小胶质细胞表达OX40L对T细胞增殖与凋亡的影响

目的鉴定免疫共刺激分子OX40配体（OX40 ligand，OX40L）在小胶质细胞上的表达，并探讨OX40L信号在小胶质细胞对中枢神经系统内T细胞增殖与凋亡中的作用。方法通过RT-PCR、免疫印迹和流式细胞术检测小胶质细胞株N9活化前后OX40L在mRNA和蛋白水平的表达变化，细胞免疫化学法鉴定原代小胶质细胞上OX40L表达情况。体外将小胶质细胞株N9与活化后T细胞共培养并阻断OX40L信号后，^3H-TdR掺入实验和FITC-annexin-Ⅴ／PI荧光染色方法分别检测T细胞的增殖和凋亡情况，ELISA检测T细胞分泌IL-2的水平。结果小胶质细胞株N9活化前后均有OX40L表达，其蛋白表达率由23％增加为94％；原代小胶质细胞活化后表达OX40L。小胶质细胞表达OX40L后显著增强了T细胞增殖和IL-2分泌，抑制了T细胞凋亡。结论小胶质细胞活化后表达OX40L分子，OX40L-OX40信号可促进活化后T细胞增殖，抑制其凋亡，从而可能在维持中枢神经系统内T细胞免疫应答效应中发挥重要作用。有助于了解中枢神经系统内固有细胞和T细胞的相互作用机制，进一步认识OX40L的表达及功能。     

Graves病患者外周血OX40和OX40L分子表达的研究

探讨OX40和OX40L分子在Graves病患者外周血T淋巴细胞和单核细胞上的表达及其在Graves病发病机制中的可能作用。采用流式细胞仪检测技术对50例初发Graves病患者和30例健康志愿者外周血T细胞上OX40和单核细胞上OX40L的表达水平进行分析,并对28例治疗前后病人淋巴细胞上OX40/OX40L的表达进行了比较。结果:与正常对照组比,初发Graves病患者外周血CD4+T细胞上OX40表达水平明显升高,而CD8+T细胞上OX40表达水平无显著变化;同时,还检测到单核细胞上OX40L表达水平也明显增加。治疗后,FT3(游离三碘甲腺原氨酸)值恢复至健康对照组表达范围的Graves病患者其CD4+T细胞上OX40和单核细胞上OX40L的表达均显著降低至正常水平;而FT3值仍偏高的患者单核细胞上OX40L的表达降低,但未降至健康对照组表达范围,CD4+T细胞上OX40的表达则无显著变化。Graves病患者外周血T细胞和单核细胞上分别存在OX40和OX40L的异常表达,且与治疗效果密切相关,提示OX40/OX40L信号在T细胞与单核细胞相互作用过程中可能有助于自身反应性T细胞的持续活化,从而参与Graves病的免疫发生发展。     

ICOS/ICOSL、OX40/OX40L及CD40/CD40L在系统性红斑狼疮患者外周血表达水平及其临床意义

本研究旨在检测SLE患者外周CD4+T细胞表面ICOS、OX40、CD40L及B细胞表面ICOSL、OX40L、CD40分子的表达情况,并探索其临床意义。采用流式细胞术,我们检测SLE患者及健康对照外周CD4+T细胞表面ICOS、OX40、CD40L及B细胞表面ICOSL、OX40L、CD40分子的表达,并分析其与SLE临床指标的相关性。结果显示,SLE患者外周CD4+T细胞上ICOS、OX40、CD40L及B细胞上ICOSL、OX40L、CD40分子的表达均明显高于健康对照组(均P0.05),且SLE患者CD4+T细胞表面ICOS的表达与患者血清IgG水平呈现正相关,B细胞表面ICOSL的表达与患者血清抗dsDNA抗体水平正相关,B细胞表面OX40L的表达与患者血清抗核抗体水平正相关(均P0.05)。上述结果表明SLE患者外周CD4+T细胞上ICOS、OX40、CD40L及B细胞上ICOSL、OX40L、CD40分子均发生上调,并与SLE自身抗体水平呈现正相关,提示分别表达于T细胞和B细胞表面的ICOS/ICOSL、OX40/OX40L及CD40/CD40L分子,通过相互作用参与SLE的致病过程。     

OX40信号在免疫应答中的作用

OX40是表达在活化T细胞上的一种糖蛋白，近年来发展OX40及其配体的作用有与CD4^ T细胞的活化、T细胞与B细胞的相互作用以及Th1、Th2发育，还有某些疾病的发生、发展关系密切。     

不明原因复发性流产患者蜕膜组织中OX40/OX40L信号轴表达与T细胞亚群相关因子的关系研究

目的 分析研究OX40/OX40L信号在不明原因复发性流产患者绒毛组织中的表达及其临床意义.方法 选取43例不明原因复发性流产患者(URSA组)和40例行人工流产术孕妇(NC组),RT-PCR和Western blot分析OX40/OX40L-NFAT1信号途径相关基因和蛋白表达情况,流式细胞术检测T细胞亚群变化,分析...     

OX40信号在免疫应答中的作用

OX4 0是表达在活化T细胞上的一种糖蛋白 ,近年来发现OX4 0及其配体的作用可能与CD4 + T细胞的活化、T细胞与B细胞的相互作用以及Th1、Th2发育 ,还有某些疾病的发生、发展关系密切。     

OX40/OX40L的生物学特征及功能

OX4 0 /OX4 0L是机体免疫应答过程中一对重要的协同刺激分子 ,参与了T细胞的活化、增殖和迁移 ,以及生发中心的形成和DC的分化成熟 ,在介导肿瘤免疫应答和自身免疫性疾病的发生发展中具有重要作用。文章就OX4 0 /OX4 0L这对共刺激分子的生物学特征及其在机体免疫应答过程中的功能作一综述     

OX40和OX40L在原发性干燥综合征患者外周血中的表达及临床意义

目的 检测原发性干燥综合征(pSS)患者外周血单个核细胞表面共刺激分子OX40和OX40L的表达,并探讨其临床意义.方法 采用免疫荧光标记流式细胞技术检测51例pSS患者及36例健康志愿者外周血T细胞表面OX40的表达及CD14+单核细胞和CD19+B细胞表面OX40L分子表达,比较11例初诊pSS患者治疗前后OX40和OX40L表达水平变化,分析其临床意义.结果 与健康志愿者相比,pSS患者外周血CD4+T细胞表面OX40表达显著增高(8.65％ ±3.51％ vs 5.68％ ±1.68％,P＜0.01),而CD8+T细胞表面OX40的表达无统计学差异.pSS患者表面OX40L的表达,在外周血中CD14+单核细胞(6.76％±3.60％ vs 3.15％±1.89％,P＜0.01)和CD19+B细胞(4.69％ ±2.40％ vs 2.76％ ±1.33％,P＜0.01)中均高于健康志愿者.活动期的pSS患者外周血OX40和OX40L的表达高于非活动期患者,伴发多系统损伤pSS患者外周血OX40和OX40L分子的表达显著高于单纯外分泌腺损伤患者.治疗后CD4+T细胞表面OX40的表达及CD14+单核细胞和CD19+B细胞表面OX40L的表达显著下降.结论 pSS患者外周血单个核细胞表面OX40和OX40L异常高表达,且与疾病活动度、组织损伤及治疗密切相关.     

101 OX40信号在免疫应答中的作用

OX40是表达在活化T细胞上的一种糖蛋白，近年来发现OX40及其配体的作用可能与CD4+ T细胞的活化、T细胞与B细胞的相互作用以及Th1、Th2发育，还有某些疾病的发生、发展关系密切。     

Monosomy 1p36 uncovers a role for OX40 in survival of activated CD4+ T cells

Monosomy 1p36 is a subtelomeric deletion syndrome associated with congenital anomalies presumably due to haploinsufficiency of multiple genes. Although immunodeficiency has not been reported, genes encoding costimulatory molecules of the TNF receptor superfamily (TNFRSF) are within 1p36 and may be affected. In one patient with monosomy 1p36, comparative genome hybridization and fluorescence in- situ hybridization confirmed that TNFRSF member OX40 was included within the subtelomeric deletion. T cells from this patient had decreased OX40 expression after stimulation. Specific, ex vivo T cell activation through OX40 revealed enhanced proliferation, and reduced viability of patient CD4+ T cells, providing evidence for the association of monosomy 1p36 with reduced OX40 expression, and decreased OX40-induced T cell survival. These results support a role for OX40 in human immunity, and calls attention to the potential for haploinsufficiency deletions of TNFRSF costimulatory molecules in monosomy 1p36.     

Synergistic OX40 and CD30 signals sustain CD8+ T cells during antigenic challenge

Prior to acquiring a memory phenotype, antigen‐activated CD8⁺ T cells need to expand and then undergo a contraction phase. Utilizing two different antigenic stimuli, we provide evidence that the tumor necrosis factor receptors OX40 and CD30 integrate synergistic signals during the expansion phase to help maintain CD8⁺ effectors. Thus, double deficiency in OX40 and CD30 leads to CD8⁺ cell loss during expansion after immunization either with OVA or with murine CMV. Following their contraction, OX40‐ and CD30‐deficient CD8⁺ T cells persist normally in CMV‐infected mice. In contrast, persistence after OVA challenge is dependent on OX40 and CD30. Collectively, our data define the important role of both OX40 and CD30 during CD8⁺ T‐cell activation, and show that long‐term CD8 persistence after contraction is regulated not only by stimulatory receptors but also by the nature of the antigen or how the antigen is presented.     

Anti-OX40 stimulation in vivo enhances CD8+ memory T cell survival and significantly increases recall responses

There is growing evidence that engagement of OX40 (CD134), a member of the TNF receptor superfamily, can directly stimulate antigen-specific CD8+ T cells. It has been shown that CD8+ T cells express OX40 following activation, but the response of antigen-specific CD8+ T cells to OX40 stimulation has not been fully characterized. We utilized an antigen-specific transgenic CD8+ T cell model (OT-I) to determine if OX40 engagement can boost the generation of antigen-specific CD8+ T cell memory. Our results demonstrate that enhanced OX40 costimulation, via an agonist anti-OX40 antibody, increases CD25 and phospho-Akt expression on the antigen-specific CD8+ T cells and significantly increases the generation of long-lived antigen-specific CD8+ memory T cells. The increased numbers of memory CD8+ T cells generated via anti-OX40 treatment still required the presence of CD4+ T cells for their long-term maintenance in vivo. In addition, anti-OX40 costimulation greatly enhanced antigen-specific CD8+ T cell recall responses. These data show that OX40 engagement in vivo increases the number of antigen-specific CD8+ memory T cells surviving after antigen challenge and has implications for the development of more potent vaccines against pathogens and cancer.     

Cooperation between CD4 and CD8 T cells for anti-tumor activity is enhanced by OX40 signals

The relative contribution of OX40 (CD134) to priming of CD8 T cells in complex systems where CD4 and CD8 cells respond and cooperate together is not clear. We previously found that OX40 expressed on tumor-reactive CD8 T cells controls their initial persistence when adoptively transferred in vivo and is required for delayed tumor growth. We now show that exogenous stimulation of OX40 with agonist antibody augments its ability to suppress the growth of new as well as established tumors, correlating with marked expansion of adoptively transferred CD8 T cells. Concomitantly, anti-OX40 strongly enhanced the number of tumor antigen-reactive CD4 T cells. Moreover, the augmented accumulation of CD8 T cells was prevented in animals lacking MHC class II or depleted of CD4 cells and did not occur in OX40-deficient animals receiving wild-type CD8 cells, demonstrating that non-CD8 cells are the major target of OX40 signals. These results suggest that while OX40 signaling to a CD8 T cell can control its expansion, OX40 expressed on non-CD8 cells strongly influences CD8 priming and in vivo activity. OX40 therefore represents an important signal for allowing effective cooperation between CD4 and CD8 cells and for promoting cell interplay and tumor rejection where CD8 activity is limiting.     

OX40 engagement stabilizes Mxd4 and Mnt protein levels in antigen-stimulated T cells leading to an increase in cell survival

OX40 engagement on activated T cells leads to increased proliferation, expansion and survival of Ag-specific T cells. Direct ex vivo examination of Ag-stimulated murine T cells show that the Myc antagonists, Mxd4 and Mnt, are transiently upregulated and translocated to the nucleus following OX40 engagement and may be involved in suppressing cell death. Both Mxd4 and Mnt are upregulated following OX40 stimulation through increased protein stability and we identify a critical phosphorylation site in Mxd4 that controls Mxd4 stability. The upregulation of Mxd4 and Mnt contributes to OX40-mediated T-cell survival because siRNA knockdown of Mxd4 and Mnt led to increased cell death. We hypothesize the upregulation of c-Myc following OX40 engagement drives T-cell proliferation and that upregulation of Mxd4 and Mnt suppresses Myc-dependent cell death. Thus, Mxd4 and Mnt upregulation following OX40 engagement most likely increases T-cell survival.     

A recombinant vesicular stomatitis virus encoding HIV-1 receptors and human OX40 ligand efficiently eliminates HIV-1-infected CD4-positive T cells expressing OX40

OX40 protein is highly expressed on activated CD4-positive T cells that are susceptible for human immunodeficiency virus type 1 (HIV-1) infection. To target and kill HIV-1-infected OX40(+) T cells, we used a recombinant vesicular stomatitis virus (rVSV) lacking its envelope glycoprotein (ΔG) and instead expressing HIV-1 receptors CD4/CXCR4 and OX40 ligand (OX40L). Expression of OX40L as well as HIV-1 receptors on the VSV particles led to specific infection of OX40(+) T cells, including primary cells, either acutely or chronically infected with X4 HIV-1. Consequently, the rVSV rapidly eliminated these infected cells and caused a marked reduction of HIV-1 viral load in culture. Inclusion of the OX40L gene in the VSV recombinant led to significantly better infection and HIV-1 elimination compared with an rVSVΔG expressing only HIV-1 receptors. A novel rVSVΔG encoding both HIV-1 receptors and OX40L has a potentially greater therapeutic value than an rVSVΔG expressing only HIV-1 receptors.     

Expression of OX40 (CD134) on CD4+ T-cells from patients with myasthenia gravis

Myasthenia gravis (MG) is commonly regarded as the prototype of an antibody-mediated, organ-specific autoimmune disease. Antibodies against the acetylcholine receptor (AChR) on the muscle endplate trigger its typical clinical manifestations of weakness and fatiguability. T-B cell interactions are thought to play a crucial role in the pathogenesis of MG. OX40 (CD134), a costimulatory molecule that is expressed on activated CD4+ T-cells, might contribute to the development or pathogenesis of immune-mediated diseases such as rheumatoid arthritis and graft-versus-host disease. In the present study, we investigated the expression of OX40 on CD4+ T-cells from patients with MG and healthy individuals. Results from 36 MG patients and 28 healthy controls revealed that more freshly isolated CD4+ T-cells from MG patients expressed OX40 than cells from healthy individuals. High levels of antibodies against the AChR, thymic hyperplasia and onset at an early age were associated with elevated expression of OX40. Upon activation by various concentrations of anti-CD3 antibodies, CD4+ T-cells from MG patients showed a tendency toward higher levels of OX40 expression than cells from healthy individuals. Given the role of OX40 in the immune system, we conclude that OX40 might contribute to the development of MG.