The standardization of technique of detection of blood cells cytokine production ex vivo

The standardized technique to detect the blood cells cytokine production ex vivo was developed. The complex of mitogens of phytohemagglutinin P, phytohemagglutinin M, lipopolysaccharide, concanavalin A is applied to provide the mitogen activation. This approach permits to activate the different types of immunocompetent cells and to induce the secretion of cytokine representative series. It is demonstrated that the application of this technique permits to receive the reproducible results of the secretion of cytokine following the standard procedure. The standard values of spontaneous and mitogene-induced production of cytokines by blood cells of healthy human are determined.     

脐血CD34+细胞和外周血单核细胞两种来源的树突状细胞特性的比较研究

目的　体外大量扩增和纯化具有典型表型、形态和功能的树突状细胞（ＤＣ）,以进行相关基础研究和临床应用。方法　采用免疫磁珠法分离脐血ＣＤ３４ ＋ 细胞及外周血去Ｂ、去Ｔ淋巴细胞的单个核细胞（ 单核细胞） ,然后以ＧＭＣＳＦ、ＩＬ４、ＴＮＦα、Ｆｌｔ３ 配基（ＦＬ）、ＳＣＦ等不同的细胞因子配伍,分别诱生ＤＣ,通过流式细胞仪、电镜、光镜分析其特性,同时检测其刺激同种Ｔ细胞增殖的能力。结果　脐血与外周血诱生ＤＣ的方案不同,由脐血ＣＤ３４＋ 细胞诱导ＤＣ 时,ＧＭＣＳＦ＋ ＴＮＦα＋ ＳＣＦ＋ ＦＬ 组合可使ＣＤ１ａ＋ 细胞比例增至（２７ ．１８ ±１－５６）％ ,明显高于单独应用ＧＭＣＳＦ组［（０．６５±０ ．３８）％ ］ 。外周血单核细胞诱导的ＤＣ,则ＧＭＣＳＦ＋ 高剂量ＩＬ４（１０００ Ｕ／ｍｌ） 组合效率最高,诱生的ＣＤ１ａ ＋ 细胞可达（２１ ．８０ ±０－３２） ％ 。两种来源的ＤＣ在表型及形态上差异无显著性,两者同样具有刺激同种异体淋巴细胞增殖的能力。结论　从脐血和外周血均可诱生ＤＣ,根据应用目的的不同对其进行选择,这为ＤＣ用于临床治疗选择不同细胞来源提供了实验基础。     

G-CSF动员的供体外周血树突状细胞免疫生物学特性的研究

目的探讨从以G-CSF动员、CS-3000 plus血细胞分离机采集的供者外周血中诱导产生不同特性树突状细胞(DC)的可行性及DC的生物学特性。方法实验组为用CS-3000 plus血细胞分离机采集的5名造血干细胞捐献者的单核细胞(PBMCs),PBMCs培养贴壁后,经含IL-4、GM-CSF的无血清培养基诱导培养7 d,进一步分为4组:未刺激、肿瘤坏死因子α(TNF-α)、IL-10+TNF-α、抗胸腺球蛋白(ATG)+TNF-α组;对照组为5名健康献血者周血,亦按上述条件分组,每组复孔。后2组分别为IL-10、ATG诱导1 d后再加入TNF-α诱导1 d;分别测定各组DC的免疫表型、IL-12(P70)分泌、抗原吞噬以及异基因T淋巴细胞刺激反应。结果诱导培养9 d后可获得非成熟DC(iDC),单纯TNF-α刺激后,HLA-DR、CD11c、CD40、CD80的表达均明显增高,IL-12分泌增加,对异基因T淋巴细胞刺激反应性增强;而IL-10可以使CD1a表达上调,IL-10和ATG均抑制HLA-DR、CD11c、CD40、CD80的表达;与诱导的成熟DC相比,IL-10、ATG诱导DC的IL-12(P70)的分泌、对异基因淋巴细胞刺激反应性均减低,抗原摄取能力增强,但ATG、IL-10诱导的DC生物学特性不完全一致;动员的供体与对照健康献血者诱导的DC在产率,HLA-DR、CD11c表达,成熟诱导后CD11c、CD40、CD80表达,IL-12分泌,异基因T细胞刺激反应性等相比均明显减低。结论G-CSF动员的供体单核细胞PBMCs通过常规诱导可以产生iDC,TNF-α可诱导其分化成熟,IL-10、ATG可以使其获得致耐受的特性;与健康献血者相比,G-CSF动员的供体DC表型和功能部分减低,;虽然动员的供体DC产率不及健康献血者,但血细胞分离机可以可采集到大量的单个核细胞(PBMCs),因此G-CSF动员的外周血有望成为不同DC的重要来源途径。     

原发性胆汁性肝硬化患者树突状细胞中细胞因子及其信号转导抑制分子变化的意义

目的 观察细胞因子信号转导抑制分子(SOCS)在原发性胆汁性肝硬化(PBC)患者树突状细胞(DC)及其表型和分泌细胞因子的变化,以研究SOCS在PBC发病机制中的作用.方法 对10例PBC患者和8名健康人,用流式细胞术(FCM)分析其DC表型CD83、CD86和人类白细胞抗原DR(HLA-DR),用酶联免疫吸附测定法(ELISA)检测DC培养上清液中细胞因子白细胞介素-10(IL10)、IL-12和干扰素-γ(IFN－γ)含量,用免疫印迹法(WB)测定DC中SOCS1和SOCS3水平;并评价分析这些指标在2组中的变化特征.结果 PBC患者外周血中DC细胞表型CD83、CD86和HLA-DR 的表达率分别为(79.4±4.8)％、(86.5±6.3)％和(90.0±3.5)％,均高于健康对照组的表达率[(68.3±4.1)％、(74.2±6.3)％和(83.6±7.6)％,t值分别为5.340、4.120和2.514,P均＜0.05];DC分泌的IL-12和IFN-γ含量分别为(53.5±11.1)、(32.0±9.0)ng/L,与健康对照组的细胞因子含量[(32.1±10.7)、(15.4±8.1)ng/L]相比,IL-12和IFN-γ均显著升高(t值分别为4.123和3.818,P均＜0.01);IL-10含量为(7.0±4.6) ng/L,与健康对照组[(5.8±4.2) ng/L]相比,差异无统计学意义(t=0.563,P＞0.05);WB检测PBC组DC中SOCS1和SOCS3的表达比健康对照组明显降低.结论 PBC患者体内DC更倾向于成熟状态,其抗原递呈能力明显增强,SOCS的低表达可能与免疫平衡紊乱和免疫耐受破坏有关.     

脐血CD34^＋细胞和外周血单核细胞两种来源的树突状细胞特性？…

目的 体外大量扩增和纯化具有典型表型、形态和功能的树突状细胞（ＤＣ）、以进行相关基础研究和临床应用。方法 采用免疫磁珠江分离脐血ＣＤ３４＾＋细胞及外周血去Ｂ、去Ｔ淋巴细胞的单个核细胞（单核细胞）,然后以ＧＭ－ＣＳＦ、ＩＬ－４、ＴＮＦα、Ｆｌｔ３配基（ＦＬ）、ＳＣＦ等不同的细胞因子配伍分别诱生ＤＣ,通过流式细胞仪、电镜、光镜分析其特性,同时检测其刺激同种Ｔ细胞增殖的能力。结果 脐民外周血诱生ＤＣ的方     

人外周血单核细胞体外诱导树突状细胞的形态学观察与功能研究

目的：探讨从人外周血单核细胞体外培养扩增的树突状细胞(dendritic cell,DC)形态学特征及其活性。方法：人外周血常规分离单个核细胞，粘附6h后去除悬浮细胞，以细胞因子粒细胞-巨噬细胞集落刺激因子(GM-CSF)、白细胞介素-4(IL-4)进行诱导培养7d，并进行形态学特征，细胞表型和淋巴细胞刺激能力鉴定。结果：培养1周即可得到大量DC，形态学观察可见细胞形态不规则，细胞表面大量突起，为典型的DC特征，免疫组化和间接免疫荧光显示CDla阳性表达率达80％～95％，并能刺激同种淋巴细胞增殖反应。结论：人外周血单核细胞可经GM-CSF、IL-4诱导培养成DC，具有典型的树突状细胞的形态学特征及抗原呈递能力。     

体外纯化培养外周血来源的树突状细胞的研究

目的建立来源于外周血的树突状细胞(DCs)的纯化培养方法并观察DCs的形态及功能。方法以Fi-coll密度梯度离心法从正常人外周血中分离出外周血单个核细胞(PBMNC)后,用体外培养的手段,采用培养黏附法或经免疫磁珠筛选法,获得单核细胞;分别加入不同浓度的细胞因子(重组人粒细胞-巨噬细胞集落刺激因子重组人白介素4重组人肿瘤坏死因子α)诱导培养,培养12 d诱导出DCs;用光镜和电镜观察培养的DCs,用流式细胞仪检测DCs表面的细胞表型(CD80、CD83、CD86、CD1α、HLA-DR),MTT法检测DC对T细胞的刺激增殖效应。结果在体外诱导出外周血来源的成熟DCs,电镜和光镜分析表明具有DCs的典型形态,所培养的细胞表面高表达CD80、CD83、CD86、CD1α、HLA-DR,并具有刺激异基因淋巴细胞增殖的能力。结论应用外周血来源的单个核细胞,采用培养黏附法或免疫磁珠分选法分选出的单核细胞,细胞因子培养12 d可得到成熟正常的DCs。     

In vitro production of dendritic cells from human blood monocytes for therapeutic use

Dendritic cells (DC) are professional antigen-presenting cells that are promising adjuvants for clinical immunotherapy. Methods to generate in vitro large numbers of functional human DC using either peripheral blood monocytes or CD34(+) pluripotent hematopoietic progenitor cells have been now developed. For this purpose, their in vitro production for further clinical use need to fit good manufacturing practice (GMP) conditions. In the present review, we give our experience of such a procedure: it includes collection of mononuclear cells by apheresis, separation of monocytes by elutriation, and culture of monocytes with GM-CSF + IL-13 + human serum (autologous patient's serum or AB serum) or in a serum-free medium (AIM V). The characteristics of monocyte-derived DC grown in these various conditions varied mainly regarding their phenotype and their morphology in confocal microscopy, whereas no significant differences were found in their capacity to phagocytize latex particles and to stimulate allogeneic (MLR) or autologous lymphocytes (antigen-presentation tests). The DC were also cryopreserved in bags (either by putting the bags directly in a -80 degrees C mechanical freezer or using a classical liquid nitrogen controlled-rate freezer at -1 degrees C/min) in a solution containing 10% dimethyl sulfoxide (Me(2)SO) and 2% human albumin in doses of DC available for several infusions. The mean recoveries after freezing and thawing were not statistically different (around 70%). The immunophenotype of DC, as well as the T lymphocyte-stimulating capacity, were not modified by the freezing--thawing procedure. The results obtained demonstrate that the experimental conditions we set up are easily applicable in clinical trials and lead to large numbers of well-defined DC. Clinical trials using DC already published will be discussed.     

Comparison of phenotypic and functional dendritic cells derived from human umbilical cord blood and peripheral blood mononuclear cells

Dendritic cells (DC) are important accessory cells that are capable of initiating an immune response. Generation of functional DC has potential clinical use in treating diseases such as cancer. In this report, we have demonstrated the generation of functional DC from mononuclear cells isolated from human umbilical cord blood cells (UCBC) and peripheral blood cells (PBC) using a defined medium Prime Complete Growth Medium (PCGM) (GenePrime LLC, Gaithersburg, MD). DC generated using PCGM showed the typical phenotype of DC as determined by flow cytometry and electron microscopy. Further analysis of the DC using confocal microscopy showed localization of the antigen and major histocompatibility complex (MHC) molecules in the cytoplasm 3-5 days following tumor antigen loading into DC. Subsequently, the tumor antigen-MHC complex was localized on the surface of DC. DC generated from UCBC or PBC also increased (p < 0.001) the allogeneic mixed lymphocyte reaction, confirming their immune accessory functions compared to a control mixed lymphocyte reaction (MLR) without DC added. Interestingly, DC generated using PCGM medium also significantly enhanced the hematopoietic colony (CFU-C)-forming ability. Furthermore, addition of 5% DC derived from cord blood loaded with tumor antigen also significantly (p < 0.001) increased peripheral and cord blood-derived antigen-specific cytotoxic T lymphocyte (CTL)-mediated killing of human leukemic cells (K562) and breast cancer cells (MDA-231). Thus, these results show that functional DC generated from cord blood using a defined medium are a useful source of accessory cells for augmenting CTL-mediated cytotoxicity and have potential use in cellular therapy for human leukemia and breast cancer.     

明胶法富集外周血单核细胞并刺激其成熟为树突状细胞

背景：如何简易高效分离纯化人外周血单核细胞并刺激成熟为树突状细胞,未见标准化操作流程。目的：观察明胶法分离外周血单核细胞的效率以及将分离出的单核细胞刺激成熟为树突状细胞的表型特征,并与普通塑料黏附法对比。方法：使用人淋巴细胞分离液分离人外周血得到单个核细胞,根据培养瓶是否进行明胶包被分为明胶包被组和普通塑料组。均分单个核细胞,按组别分离获得单核细胞并诱导刺激成熟为树突状细胞。计数各组所得单核细胞数,使用流式细胞仪检测2组单核细胞的CD14阳性率、T、B淋巴细胞污染率、树突状细胞非成熟期和成熟期CD1a,CD83的表达情况,锥虫蓝拒染法计算细胞活率,观察对比2组血小板污染情况。结果与结论：明胶包被组单核细胞数及CD14阳性率显著高于普通塑料组（P〈0.05）,普通塑料组淋巴细胞污染率显著高于明胶包被组（P〈0.05）。2组细胞活率及树突状细胞表型差异无显著性意义（P〉0.05）。明胶包被组血小板污染率低于普通塑料组。提示明胶法可以简单高效分离出单核细胞并成功刺激成熟为树突状细胞。     

Citrus pectin affects cytokine production by human peripheral blood mononuclear cells

Dietary fibers, including pectin, have been shown to exert a favorable effect on a wide spectrum of pathological conditions. Their positive influence on human health is explained by their anti-oxidative, hypocholesterolemic and anti-cancerous effects. However, little has been reported about their activity on the immune system. Therefore, the present study was undertaken to examine the effect of citrus pectin (CP) on cytokine production by human peripheral blood cells (PBMC). PBMC were incubated without or with CP at different degrees of esterification (DE) (∼30, ∼60 and ∼90% esterified pectin, assigned as DE30, DE60 and DE90, respectively) for detection of IL-1β, IL-1ra, TNFα, IL-6 and IL-10 secretion. Incubation with DE60 and DE90 induced a dose-dependent inhibition of the pro-inflammatory cytokine IL-1β secretion, whereas D30 did not affect this function. However, CP at all three esterification degrees did not alter the secretion of the additional pro-inflammatory cytokines examined, i.e. TNFα and IL-6. Conversely, CP at DE60 and DE90 caused a dose-dependent increased secretion of the anti-inflammatory cytokines IL-1ra and IL-10, whereas D30 did not affect the production of IL-1ra and decreased that of IL-10. The findings indicate that CP possesses the capacity to exert an immunomodulatory response in human PBMC which may have a favorable effect on human health.     

Efficient ex vivo expansion of Valpha24+ NKT cells derived from G-CSF-mobilized blood cells

Natural killer T (NKT) cells are involved in the function of innate immune systems and also play an important role in regulating acquired immune responses. In previous reports, we showed that Valpha24+ NKT cells proliferated more efficiently from granulocyte-colony stimulating factor (G-CSF)-mobilized peripheral blood mononuclear cells (PBMC) than from non-mobilized PBMC. However, the mechanism of this enhanced NKT cell expansion is not yet clear. The goal of this research was to develop culture conditions for the more efficient ex vivo expansion of NKT cells. G-CSF-mobilized PBMC was cultured in AIM-V medium supplemented with 10% auto-plasma, 100 ng/mL alpha-galactosylceramide (alpha-GalCer) and 100 IU/mL recombinant human (rh) interleukin (IL)-2. The efficiency of the expansion of Valpha24+ NKT cells was evaluated on day 12. The expansion-fold of Valpha24+ NKT cells was augmented depending on the proportion of CD14+ cells at the beginning of culture. The depletion of Valpha24+ NKT cells abrogated the expansion of Valpha24+ NKT cells. Depletion of CD56+ NK cells from mobilized PBMC enhanced, and add-back of purified CD56+ NK cells suppressed the expansion of Valpha24+ NKT cells. Experiments with different timings for the addition of cells, IL-2 and alpha-GalCer suggested that follow-up supplementation with IL-2 or CD14+ cells should be avoided for the efficient expansion of Valpha24+ NKT cells. These results should be useful for the development of an efficient and practical expansion protocol for adoptive immunotherapy with Valpha24+ NKT cells.     

健康人外周血树突状细胞体外培养及表型鉴定

目的 分离人外周血单个核细胞,经体外诱导培养获取成熟树突状细胞(DC),并对树突状细胞表型表达鉴定,为进一步研究DC功能提供基础.方法 取健康成人新鲜外周血,经密度梯度离心法分离获得外周血单个核细胞,2 h贴壁后加入粒细胞集落刺激因子(GM-CSF)、白介素(IL)-4,第6天加入肿瘤坏死因子-α(TNF-α)刺激DC成熟,倒置显微镜观察每日细胞形态;分别于第1天、第6天、第8天用流式细胞仪对其进行表型鉴定;同种异体混合淋巴细胞反应观察对T细胞的抗原提呈能力 倒置显微镜下DC细胞形态不规则,表面有毛刺状突起,呈DC典型形态学特征;成熟DC细胞表面CD1a、CD80、CD83、人类白细胞抗原(HLA)-DR表达明显增加,混合淋巴细胞反应OD值增加.结论 用GM-CSF、IL-4和TNF-α可以诱导健康成人外周血单个核细胞,培养出成熟的DC细胞,为进一步研究DC功能提供基础.     

Infusion of unpulsed dendritic cells derived from granulocyte/macrophage colony-stimulating factor-mobilized peripheral blood CD34+ cells and monocytes in patients with advanced carcinoma

Dendritic cells are potent antigen-presenting cells that are reduced in number and function in cancer patients. The infusion of dendritic cells pulsed with tumor-associated antigens has demonstrated antitumor immunologic activity. The effects of dendritic cells derived from granulocyte/macrophage colony-stimulating factor (GM-CSF)-mobilized peripheral blood CD34(+) cell and monocyte precursors when administered without antigen pulsing was examined. Patients with metastatic pancreatic and colorectal cancer received GM-CSF for 5 days. Blood was collected by a 250-ml phlebotomy. Dendritic cells were derived from CD34(+) cells with culture in GM-CSF, tumor necrosis factor-alpha, and serum-free media or from monocytes with culture in GM-CSF, interleukin-4, and autologous serum. From 2.0 to 9.4 x 10(6) dendritic cells were generated from CD34(+) cells and from 71 x 10(6) to 210 x 10(6) dendritic cells were generated from monocytes. Dendritic cells generated from CD34(+) cells expressed more CD1a than dendritic cells generated from monocytes; the ability to stimulate mixed lymphocyte reactions in vitro was not significantly different. Six patients received a single intravenous infusion of up to 5 x 10(6) autologous CD34(+) cell derived, and 6 patients, up to 50 x 10(6) monocyte-derived dendritic cells. The infusion was well tolerated. Increases in skin test reactivity and peripheral blood proliferative responses to the recall antigen, candida, were observed after the infusion of dendritic cells of both derivations. Changes in skin test reactivity and peripheral blood proliferative responses to tumor-associated peptides, including Ras and Muc1, were not. Significant numbers of functionally competent dendritic cells can be generated from patients with advanced carcinoma after GM-CSF mobilization. The infusion of these dendritic cells has nonspecific immunomodulatory activity that may have clinical significance.     

人与家兔脂肪来源干细胞体外培养特性的比较

背景：不同种属来源的脂肪来源干细胞在体外培养时特性是否存在差异目前尚未定论。目的：观察在相同培养条件下,人与家兔脂肪来源干细胞体外培养特性的异同。方法：体外分离人腹部取皮植皮术来源的脂肪来源干细胞、家兔背部皮下脂肪来源的脂肪来源干细胞,体外培养并传代,观察各自生长形态,取第3代脂肪来源干细胞,比较二者生长及增殖能力、表面CD分子鉴定情况及成脂、成骨分化能力。结果与结论：人和家兔皮下脂肪均能在体外分离出＂成纤维细胞样＂贴壁生长呈长梭形的细胞;人脂肪来源干细胞一般6～8d可传代,兔脂肪来源干细胞则需要四五天传代。四唑盐结果显示兔、人脂肪来源干细胞分别在第4,6天达到生长高峰。表面标记流式鉴定二者均显示CD29＋CD31-。体外分离培养的人脂肪来源干细胞和兔脂肪来源干细胞均具有干细胞的培养特性。与人脂肪来源干细胞相比,兔脂肪来源干细胞具有更强的增殖和诱导成脂能力,但诱导成骨能力较差,家兔是做脂肪移植研究实验动物不错的选择。     

人外周血树突状细胞低温保存的优化研究

目的探寻冻存树突状细胞(DCs)优化的冷冻保护剂组合。方法配制含不同浓度二甲基亚砜(DM-SO)的3种冷冻保护剂组合,A组:5%DMSO+6%羟乙基淀粉(HES)+4%人血清白蛋白(HAS);B组:10%DMSO+40%FCS;C组:12%DMSO+40%FCS,比较3组冷冻保护剂对人外周血CD14+单个核细胞诱导产生的成熟树突状细胞(mDCs)的冻存效果:采用两步法将mDCs冻存于-80℃冰箱过夜后转移至-196℃液氮气相中放置24 h,再将冻存的mDCs复苏后继续培养,并检测、比较冻存前后DC的形态、存活率、细胞表型及其对同种异体T细胞刺激活性的差异。结果 3组不同组合冷冻保护剂冷冻保存的mDCs复苏后其存活的细胞的形态没有发生明显改变,仍保留其成熟表型,并具备对T细胞的刺激活性。结论 3种不同浓度的DMSO冷冻保存mDCs,5%DMSO+6%HES+4%HSA组合更适宜。     

Interleukin 7 induces cytokine secretion and tumoricidal activity by human peripheral blood monocytes

Peripheral blood monocytes can be induced by stimuli such as bacterial lipopolysaccharide (LPS) to secrete an array of cytokines. We have studied the effects of interleukin 7 (IL-7) on human peripheral blood mononuclear cells (PBMC) and found that IL-7 is a relatively potent inducer of IL-6 secretion IL-6 protein levels were determined either by the B9 hybridoma growth factor assay or by enzyme-linked immunosorbent assay, and mRNA for IL-6 was analyzed by Northern hybridization. Detailed examination revealed that, among PBMC, monocytes, rather than lymphocytes, were secreting IL-6 in response to IL-7. In contrast to the low concentrations of IL-7 required to stimulate T cell growth and differentiation (as low as 0.1 ng/ml), relatively high concentrations of IL-7 were necessary to induce IL-6 secretion by monocytes (at least 10 ng/ml). An optimal concentration of IL-7 (100 ng/ml) induced monocytes to secrete 10-fold more IL-6 than an optimal concentration of IL-1 beta (10 ng/ml), and almost as much as LPS. However, significantly more IL-7 than IL-1 beta was required to induce detectable levels of IL-6. The kinetics of IL-6 secretion by monocytes were identical in response to IL-7, IL-1 beta, or LPS, with IL-6 protein detectable in culture supernatants as early as 2 h after the initiation of culture. IL-4 was found to markedly inhibit the ability of IL-7 or LPS to induce IL-6 mRNA and IL-6 secretion. In addition to promoting IL-6 production, IL-7 induced the secretion of immunoreactive IL-1 alpha, IL-1 beta, and tumor necrosis factor alpha (TNF-alpha) by monocytes. IL-7 also induced monocyte/macrophage tumoricidal activity against a human melanoma cell target, an activity that may be related to the secretion of IL-1 alpha, IL-1 beta, and TNF-alpha. Finally, we used a whole blood culture system as a bridge to in vivo analysis to demonstrate that IL-7 induces cytokine secretion in the absence of culture medium, fetal calf serum, and adherence to plastic. Our data suggest that IL-7, in addition to regulating lymphocyte growth and differentiation, has potent effects on cells of the monocytic lineage. Thus, IL-7 may be an important mediator in inflammation and in the macrophage immune response to tumors.     

Gender differences in cytokine secretion by human peripheral blood mononuclear cells: role of estrogen in modulating LPS-induced cytokine secretion in an ex vivo septic model.

Clinical studies demonstrate a better outcome of sepsis in females. Elevated estrogen levels and plasma cytokine imbalance occur in septic patients. We propose that gender-different cytokine secretion by the peripheral blood mononuclear cells (PBMCs) in sepsis determines the clinical outcome. A 2 x 10(6) PBMC sample from healthy volunteers (10 males and 10 females) was incubated with 1 ng/mL of lipopolysaccharide (LPS), estradiol (E2; 0, 0.03, 0.3, 3.0, 30 ng/mL), or 1 ng/mL of LPS + E2 (0, 0.03, 0.3, 3.0, 30 ng/ml), and supernatant cytokine levels were measured. Tumor necrosis factor alpha (TNF alpha) and interleukin (IL)-6 production by PBMCs from both sexes was time-dependently stimulated by LPS. At 6 h after LPS challenge, the TNF alpha level of male PBMCs was significantly higher but IL-6 secretion by female PBMCs was higher (two-way ANOVA: P < 0.05). E2 alone stimulated cytokine secretion by male PBMCs. Addition of the same E2 concentration as in sepsis patients' plasma modulated LPS-induced cytokine production. No significant sex differences in LPS-stimulated TNF alpha or IL-6 secretion by PBMCs were found, but IL-10 secretion by male PBMCs was significantly suppressed. This study demonstrated a gender difference in PBMCs responsiveness to LPS and E2 stimulation and E2-modulated cytokine secretion. In this PBMCs model of sepsis, only the supernatant IL-10 level was significantly lower in males. These ex vivo findings may partially explain the mechanism underlying the poorer outcome of male sepsis patients.