妊娠期uNK、pNK细胞NKG2A与NKG2D的表达及其生物学意义的研究

目的:研究妊娠期妇女子宫NK细胞(uNK细胞)与外周血NK细胞(pNK细胞)表面NKG2A和NKG2D及其相应配体的表达,探讨uNK细胞表面NKG2A和NKG2D的不平衡表达与母胎界面所形成的免疫耐受关系。方法:采用流式细胞术检测30例孕6～9周的正常妊娠妇女uNK细胞和pNK细胞NKG2A、NKG2D的表达状况;RTPCR技术检测绒毛膜组织HLAE、MICA的表达。结果:子宫NK细胞NKG2A的表达显著高于外周血NK细胞,二者分别为(97.86±1.75)%与(33.35±10.92)%;子宫NK细胞NKG2D的表达水平与外周血NK细胞相近,分别为(93.21±4.52)%与(97.80±1.72)%,滋养层组织仅检测到HLAEmRNA的表达。结论:妊娠期子宫NK细胞表面高表达抑制性受体NKG2A,同时滋养层组织表达相应的配体HLAE,这可能是维持母胎界面免疫耐受的重要因素。     

Natural killer (NK) cells from killers to regulators: distinct features between peripheral blood and decidual NK cells

Natural killer (NK) cells are a key component of innate immunity, particularly crucial during the early phase of immune responses against certain viruses, parasites, and microbial pathogens. The role of NK cell during pregnancy has been vividly discussed over the past years and it is now becoming increasingly clear that NK cells control pregnancy maintenance at several levels. In normal pregnancy, it appears that they provide benefit by properly secreting cytokines, chemokines and angiogenic factors rather than functioning as cytotoxic effector cells. However, as they are endowed with all the cytolytic weapons, they promptly become capable of attacking fetal and maternal tissues during infection and inflammation.     

树突状细胞与自然杀伤细胞在免疫应答中的相互作用

树突状细胞(dendritic cells,DC)是专职的抗原提呈细胞,它们在免疫应答中发挥的作用越来越受到重视。NK细胞是固有免疫中的一种重要的效应细胞。当两者共培养后,在免疫应答中具有互惠作用。现就两者的生物学活性以及在免疫应答中相互作用的机制等方面作一综述。     

The interaction between NK cells and dendritic cells in bacterial infections results in rapid induction of NK cell activation and in the lysis of uninfected dendritic cells

NK and DC reciprocal interactions have only recently been investigated. In this study, we focused on the interplay between NK cells and DC in two models of bacterial infection. Immature monocyte-derived DC were cultured in the presence of live Escherichia coli or bacillus Calmette-Guérin. Upon exposure to either extracellular or intracellular bacteria, DC underwent maturation as assessed by the increased levels of expression of CD80,CD86, and HLA molecules and the de novo expression of CD83 and CCR7. Significant amounts of TNF-alpha and IL-12 were released by DC upon infection, whereas IL-2 and IL-15 were barely detectable in culture supernatants. Both infected and uninfected DC were capable of inducing in fresh autologous NK cells the expression of CD69 and HLA-DR and of inducing cell proliferation. Remarkably, however, infected DC were much stronger inducers of NK cell activation and proliferation than uninfected DC. Thus, after just 24 h of NK/DC coculture, only those NK cells that had been exposed to bacteria-infected DC had acquired the ability to lyse autologous immature DC. In addition, infected DC were more resistant to NK-mediated lysis as a consequence of the up-regulation of HLA class I molecule expression on their surface. This study suggests a regulatory circuit involving NK cells and DC in which DC-induced NK cell activation is effectively enhanced by the presence of pathogens. Activated NK cells, by limiting the supply of immature DC, may then exert a control on subsequent innate and adaptive immune responses.     

乳凝集素对脐带血树突状细胞功能的调节作用

目的研究乳凝集素(lactadherin)对未成熟树突状细胞吞噬功能以及对成熟树突状细胞刺激初始T细胞增殖能力等方面的调节作用。方法 ficoll密度梯度离心法分离脐带血单个核细胞,加入细胞因子IL-4、GM-CSF、TNF-α(成熟组应用)诱导分化为树突状细胞(dendritic cell,DC),阳性对照组分别在第0天或第5天起加入lactadherin,各组均培养至第7天时收集细胞,流式细胞仪检测各组未成熟DC吞噬FITC-DEXTRAN的能力,MTT法检测各组成熟DC刺激初始T细胞增殖能力的变化。结果同时加入lactadherin诱导培养时,未成熟DC对抗原(FITC-DEXTRAN)的吞噬功能增强,在培养第0天时即加入lactadherin组培养完成后吞噬功能增强更为明显;成熟组DC刺激初始T细胞增殖的能力也较无lactadherin组明显增强(P<0.001),且以第5天加入组培养完成时刺激增殖作用更为显著。结论 lactadherin能够增强DC细胞的免疫功能,包括未成熟时的抗原吞噬摄取和成熟时刺激T细胞增殖,激活适应性免疫应答等。     

没食子儿茶素没食子酸酯对中波紫外线辐射后树突状细胞功能的影响

目的 观察没食子儿茶素没食子酸酯（epigallocatechin gallate，EGCG）对中波紫外线（UVB）辐射后树突状细胞（DC）功能的影响并探讨其可能的机制。方法 分离外周血单核细胞，经细胞因子诱导DC成熟后，再使用不同剂量的UVB照射DC，将经EGCG处理或未处理的DC与淋巴细胞进行混合培养，72h后用MTF法检测DC刺激淋巴细胞增殖能力；用流式细胞术分析DC表面CDS0、CD86、HLA-DR、CD40分子表达的变化；酶联免疫吸附试验（ELISA）检测DC培养24h后上清液中IL-10及IL-12分泌水平。结果UVB以剂量依赖的方式抑制DC刺激同种异体淋巴细胞增殖能力，并以剂量依赖的方式抑制DC表面共刺激分子的表达；使用浓度为200μg／ml的EGCG处理DC后，各剂量组UVB所致的免疫抑制作用均可得到部分改善，与单纯照光组相比，UVB＋EGCG组的抑制率分别比同剂量UVB组减少了60．0％、60．4％、59．2％、40．8％及12．2％，当EGCG浓度大于100μg／ml时，EGCG对DC表面共刺激分子的表达有促进作用；UVB照射对DCIL-12及IL-10因子的分泌未有显著影响，经EGCG处理并照射UVB的DCIL-12分泌水平显著降低，但IL-10分泌水平显著提高（P〈0．05）。结论 EGCG具有调节中波紫外线辐射后DC细胞免疫功能的作用，其作用与促进DC表面共刺激分子表达及影响其IL-12及IL-10分泌有关。     

孕酮对人树突状细胞成熟和免疫功能的影响

目的：研究孕酮（P₄）对人外周血来源树突状细胞（DCs）成熟和免疫学功能的影响。方法：在人外周血来源DCs体外培养时加入两种浓度的P₄ (10-7 mol/L和10-6 mol/L)处理，光镜和电镜下观察DCs的生成情况及形态变化，以流式细胞仪分析各组细胞的免疫表型，用ELISA方法测定其分泌的IL-10和IL-12水平，［3H］-TdR掺入法检测体外混合淋巴细胞反应中DCs刺激同种反应性T细胞的增殖能力。结果：加入P4培养后, DCs树突状和膜面状伪足减少，表达低水平MHC-II分子和共刺激分子CD40、CD80和CD86，其分泌的IL-10水平升高，IL-12水平明显下降，DCs刺激同种反应性T细胞的功能显著下降。结论：P₄抑制人外周血来源DCs的成熟，对其免疫学功能具有负性调节作用。     

Modification of anti-tumor immunity by tolerogenic dendritic cells

Immunosuppressive functions of glucocorticoids (GC) can be mediated via various mechanisms, including the modulation of dendritic cells (DC). Our study investigates the effects of tolerogenic GC-treated DCs on NK and T cell anti-tumor responses in OT-1/Rag^?/? mice, expressing a transgenic TCR in CD8⁺ T cells. The effects caused by GC-treated DCs were compared to the responses to immunogenic, CpG-activated DCs. The effects of DCs on anti-tumor immune responses were analyzed using the EG7 tumor model, where the tumor cells express the peptide epitope recognized by OT-1 T cells. We observed that immunization with CpG and peptide-treated DCs protected against tumor growth by activation of NK cell response. Also, immunogenic DCs induced the expansion of cytotoxic CD8⁺OT-1 cells, expressing activation markers CD44 and CD69 and producing IFNγ. In contrast, the peptide and GC-treated DCs in OT-1 mice increased the numbers of immature Mac-1⁺CD27^? NK cells as well as Foxp3⁺ and IL-10 secreting CD8⁺OT-1 cells with suppressive properties. We conclude that the generation of tolerogenic DCs is one of many immunosuppressive mechanisms that can be induced by GC. Our study demonstrated that tolerogenic DCs modify anti-tumor immune response by suppressing NK cell activity and stimulating the formation of IL-10-secreting CD8⁺ Tregs.     

Simple enumerations of peripheral blood natural killer (CD56+ NK) cells, B cells and T cells have no predictive value in IVF treatment outcome

BACKGROUND: To evaluate the association between the absolute counts of the peripheral natural killer (NK) cells (including total CD56(+) NK cells, CD56(dim) NK cells and CD56(bright) NK cells), B cells and T cells on the implantation rate and miscarriage rate after IVF treatment. METHODS: This was a prospective observation study. A total of 138 patients who underwent IVF treatment from December 2002 to July 2003 were recruited to the study. Blood samples were obtained on the day of vaginal oocyte retrieval prior to the procedure. The absolute counts of lymphocytes, NK cells, B cells and T cells were identified by flow cytometry. These absolute counts and their relationships to IVF treatment outcome and miscarriage rate were analysed. RESULTS: There were no significant differences with regard the mean values of absolute lymphocyte count, T cell count, B cell count and NK cell count (including total CD56(+) NK, CD56(dim) NK and CD56(bright) NK cells) between the pregnant and non-pregnant groups and also between the ongoing pregnancy and miscarriage groups. The cause of infertility, duration of infertility, basal FSH levels, number of previous failed IVF treatments, number of previous miscarriages and stimulation characteristics were not significantly different between the pregnant and non-pregnant groups. Previous studies have suggested that women with a history of recurrent miscarriage and those with infertility accompanied by recurrent failed IVF treatments are associated with a peripheral blood NK cell percentage >12%, therefore further analysis of peripheral CD56(+) NK cell levels <12% (group A) and >12% (group B) was performed. There was no significant difference in implantation rate (group A: 17.0%; group B: 23.2%), pregnancy rate (group A: 36.6%; group B: 47.7%) or miscarriage rate (group A: 23.3%; group B: 28.6%). CONCLUSION: There were no significant differences between simple enumerations of peripheral blood NK cells (including total CD56(+) NK, CD56(dim) NK and CD56(bright) NK cells), B cells and T cells with IVF treatment outcome and pregnancy outcome. Women who had a peripheral NK cell level >12% did not have higher number of previous pregnancy losses. Importantly their pregnancy rate was not reduced and their miscarriages were not increased compared to women who had a peripheral NK cells level <12%.     

雌二醇对人树突状细胞成熟和功能的影响

目的：研究雌二醇(17β-estradiol, E2)对人外周血来源树突状细胞(DCs)成熟和免疫学功能的影响。 方法： 在人外周血来源DC体外培养时加入两种浓度的E2 (10-7 mol/L和10-6 mol/L)处理，光镜和电镜下观察DCs的生成情况及形态变化，以流式细胞仪分析各组细胞的免疫表型，用ELISA方法测定其分泌的IL-12水平，［3H］-TdR掺入法检测体外混合淋巴细胞反应中DCs刺激同种反应性T细胞的增殖能力。 结果： 加入E2培养后, DCs树突状和膜面状伪足减少，表达低水平MHC-II分子和共刺激分子CD40、CD80和CD86，其分泌的IL-12水平明显下降，DCs刺激同种反应性T细胞的功能显著下降。 结论： E2抑制人外周血来源DC的成熟，对其免疫学功能具有负性调节作用。     

病毒性心肌炎患者外周血单核细胞来源DCs的功能研究

目的:体外诱导病毒性心肌炎患者外周血单核细胞来源的DCs(Mo-DCs),并探讨其功能状态的变化,为寻求病毒性心肌炎的致病机制和新的治疗途径提供实验依据。方法:无菌分离18例临床病毒性心肌炎患者及20例健康志愿者外周血单核细胞,分别加入粒细胞巨噬细胞集落刺激因子(granulocyte-macrophage colony-stimulating factor,GM-CSF)和白细胞介素4(IL-4)诱导外周血Mo-DCs,应用免疫荧光标记技术、流式细胞分析和酶联免疫吸附试验(ELISA)等方法比较病毒性心肌炎患者和健康志愿者外周血Mo-DCs的表型、吞噬能力和表达细胞因子的差异。结果:病毒性心肌炎患者外周血Mo-DCs表达较高水平的CD83、CD80、CD86和MHCⅡ,但是吞噬能力下降,并且分泌较高水平的TNFα-(P<0.01)和IL-12(P<0.01),可以更有效地刺激T淋巴细胞增殖。结论:病毒性心肌炎患者外周血Mo-DCs处于较成熟功能状态,且表达较高水平的IL-12和TNFα-。进而有可能通过调节T细胞、NK细胞和巨噬细胞发挥效应而在病毒性心肌炎的发生发展中起到举足轻重的作用。     

Function and subsets of dendritic cells and natural killer cells were decreased in gastric cancer

Dendritic cells (DCs) and natural killer (NK) cells initiate specific immune responses against tumor cells. The aim of the present study was to determine the cytotoxicity and the subsets of the DC and NK cells and the cytokines level of DC and NK cells from cancer tissue and peripheral blood in the gastric cancer patients. Cytotoxicity of DC and NK was determined using the Cytotox non-radioactive assay. The cytotoxic activity of DC or NK isolated from cancer tissue and peripheral blood was attenuated in gastric cancer patients. CD11c, CD80, CD83, CD16, CD57 and CD69 were decreased in the cancer tissue and peripheral blood in the gastric cancer patients. CD86, CCR7 and CD59 were no significance in the cancer tissue and peripheral blood from gastric cancer patients. Tumor necrosis factor (TNF)-α, interleukin (IL)-2, T-bet and IL-15Rβ levels were decreased in DC and NK from the gastric cancer tissue and peripheral blood in the gastric cancer patients. IL-15 and IL-15Rα level were no significance in DC and NK in the gastric cancer tissue and peripheral blood in the gastric cancer patients. These results indicate that the cytotoxic activity and subsets and cytokines of DC and NK cells in the cancer tissue and peripheral blood in the gastric cancer patients were decreased. The decrease of subsets content and cytokines of DC and NK may contribute to a decrease in the function of DC and NK in the tissue and peripheral blood in the gastric cancer patients.     

IL-4 is more effective than IL-13 for in vitro differentiation of dendritic cells from peripheral blood mononuclear cells

Dendritic cells (DCs) are the most potent professional antigen-presenting cells which can activate T cells to induce the primary immune response. For clinical studies, DCs are often differentiated in vitro from peripheral blood mononuclear cells (PBMCs) through treatment with granulocyte macrophage colony-stimulating factor (GM-CSF) and IL-4. However, IL-13, a cytokine closely related to IL-4, has also been reported to induce differentiation equally or more efficiently when used with GM-CSF. For the present study, we compared the DC characteristics exhibited by iDCs and LPS-matured DCs differentiated from PBMCs using GM-CSF and IL-4 or IL-13. Physical characteristics examined include cellular morphology and surface phenotype. Functional traits investigated include FITC-dextran uptake, IL-10 and IL-12 production, allostimulation and cytokine production by stimulated T cells and antigen-specific T cell stimulation. Compared with IL-13-derived DCs, IL-4 treatment yielded more differentiated DCs, with extensive dendrites and higher expression of DC-SIGN, DEC-205, CD86 and HLA-DR. In addition, IL-4 DCs were more efficient at inducing allogeneic T cell proliferation and immature IL-4 DCs had higher endocytic activity at low FITC-dextran concentrations (1 microg ml(-1)). Although IL-13 was capable of generating DCs from PBMCs, it was not as effective as IL-4 in generating DC phenotype and functionality. Thus, the use of GM-CSF and IL-4 is the more efficient treatment for inducing DC differentiation from PBMCs.     

树突状细胞疫苗对慢性乙型肝炎的治疗作用

目的：探讨自体乙肝疫苗致敏的树突状细胞（DC）对慢性乙型肝炎（CHB）免疫治疗的作用。 方法： 取患者外周血20 mL分离单个核细胞，加入重组人粒细胞-巨噬细胞集落刺激因子（rGM-CSF）和白细胞介素4（IL-4）进行DC体外扩增，于培养第5 d加入50 mg/L乙型肝炎疫苗，7 d收获细胞。34例慢性乙肝患者根据年龄和发病时间分为治疗1、2、3组，皮内回输DC。对照组患者注射等量生理盐水，均每周1次，连续8次。于回输DC后2周检测患者血清乙型肝炎病毒DNA（HBV-DNA）含量。 结果： 培养可得到形态及功能典型的DC，治疗1、2、3组患者回输DC后血清HBV-DNA拷贝数均显著低于对照组（P<0.01），总应答率58.8%（20/34），对照组输注前后没有明显差异（P<0.05）；治疗1组与3组相比HBV-DNA定量拷贝数降低幅度有显著差异（P<0.01），治疗1组与2组、2组与3组相比无显著差异（P＞0.05）。 结论： 经乙型肝炎疫苗致敏的DC回输患者后，其血清HBV-DNA含量明显降低，且降低幅度与感染病毒时间和/或患者年龄有一定关系。     

慢性乙型肝炎患者外周血树突细胞CD40、CD80表达和免疫活性的体外研究

目的 :探讨慢性乙型肝炎患者DC表面协同刺激分子CD4 0和CD80表达与其抗原呈递功能的关系 ,为进一步研究慢性乙型肝炎的发病机制及治疗提供新的思路。方法 :分离培养慢性乙型肝炎患者和健康人外周血DC ,流式细胞仪测定DC表面CD4 0和CD80的表达 ,混合淋巴细胞反应测定两组DC的功能。结果 :慢性乙型肝炎患者DC表面CD4 0和CD80的表达较健康人低 ,刺激同种异种T细胞增殖反应也较健康人低。结论 :乙肝病毒感染可通过抑制患者DC表面CD4 0、CD80等协同刺激分子的表达 ,从而使其抗原呈递功能降低     

Intrahepatic and peripheral blood phenotypes of natural killer and T cells: differential surface expression of killer cell immunoglobulin‐like receptors

Deep characterization of the frequencies, phenotypes and functionalities of liver and peripheral blood natural killer (NK), natural killer T (NKT) and T cells from healthy individuals is an essential step to further interpret changes in liver diseases. These data indicate that CCR7, a chemokine essential for cell migration through lymphoid organs, is almost absent in liver NK and T cells. CD56^bright NK cells, which represent half of liver NK cells, showed lower expression of the inhibitory molecule NKG2A and an increased frequency of the activation marker NKp44. By contrast, a decrease of CD16 expression with a potential decreased capacity to perform antibody‐dependent cellular cytotoxicity was the main difference between liver and peripheral blood CD56^dim NK cells. Liver T cells with an effector memory or terminally differentiated phenotype showed an increased frequency of MAIT cells,T‐cell receptor‐γδ (TCR‐γδ) T cells and TCR‐αβ CD8⁺ cells, with few naive T cells. Most liver NK and T cells expressed the homing markers CD161 and CD244. Liver T cells revealed a unique expression pattern of killer cell immunoglobulin‐like receptors (KIR) receptors, with increased degranulation ability and higher secretion of interferon‐γ. Hence, the liver possesses a large amount of memory and terminally differentiated CD8⁺ cells with a unique expression pattern of KIR activating receptors that have a potent functional capacity as well as a reduced amount of CCR7, which are unable to migrate to regional lymph nodes. These results are consistent with previous studies showing that liver T (and also NK) cells likely remain and die in the liver.     

卵巢肿瘤患者外周血NK细胞受体NKG2A、NKG2D及NK活性检测的临床意义

通过研究卵巢癌及良性卵巢肿瘤患者外周血NK细胞表面受体的表达情况及NK活性的变化,分析探讨宿主NK细胞受体与肿瘤免疫逃逸的关系及其临床价值。分离受检者外周血单个核细胞,应用MTT法检测NK细胞的细胞毒活性,流式细胞术检测NK细胞受体NKG2D和NKG2A的表达,并结合临床病理因素作比较分析。结果显示,与良性卵巢肿瘤组和正常组相比,卵巢癌患者外周血NK细胞的细胞毒活性降低,NK细胞表面NKG2D的表达水平降低,而NKG2A的表达水平明显升高,其变化与卵巢癌的病情进展有关。此结果表明,卵巢癌患者机体NK细胞杀伤活性下降,NKG2D与NKG2A二者之间的平衡表达可能对NK细胞的功能状态起着重要的调节作用。     

乳腺癌患者外周血树突状细胞亚群及其HLA-DR表达的变化

目的：探讨乳腺癌患者外周血树突状细胞(DC)亚群和其HLA-DR表达变化及血浆中DC相关细胞因子水平的变化。方法:4色荧光流式细胞术分析57例乳腺癌术前、术后1周、术后6个月的患者及正常对照的外周血DC前体细胞pDC₁/pDC₂（CD11c+CD123-/CD11c-CD123+）比值及其HLA-DR的表达；酶联免疫吸附法检测血浆细胞因子白细胞介素-12p40（IL-12p40）、白细胞介素-10（IL-10）、γ-干扰素（IFN-γ）、白细胞介素-4（IL-4）水平。结果:57例乳腺癌患者中, 2例Ⅲ期、4例Ⅳ期外周血pDC缺乏，其余患者Ⅰ、Ⅱ、Ⅲ、Ⅳ期外周血pDC₁/pDC₂比值分别为1.62±0.59、1.41±0.63、0.91±0.32、0.81±0.29，均显著低于对照组（1.94±0.44,P<0.05）；Ⅰ、Ⅱ、Ⅲ期患者术后1周pDC₁/pDC₂比值为1.71±0.47、1.52±0.54、1.04±0.36，与术前比较均无显著差异（P>0.05），但显著低于对照组（P<0.05）; 术后6个月pDC₁/pDC₂比值分别为1.92±0.72、1.63±0.65、1.28±0.34，与术前比较，均有显著提高（P<0.05），但与对照组比较，仅Ⅰ期患者恢复正常（P>0.05）,Ⅱ、Ⅲ期患者仍然显著降低（P<0.05）。乳腺癌患者pDC亚群HLA-DR表达以及血浆中IL-12p40、 IL-10、IFN-γ、IL-4水平及IL-12p40/IL-10、IFN-γ/IL-4比值与对照组比较均无显著差异（P>0.05）。结论:Ⅰ-Ⅳ期乳腺癌患者外周血pDC₁/pDC₂比值降低，部分Ⅲ、Ⅳ期患者外周血pDC缺乏。pDC的HLA-DR表达及DC分泌相关细胞因子的能力没有同步变异。术后患者pDC亚群Ⅱ、Ⅲ期明显改善，Ⅰ期恢复正常。