Cyr61对外周血NK细胞的增殖和活性调节

目的:体外实验探讨Cyr61对外周血NK(pNK)细胞的增殖和活性的影响。方法:磁珠分选得到纯化的pNK细胞;流式细胞术检测pNK细胞的抑制性和活化性受体、细胞因子IFN-γ的生成和细胞毒性。结果:Cyr61促进外周血淋巴细胞中pNK细胞的增殖,降低CD16的表达;降低淋巴细胞中pNK细胞的活化性受体NKG2D、NKp30和CD244的表达,提高抑制性受体KIR3DL1的表达;能够促进纯化pNK细胞的KIR2DL1表达,降低纯化pNK细胞的胞内IFN-γ生成和细胞毒性。结论:Cyr61对pNK细胞活化的抑制作用,支持了其他学者关于Cyr61在正常妊娠和子痫前期的发病方面可能发挥重要作用的研究结果。     

膜型/分泌型MICA对NK细胞受体NKG2D的相反调节效应及其对NK细胞受体谱的影响

目的　观察膜型和分泌型MICA对NK细胞受体表达的影响 ,以探讨NK细胞抗肿瘤活化机制及肿瘤细胞表达MICA分子的意义。方法　用MTT法测定人NK细胞系 (NK92 )的细胞毒活性 ;用RT PCR或FACS检测NK细胞受体 (NKG2D ,NKG2A B ,KIR2DL1,KIR2DS1)及NKG2D的识别配体MICA的表达。结果　肿瘤细胞表面的MICA分子可上调NKG2D的表达 ,下调抑制性受体NKG2A B和KIR2DL1的表达 ;而分泌型MICA (sMICA)分子对NKG2D及抑制性受体的表达均有抑制作用。结论　膜型MICA分子可上调NKG2D的表达 ,激发NK细胞对肿瘤细胞的细胞毒效应 ;分泌型MICA分子则通过降低NKG2D的表达下调机体的抗肿瘤免疫效应 ,肿瘤细胞分泌sMICA分子为肿瘤发生免疫逃逸的机制之一。     

K562细胞转染HLA-B分子对NK细胞杀伤功能的影响

为了研究不同HLA B分子对NK细胞杀伤活性的影响 ,我们分别构建pcDNA3 HLA B 390 5 2、B 2 70 4、B 5 1 0 2 2基因真核表达载体 ;借助脂质体将各质粒转染入K5 6 2细胞 ,经G4 1 8筛选 ,分别获得阳性表达细胞株 ;并应用LDH法检测转染细胞对不同个体外周血NK细胞杀伤活性的抑制效应。结果显示 :与转染了空质粒的对照组相比 ,外周血NK细胞对K5 6 2 B39的杀伤率无明显影响 ,而对K5 6 2 B2 7,K5 6 2 B5 1的杀伤率降低。当使用针对NK细胞受体KIR3DL1的单抗DX9封闭NK细胞后 ,此抑制效应大部分消失。提示靶细胞表达HLA Bw4分子可明显抑制NK细胞的杀伤效应 ,而表达HLA Bw6分子对NK细胞杀伤功能无明显影响     

双表达外源性4-1BBL/IL-15的K562细胞活化外周血淋巴细胞的研究

为肿瘤过继免疫治疗开发体外激活T细胞、NK细胞的高效途径,研究双表达外源性4-1BBL和IL-15的K562细胞刺激外周血淋巴细胞活化的能力。采用分子克隆技术,分别将4-1BBL和IL-15基因插入双表达载体pVITRO-2,命名为pV4-1BBL-IL-15。经测序鉴定后,利用脂质体介导的转染及潮霉素筛选,获得稳定双表达4-1BBL、IL-15分子的K562细胞(K562/4-1BBL/IL-15)。经流式细胞仪(FACS)分选后,K562/4-1BBL/IL15细胞和K562细胞分别用丝裂霉素C处理,与外周血淋巴细胞孵育24 h,FACS检测淋巴细胞表面活化性受体CD69的表达。对NK细胞不仅同时检测活化性受体NKG2D的表达,还用乳酸脱氢酶释放法观察NK细胞受不同刺激细胞作用后,细胞毒活性的变化。结果显示受K562/4-1BBL/IL15细胞刺激后,T细胞CD69的表达无明显变化。γδT细胞CD69表达增长5倍。NK细胞CD69表达增长6倍,而NKG2D的表达增加1.5倍;NK细胞受K562/4-1BBL/IL15细胞作用72 h后,细胞毒活性明显提高。提示双表达4-1BBL/IL-15的K562细胞能够高效激活γδT细胞及NK细胞,有望用于肿瘤的过继免疫治疗。     

人外周血NK细胞及NKT细胞受体及亚群的差异表达与类风湿关节炎的关系

目的:探讨初诊类风湿关节炎(RA)患者的外周血NK和NKT细胞的活化性、抑制性受体及亚群表达水平的变化,揭示其在RA发病中的可能机制。方法:检测32例初诊RA患者和15例健康人的外周血NK和NKT细胞及其活化性受体和抑制性受体,对自发和刺激后的NK、NKT细胞分泌的IFN-γ、NKT细胞和CD107a+NK细胞进行检测,分析各细胞亚群与临床指标之间的潜在关系。结果:与健康对照组相比,初诊RA患者的NK细胞的比例显著降低(P=0.026);RA患者NK细胞活化性受体NKG2D+,NKP46+和NKT细胞活化性受体NKG2C+,NKG2D+,NKP46+的比例显著增高(P=0.011,P=0.010,P<0.001,P=0.032,P=0.001);NK细胞抑制性受体KIR2DL3+、KIR3DL1+和NKG2A+和NKT细胞抑制性受体KIR2DL3+,NKG2A+的比例显著降低(P=0.002,P=0.002,P=0.014,P=0.027,P=0.002);刺激后的IFN-γ+NK和IFN-γ+NKT细胞的比例,自发和刺激后的CD107a+NK细胞的比例在RA患者中要显著高于对照组(P=0.037,P=0.004,P=0.001,P=0.001)。此外,NK细胞、抑制性NK细胞受体NKG2A+和KIR2DL3+的比例和初诊RA患者的DAS28值显著相关(r=0.357,P=0.045;r=0.399,P=0.024;r=0.468,P=0.021)。结论:人外周血NK细胞及NKT细胞受体及亚群的差异表达、细胞功能的变化可能诱发RA的自身免疫反应。     

慢性乙型肝炎患者外周血CD8^＋ T细胞的KIR3DL1表达的探讨

目的：检测慢性乙型肝炎患者外周血CD8＋T细胞的KIR3DL1表达情况。方法：：采用流式细胞术检测慢性乙型肝炎患者外周血CD8＋T细胞的KIR3DL1分子表达,并与正常对照组比较。结果：慢性乙型肝炎患者外周血CD8＋T细胞的KIR3DL1分子表达明显高于对照组。结论：慢性乙型肝炎患者CD8＋T细胞的KIR3DL1表达显著增加。     

KIR在NK-92MI及K562细胞中的基因型及表达谱分析

目的:分析杀伤细胞免疫球蛋白样受体(KIR)在NK-92MI及K562细胞中的基因型及表达谱, 探索KIR受体的表达调控规律.方法:采用PCR、 RT-PCR及分子克隆测序技术, 检测K562及NK-92MI细胞中KIR2DL1、 2DL2、 2DL3、 2DL4、 2DL5、 2DS1、 2DS2、 2DS3、 2DS4、 2DS5、 3DL1、 3DL2、 3DL3、 3DS1、 2DP1、 3DP1的基因型, 及KIR2DL1、 KIR2DL2、 KIR2DL3、 KIR3DL1、 KIR2DS1、 KIR2DS3及KIR2DS2/4受体mRNA的表达.结果:K562细胞携带KIR2DL1、 2DL2、 2DL3、 2DL4、 2DL5A、 2DS2、 2DS4*003-006、 2DS5、 3DL1、 3DL2、 3DL3基因, 但不表达KIR.NK-92MI细胞携带KIR2DL1、 2DL2、 2DL3、 2DL4、 2DS2、 2DS4*001/002、 2DS4*003-006、 3DL1、 3DL2、 3DL3, 但只表达KIR2DL1、 KIR2DL3及KIR2DS2/4.结论:K562细胞及NK-92MI细胞均携带KIR2DL1、 2DL2、 2DL3、 2DL4、 2DS2、 2DS4*003-006、 3DL1、 3DL2、 3DL3.NK-92MI细胞表达KIR受体, K562细胞不表达上述KIR, KIR呈细胞特异性表达.     

IFN-γ上调的单核细胞表面MHC-I类链相关分子促进NK细胞活化

目的:研究IFN-γ诱导上调表达的单核细胞MHC-I类链相关分子(MICs)分子对NK细胞的活化作用.方法:采用密度梯离离心法分离人外周血单个核细胞(PBMC),以免疫磁珠法从PBMC中特异性分选单核细胞及NK细胞,以细胞因子IFN-γ、TNF-α刺激单核细胞后,再将单核细胞与NK细胞共培养,以流式细胞术(FCM)检测NK细胞表面CD69分子及胞内IFN-γ表达,以51Cr释放试验检测NK细胞对K562细胞的杀伤效应.结果:IFN-γ上调人单核细胞表面MICs表达;IFN-γ刺激的单核细胞能促进异体NK细胞CD69及胞内IFN-γ表达,能增强NK细胞对K562细胞的杀伤效应;单核细胞的这种效应至少部分依赖于IFN-γ上调的MICs分子,因为用抗MIC抗体封闭或用细胞小室阻断细胞接触,可以明显地抑制NK细胞的活化.结论:IFN-γ上调人单核细胞表面MICs分子介导了NK细胞的活化.     

HLA-Gα1结构域Met76和Gln79在KIR2DL4特异性识别中的作用研究

目的 探讨HLA-G α1结构域中特异的Met76和Gln79两个位点在HLA-G特异性受体KIR2DL4识别中的作用.方法 采用真核表达载体CD51neg1,克隆表达KIR2DL4胞外区与IgGFc段的可溶性融合蛋白;利用“桥式”PCR和“点突变”方法,将位于HLA-G目的基因α1结构域中编码Met76和Gln79的密码子突变为Ala76,79（HLA-mG）,通过逆转录病毒表达载体分别使野生型HLA-G及其突变体在HLAⅠ分子阴性的K562细胞上表达.流式细胞术分别测定KIR2DL4-IgG Fc融合蛋白与野生型HLA-G及Met76、Gln79→Ala76,79 HLA-G突变体结合的荧光强度,通过比较两者的平均荧光强度分析HLA-G分子Met76、Gln79残基在HLA-G与其受体KIR2DL4识别过程中的作用.结果 Western blot结果显示,本实验成功表达KIR2DL4-IgG Fc融合蛋白.FACS结果表明,野生型HLA-G及Met76、Gln79→Ala76,79 HLA-G突变体在K562细胞上高表达.Met76、Gln79突变为Ala76,79后能显著影响KIR2DL4对HLA-G分子的识别.结论 HLA-Gα1结构域中Met76和Gln79可能是其特异性受体KIR2DL4识别的关键位点.     

阻断KIR2DL4(CD158d)增强NK细胞的杀伤功能

目的利用抗体阻断人原代培养的自然杀伤(NK)细胞表面的杀伤细胞免疫球蛋白样受体2DL4(KIR2DL4),抑制其与配体人白细胞抗原G(HLA-G)的结合,观察对NK细胞杀伤功能的影响。方法用免疫磁珠法分离人NK细胞并培养,流式细胞术检测所得NK细胞的纯度;流式细胞术检测NK细胞表面KIR2DL4的表达水平和人乳腺癌SK-BR-3细胞表面HLA-G的表达水平;将NK细胞与SK-BR-3细胞共培养,并加入KIR2DL4的阻断抗体,ELISA检测NK细胞分泌γ干扰素(IFN-γ)的水平,利用流式细胞术检测NK细胞表面CD107a的表达水平,以检测其脱颗粒情况。结果分离得到的人原代NK细胞纯度可达90%以上;共培养实验发现,KIR2DL4的阻断抗体可促进NK细胞分泌IFN-γ,且NK细胞表面CD107a的表达水平也明显提高,提示其脱颗粒能力增强。结论阻断KIR2DL4信号可明显促进NK细胞的杀伤功能,KIR2DL4在NK细胞杀伤靶细胞的过程中发挥抑制性作用。     

两种HLA-B分子对外周血单个核细胞分泌细胞因子的影响

为了解HLA B2 7和B39分子对外周血单个核细胞 (PBMC )分泌IFN γ和TNF α的影响。我们将外源HLA B 2 70 4和B 390 5 2基因分别表达在HLAI类分子缺陷的K5 6 2细胞表面 ,与PBMC作用 12h后 ,用ELISA法检测IFN γ和TNF α的含量。结果显示 :HLA B2 7分子能显著抑制PBMC分泌IFN γ ,而对TNF α分泌的影响不显著 ;而HLA B39表达于K5 6 2细胞后 ,均不能影响IFN γ、TNF α分泌。提示HLA B2 7分子与HLA B39分子影响PBMC分泌细胞因子的能力不同     

Inhibitory Killer Immunoglobulin-like Receptors to self HLA-B and HLA-C ligands contribute differentially to Natural Killer cell functional potential in HIV infected slow progressors

Inhibitory Killer Immunoglobulin-like Receptors (iKIR) interact with their ligands, HLA molecules, to license Natural Killer (NK) cells for functional competence. Previous studies stimulating peripheral blood mononuclear cells (PBMCs) with the HLA-devoid K562 cell line revealed that NK cells from individuals with an iKIR encoded by the KIR3DL1 locus with self HLA-Bw4 as their ligands, had higher frequencies of tri-functional NK cells that expressed the degranulation marker CD107a and secreted Interferon-γ and Tumor Necrosis Factor-α than those from individuals who were homozygous for HLA-Bw6 alleles, which are not ligands for these iKIR. To assess the effect of other iKIR to self-HLA (S-iKIR) on the NK cell response, we compared HIV-infected slow progressors (SP) carrying S-iKIR to HLA-C alleles with or without S-iKIR to HLA-Bw4. We show that S-iKIR to HLA-B and C alleles differ in their contribution to NK cell functional potential in HIV-infected SP upon stimulation with K562 targets.     

Characterization of cord blood natural killer and lymphokine activated killer lymphocytes following ex vivo cellular engineering.

Cord blood (CB) natural killer (NK) and lymphokine-activated killer (LAK) cytotoxic cells are poorly characterized but might be used to treat minimal residual and/or recurrent malignant disease. Currently, there is no mechanism to use CB for adoptive cancer cellular immunotherapy after CB transplantation (CBT). Recognizing this as a deficiency, we hypothesized that CB aliquots could be engineered ex vivo for potential donor lymphocyte infusion after CBT. Cryopreserved CB aliquots were thawed, depleted of monocytes, and cultured in serum-free medium alone or serum-free medium with anti-CD3 and interleukins 2, 7, and 12 combined with antibody/cytokines for 48 hours. Immunophenotyping, cytotoxicity, and proliferation were evaluated. A significant expansion of CD3+ was seen, in addition to increases in lymphocyte subsets of CD8+, CD8+/CD25+, and CD3+/45RO+ versus medium alone. A significant enhancement of CD3 proliferation (P<.001), NK cytotoxicity, NK subset expansion, LAK cytotoxicity, and T-helper 1 subset expansion was also demonstrated. Significant enrichment was seen in NK CD16+/CD56+bright, CD16+/CD56+dim, CD56+bright and CD56+dim/KIR3DL1+, CD56+bright and CD56+dim/KIR2DL1+, CD56+bright and CD56+dim/KIR2DL2+ and CD94+/NKG2a+ subsets. These increases in CB NK subsets were in part secondary to augmentation of cell survival. Further, survival of NOD-SCID mice xenografted with human K562 cells and treated with CB cells expanded with antibody/cytokines was significantly higher than that in animals that received no treatment (phosphate buffered saline) and those that were treated with CB ex vivo expanded in medium alone (P<.005, respectively). These data suggest that cryopreserved CB cells could be ex vivo engineered for potential use as adoptive cancer cellular immunotherapy for donor lymphocyte infusion after CBT.     

The natural killer cell-mediated killing of autologous dendritic cells is confined to a cell subset expressing CD94/NKG2A,but lacking inhibitory killer Ig-like receptors

The cognate NK-DC interaction in inflamed tissues results in NK cell activation and acquisition of cytotoxicity against immature DC (iDC). This may represent a mechanism of DC selection required for the control of downstream adaptive immune responses. Here we show that killing of monocyte-derived iDC is confined to the NK cell subset that expresses CD94/NKG2A, but not killer Ig-like receptors (KIR). Consistent with these data, the expression of HLA-E (i.e. the cellular ligand of CD94/NKG2A) was down-regulated in iDC. On the other hand, HLA-B and HLA-C down-regulation in iDC was not sufficient to induce cytotoxicity in NK cells expressing KIR3DL1 or KIR2DL. Remarkably, CD94/NKG2A(+)KIR(-) NK cells were heterogeneous in their ability to kill iDC and an inverse correlation existed between their CD94/NKG2A surface density and the magnitude of their cytolytic activity. It is conceivable that the reduced CD94/NKG2A surface density enables these cells to efficiently sense the decrease of HLA-E surface expression in iDC. Finally, most NK cells that lysed iDC did not kill mature DC that express higher amounts of HLA class I molecules (including HLA-E)as compared with iDC. However, a small NK cell subset was capable of killing not only iDC but also mature DC.     

Inhibition of CD28-mediated natural cytotoxicity by KIR2DL2 does not require p56(lck) in the NK cell line YT-Indy.

CD28 functions as a cytotoxicity activation receptor in the NK cell line YT-Indy. To analyze the requirement of p56(lck) kinase in the function of killer inhibitory receptors, we transfected the p56(lck) negative YT-Indy cell line with the cl43 gene encoding for KIR2DL2. Pervanadate treatment revealed KIR2DL2 phosphorylation in YT-Indy-cl43, as well as SHP1/SHP2 recruitment. YT-Indy-cl43 cells were inhibited in their ability to lyse target cells expressing HLA-Cw3, a ligand for KIR2DL2. This inhibition was blocked by anti-KIR2DL2 or anti-HLA class I mAb. CD28 crosslinking on YT-Indy-cl43 enhanced tyrosine phosphorylation of PLC-gamma1. The simultaneous ligation of KIR2DL2 with mAb resulted in a decrease in CD28-induced tyrosine phosphorylation of PLC-gamma1 confirming that dephosphorylation of this protein is involved in the KIR2DL2-induced inhibition of CD28-mediated cytotoxicity. As YT-Indy-cl43 did not express detectable levels of p56(lck), these results indicate that this kinase is not required for transmitting the negative signals generated by KIR2DL2 ligation.     

Biphasic response of NK cells expressing both activating and inhibitory killer Ig-like receptors

NK cells can co-express inhibitory and activating killer Ig-like receptors (KIR) recognizing the same HLA class I ligand. We present evidence from experiments with NK cells expressing both activating (KIR2DS2) and inhibitory (KIR2DL2 and KIR2DL3) receptors that the activating KIR can function without apparent interference from the inhibitory KIR. These studies used CD158b mAb that is equally reactive with KIR2DS2, KIR2DL2 and KIR2DL3. First, we show using plastic-immobilized CD158b mAb that the activating KIR2DS2 is stimulated, resulting in NK cell division and degranulation. Second, we show using soluble CD158b mAb and FcRII (+) P815 cells that high concentrations of CD158b mAb trigger the inhibitory KIR, whereas low concentrations stimulate the activating KIR2DS2 resulting in NK cell division and cytolysis. These results demonstrate that the activating KIR2DS2 can function on cells co-expressing the inhibitory KIR2DL2 and/or KIR2DL3, indicating the potential for independent function of activating KIR with natural ligand.