环孢素A联合沙利度胺治疗骨髓增生异常综合征对T细胞亚群影响的初步研究

为探讨环孢素A联合沙利度胺治疗骨髓增生异常综合征对T细胞亚群的影响,我们对2007年6月至2012年6月我院血液内科门诊和住院低中危MDS患者22例,在给予环孢素A联合沙利度胺治疗前后,应用流式细胞仪对于患者和健康志愿者外周血标本进行T淋巴细胞亚群检测。我们发现:CD4+T细胞在MDS患者外周血的百分比低于正常对照组(P<0.05),CD4/CD8比值与正常对照组相比有显著性差异(P<0.05)。治疗显效组患者治疗后的CD4+T细胞百分率增高(P<0.05),CD8+T细胞百分率减低(P<0.01),CD4/CD8比值在治疗前后有显著性差异(P<0.05)。在治疗前,无效组和显效组在T细胞总数百分率,CD4+T、CD8+T细胞百分率以及CD4/CD8的比值均有统计学意义(P<0.05)。由此我们认为,MDS患者存在T淋巴细胞亚群免疫失调,细胞免疫功能紊乱。CsA以及沙利度胺治疗MDS的机制可能与Th,Ts细胞比率改变有关。     

再生障碍性贫血患者外周血CD4~＋CD25~＋调节性T细胞及Foxp3的变化及临床意义

目的:探讨再生障碍性贫血(AA)患者外周血中CD4+CD25+调节性T细胞(Tress)及Foxp3的表达及临床意义.方法:25例AA病人,其中含非重型再障(nSAA)18例、重型再障(SAA)7例,采用四色流式细胞检测技术分析从患者外周血单个核细胞(PBMC)中CD4+T细胞、CD4+CD25+/CD4+、CD4+CD25high/CD4+T细胞百分比及绝对计数,并进一步分析AA患者PBMC的CD4++CD25+、CD4+CD25low及CD4+CD25highT细胞中Foxp3+T细胞的百分比,同时利用RT-PCR方法检测PBMC中Foxp3mRNA表达水平,并与29例正常对照组的上述指标进行比较.结果:与正常对照组相比,SAA患者及nSAA患者PBMC中CDM+T细胞、CD4+CD25+/CD4+、CD4+CD25high/CD4+百分比及绝对计数减低(P<0.05),并且SAA组明显低于nSAA组(P<0.001);从患者CD+CD25+、CD4+CD25low及CD4+CD25highT细胞中Foxp3的表达较正常对照组减低(P<0.05);AA患者PBMC中Foxp3 mRNA表达水平与正常对照组没有明显差别(P>0.05).结论:CD4+CD25+调节性T细胞减低可能与从的发病有关,SAA的Treg表达低于nSAA,为其作为从病情变化的判断指标提供进一步的依据.     

CD200 与CD4+ CD25+ CD127low Treg 在强直性脊柱炎中的意义

目的:研究强直性脊柱炎(AS)患者外周血淋巴细胞中CD200的表达水平,分析CD200及Treg与IL-6、SAA的相关性,探讨CD200与AS免疫功能的关系以及诊断效能,为辅助AS的诊断、免疫评估提供帮助。方法:从74例AS患者和50例健康志愿者中收集外周血。流式细胞术检测淋巴细胞亚群、Treg的百分率及CD200的表达率,并用ELISA法检测血清中CD200的浓度,上转发光法测定IL-6的浓度,胶乳免疫比浊法测定SAA的浓度。结果:与对照组相比,AS活动组CD4~+T细胞、CD19~+B细胞的百分率均增高(P0.05),CD8~+T细胞、Treg的百分率均减低(P0.05),CD3~+T细胞的百分率无明显差异;稳定组CD4~+T细胞、CD8~+T细胞、CD19~+B细胞、Treg的百分率与对照组均无显著差异。与对照组比较,活动组(CD3~+、CD4~+、CD8~+)T细胞中CD200的表达率和血清中CD200的浓度以及稳定组(CD3~+、CD4~+)T细胞中CD200的表达率和血清中CD200的浓度均减低(P0.05);而稳定组CD8~+T细胞、CD19~+B细胞中CD200的表达率及活动组CD19~+B细胞中CD200的表达率无显著差异。与对照组比较,活动组血清中IL-6、SAA的浓度明显升高(P0.05);而稳定组IL-6的浓度轻度升高(P0.05),SAA的浓度无差异。活动组CD3~+T淋巴细胞中CD200的表达率与Treg呈正相关,与IL-6呈负相关,但与SAA不相关;Treg的百分率与IL-6负相关,与SAA不相关。CD200对AS的诊断优于Treg、SAA,而与IL-6的诊断效能相当。结论:AS活动期患者存在淋巴细胞亚群紊乱,CD200和Treg的表达率降低,两者可能参与了AS的发病,为辅助AS的诊断和免疫功能的判断提供理论依据。     

环磷酰胺和环孢素A对SLE患者外周血Th细胞亚群免疫调节的作用

目的:探讨环磷酰胺(CY)和环孢素A(CsA)对SLE患者外周血Th细胞亚群的免疫调节作用.方法:以10例重度活动的SLE患者和6例正常对照的PBMC为研究对象,将细胞悬液分为空白组、植物血凝素(PHA)刺激组、PHA CY组、PHA CsA组、CY组和CsA组分别给药,体外细胞培养24 h后,利用三色流式细胞术检测CD4 IL-10 T细胞、CD4 IFN-γ T细胞比例和CD8 IL-10 T细胞、CD8 IFN-γ T细胞等比例,同时记录相应细胞的荧光强度.结果:CsA促进静息和活化状态下PBMC培养中表达CD4 IL-10 T细胞比例增加,同时CD4 T细胞表达IL-10荧光强度增强.CY虽然促进SLE PBMC培养中表达CD4 IL-10 T细胞比例增加,但对CD4 T细胞表达IL-10的荧光强度无明显增强.CsA抑制PBMC培养中表达CD8 IL-10 T细胞的比例,同时CD8 T细胞表达IL-10的荧光强度减弱.而CY虽然抑制SLE PBMC培养中表达CD8 IL-10 T细胞的比例,但CD8 T细胞表达IL-10的荧光强度却是减弱的.CsA对活化状态下正常对照和SLE PBMC培养中表达CD4 IFN-γ T细胞比例的抑制作用优于CY,且CY对SLE患者PBMC培养中CD4 T细胞表达IFN-γ荧光强度抑制作用也是减弱的.CsA和CY均可抑制活化状态下,正常对照PBMC和静息状态下SLE PBMC培养中表达CD8 IFN-γ T亚群细胞的比例,且CY的抑制作用优于CsA.但CY对SLE PBMC培养中CD8 T细胞表达IFN-γ荧光强度的增强作用不如CsA.结论:CsA和CY均能使CD4 T细胞受抑,CD8 T细胞上升.但CsA对T细胞活化,炎症相关细胞因子表达启动的反应更为敏感,免疫调节作用更为显著.     

环孢素A对LPS诱导的早期炎症反应的影响

目的研究环孢素A(cyclosporin A,CsA)对脂多糖(lipopolysaccharide,LPS)诱导的小鼠早期炎症反应的影响。方法小鼠腹腔内注射LPS诱导炎症反应,静脉注射不同浓度的CsA。6h后取血清,使用ELISA方法观察炎性因子IFN-γ和IL-6的含量;取脾细胞,使用流式细胞仪观察CD4+和CD8+T细胞表面的活化分子CD69表达;并使用细胞内细胞因子染色的方法,观察CD4+和CD8+T细胞IFN-γ和IL-4的产生水平。结果 CsA可以明显降低LPS诱导的小鼠血清中IFN-γ的水平,抑制CD4+和CD8+T细胞表面CD69分子的表达,抑制T细胞IFN-γ和IL-4的产生,均表现为剂量依赖性抑制关系。结论 CsA剂量依赖性抑制LPS诱导的小鼠早期炎症反应。     

G-CSF联合预激化疗方案对骨髓增生异常综合征的疗效及其与共刺激分子表达的关系

目的:探讨粒细胞集落刺激因子(G-CSF)联合高三尖衫酯碱和小剂量阿糖胞苷预激化疗(GHA)方案对骨髓增生异常综合征(MDS)的疗效及其与共刺激分子表达的关系。方法:58例MDS患者随机分为研究组和对照组,每组29例,分别采用GHA方案和HA方案进行化疗,观察并比较两组的疗效和不良反应,同时检测两组CD3+、CD4+T细胞表面共刺激分子的表达。结果:经1个疗程化疗后,研究组有效率为68.9%,显著高于对照组P0.0)。研究组和对照组治疗前CD3+、CD4+T细胞表面的CD28+表达较正常组显著降低,CTLA-4+的表达以及CTLA-4+/CD28+则显著高于正常组(P0.05);治疗后研究组和对照组的CD28+表达均较治疗前显著升高,CTLA-4+的表达以及CTLA-4+/CD28+则较治疗前显著降低(P0.05);研究组治疗后各指标值均已趋于正常,与正常组比较差异无统计学意义(P0.05),其变化趋势则均明显优于对照组(P0.05);而对照组治疗后的各指标值虽有所好转,但与正常组比较差异仍有统计学意义(P0.05)。结论:GHA预激化疗方案对MDS疗效肯定,不良反应较轻,是高效低毒的新型化疗方案,其疗效可能与CD3+、CD4+T细胞表面共刺激分子的表达有关。     

流式细胞术对骨髓增生异常综合征和再生障碍性贫血患者骨髓细胞免疫表型的分析

检测骨髓增生异常综合征(MDS)和再生障碍性贫血(AA)患者骨髓细胞免疫表型特征,探讨其对二者发病机制、分型诊断及鉴别诊断的临床意义。选用多种单克隆抗体,应用直接免疫荧光法采用流式细胞术CD45/SSC设门,对23例MDS、14例AA、9例正常对照的骨髓细胞各免疫标志的表达率进行检测。结果:MDS组与正常对照组相比其造血干/祖细胞抗原CD34、HLA-DR、髓系早期抗原CD13、CD33、单核系抗原CD14、T淋巴细胞抗原CD7的表达率增高,髓系成熟抗原CD15、B淋巴系抗原CD19、CD20的表达率降低,DI值增高;由RA进展至RAEB,CD34、HLA-DR、CD13、CD33、CD14、CD7的表达率逐渐增高,CD15、CD3、CD19、CD20的表达率逐渐减低,DI值逐渐增高。AA组与正常对照组相比其CD34、CD13、CD33、CD15的表达率降低,CD3、CD7、CD25、CD22的表达率增高。MDS组与AA组相比其CD34、HLA-DR、CD13、CD33、CD14的表达率增高,CD3、CD5、CD7、CD15、CD19、CD20、CD22、CD25的表达率显著降低。MDS和AA患者骨髓细胞免疫表型分析,有助于揭示二者的发病机制,为临床提供新的诊断、分型及鉴别诊断方法。     

霉酚酸酯联合环孢素A治疗GVHD后T细胞亚群的变化

为了解霉酚酸酯 (MMF )联合环孢素A (CsA )治疗移植物抗宿主病 (GVHD )后T淋巴细胞亚群的变化。我们采用免疫荧光标记和流式细胞仪技术 ,分析了 6例GVHD患者的T淋巴细胞亚群以及活化T细胞标志。发现在MMF治疗后患者的CD3+ CD4+ T细胞明显降低 ,CD3+ CD8+ T细胞明显增高 ,CD4/CD8比值下降 ;CD2 5 + CD4+ 和CD6 9+ CD8+ T细胞均升高。结果初步显示 ,MMF可能主要作用于CD3+ CD4+ T细胞 ,并与CsA在治疗GVHD方面有协同作用。     

麝雄灸线疗法对淋巴结结核患者细胞免疫功能的影响

本文对经麝雄灸线疗法治疗前后淋巴结结核患者外周血细胞免疫功能及数目进行了检测,研究结果表明,淋巴结结核患者外周血单个核细胞对PHA刺激的增殖反应性低下,T淋巴细胞数目减少,CD4~+/CD8~+细胞比值降低,经麝雄灸线疗法治疗后,患者外用血总T淋巴细胞(CD3~+),T辅助细胞(CD4~+)数目增多,CD4~+/CD8~+细胞比值升高,外周血单个核细胞对PHA刺激的增殖反应性回升到正常水平。     

环孢菌素通过FLIP影响再生障碍性贫血患者CD8+T细胞亚群CD28的表达

目的研究共刺激分子CD28在再生障碍性贫血（AA）患者的不同T细胞亚群中的表达变化，及其与凋亡抑制蛋白FLIP的关系。方法取21例AA患者环孢菌素A（CyA）治疗前后的外周血，应用流式细胞仪检测T细胞CIMCD28、CD8CD28的表达；磁珠分选患者治疗前后外周血的CD8^＋T细胞，RT-PCR检测治疗前后FLIP、Caspase-8表达变化；分选获得的治疗前的CD8^＋ T细胞体外经CyA处理后检测其CD28、FLIP、Caspase-8的表达变化。结果AA患者的CD8^＋ CD28^＋ T细胞的比例较正常人显著升高，治疗有效者该亚群的细胞比例在治疗后趋于正常；患者CD8^＋ T细胞的FLIP表达显著上调，但Caspase-8的表达无明显变化；CyA能下调患者CD8^＋T细胞的FLIP的表达。结论AA患者CD8^＋CD28^- T细胞亚群比例升高与FLIP表达增加有关，CyA能抑制FLIP的表达，降低CD8^＋CD28^-T细胞的比例。     

Participation of the CD69 Antigen in the T-Cell Activation Process of Patients with Systemic Lupus Erythematosus

Accumulating evidence has implicated T cells in the pathogenesis of systemic lupus erythematosus (SLE). The CD69 antigen is an integral membrane protein rapidly induced on the surface of activated lymphocytes. We obtained CD4⁺ and CD8⁺ T cells from normal subjects and patients with SLE. The percentage of CD69 expression in freshly isolated cells and after in-vitro incubation with mitogens was quantified by three-colour immunofluorescent staining. Expression of this protein was increased in both CD4⁺ and CD8⁺ T-cell subsets from SLE patients when compared with normal cells, although the difference was significant only in the CD8⁺ T-cell subset ( P  = 0.05). Cellular activation increased CD69 expression. When stimulated with anti-CD2/CD2R or phytohaemagglutinin (PHA), the percentage and absolute numbers of CD69⁺ cells were lower in patients than in controls. Addition of anti-interleukin (IL)-10 monoclonal antibody (MoAb) increased the percentage of in-vitro CD69 expression in SLE cells. These results suggest that the peripheral blood lymphocytes from patients with SLE have an intrinsic defect that alters their activation process, including the expression of CD69, and might explain some of the T immunoregulatory abnormalities observed in these patients.     

神经营养素受体在人外周血T细胞中表达的研究

目的 研究人外周血CD4^ /CD8^ T细胞4种神经营养素受体基因的转录。方法 应用尼龙手法分离出T细胞，磁式细胞分离法（MACS）分离CD4^ /CD8^ T细胞亚群，再以RT－PCR法研究4种神经营养素受体在两种T细胞亚群上的表达。结果 未经刺激的CD4^ /CD8^ T细胞亚群不表达任何神经营养素受体。经PHA或PPD刺激后，CD4^ /CD8^ T细胞亚群表达trkA,CD8^ T细胞亚群表达trkC；而在各种状态下的T细胞上均未见表达trkB及p75^NGFR。结论神经营养素受体在两种T细胞亚群中有不同的表达格局，提示不同T细胞亚群受神经营养素调节的模式可能各不相同。     

同种异基因移植引流淋巴结及外周血T细胞活化分析

目的:研究同种异基因移植早期局部引流淋巴结和外周血T细胞的活化情况。方法:以小鼠前臂皮下非血管化心肌移植为模型,利用流式细胞术分析前臂引流淋巴结及外周血不同T细胞亚群的CD69表达水平。结果:同种异基因移植后72h,引流淋巴结CD4⁺T细胞和CD8⁺T细胞的CD69表达百分率均明显高于移植前(P＜0.01),且CD8⁺T细胞的表达水平高于CD4⁺T细胞(P＜0.01);各组外周血CD4⁺T细胞和CD8⁺T细胞的CD69表达百分率均无显著差异;局部应用弗氏完全佐剂和全身应用CsA可分别增强和抑制同种异基因移植后CD4⁺T细胞和CD8⁺T细胞的CD69表达(P＜0.05或P＜0.01)。结论:局部引流淋巴结T细胞CD69的表达水平可及时反映受者T细胞对同种异基因抗原的识别情况。     

Viral load and CD69 molecule expression on freshly isolated and cultured mitogen-stimulated lymphocytes of children with perinatal HIV-1 infection

HIV-1 in adults changes the proportion of mitogen-stimulated lymphocytes expressing the CD69 activation molecule, but little is known about this molecule expression on lymphocytes of HIV-1-infected (HIV-1+) children. Freshly isolated CD3+, CD4+, CD8+ and CD19+ and phytohaemagglutinin (PHA)-stimulated CD3+, CD4+ and CD8+ lymphocytes co-expressing CD69 were investigated cross-sectionally (adopting a MoAb double-staining technique) in 24 HIV-1+ children with severe disease and given anti-retroviral therapy and in 24 age-matched healthy children. CD69 results in HIV-1+ children were correlated with plasma HIV-1 RNA load prospectively determined. HIV-1+ compared with healthy children had higher frequencies of freshly isolated CD3+CD69+ (2.4 +/- 2.2% versus 0.9 +/- 0.5%; P = 0.002) and CD8+CD69+ (1.5 +/- 1.1% versus 0. 5 +/- 0.2%; P < 0.0001) lymphocytes. The frequencies of CD4+CD69+ and CD19+CD69+ lymphocytes were similar. High viral load correlated with an elevated proportion of freshly isolated CD3+CD69+ and CD8+CD69+ lymphocytes. HIV-1+ children showed reduced frequencies of PHA-stimulated CD3+CD69+ (60.7 +/- 7.6% versus 86.1 +/- 7.6%; P < 0. 001), CD4+CD69+ (73.6 +/- 18.2% versus 92.6 +/- 5.1%; P < 0.001), and CD8+CD69+ (51.0 +/- 19.1% versus 65.3 +/- 15.4%; P = 0.007) lymphocytes. Virologic worsening within 6 months correlated with a low proportion of PHA-stimulated CD3+CD69+ and CD8+CD69+ lymphocytes. CD69 molecule expression reflected the coexistence of immune activation and immune deficiency in HIV-1 infection. Changes partly differed from those observed in HIV-1+ adults. CD8+CD69+ (but not CD4+CD69+) lymphocyte proportion correlated with virologic course, and an impaired ability of CD8+ lymphocytes to express CD69 upon PHA stimulation preceded a virologic worsening.     

再生障碍性贫血患者淋巴细胞表型变化

目的：研究再生障碍性贫血（AA）患者骨髓（BM）及外周血（PB）淋巴细胞及其活化相关分子的表达及临床意义。方法：采用单色和双色免疫荧光标记法，流式细胞仪分析AA患者的BM和PB中淋巴细胞膜分子的表达。结果：AA患者BM和BP中CD8^ 细胞增加，CD4／CD8比例下降，BM在CD25^ 细胞和HLA－DR^ 细胞增多，急性AA增加尤为显著（P＜0．01），BM中CD16^ 或CD56^ 细胞也明显增多（P＜0．05），双标记分析提示T细胞主要为CD8^ 细胞：急性AA患者CD8^ -CD25^ 细胞显著增多（P＜0．01），AA患者BM中淋巴细胞活化相关分子表达增多，尤其4－1BB^ ,CD95L^ 和CD40L＋细胞显著增多（P＜0．01），结论：AA患者BM中淋巴细胞活化相关膜分子增多，是AA免疫功能异常及最终导致造血功能衰竭的原因之一。     

Activation of human intraepithelial lymphocytes reduces CD3 expression

The aim of this study was to examine in detail the low functional capacity of human intraepithelial lymphocytes (IELs) in response to phytohaemagglutinin (PHA) and CD3 ligation. Human IELs were extracted from jejunal mucosa obtained from patients undergoing gastric bypass operations for morbid obesity and compared to peripheral blood (PB) lymphocytes composed predominantly of CD8+ T cells. Calcium influx ([Ca2+]i) was analysed using Fura-2-loaded cells; IL-2 receptor expression was measured by immunofluorescence and flow cytometry; IL-2 binding was determined using radiolabelled IL-2; IL-2 production was quantified by ELISA; and apoptosis was detected with Apo 2.7 staining. Compared to naive PB CD8+ T lymphocytes, calcium influx by IELs was only transient with CD3 ligation and low in amplitude with PHA. IL-2 receptor expression was reduced after CD3 ligation, yet normal in numbers and affinity after PHA stimulation. Both cell types secreted similar amounts of IL-2. CD3 expression on IELs, but not PB CD8+ T cells, declined upon activation, due partly to incomplete reexpression after modulation. Little apoptosis was found. The partial activation of IELs in response to PHA and CD3 ligation, as manifested by diminished [Ca2+]i, resulted in a decline in CD3 expression.     

Soluble and cellular markers of immune activation in patients with systemic sclerosis

The peripheral blood lymphocyte pattern, the lymphocyte responses in vitro, as well as the soluble markers of immune activation were studied in 24 patients with systemic sclerosis (SSc patients). The proportions of total T cells (CD3), their CD4 subset, as well as B lymphocytes were within the normal range. The relative proportion of CD8 lymphocytes, however, was significantly reduced. Patients with SSc had a slightly lower percentage of CD4/4B4+ cells, whereas their proportion of CD4/2H4+ cells was elevated as compared to healthy controls. The proportion of lymphocytes expressing the interleukin-2 receptor (IL-2R) was significantly higher in SSc patients. The proliferative responses of peripheral blood mononuclear cells to PHA stimulation were reduced in the patient group, while expression of IL-2R on lymphocytes after such in vitro stimulation was comparable to that of controls. Expression of IL-2R on patient but not control lymphocytes was increased after in vitro exposure to laminin. Such exposure failed to induce IL-2 production or cell proliferative responses. Soluble plasma IL-2R level (sIL-2R) and soluble CD8 (sCD8) molecule levels in SSc patients were significantly elevated. These results indicate the presence of an ongoing lymphocyte activation in this disease process.     

原发性胆汁性肝硬化患者共刺激分子B7-H4的检测及临床意义

目的 探讨原发性胆汁性肝硬化(primary biliary cirrhosis,PBC)患者共刺激因子B7-1t4的表达及其与疾病发病机制的关系.方法 分别采用荧光实时定量PCR法(real-time PCR)、酶联免疫吸附试验(ELISA)及流式细胞术(FCM)检测65名PBC患者外周血单个核细胞(PBMC)B7-H4mRNA表达水平、血清IL-2水平以及CD4+、CD8+ T细胞亚群和T细胞表面B7-H4表达百分率,同时监测抗线粒体抗体(anti-mitochondrial antibody,AMA)及临床各项生化指标的关系.结果 (1)PBC患者PBMC B7-144 mRNA水平及T细胞表面B7-H4表达百分率显著低于非PBC肝硬化组及健康对照组(P<0.01).(2)活化72 h后各实验组及对照组IL-2含量及CD4+、CD8+、CD4+ CD8+T淋巴细胞表达水平均低于活化前,以非PBC肝硬化组与健康对照组降低显著(P<0.05);PBC组IL-2含量及CD4+、CD4+ CD8+ T淋巴细胞表达水平高于非PBC肝硬化组与健康对照组(P<0.01).(3)AMA-M2阳性患者血清谷丙转氨酶(ALT)、谷草转氨酶(AST)、碱性磷酸酶(ALP)及γ-谷氨酰转肽酶(GGT)水平升高,其中ALP及GGT升高显著(P<0.05);AMA-M2阳性患者与阴性患者T细胞表面B7-H4表达百分率差异无统计学意义(P>0.05).结论 共刺激因子B7-H4对PBC患者体内T细胞活化增殖及细胞因子分泌的抑制作用减弱,为研究PBC的发生发展和阐明PBC的发病机制提供了试验资料.     

Rapid expression of the CD69 antigen on T cells and natural killer cells upon antigenic stimulation of peripheral blood mononuclear cell suspensions

The CD69 antigen has been identified as the earliest activation marker on the surface of cytokine- or mitogen-activated lymphocytes. The expression of this molecule may be a useful early marker of antigen- or allergen-specific activation of lymphocytes in vitro. We evaluated the expression of the CD69 and CD25 antigens on antigen- or allergen-stimulated lymphocytes and the proliferative responses as detected by thymidine incorporation. Peripheral blood mononuclear cells (PBMC) of allergic patients sensitized to Dermatophagoides pteronyssinus , bovine casein, or nickel sulfate were cultured in the absence or presence of clinically relevant allergens, tetanus toxoid, or recombinant interleukin (IL)-2. The respective binding of CD69 or CD25 antibodies to PBMC and thymidine incorporation were measured. An early expression of CD69, but not of CD25, antigen was detectable after 24-72 h of stimulation on up to 80% of natural killer (NK) cells and up to 10% of CD4⁺ T cells in PBMC cultures. Anti-IL-2 antibodies inhibited these increases of CD69 on NK cells and T cells by up to 60%. After 6 days of antigenic stimulation, the rates of both CD25⁺ and CD69⁺ lymphocytes were higher. Seventy-four percent of the CD25⁺ PBMC but only 55% of the CD69⁺ cells were CD3⁺ T lymphocytes at this time. No qualitative differences were detectable in allergen- or tetanus-toxoid-stimulated PBMC from allergic patients. The high expression of CD69 on NK cells in antigen-stimulated cultures suggests that these cells are easily activated by cytokines from antigen-stimulated T cells. CD69⁺ NK cells may serve as early-indicator cells in cultures with antigen- or allergen-stimulated mononuclear cells.