IL-2、IL-15对NK细胞亚群表型和功能的调节作用

目的 探讨IL-2和IL-15对NK细胞亚群表型和功能的调节作用。方法 采用双色免疫荧光染色和流式细胞仪分析，比较IL-2和IL-15对新鲜分离外周血单个核细胞（PBMC)中NK细胞及经混合淋巴细胞培养(MLC)活化的NK细胞表型的调节作用；用4h ^51Cr释放实验检测IL-2和IL-15对NK细胞杀伤水平的影响。结果 在PBMC培养中，当IL-2或IL-15最终为50U／mL时，能明显上调PBMC中CD56^ NK细胞的比例，且IL-15对CD56^bright亚群增殖的促进作用强于IL-2；在MLC中，当IL-2或IL-15为50U／mL时，能够促进MLC活化的NK细胞比率的增加，NK细胞亚群由CD56^dim为主转变成CD56^bright为主，此诱导作用IL-2强于IL-15。IL-2和IL-15都能上调PBMC和MLC中NK细胞杀伤水平，并呈剂量依赖关系，在PBMC中，当IL-15为50U／mL时，IL-15对NK细胞杀伤水平的促进作用强于IL-2；而在MLC中当IL-2为50U／mL时，对NK细胞杀伤水平的促进作用高于IL-15。在PBMC中，同时加入50U／mL的IL-15和IL-2，NK细胞杀伤率高于单独加入IL-15或IL-2。结论 IL-15促进PBMC中NK细胞向CD56^bright亚群分化和杀伤水平强于IL-2，而IL-2促进同种异体抗原诱导的活化NK细胞向CD56^bright亚群分化和杀伤水平则高于IL-15。这种反应格局的差别，可能与不同条件下NK细胞IL-2或/和IL-15细胞因子受体表达不同以及同时有其他细胞因子的协同作用有关。     

NK细胞的活化及其介导的抗病毒作用

NK细胞是一类独特的淋巴细胞亚群,占人外周血淋巴细胞的10%～15%,其表面标志为CD3-CD19-CD16+CD56+。根据CD56分子的表面密度,将NK细胞分为:CD56bright和CD56dim两个亚群,前者以分泌细胞因子为主,后者以杀伤功能为主。NK细胞不表达T细胞的表型(CD3或TCR),也不表达B细胞的表型(CD19或BCR)。NK细胞具有如下特点:①强大的细胞毒活性。它对刺激因素产生的应答十分迅速,而且免疫应答强度高。②杀伤活性无需抗原刺激,也不受MHC分子的限制。病毒感染或恶性转化细胞的     

NK细胞和IL-2分泌细胞在新生儿脐血中的表达

在机体自身免疫调节中NK细胞和IL 2分泌细胞起重要作用 ,因此 ,研究NK细胞和IL 2分泌细胞的表达 ,将有助于我们了解机体细胞免疫的功能 ,新生儿细胞免疫不成熟 ,是其易于感染的重要原因 ,有关于新生儿脐血细胞免疫功能的研究 ,国内有些报道[1,2 ] ,但NK细胞和IL 2分泌细胞方面的研究甚少 ,本文将新生儿NK细胞和IL 2分泌细胞检测结果报道如下 :1　材料与方法1 1　检测对象　随机选择我院产科母孕期健康足月顺产新生儿 70例作为脐血组 ,其中男 4 0例 ,女 30例 ,平均胎龄 39周 ,平均出生体重 30 5 0g ,出生阿氏评分≥ 9分 ,体检正常 ,其…     

THC抑制IL—2激活NK细胞的机理

THC(delta-9-tetrahydrocannabinol)是毒品大麻(marijuana)的主要心理活性成分,对白细胞介素-2(IL-2)激活NK细胞活性有非常显著的抑制作用。为了探讨THC抑制NK活性的机理,本实验用重组人IL-2-鼠NK细胞系统,从配体-受体结合的角度研究了THC对IL-2激活NK细胞活性的影响。结果表明:16μmol～32μmolTHC处理(台盼兰排除和~3H-TdR掺入法证明对NK细胞无毒性作用),能显著降低NK细胞与IL-2的特异结合;减少NK细胞表面的IL-2受体数目;但THC并不显著改变IL-2与受体结合的平衡解离常数(kd值);也不影响Tac单克隆抗体与β链Tac位点的结合。     

鞭毛蛋白与IL-12协同诱导人NK细胞产生IFN-γ机制的探讨

目的:探讨细菌鞭毛蛋白(flagellin)与IL-12协同诱导人NK细胞产生IFN-γ的作用和机制。方法:自正常人静脉血中分离PBMCs,分别与培养液(medium)、flagellin、IL-12或flagellin+IL-12共同培养。三天后,利用酶联免疫吸附法(ELISA法)检测培养上清中IFN-γ的水平。收集初次培养组细胞,洗去刺激后进行二次培养,检测IFN-γ的产生。利用流式细胞仪检测NK细胞上IL-12Rβ1和TLR5的表达情况。结果:一次培养的结果表明,flagellin或IL-12单独刺激PBMCs可诱导较低水平IFN-γ的产生。共同刺激下,可协同诱导高水平IFN-γ产生。二次培养结果表明,不同剂量IL-12的刺激flagellin初次培养组细胞,IFN-γ的产生呈剂量依赖性的增加;IL-12初次刺激组细胞在flagellin的二次刺激下,IFN-γ的产生亦呈剂量依赖性增加。流式结果表明,flagellin可上调NK细胞IL-12Rβ1的表达。IL-12可上调NK细胞TLR5的表达。结论:flagellin通过上调NK细胞IL-12Rβ1的表达,IL-12通过促进NK细胞TLR5的表达,从而协同诱导IFN-γ的产生。     

人早孕期蜕膜基质细胞对蜕膜NK细胞分泌IL-22的调节作用

目的:探讨蜕膜基质细胞(Decidual stromal cells,DSCs)与蜕膜NK细胞(dNK)共培养后IL-22的分泌水平。方法:收集早孕蜕膜组织,分离蜕膜基质细胞(DSCs)及蜕膜免疫活性细胞(Decidual immunocytes,DICs),磁珠分选蜕膜CD56brightCD3-NK细胞,再与DSC按不同比例直接接触共培养(dNK∶DSC为1∶1、1∶2、1∶3)24小时,收集上清。ELISA检测上清中IL-22的表达。结果:与对照组相比,DSC能上调dNK分泌IL-22。结论:蜕膜基质细胞可以促进蜕膜NK细胞分泌IL-22。     

武汉地区正常人外周血T细胞亚群、NK细胞活性、诱生IFN、IL-2能力和血清IFN-α水平的研究

本文检测了武汉地区70例健康献血员(年龄:30～45岁),男女各35例)外周血T细胞亚群、NK细胞活性、诱生IFN-α、IFN-γ,IL-2能力和血清IFN-α水平。结果表明除女性受试者外周血NK细胞活性显著性地低于男性外,其他各项指标男女性别之间虽有差异,但均无显著性意义。     

IL-23与IL-12诱导NK细胞功能的异同及机制初探

目的探讨细胞因子IL-23与IL-12对NK细胞功能的影响及可能的机制。方法密度梯度离心法分离人外周血单个核细胞(PBMCs)或磁珠纯化NK细胞,不刺激或用IL-23或IL-12刺激,用流式细胞术和ELISA法检测NK细胞产生IFN-γ的情况;以K562或Jurkat细胞作为靶细胞,用流式细胞术检测NK细胞的杀伤功能并分析NK细胞在不同的刺激条件下杀伤相关分子的表达情况及pSTAT的表达情况。结果与未刺激组相比,IL-23和IL-12均可以诱导NK细胞呈剂量和时间依赖方式产生IFN-γ;但IL-12而非IL-23可以增强NK细胞对靶细胞K562或Jurkat细胞的杀伤功能。进一步研究表明,IL-12而非IL-23可以诱导杀伤相关分子TRAIL及CD107a/b的表达。此外,IL-12诱导NK细胞表达更高水平的pSTAT4,而IL-23诱导NK细胞表达更高水平的pSTAT3。结论与IL-12相比,IL-23亦可以诱导NK细胞产生细胞因子但不能增强NK细胞的杀伤功能,IL-23不能诱导杀伤相关分子TRAIL及CD107a/b的表达,IL-23可以诱导低水平的pSTAT4但高水平的pSTAT3的表达。     

绿脓杆菌制剂与IL-12在诱导人NK细胞IFN-γ产生中的协同作用

探讨绿脓杆菌制剂(piliated Pseudomonas Aeruginosa,PPA)与IL-12协同诱导人PBMC和NK细胞IFN-γ的产生。分离健康人PBMC和纯化NK细胞分别与培养液、PPA、IL-12或PPA+IL-12共同培养,利用酶联免疫吸附法(ELISA)检测无细胞培养上清中IFN-γ的水平。同时采用流式细胞仪在单个细胞水平上分析PPA和IL-12诱导IFN-γ产生的淋巴细胞亚群。结果显示,单独应用亚适剂量的IL-12或PPA刺激人PBMC或纯化NK细胞,不能诱导或只能诱导低水平IFN-γ的产生。当PPA和IL-12共同与人PBMC或纯化NK细胞孵育后,PPA呈时间和剂量依赖性与IL-12协同诱导PBMC和纯化NK细胞产生大量IFN-γ。细胞亚群分析的结果表明,PPA和IL-12协同诱导CD56+NK细胞产生IFN-γ,但对CD4+T和CD8+T细胞无明显作用。PPA与IL-12协同促进NK细胞IFN-γ的产生,提示PPA和IL-12能直接刺激NK细胞发生免疫应答。     

重组IL-2激活的胎儿肝脾细胞LAK样活性

本研究证明,胎儿肝脾细胞经重组IL-2作用96小时,可产生显著的LAK样活性,在重组IL-2 1000u/ml,E:T为100:1其杀伤率分别达60%和62%。如果这一体外试验结果在体内应用中得到证实,无疑将给临床获取LAK细胞提供一条新的途径。     

rIL-4 differentially regulates rIL-2-induced murine NK and LAK killing in CD8+ and CD8- precursor cell subsets

Interleukin 4 (IL-4) and IL-2 have complementary or synergistic roles in many aspects of lymphocyte development. IL-2 supports the induction of cytolytic activity in cytotoxic T lymphocyte (CTL), natural killer (NK), and lymphokine-activated killer (LAK) cells. IL-4 has also been shown to support CTL and LAK in primary murine spleen cell culture. This report demonstrates that IL-4 selectively down-regulates IL-2 inducible murine CD8- precursors of NK cells. For maximal regulatory effect it is necessary to add IL-4 to cultures before 40 h. Enrichment for NK1.1+ cells failed to recover precursor cells which are down-regulated in overnight cultures or can be cultivated in vitro to yield NK cytolytic activity. Furthermore, phenotypic analysis of effector cells demonstrated a marked inhibition of development of NK1.1+ cells in cultures containing IL-4 plus IL-2 versus IL-2 alone. Thus, it appears that IL-4 down-regulates the precursors of murine NK cells by inhibiting proliferation and/or development. In addition, we show that IL-2-induced murine LAK activity mediated by CD8- precursor cells is unaffected by IL-4, while CD8(+)-derived LAK cells are up-regulated by co-culture with IL-4 and IL-2. Analysis of these data relative to reports documenting down-regulation of human LAK by IL-4 suggests that in vitro cultured, IL-2-activated murine NK cells are the correlates to what are commonly described as human LAK cells. The discrepancy may stem from differences in the characteristics of target cells used in the murine versus the human systems. These results clarify the conflicting reports on the effect of IL-4 on killing activity.     

抗CD4单抗增强抗CD3单抗／IL—2活化的肿瘤特异性T细胞的抗瘤活性

目的探讨抗CD4mAb增强抗CD3mAb刺激的肿瘤特异性T细胞增殖和杀瘤活性的作用。方法将肿瘤细胞免疫的小鼠脾细胞,采用4种不同的方案培养1单独加2×104U/LrIL2IL2组2单独加抗CD3mAb抗CD3组3加抗CD3mAb48h后,再加入抗CD3mAb和2×104U/LrIL2抗CD3 IL2组4同时加抗CD3mAb和抗CD4mAb48h后,再加入抗CD3mAb、抗CD4mAb和2×104U/LrIL2抗CD3 IL2 抗CD4组。然后分别检测4组效应细胞的增殖水平、杀瘤活性及表型。结果抗CD3 IL2组细胞的3HTdR掺入量在第6,12和20d分别为:22045、13986和1931;抗CD3 IL2 抗CD4组细胞的3HTdR掺入量在第6、12和20d,分别为46193、31047和7443,后者明显高于前者P0.05。在培养12d时,抗CD3 IL2组的细胞对FBL3细胞株的最大杀伤率为83.6%;抗CD3 IL2 抗CD4组细胞的最大杀伤率为91.7%。细胞表型:FACS分析表明,抗CD3 IL2 抗CD4组培养12d的细胞,99%以上为Thy1.2 细胞,且CD4 、CD25 细胞的百分率均高于抗CD3 IL2组。结论抗CD4mAb对抗CD3mAb刺激、IL2诱导的肿瘤特异性T细胞的增殖和杀瘤活性具有增强作用。     

Modulation of human NK cells by interferon and prostaglandin E2

Our studies have shown that stimulation of human natural killer (NK) cells by poly I:C does not depend on or require monocytes. In contrast, the presence of monocytes in a mixed population of mononuclear cells stimulated by poly I:C suppresses NK activity. The suppression can be partially overcome if indomethacin (10(-6) M) is added to the culture during stimulation. Culture supernatants from poly I:C stimulated monocytes do not have detectable levels of anti-viral activity but contained appreciable amounts of PGE2. Our results offer an explanation as to how NK cells may protect themselves from suppression by PGE2. We have demonstrated that IFN-activated NK cells become resistant to PGE2-mediated suppression; moreover the suppression does not require cells other than the large granular lymphocytes, the major effector cell type for NK. Taken together, the data suggest that stimulation of NK cells is dependent on and regulated by the relative levels of interferon produced by lymphocytes and PGE2 produced by monocytes.     

Human tumor-induced and naturally occurring Treg cells differentially affect NK cells activated by either IL-2 or target cells

NK cells play a crucial role in the eradication of tumor cells. Naturally occurring (n) Treg cells and induced (i) Treg cells are two distinct Treg subsets. While the interaction of nTreg cells with NK cells has been investigated in the past, the role of tumor iTreg cells in the modulation of NK-cell function remains unclear. Tumor iTreg cells were generated from CD4(+) CD25(-) T cells in the presence of autologous immature DCs, head and neck cancer cells and IL-2, IL-10, and IL-15. The effect of iTreg cells and nTreg cells on the expression of NKG2D, NKp44, CD107a, and IFN-γ by NK cells, as well as NK tumor-cytolytic activity, were investigated. iTreg cells - similar to recombinant TGF-β and nTreg cells - inhibited IL-2-induced activation of NK cells in the absence of target cell contact. Surprisingly, and in contrast to nTreg cells, iTreg cells enhanced NK-cell activity elicited by target cell contact. The cytolytic activity of NK cells activated by iTreg cells was mediated via perforin and FasL. We conclude that tumor iTreg cells inhibited IL-2-mediated NK-cell activity in the absence of target cells, whereas the tumoricidal activity of NK cells was enhanced by iTreg cells. Our data suggest a complex, previously not recognized, differential regulation of human NK activity by iTreg cells in the tumor microenvironment.     

Arousal and inhibition of human NK cells

Summary: NK cells express receptors for polymorphic MHC class I molecules that inhibit killing of potential target cells bearing appropriate class I allotypes. Here we review the membrane receptors on human NK cells that are known to initiate cell-mediated cytotoxicity and demonstrate regulation of these responses by the killer cell inhibitory (KIR) receptors.     

Recognition of autologous dendritic cells by human NK cells

NK cells can recognize and kill tumor as well as certain normal cells. The outcome of the NK-target interaction is determined by a balance of positive and negative signals initiated by different target cell ligands. We have previously shown that human NK cells kill CD40-transfected tumor targets efficiently, but the physiological significance of this is unclear. We now demonstrate that human NK cells can kill dendritic cells (DC), known to express CD40 and other co-stimulatory molecules. The killing was observed with polyclonal NK cells cultured short term in IL-2 as well as with NK cell clones as effectors, and with allogeneic as well as autologous DC as targets. NK cell recognition could be inhibited, but only partially, by preincubation of target cells with monoclonal antibodies against CD40, suggesting that this molecule may be one of several ligands involved. Addition of TNF-alpha of the cultures stimulated the development of a more mature DC phenotype, while addition of IL-10 resulted in a less mature phenotype, with lower expression of CD40 and other co-stimulatory molecules. Nevertheless, such DC were more NK susceptible than the differentiated DC. This may be partly explained by a reduced MHC class I expression observed on such cells, since blocking of MHC class I molecules on differentiated DC or CD94 receptors of NK cells led to increased NK susceptibility. The results show that NK cells may interact with DC, and suggest that the outcome of such interactions depend on the cytokine milieu.