食管鳞癌患者外周血Th17细胞的检测及意义

目的检测食管鳞癌患者外周血Th17细胞的比例变化,探讨其临床意义。方法采用流式细胞术检测33例食管鳞癌患者及18例健康志愿者外周血单个核细胞中Th17细胞占CD4＋T细胞的比例;收集患者的临床及病理资料,分析Th17细胞的比例变化与临床及病理特征的关系。结果食管鳞癌患者外周血单个核细胞中Th17细胞占CD4＋T细胞的比例为（6.3±3.5）%,显著高于健康对照组的（1.8±1.2）%（P〈0.01）;食管鳞癌患者外周血Th17细胞比例与患者年龄、性别及肿瘤位置、大小、分化程度及浸润深度无明显相关性（P〉0.05）,与淋巴结转移情况及TNM分期明显相关（P均〈0.01）。结论 Th17细胞参与了食管鳞癌的发生、发展,检测其水平对判断病期及预后有一定价值。     

外周血自然杀伤T细胞比例变化与非酒精性脂肪性肝病的关系

目的 探索外周血自然杀伤T(NKT)细胞比例变化与非酒精性脂肪性肝病(NAFLD)的关系.方法 应用流式细胞术检测60例NAFLD患者和60名年龄、性别配对的正常对照者外周血NKT细胞比例,同时比较两组间各项临床变量的差异并分析各项临床变量与外周血NKT细胞比例变化的关系,Logistic回归分析筛选NAFLD发病的危险因素.结果 正常对照组外周血NKT细胞比例的中位数及四分位数区间为1.48%(1.23%～1.98%),NAFLD组为1.12%(0.87%～1.54%),两组差异有统计学意义(P＜0.001).Spearman相关分析发现外周血NKT细胞比例与体重指数、腹围、丙氨酸转氨酶水平呈负相关(r值分别为-0.322、-0.237、-0.217;P值分别为0.001、0.021、0.035).Logistic回归分析发现外周血NKT细胞比例、体重指数、天冬氨酸转氨酶、空腹血糖与NAFLD的发病危险因素有关(OR值分别为0.107、2.991、1.148和3.133,P值分别为0.023、0.003、0.026和0.013).结论 NAFLD患者外周血NKT细胞比例是下降的,且该比例下降可能是NAFLD发病的危险因素之一.     

食管鳞癌患者外周血NK细胞、γδ T细胞变化的临床意义

目的探讨食管鳞癌患者外周血NK细胞、γδT细胞变化的临床意义。方法选择食管鳞癌患者35例（食管鳞癌组）,体检健康者18例（对照组）;采用流式细胞仪检测两组外周血NK细胞、γδT细胞。结果与对照组比较,食管鳞癌组NK细胞占淋巴细胞的比例稍升高、但无统计学差异（P〉0.05）,γδT细胞占淋巴细胞的比例明显降低（P〈0.05）;食管鳞癌组0～Ⅱ期患者的NK细胞比例明显高于Ⅲ～Ⅳ期者（P〈0.01）,0～Ⅱ期与Ⅲ～Ⅳ期患者γδT细胞占淋巴细胞的比例无统计学差异（P〉0.05）。结论食管鳞癌患者免疫功能紊乱,且随病情加重而发展。     

特发性血小板减少性紫癜患者外周血单个核细胞中糖皮质激素诱导的亮氨酸拉链蛋白mRNA表达的研究

目的探讨特发性血小板减少性紫癜（ITP）患者使用糖皮质激素治疗前后外周血单个核细胞中GILZmRNA的表达及作用。方法选择未使用糖皮质激素治疗的ITP患者23例（病例对照组）、使用糖皮质激素治疗后的患者22例（治疗组）及健康体检者22例（正常对照组）作为研究对象,采用RT—PCR法检测其外周血单个核细胞中GILZmRNA的表达,同时采用ELISA法检测其血清中IFN-γ、IL-10的表达。结果与正常对照组相比,病例对照组GILZmRNA表达明显降低（P〈0．01）,IFN-γ表达明显升高（P〈0．01）,IL-10表达明显降低（P〈0．01）,而治疗组GILZmRNA、IFN-γ、IL-10表达差异则无明显统计学意义（P均〉0．05）。结论糖皮质激素可以上调TP患者外周血单个核细胞中GILZmRNA表达;GILZmRNA表达上调可明显抑制Th1细胞因子分泌,增强Th2细胞因子分泌,纠正ITP患者血清中Th1／Th2的失衡。     

香烟烟雾提取物对CD4^＋T细胞向Th17细胞和调节性T细胞分化的影响

目的观察香烟烟雾提取物（CSE）对CD4^＋T细胞向Th17细胞和调节性T细胞分化的影响,为探索香烟烟雾暴露导致气道慢性炎症的机制提供实验依据。方法采用免疫磁珠法分离纯化健康志愿者外周血CD4^＋T细胞,以1×10^6／ml细胞密度接种于96孔培养板,分为以下8个组①空白对照组;②T细胞刺激剂组：加入T细胞刺激剂抗人CD3／28抗体微磁珠;③T细胞刺激剂CSE干预组：CD3／28＋2%CSE;④细胞因子组：CD3／28＋细胞因子;⑤细胞因子CSE干预组：CD3／28＋细胞因子＋2％CSE;⑥芳香烃受体（AHR）激动剂6-甲酰基吲哚[3,2-b]咔唑（FICZ）组CD3／28＋细胞因子＋FICZ;⑦AHR拮抗剂白藜芦醇组：CD3／28＋细胞因子＋2％CSE＋白藜芦醇;⑧溶剂对照组：CD3／28＋细胞因子＋DMSO。细胞因子为含TGF-β/IL-1β／IL-6／IL～23的混合细胞因子,以诱导Th17细胞和调节性T细胞分化。培养5d后,收集细胞,采用流式细胞术检测细胞表面分子CD4^＋CD25^＋Foxp3^＋细胞（Treg细胞）,以及胞内细胞因子IL-17＋的CD4^＋T细胞（Th17细胞）,计算各种刺激培养条件下,诱导生成的Th17及Treg细胞占CD4^＋T细胞的百分比。结果①CSE对Th17细胞分化的影响：空白对照组Th17细胞比例为（0．69±0．12）％,加入T细胞刺激剂后为（1．32±0．12）％,在此基础上加入CSE的干预组IL-17＋细胞比例升高为（2．17±0．24）％,（t=3．21,P〈0．01）;细胞因子组IL-17＋细胞比例为（1．35±0．08）％,而在此基础上加入CSE的干预组Th17细胞升高为（2．58±0．39）%（t=3．13,P〈0．01）。②CSE对Treg细胞分化的影响：在空白对照组中,Treg细胞占CD4^＋T细胞中的比例为（0．21±0．19）％,在加入T细胞刺激剂后,Treg细胞比例升高（3．59±0．37）％,加入细胞因子后,Treg细胞比例明显增加（5．85±0．76）％;在继续加入CSE干预后,Treg细胞比例明显减少（3．07±0．33）％（t=3．74,P〈0．01）;同样,T细胞刺激剂CSE干预组也出现Treg细胞比例减少（2．19±0．19）％,（t=2．71,P〈0．05）。③AHR活化对Treg细胞和Th17细胞分化的影响：AHR激动剂FICZ组的Treg细胞比例明显低于细胞因子组[（2．60±0．40）％,（5．85±0．76）％]（t=4．18,P〈0．01）,但Th17细胞比例升高[（2．86±0．43）％,（1．35±0．08）％]（t=3．65,P〈0．01）。AHR阻断剂白藜芦醇组中的Treg细胞比例和Th17细胞比例均低于细胞因子组,分别为[（0．33±0．14）％,（5．85±0．76）％],（t=7．71,P〈0．01）和[（0．42±0．07）％,（1．35±0．08）％],（t=8．87,P〈0．001）,并且和空白对照组接近,在细胞培养第5天通过7-AAD-AnnexinV对该组细胞检测并未发现细胞异常凋亡或死亡情况,结合该组细胞培养过程中的镜下形态推测该实验组CD4^＋T细胞的分化增殖受到白藜芦醇抑制。结论CSE可促进CD4^＋T细胞向Th17细胞分化,并抑制Treg细胞分化,这一过程可能通过AHR诱导。     

流式细胞仪检测急性病毒性心肌炎T淋巴细胞亚群及NK细胞的意义

目的观察急性病毒性心肌炎T淋巴细胞亚群及自然杀伤（NK）细胞的意义，探讨其发病机制。方法采用流式细胞术对急性病毒性心肌炎病人（观察组）进行CD3、CD4、CD8和NK细胞淋巴细胞亚群检测，并设正常人群作对照组。结果观察组CD8和NK明显高于对照组（P〈0．01），CD4和Th／Tc比值明显低于对照组（P〈0．01），观察组CD3的变化不明显（P〉0．05）。结论急性病毒性心肌炎病人淋巴细胞亚群中CD4、CD8和NK细胞亚群异常增殖；而且Th／Tc比例失衡，揭示细胞免疫功能紊乱与急性病毒性心肌炎有关。     

不同基因型慢性乙型肝炎患者外周血辅助性T细胞分化和树突状细胞的功能

目的探讨不同基因型的慢性乙型肝炎（乙肝）患者体内辅助性T细胞（Th）和树突状细胞（DCs）功能差别。方法检测29例不同基因型慢性乙肝患者外周血Th细胞因子（IL-12、IL-2、IL-4）的表达，并对其中20例不同基因型患者进行外周血DC的分离和体外诱导培养，观测其形态和数量变化，检测DC分泌的IL-12含量，对数据应用t检验进行统计学分析。结果慢性乙肝患者与正常对照组比较，外周血IL-12、IL-2、IL-4表达明显升高（t=2．9272，P〈0．01；P〈0．01；P〈0．05）。C型患者组与D型患者组比较，丙氨酸转氨酶（ALT）、IL-12、IL-2、Th1／Th2明显升高（t=2．4626，P〈0．05；P〈0．05；P〈0．05；P〈0．01），IL-4明显降低（P〈0．05）。慢性乙肝患者外周血的单核细胞经培养和细胞因子诱导后，可获得成熟的具有典型形态的DC。慢性乙肝患者组与正常对照组比较，DC数量明显减少（t=5．4186，P〈0．01）。DC分泌的IL-12水平明显降低（t=3．265，P〈0．01）。不同基因型患者之间DC的数量与DC分泌IL-12差异无统计学意义。结论慢性乙肝患者体内存在Th分化的不平衡；C型慢性乙肝患者体内Th1优势应答，肝脏炎症较重，治疗效果及预后较差。     

三种来源CIK细胞体外增殖及杀伤活性比较

目的为白血病的治疗提供理论依据。方法用Fieoll两步分离法分别从正常人、非霍奇金淋巴瘤患者外周血和脐血中分离获得单个核细胞;细胞因子诱导培养成细胞因子诱导的杀伤细胞（CIK）。流式细胞仪检测CIK的免疫表型,MTT法测定其对白血病K562细胞的杀伤活性。结果三种不同来源的单个核细胞均可诱导成CIK,脐血来源的CIK其扩增效率和杀伤活性均优于其他两种来源,差异有显著性（P〈0．01）。结论脐血来源的CIK细胞体外增殖快,杀伤活性强;脐血具有来源方便、免疫原性弱、含有大量造血干细胞、单个核细胞提取率高、输注时移植物抗宿主病（GVHD）发生率低等优点,白血病治疗时可优先考虑。     

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。     

树突状细胞增强细胞因子诱导的杀伤细胞抗神经胶质瘤细胞作用及机制研究

目的探讨细胞因子诱导的杀伤细胞（CIK）与树突状细胞（DC）共培养后DC-CIK混合细胞抗神经胶质瘤细胞的免疫作用。方法分离健康人外周血单个核细胞,分别于体外诱导DC和CIK,然后共培养成DC-CIK细胞。实验分DC组、DC-CIK组、DC-T组和CIK组。Elisa试剂盒检测各组培养上清中IL-12和IFN．1的含量,流式细胞仪检测细胞表型,CCK一8法体外检测对神经胶质瘤细胞的杀伤活性。结果DC-CIK组培养上清中IL-12和IFN-1的含量分别为（110．24±2．22）mg／L和INF·Y／（913．46±20．64）mg／L,明显高于其它三组（P〈0．05）。DC—CIK组cDi细胞（61．34-1．31）％、CD3／CD56细胞（29．4±1．03）％也明显增加（P〈0．05）。对神经胶质瘤细胞的杀伤活性,DC—CIK组为（54．67±2．62）％,与DC组（19．44±1．07）％、DC—T组（21．27±1．85）％和CIK组（36．52±2．06）％比较,差异有统计学意义（P〈0．05）。结论DC—CIK细胞能诱导明显的神经胶质瘤细胞杀伤活性,为颅内肿瘤的免疫治疗提供了依据。     

The effect of iron, iron-binding proteins and iron-overload on human natural killer cell activity

The in vitro natural killer (NK) activity of peripheral blood lymphocytes (PBL) was assessed in 13 patients with genetic haemochromatosis (HC) and 27 normal subjects, using a ⁵¹Cr-release cytotoxicity assay against the target K-562 leukaemic cell line. Mean NK function did not differ between these two groups. This conclusion differs from the reported deficit in NK activity in other diseases in which increased iron stores may occur, including alcoholic cirrhosis and β-thalassaemia major. The effect of ferric citrate (0.1–1.0 mmol/1), normal human liver ferritin (100–10 000 μg/1) and transferrin (2 g/1) on NK activity was also assessed for both groups. In neither group was NK activity affected by any of these additives. These results suggest that peripheral blood NK function is not compromised in haemochromatosis, and that the diminished NK activity which has previously been reported in some patients with thalassaemia or alcoholic cirrhosis is due to factors other than to a direct effect of increased iron stores.     

Deficiency of inducible suppressor cell activity in the Chediak-Higashi syndrome

Peripheral blood lymphocytes from two Chediak-Higashi syndrome (CHS) patients were examined for their 1) natural killer (NK) cell functions 2) concanavalin A (Con A)-inducible suppressor cell activity, 3) soluble suppressor factor production, and 4) responsiveness to interferon alpha and interleukin-2 in comparison with age-matched normal controls. Peripheral blood lymphocytes or NK-enriched large granular lymphocytes from Chediak-Higashi syndrome patients showed negligible cytotoxic activity against several target cells. Although the NK activity of Chediak-Higashi syndrome lymphocytes could not be restored to normal levels by treatment with either interferon or interleukin-2, the percent enhancement of NK activity was higher for the patients than the controls. Soluble suppressor factor activity of culture supernates from the lymphocytes of Chediak-Higashi syndrome patients significantly inhibited the NK activity of allogeneic, normal peripheral blood lymphocytes, whereas lymphocytes from Chediak-Higashi syndrome patients precultured with Con A failed to suppress the cytotoxic activity of normal lymphocytes. These results demonstrate a previously unrecognized suppressor cell dysfunction in CHS patients.     

Natural killer cell and islet killer cell activities in Type 1 (insulin-dependent) diabetes

Summary Peripheral blood mononuclear cells from 20 Type 1 (insulin-dependent) diabetic patients were examined for natural killer cell activity using the K562 cell line as⁵¹Cr labeled targets. Mean natural killer cell cytotoxicity mediated by enriched non-T cells from patients (37 ± 4.0%) was lower (p < 0.03) than in controls (56 ± 3.7%). Specificity was evaluated by examining other patient subgroups. Mean non-T cell mediated natural killer cell activity in Type 2 (non-insulin-dependent) diabetic patients and Type 1 patients with long term disease was 65±54% and 62±4.8% respectively (p<0.003 vs new onset Type I patients). Longitudinal studies of new onset Type 1 patients during the remission (honeymoon) phase revealed persistently impaired natural killer cell activity in 3 of 4 patients. In 30 new onset and 11 remission Type 1 diabetic patients, mean non-T cell-mediated cytotoxicity was also measured using dispersed⁵¹Cr labeled islet target cells. Mean islet cytotoxicity mediated by cells from new onset patients was 34±2.4%, whereas in non-diabetic control subjects mean cytotoxicity was 25 ± 1.8% (p < 0.005). During remission, islet cytotoxicity remained at similar or elevated levels in most patients. In patients evaluated simultaneously for K562 and islet cell cytotoxicity, natural killer cell activity was decreased, whereas islet killing was increased. These results suggest a dichotomy in natural killer cell and islet killer cell activities in new onset Type 1 diabetes that could have an important role in the pathogenesis of Type diabetes.     

A long-term study of patients with chronic natural killer cell lymphocytosis

Chronic natural killer cell lymphocytosis is a persistent state of natural killer (NK) cell (CD3-CD16/CD56+) excess in the peripheral blood that is not associated with clinical lymphoma. In 16 consecutive patients (median age 60.5 years, range 7-77), males were overrepresented (M:F 7:1) and the median absolute NK cell count was 4.09 x 10(9)/l (range 1.2-16.6). Bone marrow examination was performed in 14 patients and showed atypical granulomata in two; chromosome studies in seven patients were normal. Clonal T-cell receptor gene rearrangement was not found in any of 12 patients evaluated. At presentation, seven patients (44%) had no clinical symptoms or signs and the others had vasculitic skin lesions (three patients), non-neutropenic fever (three patients), recurrent neutropenic infection (two patients), musculoskeletal symptoms (two patients), peripheral neuropathy (two patients), aphthous ulcers (one patient), and splenomegaly (one patient). Five patients had anaemia, five had neutropenia, and two had thrombocytopenia. After a median follow-up of 5.1 years (range 0-10.2) from immunophenotypic diagnosis or 5.7 years (range 0.1-14.1) from documentation of absolute lymphocytosis, vasculitic glomerulonephritis developed in one patient, accelerated splenomegaly developed in a patient receiving myeloid growth factor treatment, and severe aplastic anaemia developed in one patient. Treatment with nonsteroidal anti-inflammatory drugs or immunosuppressive agents was variably successful.     

Lymphoproliferative disease of 'lak cell' precursor large granular lymphocytes in association with celiac disease

We have investigated a case of lymphoproliferative disease of large granular lymphocytes (LDGL) occurring in association with celiac disease, anemia, neutropenia, and carcinomas of the endometrium, breast, and skin. The large granular lymphocyte (LGL) proliferation was monoclonal, T cell in origin, with T cell receptor β-chain gene rearrangement, and a CD3⁺, CD8⁺, CD16^± phenotype. In spite of the high frequency of LGL, natural killer (NK) cell activity was absent. Stimulation with interleukin-2 in vitro, however, resulted in high lymphokine-activated killer (LAK) cell activity against NK-resistant targets. The T-cell nature of the LAK precursor cells is in contrast to the majority seen in normal peripheral blood. Therapeutic trials of cyclosporin A, low-dose cyclophosphamide, and levamisole were unsuccessful in reducing transfusion requirements. This case is unique in the association of LDGL with celiac disease. It is also unique in that the patient had been followed for several years prior to the onset of the LDGL. The case extends the list of lymphoproliferative disorders documented to be associated with celiac disease and, conversely, adds to our knowledge of lymphoproliferative disorder of LGL and its 'dysimmune' manifestations.     

Analysis of natural killer (NK) cell activity and adhesion molecules on NK cells from umbilical cord blood

The activity of natural killer (NK) cells in human umbilical cord blood (CB) has been reported to be low, compared with that in adult peripheral blood (PB) in vitro. To examine the cause of this, after dividing the CD56+/CD3- cells in CB and PB into CD56bright and CD56dim NK cells, the NK cell activities and the expression of various surface antigens were assayed for each fraction. The NK cell activity of CD56dim NK cells in CB was significantly lower than that in PB (P = 0.0003), whereas, there was no significant difference between the NK cell activity of CD56bright NK cells in PB and CB. The expression levels of adhesion molecules (CD2, CD11a, CD18, DNAX accessory molecule-1), CD16, and CD57 for CD56dim NK cells in CB were significantly lower than those in PB, and approximately one-third of CB CD56dim NK cells were capable of forming conjugates with K562 cells, compared with PB CD56dim NK cells. Furthermore, the inhibition of both the NK cell activities and binding of CD56dim NK cells in PB and CB by monoclonal antibody against each of these adhesion molecules suggests that they play an important role in NK cell activity. These findings show that the low NK cell activity in CB is caused by the low NK cell activity of CD56dim NK cells and that the low expression level of adhesion molecules on CB CD56dim NK cells may contribute to this low NK cell activity.     

Natural killer cell depletion and diabetes mellitus in the BB/Wor rat (revisited)

Summary The BB/Wor diabetes-prone rat is an animal model of human insulin-dependent diabetes mellitus. In this model of spontaneous autoimmunity, natural killer cells are candidate cytotoxic effector cells, believed to be the mediators of beta-cell cytolysis in vivo. We therefore studied the effects of an anti-natural killer cell monoclonal antibody on the spontaneous development of diabetes in the BB/Wor rat. The 3.2.3 monoclonal antibody recognizes a molecule present on rat natural killer cells and selectively depletes these cells in vivo. Chronic treatment of diabetic-prone rats with 3.2.3 monoclonal antibody cleared circulating phenotypic natural killer cells, depleted in vitro spleen natural killer cell function, and profoundly reduced intra-islet accumulation of 3.2.3⁺ cells, but did not prevent or delay the onset of diabetes. These results indicate that natural killer cells are not necessary for the development of spontaneous diabetes in BB/Wor rats.     

Therapeutic Effect of Repeated Natural Killer T Cell Stimulation in Mouse Cholangitis Complicated by Colitis

Primary sclerosing cholangitis is often complicated by ulcerative colitis. Recently, we reported on Th1-dominant cholangitis associated with experimental colitis, and natural killer T (NKT) cells might play an important role in this model. The aim of this study was to clarify the immunopathogenic role of NKT cells in this model using α-galactosylceramide. CD-1 mice were administered 2.0% dextran sulfate sodium for 29 days and injection of α-galactosylceramide was performed every 5 days, then inflammation was assessed. Mononuclear cells from the liver were analyzed with respect to cytokine production and the surface marker. α -Galactosylceramide improved survival rate, weight gain, and inflammation score. Also, interferon-γ release from MNC, CD4/CD8 ratio, NKT cell population, and NK cell population were decreased by this treatment. These findings indicate that repeated stimulation of NKT cells modifies the Th1/Th2 balance to reduce Th1 dominance, and this may be a mechanism by which α -galactosylceramide has a therapeutic effect.     

Intrahepatic natural killer T cell populations are increased in human hepatic steatosis

AIM: To determine if natural killer T cell (NKT) populations are affected in nonalcoholic fatty liver disease (NAFLD). METHODS: Patients undergoing bariatric surgery underwent liver biopsy and blood sampling during surgery. The biopsy was assessed for steatosis and immunocyte infiltration. Intrahepatic lymphocytes (IHLs) were isolated from the remainder of the liver biopsy, and peripheral blood mononuclear cells (PBMCs) were isolated from the blood. Expression of surface proteins on both IHLs and PBMCs were...     

Natural killer or natural killer/T cell lineage large granular lymphocytosis associated with dasatinib therapy for Philadelphia chromosome positive leukemia

Dasatinib, a dual tyrosine kinase inhibitor, is known to modulate or suppress T-cell activation and proliferation. We report a series of 8 patients who developed chronic peripheral lymphocytosis, identified as natural killer cells or natural killer/T-cells based on their large granular lymphocyte morphologies and CD16⁺, CD56⁺, CD3⁻ or CD3⁺ immunophenotypic profiles, out of 18 patients receiving dasatinib therapy. All cases that developed large granular lymphocyte lymphocytosis achieved optimal molecular response (8/8 in large granular lymphocyte⁺ patients vs. 3/10 in large granular lymphocyte⁻ patients, p=0.002). A ⁵¹Cr release assay demonstrated that natural killer cell cytotoxicity has been enhanced in a case of large granular lymphocyte lymphocytosis compared to normal healthy donors, and that natural killer cell cytotoxicity in dasatinib-responders was superior to that in non-responders. In summary, the present study suggests that natural killer or natural killer/T cell lineage large granular lymphocyte lymphocytosis develops in association with dasatinib therapy and that large granular lymphocyte might have a therapeutic effect on Ph⁺ leukemic cells.