正常人外周血TCRVα24+ NKT细胞体外活化特性观察

目的:探讨正常人外周血自然杀伤T(NKT)细胞的数量以及体外活化后表达CD69、IFN-γ和IL-4的规律并与CD3⁺ T细胞进行比较。方法:取正常成人外周血,直接三色荧光标记后溶血获取有核细胞,或以佛波醇酯(PDB)+离子霉素(Ion)刺激并培养6h,经三色荧光标记后溶血并获取有核细胞,以流式细胞术分析NKT细胞和T细胞的数量以及表达CD69和IL-4、IFN-γ的情况。结果:NKT细胞约占外周血T淋巴细胞总数的(1.34±0.42)%(x±s);PDB+Ion活化6h后NKT细胞CD69表达率为(96.71±1.33)%,明显高于对照组(11.47±2.86)%(P＜0.05);同样条件下CD3⁺T细胞CD69表达率分别为(98.60±0.47)%和(1.07±0.45)%(P＜0.05);当莫能菌素(monensin)存在时以PDB+Ion刺激6h后,IL-4阳性NKT细胞的百分比为48.62±2.44,明显高于对照组31.57±3.31(P＜0.05);IFN-γ阳性NKT细胞百分比为46.65±11.91,也高于对照组13.45±6.29(P＜0.01)。CD3⁺T细胞在刺激后表达IL-4和IFN-γ均明显升高,但IL-4表达率远远低于NKT细胞;而且对照组CD3⁺T细胞两种细胞因子表达率都明显低于NKT细胞。结论:正常成人外周血含有少量的NKT细胞,这些细胞IL-4和IFN-γ的表达率明显高于CD3⁺T细胞,是特定微环境里的重要免疫调节细胞。     

肝癌细胞冻融抗原负载树突状细胞瘤苗的制备与活化

目的: 探讨制备肝癌树突状细胞(DCs)瘤苗和体外诱导DCs活化的优化方法。方法: 取健康人新鲜血50mL, Ficoll密度梯度离心分离外周血单个核细胞(PBMC), 制备肝癌细胞冻融抗原, 采用不同因子组合培养PBMC, 诱导和激活DCs, A组: rhGM-CSF+IL-4; B组: rhGM-CSF+IL-4+冻融抗原负载;C组:rhGM-CSF+IL-4+TNF-α; D组: rhGM-CSF+IL-4+TNF-α+冻融抗原负载。结果: 各组均诱导出DCs, 并高表达CD11c和CD54, 冻融抗原可明显上调CD86、CD80、HLA-DR表达和IL-12 p40分泌(P<0.01), TNF-α促进CD86表达的作用更显著, 但对IL-12分泌无影响, 依次用TNF-α诱导和冻融抗原负载可进一步促进CD86表达和IL12 p40分泌(P<0.05)。CD54和HLA-DR双标记免疫细胞化学染色显示, 各组DCs大多为CD54⁺。表达HLA-DR的DCs均为CD54⁺HLA-DR⁺, 其中, A组CD54⁺HLA-DR⁺细胞数量最少, D组最多, 平均每个细胞HLA-DR的表达水平也与此对应。结论: 采用rhGM-CSF、IL-4诱导的未成熟DCs, 依次使用TNF-α刺激与肝癌细胞冻融抗原修饰可有效促进DCs的活化与成熟。     

人外周血CD8+T细胞CD28、CD56及CD57表达水平的老年性改变

目的:通过对健康老年人与青年人外周血CD8⁺T细胞CD28、CD56及CD57表达水平的比较性研究,探讨免疫衰老的细胞学机制。方法:采用三色免疫荧光标记流式细胞术分析青年组(20-35岁)与老年组(60-75岁)外周血CD8⁺CD28⁺、CD8⁺CD56⁺及CD8⁺CD57⁺T细胞水平。结果:老年组外周血CD8⁺CD28⁺T细胞明显低于青年组,阳性百分率分别为34.07±5.29和49.84±7.43(P＜0.05);而老年组CD8⁺CD56⁺T细胞及CD8⁺CD57⁺T细胞均明显高于青年组,前者阳性百分率分别为6.60±2.40和2.10±0.35,后者阳性百分率分别为41.82±6.01和22.89±2.80(P＜0.05)。结论:老年人CD8⁺T细胞CD28、CD56及CD57的表达率均随年龄增长有明显改变;CD28表达下降可能是引起免疫系统功能降低的重要原因,而CD56、CD57表达水平的增加则可能是机体对细胞免疫功能下降的一种代偿性适应。     

血管内皮祖细胞的体外扩增特性研究

目的:探讨血管内皮祖细胞(EPCs)在体外扩增特性。方法:利用磁性活化细胞分选系统(MACS)系统富集CD34⁺细胞,在相同条件下与同批的单个核细胞(MNC)、CD34⁺和CD34^-混和细胞进行对照培养,比较EPCs体外扩增效果。另外研究血管内皮生长因子(VEGF)和传代培养对细胞分化、扩增动力学和细胞凋亡的影响。应用细胞免疫化学和流式细胞术对细胞定性定量分析。结果:MNC培养、CD34⁺和CD34^-细胞混和培养明显高于CD34⁺细胞单独培养EPCs扩增率(P＜0.05),一旦细胞形成线索样结构行传代培养明显低于未传代的细胞凋亡(P＜0.05)。VEGF对细胞凋亡(P＞0.05)无明显影响,这些分化的EPCs免疫细胞化学染色CD34、vWF、KDR、CD31阳性,并且吞噬乙酰化低密度脂蛋白(Ac-LDL)。培养7d流式细胞检查CD34⁺、AC133^＋分别占贴壁(AT)细胞的68.2%±6.3%(n=6)、57.2%±9.8%(n=6)。结论:MNC培养、CD34⁺和CD34^-细胞混和培养提高了EPCs扩增率,早传代使凋亡率明显降低。VEGF对EPCs体外扩增无明显影响。     

CIK细胞回输联合吉西他滨和顺铂治疗鼻咽癌放疗后肝肺转移瘤的效果及机制研究

目的: 观察评价细胞因子诱导杀伤(CIK)细胞回输联合吉西他滨和顺铂(GP)方案化疗治疗鼻咽癌放疗后肝肺转移瘤的近远期疗效,并探讨其机制。方法: 2007年8月至2008年7月放疗后随访发现肝或肺转移患者30例,随机分为3组。研究1组10例行过继性CIK细胞回输联合GP化疗;研究2组10例行单纯GP化疗。对照组患者及健康志愿者各10例,不给予抗肿瘤治疗而仅进行随访。观察其近远期疗效、血清EB病毒DNA PCR定量和外周血淋巴细胞亚群分布变化。结果: CIK+GP组有效率(90%)比单纯GP组(70%)好,但2组间无明显差异;而CIK+GP组和GP组均比对照组(10%)好,差异明显。CIK+GP组最和GP组治疗后血清EBV-DNA PCR定量均有不同程度的下降,尤以CIK+GP组为明显,而对照组则无明显改变。鼻咽癌放疗后肝肺转移瘤患者外周血CD3⁺比例较健康志愿者显著低下,经CIK+GP治疗后CD3⁺比例较单纯GP化疗组有所提高;肝肺转移瘤患者和健康志愿者CD4⁺/CD8⁺比例无明显差异,经CIK+GP生物化疗后其比例明显升高,而经GP化疗后明显降低,2组之间存在明显差异。CIK+GP组、GP组和对照组2年生存率(OS)分别为60.0%、40.0%和20.0%,生存曲线分析显示3组病例之间均有明显差异(P＜0.05)。结论: CIK 细胞回输联合GP 化疗治疗鼻咽癌放疗后肝肺转移瘤具有肯定的近远期疗效并可改善其预后;两者具有协同作用,其作用可能与改变CD3⁺及CD4⁺/CD8⁺比例有关。     

自然流产中外周血和蜕膜组织自然杀伤细胞亚群的比例变化

目的和方法:采用流式细胞仪检测淋巴细胞亚群法探讨自然流产与正常早孕之间外周血和蜕膜自然杀伤细胞亚群的差异。结果:外周血中自然流产组的CD56⁺的百分率较早孕组有减少的趋势,而CD56⁺CD16⁺的百分率则较早孕组显著减少,CD16⁺的百分率两组间无差异。自然流产组的蜕膜CD56⁺、CD56⁺CD16⁺、CD16⁺的百分率均明显低于早孕组。结论:蜕膜中CD56⁺NK细胞的减少可能是自然流产的原因之一,外周血中CD56⁺和CD56⁺CD16⁺NK细胞的丢失可能对自然流产的发生具有诊断价值。     

镁对哮喘患者外周血CD4+ CD25+调节性T细胞凋亡及Foxp3表达的影响

目的:观察镁对分离培养的健康人和哮喘患者外周血CD4⁺CD25⁺调节性T细胞凋亡及叉头框蛋白3(Foxp3)表达的影响。方法:经磁珠分离法分离出健康人和哮喘患者外周血CD4⁺CD25⁺T细胞,分镁剂干预组(10 mmol/L)及空白组培养72 h后,用流式细胞仪检测CD4⁺CD25⁺T细胞的凋亡率及Foxp3表达情况。结果:(1)健康人外周血CD4⁺CD25⁺T细胞的纯度为77.4％~92.3%,哮喘患者CD4⁺CD25⁺T细胞的纯度为75.2％~93.8％。(2)CD4⁺CD25⁺T细胞占外周血CD4⁺T细胞的比例在健康组为4.12%~7.98%,在哮喘组为4.51%~8.68%,两者没有显著差异(P＞0.05)。(3)镁(10mmol/L)可以诱导健康组及哮喘组外周血CD4⁺CD25⁺T细胞凋亡率增加(P＜0.05),但对Foxp3的表达无影响(P＞0.05)。结论:镁促进CD4⁺CD25⁺T调节细胞凋亡增加可能为其治疗支气管哮喘的作用机制之一。     

妊娠期高血压疾病患者子宫蜕膜NK细胞表型分析

目的: 观察妊娠期高血压疾病患者子宫蜕膜自然杀伤细胞(dNK 细胞)的表型。方法:选取2008年8月至2009年3月在广州市暨南大学附属第一医院妇产科因妊娠期高血压疾病行剖宫产的单胎妊娠孕妇20例作为妊娠期高血压组,随机选取同期在此院因社会心理因素行选择性剖宫产的正常单胎妊娠孕妇15例作为正常对照组。收集孕晚期子宫蜕膜组织,机械研磨加梯度离心法提取蜕膜内单核细胞,流式细胞技术(FCM)筛选出dNK细胞,并检测dNK细胞表面CD56及CD16的表达情况。结果:(1)妊娠期高血压组与正常对照组CD56^brightCD16^-CD3^-dNK细胞的数量均多于CD56^dimCD16⁺CD3^- dNK细胞,且差异显著(均P＜0.01)。(2)妊娠期高血压组与正常对照组CD56^brightCD16^-CD3^- dNK细胞所占比例无显著差异(P＞0.05),CD56^dimCD16⁺CD3^- dNK细胞所占比例亦无显著差异(P＞0.05)。(3)妊娠期高血压组与正常对照组dNK细胞表面CD16分子的表达率并无显著差异(P＞0.05)。结论:妊娠期高血压疾病患者与正常孕妇孕晚期子宫蜕膜内dNK细胞表型无明显改变,均以CD56^brightCD16^-CD3^-亚型为主。     

Th17细胞联合CD3+CD8-IL-21+T细胞升高与宫颈癌发生发展的关系

目的: Th17细胞在免疫调节中起重要作用,而IL-21与Th17在分化调节和功能行使上密切相关。本研究旨在探讨Th17在宫颈癌发生发展中的作用。方法: 选取37例宫颈癌患者、25例宫颈上皮内瘤变(CIN)患者和18例健康志愿者作为研究对象,用流式细胞分析术检测外周血中Th17细胞及CD3⁺CD8^-IL-21⁺T细胞的比例。分析两者与临床病理指标之间的关系。结果: 与健康对照组相比,Th17细胞及CD3⁺CD8^-IL-21⁺ T细胞比例(占淋巴细胞百分比)在CIN组(P<0.01,P<0.05)及宫颈癌组(P<0.01,P<0.05)均明显升高。此外,2种细胞的比例都与临床分期有关,在晚期宫颈癌组明显升高(均P<0.05),并且有淋巴结转移组或脉管浸润组都明显高于相对应的无转移组(P<0.01, P<0.05)或无浸润组(均P<0.01)。此外,在健康对照组和宫颈癌组,Th17与CD3⁺CD8^-IL-21⁺ T细胞呈正相关,CD3⁺CD8^-IL-21⁺ T细胞的比例还与肿瘤大小有关(P<0.01)。结论: Th17和CD3⁺CD8^-IL-21⁺ T细胞在宫颈癌患者外周血中的比例上调,在宫颈癌的发生发展中可能起着重要作用。     

异种角膜基质异位移植对大鼠外周血T细胞亚群的影响

目的: 比较3种异种角膜基质的免疫原性。方法: 将SD大鼠36只随机分为4组,每组9只。1组为对照组,2-4组为实验组。分别获取新鲜猪、兔、鸡角膜基质,等量湿重25 mg异位植入大鼠背部皮下,术后观察伤口愈合情况,并于术后7 d、14 d、28 d获取大鼠外周血,免疫荧光标记及流式细胞仪分析比较3种异种角膜基质对大鼠CD4⁺、CD8⁺、CD25⁺、CD71⁺表型的动态影响。结果: 各组植入处皮肤无红肿、无渗出及其它改变,伤口愈合良好;各组与对照组比较:猪角膜基质组各时相表达的CD4⁺、CD8⁺、CD25⁺、CD71⁺T细胞比例无显著差异(P＞0.05);兔角膜基质组术后7 d,CD4⁺T细胞升高(P＜0.05),鸡角膜基质组术后7 d,CD4⁺、CD4⁺CD71⁺升高(P＜0.01)。结论: 3种异种角膜基质对大鼠细胞免疫原性比较:鸡>兔>猪,猪角膜基质的免疫原性最低。     

Reduced LAK cytotoxicity of peripheral blood mononuclear cells in patients with bladder cancer: Decreased LAK cytotoxicity caused by a low incidence of CD56+ and CD57+ mononuclear blood cells

The cytotoxicity of unstimulated peripheral blood mononuclear cells (US-PBMC), phytohemagglutinin (PHA)-stimulated PBMC (PS-PBMC) and interleukin-2 (IL-2)-activated PBMC (LAK cells) was assessed in patients with noninvasive and invasive transitional-cell bladder cancer and compared with those determined in healthy controls. The differences in the cytotoxicities were correlated with specific changes in the subsets of peripheral blood mononuclear cells (PBMC). PBMC from 37 patients and 13 healthy controls were tested against the bladder cancer cell line T24 in⁵¹Cr-release assays. The PBMC subsets were analyzed using monoclonal antibodies against T cells, natural killer (NK) -cells, monocytes, and activation markers. The cytotoxicities of US-PBMC, PS-PBMC, and LAK cells were all significantly lower in the cancer patients than in the controls (P<0.05). The percentages of PBMC positive for the NK-cell markers CD56 and CD57 were lowest in the patients and were correlated to the decrease in cytotoxicity. Depletion of CD56⁺ or CD57⁺ cells from PBMC prior to or after 2 days stimulation with IL-2 demonstrated that these cells are the major source of LAK-cell cytotoxicity and showed that the reduced ability of bladder cancer patient PBMC to develop LAK-cell cytotoxicity is a result of a low incidence of CD56⁺ and CD57⁺ cells in the blood. These findings indicate that IL-2 therapy alone might not be a sufficient therapy of bladder cancer patients.     

Cord Blood–Derived and Peripheral Blood–Derived Cytokine-Induced Killer Cells Are Sensitive to Fas-Mediated Apoptosis

Fas-mediated apoptosis is one of the mechanisms used by tumor cells to escape the cytotoxicity of tumor-infiltrating lymphocytes. It has been suggested that cytokine-induced killer (CIK) cells are resistant to Fas-mediated apoptosis, thereby rendering them more attractive for use in cellular immunotherapy. Unlike what was observed by others, here we show that CIK cells are sensitive to Fas-mediated apoptosis. We have observed an increase in Fas expression in the different CIK cell subpopulations (CD3⁺CD56⁻, CD3⁺CD56⁺, and CD3⁻CD56⁺) isolated from both cord blood (CB) and peripheral blood (PB). We also show that the bulk, as well as the CD3⁺CD56⁻ and CD56⁺ CB- and PB-CIK cell subpopulations were sensitive to Fas-mediated apoptosis induced by both CH11 and APO-1 antibodies, albeit with a weaker effect for the CH11 antibody on CB-CIK cells. In addition, in the presence of the APO-1 and CH11 inducers, Fas engagement inhibited the cytotoxic activity of CB- and PB-CIK cells. This new contradictory result may help explain the variable efficacy observed with CIK cells in the clinic.     

CD56bright natural killer cell subsets: Characterization of distinct functional responses to interleukin-2 and the c-kit ligand

Natural killer (NK) cells are bone marrow-derived large granular lymphocytes that express the CD56 surface antigen. The CD56^bright NK subset represents approximately 10 % of all NK cells and is thought to be the least differentiated NK cell component in blood. The most mature NK cell expresses CD56 at low density and CD16 (FcRγIII) at high density, whereas CD56^bright NK cells either lack CD 16 (CD56^brightCD16^?) or express it at low density (CD56^brightCD16^dim). c-kit is a tyrosine kinase receptor which is expressed on both CD34⁺ hemato-poietic precursor cells and CD56^bright NK cells. In the current study, we characterize interleukin (IL)-2 receptor (IL-2R) and c-kit expression in each of the CD56^bright subsets. Both the CD56^brightCD16^? and CD56^brightCD16^dim NK subsets express the high-affinity IL-2R and the c-kit receptor when isolated from fresh blood. However, each CD56^bright NK cell subset has distinct functional responses to IL-2, the c-kit ligand (KL), or both. Activation of the high-affinity IL-2R on CD56^brightCD16^? NK cells induces a proliferative response that is significantly weaker than that observed in the CD56^brightCD16^dim NK cell subset. Incubation of the CD56^brightCD16^? NK cell subset with KL significantly enhances IL-2-induced proliferation, while KL has no such effect on the CD56^brightCD16^dim NK subset. Activation of the high-affinity IL-2R in both CD56^bright subsets induces lymphokine-activated killer (LAK) activity, but the addition of KL has no effect on LAK activity. Co-stimulation of either CD56^bright subset with IL-12 and concentrations of IL-2 that only saturate the high-affinity IL-2R induces substantial interferon (IFN)-γ production. The addition of KL to this co-stimulatory signal enhances IFN-γ production in both CD56^bright NK subsets. The distinct functional responses to IL-2 and KL seen in the CD56^brightCD16^? and CD56^brightCD16^dim NK subsets provide insight into IL-2R signaling and suggest that each phenotype identifies a discrete stage of NK cell differentiation.     

CC chemokines induce the generation of killer cells from CD56+ cells

We describe here that members of the CC chemokines exhibit biological activities other than chemotaxis. Macrophage inflammatory protein (MIP)-1α, MIP-1β, monocyte chemoattractant protein-1 and RANTES, but not interleukin (IL)-8, induce the generation of cytolytic cells, designated here as CHAK (CC chemokine-activated killer) cells to distinguish them from IL-2-activated (LAK) cells. Like IL-2, CC chemokines can induce the proliferation and activation of killer cells. While incubating CC chemokines with CD4⁺ or CD8⁺ cells did not generate CHAK activity, all CC chemokines were capable of inducing CHAK activity upon incubating with CD56⁺ cells, suggesting that the primary effectors are NK cells. However, the presence of other cell types, such as CD4⁺ or CD8⁺, are necessary to induce the proliferation of CD56⁺ cells. Confirming the involvement of T cell-derived factors in inducing the proliferation of these cells, anti-IL-2 and anti-interferon-γ, but not anti-IL-1β, anti-tumor necrosis factor-α, anti-IL-8, or anti-granulocyte/monocyte-colony-stimulating factor inhibited RANTES-induced proliferation of nylon wool column-nonadherent cells. Our results may have important clinical applications for the utilization of CHAK cells in the treatment of cancer and immunodeficient patients.     

Regulation of HLA-DR and co-stimulatory molecule expression on natural killer T cells by granulocyte-macrophage colony-stimulating factor

A subset of mononuclear cells present in most tissues coexpresses receptors of both natural killer (NK) and T cells. Although linked to antiviral immunity, the function of these putative NKT cells is uncertain. We present evidence that human CD56⁺ DR^? NKT cells exhibit hybrid adaptive and innate immune functions. These cells spontaneously lysed tumour cell targets and upon engagement of T‐cell antigen receptors secreted the cytokines interferon‐γ and granulocyte–macrophage colony‐stimulating factor (GM‐CSF). Conversely, GM‐CSF treatment transformed the NKT cells into dendritic cells, inducing rapid expression of HLA‐DR and the co‐stimulatory molecules CD80 and CD86. The ability to stimulate tetanus toxoid‐specific responses from naïve T cells was acquired within 3 days of activating CD56⁺ NKT cells with GM‐CSF. These results suggest a potential role for NKT cells in the initiation and control of primary immunity during the acute phase of infection.     

肝癌患者CIK细胞的诱导及对肝癌细胞毒作用的研究

观察肝癌患者PBMC在体外诱导成CIK细胞的能力及其对肝癌细胞的细胞毒作用。对比正常人组和肝癌患者组CIK细胞和LAK细胞之间的扩增差异。用流式细胞仪检测CIK细胞表面标志CD3、CD5 6 ,3 H TdR释放法检测CIK细胞、LAK细胞对肝癌细胞系SMMC 772 1等多种细胞系的细胞毒作用。结果显示 ,肝癌组和正常组的CIK细胞扩增倍数分别达 6 4 3倍和6 7 4倍 ,CD3+CD5 6 +细胞扩增倍数均达 6 0 0倍以上 ,在细胞扩增曲线及细胞表面标志上无差异 ,远大于LAK细胞 ;肝癌组CIK对肝癌细胞SMMC 772 1、Bel 74 0 2、Hep 3b杀伤能力均达 6 5 %～ 81% ,与正常组相同 ,且与对肠癌细胞系HIC 2 5 1杀伤能力无差异 ;对正常胎肝细胞系L 0 2的细胞毒作用 <5 % ;肝癌患者CIK对耐药的和未诱导耐药的K5 6 2细胞细胞毒作用均达到 70 %左右。肝癌患者CIK和正常人CIK一样对肝癌细胞有很强的细胞毒作用 ,对耐药肿瘤同样有效 ,对正常肝细胞无损伤 ,具有临床应用前景     

Substance P primes lipoteichoic acid- and Pam3CysSerLys4-mediated activation of human mast cells by up-regulating Toll-like receptor 2

We investigated the distribution of natural killer (NK) cell subsets, their activating and inhibitory receptors, and their cytolytic potential, in primary human immunodeficiency virus (HIV)-infected (PHI) individuals at baseline and during 1 year of follow-up with or without antiretroviral therapy, and compared the results with those obtained in treatment-naïve, chronically HIV-infected (CHI) individuals, and HIV-seronegative (HN) healthy individuals. The proportion of the CD56^dim and CD56^bright subsets decreased with disease progression, whereas that of the CD56⁻ CD16⁺ subset increased. In the CD56^dim subset, the proportion of cells with natural cytotoxicity receptors (NCRs) decreased with disease progression, and their cytolytic potential was reduced. Conversely, the CD56^bright subset was characterized by a high proportion of NCR-positive, killer cell immunoglobulin-like receptor (KIR)-positive NKG2A⁺ cells in both CHI and PHI individuals, which was associated with an increase in their cytolytic potential. During the 1 year of follow-up, the PHI individuals with high viraemia levels and low CD4⁺ T-cell counts who received highly active antiretroviral therapy (HAART) had a similar proportion of NK subsets to CHI individuals, while patients with low viraemia levels and high CD4⁺ T-cell counts who remained untreated had values similar to those of the HN individuals. Our results indicate a marked perturbation of the NK cell compartment during HIV-1 infection that is multifaceted, starts early and is progressive, primarily involves the CD56^bright subset, and is partially corrected by effective HAART.     

Role of Enhanced Cellular Adhesion in IL-6-Augmented Lymphokine-Activated Killer-Cell Function

The authors demonstrated previously that a short-term treatment with IL-6 of lymphokine-activated killer (LAK) cells produces an increase in cytotoxic activity of CD56⁺/CD3⁻ effector cells generated from human PBL as well as from human thymocytes. In the study described here, the mechanisms by which IL-6 enhances LAK cytotoxicity were examined. Like untreated LAK cells, IL-6-treated LAK cells require Ca⁺⁺ to initiate cytolysis. However, IL-6 treatment of LAK cells does not alter the rate of programming for lysis. Instead, IL-6 increases target-binding capacity of CD56⁺/CD3⁻ LAK cells in association with the increased cytotoxicity. Similar to target-binding of untreated LAK cells, the binding between IL-6-treated LAK cells and target cells is dependent on Mg⁺⁺. Cellular adhesion molecules (CAM), CD1 la-c, CD18. CD54. CD56, CD58 and CD2 (T11, epitope). are up-regulated in LAK cells by culture with IL-2. Among MoAbs to these CAMs. only Abs to CD11a/CD18 (LFA-1) and CD54 (ICAM-1) decrease both target-binding and cytolysis by LAK cells. IL-6 treatment changes neither the proportion nor the intensity of CAM positive cells. However, MoAbs to CD11a/CD18 and CD54 reduce both target-conjugation and cytotoxicity of IL-6-enhanced LAK cells to the same level as control LAK cells treated with the MoAbs. IL-6-enhanced LAK functions (both target-conjugation and target-lysis) are not abrogated by MoAbs to other CAM which do not inhibit standard LAK functions. These results indicate that IL-6 up-regulates cellular events mediated by CD11a/CD18 and CD54 molecules which are involved in standard LAK functions. These events may result in activation of lytic efieclor cells, associated with an increase in target-binding and an increase in cytotoxicity.     

NK cells differentiated from bone marrow,cord blood and peripheral blood stem cells exhibit similar phenotype and functions

In the present study, we investigated the differentiation of human NK cells from bone marrow, cord blood and mobilized peripheral blood purified CD34⁺ stem cells using a potent culture system. Elutriated CD34⁺ stem cells were grown for several weeks in medium supplemented with stem cell factor (SCF) and IL-15 in the presence or absence of a murine stromal cell line (MS-5). Our data indicate that IL-15 induced the proliferation and maturation of highly positive CD56⁺ NK cells in both types of culture, although murine stromal cells slightly increased the proliferation of NK cells. NK cells differentiated in the presence of MS-5 were mostly CD56⁺ CD7⁻ and a small subset expressed CD16. These in vitro differentiated CD56⁺ NK cells displayed cytolytic activity against the HLA class I ⁻ target K562. The CD56⁺ CD16⁺ subset also lysed NK-resistant Daudi cells. Neither of these NK subsets were shown to express Fas ligand. Total CD56⁺ cells expressed high amounts of transforming growth factor-β and granulocyte-macrophage colony-stimulating factor, but no IFN-γ. Investigation of NK receptor expression showed that most CD56⁺ cells expressed membrane CD94 and NKG2-A mRNA. PCR analysis revealed that p58 was also expressed in these cells. The role of CD94 in NK cell-mediated cytotoxicity was assessed on human HLA-B7-transfected murine L cells. While a low cytotoxic activity towards HLA-B7 cells was observed, the HLA-DR4 control cells were killed with high efficiency. These studies demonstrate that cytolytic and cytokine-producing NK cells may be derived from adult and fetal precursors by IL-15 and that these cells express a CD94 receptor which may influence their lytic potential.