukemia phenotype with variations in clinical presentation, morphology, surface phenotype, and effector function. This paper reports on a 5-year-old male patient who had an unusual presentation of an NK cell leukemia that was initially diagnosed as neuroblastoma. A bone marrow (BM) aspirate showed clumps of undifferentiated cells with the following phenotype: CD56^bright+, CD33^dim+, CD45-, CD2-, CD19-, CD16-, and CD57-. Cytochemistry was noncontributory. The patient, having failed to respond to conventional neuroblastoma chemotherapy, was subsequently diagnosed as having NK cell leukemia based on functional in vitro assays. The patient responded to acute lymphoblastic leukemia (ALL) chemotherapy but relapsed 4 weeks into treatment and eventually died 25 weeks after initial presentation. The cell surface phenotype observed is consistent with a rare NK cell subset, the biology of which has not been well defined. Freshly isolated BM cells killed K562 cells in a conventional ⁵¹Cr-release assay. Both interleukin-2 (IL-2) and interferon-α (IFN-α) induced LAK activity against the Daudi cell line. IL-2 induced proliferation of the leukemic cells. TNF-α, IFN-γ, IL-6, IL-1ra, and TGF-β levels were assessed and found to be concentrated in BM, in contrast to plasma samples. TNF-α was present at a high concentration in BM (150.9 pg/ml), probably a reflection of the associated disease pathology of severe bone pain and pyrexia. In summary, this paper details clinical and laboratory investigations of a leukemia of a rare NK cell subset.     

Cytokine profile of protective anti-Trichinella spiralis CD4+ OX22− and non-protective CD4+ OX22+ thoracic duct cells in rats: secretion of IL-4 alone does not determine protective capacity

We analysed the cytokine profile of a T cell subset (CD4⁺ CD45 RC⁻) that confers protection against Trichinella spiralis infection in rats. These CD4⁺ cells are generated in the gut and appear in the thoracic duct lymph within 72 h after infection. Cytokine mRNA levels for IL-2, IL-3, IL-4, IL-5, IL-10 and IFN-γ and functional cytokine secretion for IL-4, IL-5, IFN-γ, TNF-α and mast cell differentiation activity were tested in vitro following stimulation with T. spiralis antigens. Compared to a non-protective T cell population (CD4⁺ CD45 RC⁺ or CD8⁺), also isolated from the same thoracic lymph, no significant differences were observed in the levels of mRNA for IL-2, IL-3, IL-4, IL-5, IL-10 or IFN-γ in the protective CD4⁺ CD45 RC⁻ cells. However, analysis of the cytokine activities in culture supernatant of these T cell subsets following 24 h stimulation in vitro with T. spiralis antigens showed that significant IL-4 and IL-5 activity but little IFN-γ or TNF-α was secreted by the protective CD4⁺ CD45 RC⁻ cells. Whereas the non-protective CD4⁺ CD45 RC⁺ cells secreted significant levels of IL-4, IFN-γ, mast cell differentiating activity and TNF-α but little IL-5 activity. Nonprotective CD8⁺ cells were found to secrete IL-4 but not IL-5. Production of IL-4 was essentially equal for both protective and non-protective T cell subsets. These findings suggest that the presence or absence of IFN-γ secretion, rather than IL-4 alone, determines whether a T cell subset has protective activity against T. spiralis infection in rats.     

HCV感染患者免疫细胞部分细胞因子分泌情况的初步研究

目的研究与正常人比较丙型肝炎病毒（HCV）感染患者免疫细胞分泌γ干扰素（IFN-γ）、白细胞介素10（IL-10）、肿瘤坏死因子α（TNF-α）及白细胞介素4（IL-4）的细胞频数情况,了解HCV感染对其影响。方法分离外周血单核细胞（PBMCs）,应用IL-10、IFN-γ、TNF-α及IL-4流式抗体进行细胞内因子染色,应用FACSCalibur流式细胞仪及FACSCalibur软件进行检测分析。结果HCV感染患者分泌IL-10、IFN-γ、IL-4的细胞频数在CD4＋CD8-T细胞、CD4-CD8＋T细胞、NK细胞和NKT细胞均发生明显下降;分泌TNF-α的细胞频数在CD4-CD8＋T淋巴细胞及NK细胞出现下降;HCV感染患者NK细胞、NKT细胞分泌IL-10和IFN-γ的细胞频数较CD4＋CD8-T淋巴细胞、CD4-CD8＋T淋巴细胞下降得更加明显。结论HCV感染患者的细胞免疫功能受到明显的损害,细胞因子分泌能力明显减低;固有免疫细胞功能受损可能是HCV感染慢性化的重要原因;细胞因子分泌的调节是抗HCV感染免疫治疗过程中需要调节的方向。     

白细胞介素-23对炎症性肠病患者外周血自然杀伤细胞的免疫调节作用

目的 研究白细胞介素(IL)-23对炎症性肠病(IBD)患者外周血中自然杀伤(NK)细胞促炎细胞因子分泌和细胞毒作用的影响,探讨其在IBD发病中的意义.方法 利用免疫磁珠分离12名健康人、16例克罗恩病(CD)患者和25例溃疡性结肠炎(UC)患者外周血NK细胞.体外培养NK细胞,并予空白刺激、IL-23刺激、IgG刺激或IL-23+IgG联合刺激.酶联免疫吸附试验法检测细胞培养上清中肿瘤坏死因子(TNF)-αa和干扰素(IFN)-γ分泌水平.流式细胞仪检测经不同刺激培养的NK细胞对K562细胞的细胞毒作用.结果 正常对照组的NK细胞经人IgG和IL-23单独刺激后TNF-α、IFN-γ的分泌水平未明显增高(P值均＞0.05),二者联合刺激则能显著促进TNF-α、IFN-γ分泌(P值均＜0.05).单独应用IgG刺激CD和UC患者NK细胞分泌TNF-α、IFN-γ的效果不明显(P值均＞0.05).单独应用IL-23则具刺激作用(P值均＜0.05),二者联合应用的刺激作用更明显(P值均＜0.01).IL-23单独刺激和联合刺激均不能增强正常对照组NK细胞的细胞毒作用(P值均＞0.05).但单独应用IL-23可增强UC和CD患者NK细胞的细胞毒作用(分别为51.5%±7.1%和50.2%±8.7%,P值均＜0.05),且联合刺激可进一步增强该作用(分别为65.3%±6.6%和62.4%±5.5%,P值均＜0.01).结论 IL-23能刺激IBD患者NK细胞分泌TNF-α和IFN-γ,并能增强NK细胞的细胞毒作用,可能直接参与了IBD的发病过程.     

Mature natural killer cells with phenotypic and functional alterations accumulate upon sustained stimulation with IL-15/IL-15Ralpha complexes

Cytotoxic lymphocytes such as natural killer (NK) and CD8 T cells play important roles in immunosurveillance by killing virally infected or malignant cells. The homeostatic cytokine, IL-15, promotes the development, function, and survival of NK and CD8 T cells. IL-15 is normally presented in trans as a surface complex with IL-15 receptor-alpha-chain (IL-15Rα) by dendritic cells (DCs) and monocytes. Signaling by IL-15 occurs via the IL-2/IL-15 receptor β-chain (CD122) which is expressed primarily by NK1.1(+) cells and CD8 T cells. The use of preformed complexes of IL-15 with soluble IL-15Rα complexes to boost the effector function of CD122(+) cytolytic lymphocytes such as NK and CD8 T cells has recently gained considerable attention. Here we describe the impact of transient and prolonged in vivo stimulation by IL-15/IL-15Rα complexes on NK and CD8 T cells. Whereas transitory stimulation increased the number of activated NK cells and significantly enhanced their effector function, prolonged stimulation by IL-15/IL-15Rα complexes led to a marked accumulation of mature NK cells with considerably impaired activation, cytotoxicity, and proliferative activity, and an altered balance of activating and inhibitory receptors. In contrast to NK cells, CD8 T cells exhibited an activated phenotype and robust T cell receptor stimulation and effector function upon chronic stimulation with IL-15/IL-15Rα complexes. Thus, prolonged stimulation with the strong activating signal leads to a preferential accrual of mature NK cells with altered activation and diminished functional capacity. These findings point to a negative feedback mechanism to preferentially counterbalance excessive NK cell activity and may have important implications for cytokine immunotherapy.     

Revisiting human natural killer cell subset function revealed cytolytic CD56(dim)CD16+ NK cells as rapid producers of abundant IFN-gamma on activation

The two major functions of human natural killer (NK) cells are conventionally associated with distinct cell subsets. Thus, cytolytic activity is mostly confined to the CD56(dim)CD16(+) subset, whereas cytokine production is generally assigned to CD56(bright)CD16(+/-) cells. In this study, we reevaluated the functional capabilities of these NK subsets with regard to the production of IFN-γ at different time points after cell triggering via NKp46 and NKp30 activating receptors. Different from previous studies, cytokine production was also assessed at early intervals. We show that CD56(dim) NK cells produce IFN-γ already at 2 to 4 h, whereas no cytokine production is detected beyond 16 h. In contrast, CD56(bright) cells release IFN-γ only at late time intervals (>16 h after stimulation). The rapid IFN-γ production by CD56(dim) NK cells is in line with the presence of IFN-γ mRNA in freshly isolated cells. Rapid IFN-γ production was also induced by combinations of IL-2, IL-12, and IL-15. Our data indicate that not only cytolytic activity but also early IFN-γ production is a functional property of CD56(dim) NK cells. Thus, this subset can assure a rapid and comprehensive NK cell intervention during the early phases of innate responses.     

Functional p75 interleukin-2 receptor expression on the fresh blast cells in childhood acute lymphoblastic leukemia with natural killer cell properties

Neoplastic cells of childhood acute lymphoblastic leukemia (ALL) with natural killer (NK) cell properties were studied for the expression of p75 interleukin-2 receptors (IL-2R) and the receptor functions. Freshly prepared blast cells from a patient with ALL had NK cell properties: (1) the phenotype such as CD56+, CD2+, E-rosette+, CD3-, and CD19-; and (2) the presence of spontaneous cytotoxicity against NK-sensitive K562 target cells. Although p55 Tac antigen was not detectable, there was the expression of p75 IL-2R on the freshly prepared blast cells: 70% of the cells reacted with Mik-beta 1 monoclonal antibody against p75 IL-2R as determined by flow cytometry. Two-color flow cytometry revealed that the blast cells expressed both p75 IL-2R and NKH-1. NK activity of the blast cells was augmented by their treatment with 1,000 U/ml recombinant IL-2 (rIL-2): the cytotoxicity level as percentage lysis increased to 38.7% from 22.0% when the normal lymphocyte value increased to 62.1% from 46.2%. Although the blast cells possessed no apparent level of proliferative capacity, the addition of 1,000 U/ml rIL-2 yielded a 2.7-fold increase in their thymidine uptake. These results demonstrate the expression of functional p75 IL-2R on the patient's blast cells with NK cell properties.     

β-Glucan attenuates inflammatory responses in oxidized LDL-induced THP-1 cells via the p38 MAPK pathway

AimTo investigate the immunomodulatory effects of β-(1,3/1,6)-d-glucan on atherosclerosis as well as on the molecular mechanisms of its transition.Methods and resultsHuman monocytic leukemia (THP-1) cells were differentiated into the macrophage phenotype by incubation with oxLDL in the absence or presence of β-glucan. β-glucan attenuated CD86 and CD80 expression and simultaneously reduced secretion of the inflammatory cytokines IL-2, IL-8, IL-12, TNF-α and IFN-γ. Western blot analysis showed that oxLDL treatment induced phosphorylation of p38 MAPK and ERK1/2 in PMA-differentiated THP-1 cells. However, β-glucan inhibited p38 MAPK activation. In experiments with monocytes derived from healthy donors, β-glucan inhibited IL-8, IL-12 and TNF-α production. The anti-inflammatory effects of β-glucan were also observed in atherosclerotic plaque cells.Conclusionsβ-glucan inhibited oxLDL-induced pro-inflammatory effects in macrophages via regulation of p38 MAPK phosphorylation. This novel finding may provide insight for new therapeutic strategies.     

NK cells dysfunction in systemic lupus erythematosus: relation to disease activity

Through their cytotoxic capacities and cytokine production, natural killer (NK) cells modulate autoimmune diseases. However, their role in the pathogenesis of systemic lupus erythematosus (SLE) has not been extensively studied. The aim of this study was to analyse the immunophenotypic and functional characteristics of the two major NK cell subsets in SLE and relate them with disease activity. Peripheral blood samples from 44 patients with active (n?=?18) and inactive SLE (n?=?26) and 30 controls were analysed by flow cytometry to evaluate NK cell subsets, according to: the differential expression of CXCR3 and CD57; expression of granzyme B and perforin; and production of interferon gamma (IFN-γ) and tumor necrosis alpha (TNF-α), after PMA/ionomycin activation. A clear decrease in absolute and relative numbers of circulating NK cells was found in SLE, particularly in active disease, while the proportions of the major NK cell subsets were unaffected. Active SLE was associated with a reduced CXCR3 expression on both NK cell subsets and a lower frequency of CD56^dim NK cells expressing CXCR3. Furthermore, granzyme B expression was decreased in both SLE groups, but the percentage of NK cells expressing granzyme B and perforin was higher, particularly in active disease. We found a significant decrease in the percentage of CD56^bright and CD56^dim NK cells producing TNF-α and of its expression on CD56^dim NK cells in active disease, while IFN-γ expression on CD56^bright NK cells was increased in both SLE groups. Our findings suggest that NK cell subsets exhibit unique phenotypic and functional changes that are particularly evident in active SLE, and they may have the potential to affect the disease outcome.     

ORAI1-mediated calcium influx is required for human cytotoxic lymphocyte degranulation and target cell lysis

Lymphocytes mediate cytotoxicity by polarized release of the contents of cytotoxic granules toward their target cells. Here, we have studied the role of the calcium release-activated calcium channel ORAI1 in human lymphocyte cytotoxicity. Natural killer (NK) cells obtained from an ORAI1-deficient patient displayed defective store-operated Ca(2+) entry (SOCE) and severely defective cytotoxic granule exocytosis leading to impaired target cell lysis. Similar findings were obtained using NK cells from a stromal interaction molecule 1-deficient patient. The defect occurred at a late stage of the signaling process, because activation of leukocyte functional antigen (LFA)-1 and cytotoxic granule polarization were not impaired. Moreover, pharmacological inhibition of SOCE interfered with degranulation and target cell lysis by freshly isolated NK cells and CD8(+) effector T cells from healthy donors. In addition to effects on lymphocyte cytotoxicity, synthesis of the chemokine macrophage inflammatory protein-1β and the cytokines TNF-α and IFN-γ on target cell recognition was impaired in ORAI1-deficient NK cells, as previously described for T cells. By contrast, NK cell cytokine production induced by combinations of IL-12, IL-15, and IL-18 was not impaired by ORAI1 deficiency. Taken together, these results identify a critical role for ORAI1-mediated Ca(2+) influx in granule exocytosis for lymphocyte cytotoxicity as well as for cytokine production induced by target cell recognition.     

肝细胞癌患者外周血NK细胞频率及受体表达

目的检测肝细胞癌(hepatocellular carcinoma,HCC)患者外周血NK细胞频率、功能及受体表达的变化,并分析其在HCC患者中表达特点。方法用流式细胞术检测36例HCC患者、34例乙型肝炎肝硬化(liver cirrhosis,LC)患者的外周血NK细胞频率及其受体CD158a、CD158b、NKG2D、NKP30、NKP44、NKP46的表达情况,用IL-12刺激外周血单个核细胞(peripheral blood mononuclear cell,PBMC)、流式细胞术检测NK细胞分泌IFN-γ、TNF-α的能力,并用流式细胞毒性分析法检测NK细胞对K562细胞的杀伤效率,对2组NK细胞频率、受体及功能进行分析和比较。结果 2组患者NK细胞的频率差异无统计学意义(P0.05)。CD56dimNK细胞的活化性受体NKG2D、NKP30表达在HCC组高于LC组(P0.05)。在IL-12刺激下HCC组CD56brightNK细胞IFN-γ、TNF-α表达率、CD56dimNK细胞IFN-γ表达率均低于LC组(P0.05)。HCC组NK细胞对K562的杀伤比例高于LC组(P0.05)。结论 HCC组NK细胞分泌细胞因子能力低于LC组,但杀伤功能强于LC组,可能与其表面活化性受体高表达有关。     

Behçet’s disease: immunological relevance with arthritis of ankylosing spondylitis

Behçet’s disease (BD) is a multi-system inflammatory disorder, in which cytokine balance is polarized to Th1. In this study, the cell surface molecule expression, Th1/Th2, inflammatory cytokine levels in blood, and synovial fluid of CD3⁺ T lymphocytes in BD were investigated. The study group consisted of 10 BD, 10 ankylosing spondylitis (AS) patients with peripheral arthritis, and 10 healthy subjects. Expression of cell surface molecules, intracellular IL-2, IL-5, IL-8, IL-10, IL-12, IFN-γ, and TNF-α levels in CD3⁺ T lymphocytes were determined by flow cytometry in synovial and peripheral blood mononuclear cells (PBMCs). Synovial and plasma cytokine levels were measured by ELISA and CBA. In PBMCs, CD4, CD25, HLA-DR expression and intracellular IL-12, and TNF-α levels of CD3⁺ T lymphocytes were statistically increased in BD patients compared to healthy subjects. Compare to AS patients, CD25 and HLA-DR surface expression and intracellular IFN-γ and TNF-α levels in T cells were significantly elevated in BD patients. In BD patients, there was an increase in IL-8 secretion; however, in AS patients, both Th1- and Th2-type cytokines were increased compare to healthy subjects. Intracellular cytokine expression did not show any difference in BD patients; however, IL-12 content of synovial fluid was significantly increased compared to AS patients. Our findings revealed that Th1 polarization occurred in both peripheral blood and synovial fluid of BD patients with arthritis. It is found no difference between synovial fluid analysis of BD and AS patients, showing the similarities in the pathogenesis of both diseases.     

Alterations in Tumor Necrosis Factor-α, Interferon-γ, and Interleukin-6 Production by Natural Killer Cell-Enriched Peripheral Blood Mononuclear Cells in Chronic Alcoholism: Relationship with Liver Disease and Ethanol Intake

No previous studies have been reported on human alcoholism in which the pattern of cytokine secretion by natural killer (NK) cells is explored. The goal of the present study was to evaluate the role of NK cells in the production of cytokines in patients with chronic alcoholism, analyzing at the same time the possible relationship between cytokine production and both alcoholic liver disease and ethanol (EtOH) intake. A total of 30 chronic alcoholic patients—11 without liver disease [alcoholics without liver disease (AWLD) group] and 19 diagnosed of alcoholic liver cirrhosis—were included in this study. Twenty-five age- and sex-matched healthy volunteers were analyzed as controls. Production of interferon (IFN)-γ, tumor necrosis factor-α (TNF-α), and interleukin (IL)-6 was performed on NK-enriched peripheral blood mononuclear cells (PBMC) after stimulation with IL-2 and IFN-α. In AWLD patients, the production of TNF-α was significantly reduced, compared with normal controls, under both IFN-α (p < 0.01) and IL-2 (p < 0.05) stimulation. In patients with cirrhosis, TNF-α production by PBMC enriched in NK cells varied depending on the EtOH intake status at the moment of evaluation. Accordingly, an increased concentration of this cytokine was detected in the supernatants of cirrhotic patients and active EtOH intake, particularly after IFN-α stimulation (p < 0.05); whereas, in patients with at least 1 year of alcohol withdrawal, TNF-α levels remained within normal range. The results on the production of IL-6 and IFN-γ in AWLD and cirrhotic patients showed that only cirrhotic patients with a prolonged EtOH withdrawal period display abnormal production. Accordingly, in this group of patients, a significantly increased release of IL-6 was observed after both IFN-α and IL-2 stimulation (p < 0.01 and p < 0.05, respectively). By contrast, a lower IFN-γ production (p < 0.005) was detected with respect to the control group. Our results point to the existence of an abnormal cytokine secretion by NK cells from chronic alcoholism patients, which depend on both the existence of liver disease and the status of EtOH intake.     

Development of IL-22-producing NK lineage cells from umbilical cord blood hematopoietic stem cells in the absence of secondary lymphoid tissue

Human secondary lymphoid tissues (SLTs) contain interleukin-22 (IL-22)-producing cells with an immature NK phenotype. Given their location, these cells are difficult to study. We have generated large numbers of NK22 cells from hematopoietic stem cells. HSC-derived NK22 cells show a CD56(+)CD117(high)CD94(-) phenotype, consistent with stage III NK progenitors. Like freshly isolated SLT stage III cells, HSC-derived NK22 cells express NKp44, CD161, CCR6, IL1 receptor, AHR, and ROR-γτ. IL-1β and IL-23 stimulation results in significant IL-22 but not interferon-γ production. Supernatant from these cells increases CD54 expression on mesenchymal stem cells. Thus, IL-22-producing NK cells can be generated in the absence of SLT. HSC-derived NK22 cells will be valuable in understanding this rare NK subset and create the opportunity for human translational clinical trials.     

Enrichment of interleukin-2-responsive natural killer progenitors in human bone marrow

Natural killer (NK) cells can be cultured in interleukin-2 (IL-2)- containing medium from selected human bone marrow (BM) cells obtained after the elimination of mature T and NK cells. To isolate and characterize IL-2-responsive NK progenitors in the selected BM cells, we investigated the expression of IL-2 receptors (IL-2R) on these cells. Neither CD25 (IL-2R alpha) nor IL-2R beta antigen was observed on the selected BM cells before culture. However, CD25+ cells without detectable levels of IL-2R beta antigen appeared 24 hours after culture in IL-2-containing medium. Cells were sorted from each fraction of the selected BM cells 24 hours after culture after staining with anti-CD33, anti-CD34, and anti-CD25 monoclonal antibodies. The generation of NK cells (CD3- CD56+ cells) and NK activity were observed only from the CD33-/CD34-/CD25+ cell fraction after culture in IL-2-containing medium. The frequency of IL-2-responsive NK progenitors relative to the fraction was 1/231 (95% confidence range, 1/156 to 1/289), which corresponded to the frequency relative to the total number of selected BM cells when the frequency relative to the CD33-/CD34-/CD25+ cell- fraction was converted according to the percentage of these cells in the total number of selected BM cells. These results indicated that IL- 2-responsive NK progenitors were enriched in the CD33-/CD34-/CD25+ cell fraction.     

Natural killer expansion,human leukocyte antigens‐E expression and CD14+ CD56+ monocytes in a myelodysplastic syndrome patient

Myelodysplastic syndromes (MDS) are clonal disorders characterized by ineffective hematopoiesis and possible evolution to acute leukemia. Occurrence of stem cell defects and of immune‐mediated mechanisms was evidenced as relevant for pathophysiology of MDS. Here, we described one case of MDS patient carrying CD14⁺CD56⁺ monocytes in bone marrow (BM), in the presence of a defective human leukocyte antigen (HLA)‐E expression on peripheral blood (PB) cells and of natural killer (NK) cell expansion in PB and BM. The defective HLA‐E expression and the NK expansion are proposed to be relevant for the pathogenesis of myelodysplasia in those patients showing CD14⁺CD56⁺ monocytes in BM.     

依那西普治疗降低强直性脊柱炎外周血T细胞活性

目的 研究肿瘤坏死因子(TNF)-α抑制剂依那西普(Etanercepl)对强直性脊柱炎(AS)患者外周血T细胞活性的影响.方法 10例健康志愿者,40例活动性AS患者,随机给予依那西普(50 mg,皮下注射,每周1次)或安慰剂治疗,治疗前后分离外周血单个核细胞(PBMC),酶联免疫斑点法(ELISPOT)分别检测分泌TNF-α、白细胞介素(IL)-2、干扰素(IFN)-γ的细胞数量.WST-1法检测T细胞增殖.结果 依那西普治疗后,分泌TNF-α的单核细胞数量减少;抗CD3和抗CD28抗体刺激后,分泌IL-2和IFN-γ的T细胞数量减少.CD4+/CD8+T细胞增殖没有明显变化.结论 抗TNF-α的治疗降低了AS患者外周血T细胞的活性,改善了AS患者病情.     

髓系／NK前体细胞急性白血病1例并文献复习

目的:提高对髓系/NK前体细胞急性白血病的认识.方法:报道1例髓系/NK前体细胞急性白血病资料,并复习文献,总结该病临床及实验室检查特点.结果:患者以腹部症状起病,肝脾显著肿大.流式细胞仪免疫表型分析HLA-DR( )、CD11c( )、CD11b( )、CD13( )、CD33( )、CD38( )、CD56( )、MPO( ).经两疗程CHOP方案化疗,骨髓象部分缓解,但是髓外浸润加重,后改用VDP方案,最终因出现感染、DIC、多器官功能衰竭而死亡.结论:急性NK细胞白血病具有独特的临床、组织病理学和免疫表型特征,对现有化疗不敏感,预后恶劣.     

Generation of natural killer cells from Thy 1.1+ bone marrow precursor cells in the rat

We have recently described a long-term bone marrow culture (LTBMC) system in the rat for the generation of natural killer (NK) cells from bone marrow (BM) precursors in the presence of interleukin-2 (IL-2). We found that the LTBMC-conditioned medium was essential to render the NK precursor cells responsive to IL-2. In this report, we isolated by flow cytometric cell sorting Thy 1.1+ BM cells, which have been shown to contain pluripotent stem cells and early precursor cells of various hematopoietic lineages. These Thy 1.1+ immature BM precursors did not generate any detectable NK activity when cultured for 7 days with IL-2 alone. However, when the cells were cultured with IL-2 in the presence of LTBMC-conditioned medium, NK cells were generated as demonstrated by cytolytic activity against NK-sensitive tumor targets, large granular lymphocyte (LGL) morphology, and the acquisition of NK cell-associated phenotype (72% of the cells were 3.2.3+/OX41-/CD5-). This study demonstrates the existence of an IL-2 unresponsive Thy 1.1+ NK precursor in the BM of the rat, that can differentiate to a mature NK cell in the presence of LTBMC-conditioned medium and IL-2.