JM细胞培养上清对人B淋巴细胞和小鼠脾细胞增殖的免疫调节作用

JM 是来自人胸腺不成熟 T 细胞的急性淋巴细胞白血病细胞系.本文以 SAC 刺激的人外周血纯化 B 淋巴细胞和小鼠脾细胞增殖为模型,观察了 JM 细胞培养上清(SPN_(JM))对人 B 淋巴细胞和小鼠脾细胞增殖的免疫调节作用.发现具有 T 细胞抑制活性的 SPN_(JM)对人和小鼠 B 淋巴细胞的增殖具有促进作用。在无 SAC 诱导时,SPN_(JM)与 HrIL—2协同对 B 细胞仍有促增殖作用.本实验还发现,高浓度时对 T 细胞具有抑制作用的 SPN_(JM),在低浓度时(1:640)对 T 细胞增殖亦具有促进作用.     

酮色林对体外活化的淋巴细胞细胞因子分泌的影响

目的 研究酮色林(Ketanserin,KT)对活化的淋巴细胞细胞因子分泌的调节.方法 用双抗体夹心ELASA法检测KT对脂多糖(LPS)激活的体外培养的人外周血淋巴细胞细胞因子IL-2、TNF-α、IL-10和TGF-β1分泌的影响.结果 KT浓度依赖性抑制LPS激活的人淋巴细胞致炎因子IL-2的分泌,100 μm ol/L 的KT也可抑制致炎因子TNF-α分泌,而10和100 μmol/L KT可分别浓度依赖性的提高 LPS激活的淋巴细胞分泌抗炎因子IL-10的产量,只有1 00 μmol/L KT 可显著提高LPS激活的淋巴细胞分泌抗炎因子TGF-β1.结论 KT可对体外活化的淋巴细胞细胞因子分泌进行受体非依赖性的直接调节.     

EB病毒LMP1在鼻咽癌细胞系中通过NF-κB、AP-1促进IL-8分泌

目的：探讨EB病毒LMP1分子致瘤机制，在已证实鼻咽癌细胞系中LMP1有效激活NF－κB 或AP－1的基础上，对LMP1是否通过NF－κB 或AP－1促进IL－8分泌进行探讨。方法：以稳定表达LMP1及其3种突变体，空白载体的鼻咽癌细胞系[HNE2-LMP1,NHE2-MLP1(1-185),HNE2-LMP1(1-231),HNE2-LMP1Δ187-351和HNF3－pSG5]及antisense-LMP1处理的HNF2－LMP1鼻咽癌的细胞系为材料，将IL－8报道质粒瞬时导入这些细胞系中，通过测定luciferase值以反映LMP1是否促进IL－8转录；将mut AP-1/IL-8-luc或IκB α（S32A／S36A）表达质粒导入HNE2－LMP1细胞系中，比较其IL－8报道活性，以确定LMP1是否通过AP－1或NF－κB 诱导IL－8转录；利用ELISA方法测定HNE2－LMP1，HNE2－pSG5,anti-sese-LMP1处理的HNE2－LMP1鼻咽癌细胞系中的IL－8浓度，进一步从蛋白水平上确定LMP1是否促进IL－8分泌。结果：与HNE2－pSG5相比，在HNE2－LMP1，HNE2－LMP1Δ187－351和HNE2－LMP1（1－231）细胞系中IL－8报道活性分别升高了原来水平的11．5，8．6和3．4倍，而HNE2－LMP1（1－185）对IL－8报道活性不影响。在HNE2－LMP1细胞系中IL－8蛋白水平提高了17．4倍，而antisense-LMP1则使HNE2－LMP1细胞的IL－8报道活性及蛋白水平分别下降到原来水平的18．3％和9．2％，导入mutAP-1/IL-8-luc或IκBα（S32A／S36A）的HNE2－LMP1细胞中IL－8报道活性分别下降到原有水平39％和26％，结论：鼻咽癌细胞系中LMP1可能通过NF－κAP－1促进IL－8表达。     

Is there a role of taurine bromamine in inflammation? Interactive effects with nitrite and hydrogen peroxide

Objective and Design: The myeloperoxidase system of neutrophils generates chlorinating and brominating oxidants in vivo. The major haloamines of the system are taurine chloramine (TauCl) and taurine bromamine (TauBr). It has been demonstrated in vitro that TauCl exerts both antiinflammatory and anti-bacterial properties. Much less is known about TauBr. The present study was conducted to compare bactericidal and immunoregulatory capacity of TauBr with that of the major chlorinating oxidants: HOCl and TauCl. Moreover, the effect of nitrites and H₂O₂ on TauBr activity was investigated.Materials: TauBr was prepared by reaction of HOBr with taurine. The reaction was monitored by UV absorption spectra.Methods: Bactericidal activity of TauBr, TauCl and HOCl was tested by incubation of E. coli with the compounds and determined by the pour-plate method. To test the anti-inflammatory activity the compounds were incubated with LPS and IFN- stimulated murine peritoneal macrophages. The production of following mediators was measured: nitrites by Griess reaction; TNF-, IL-6, IL-10, IL-12p40 using capture ELISA. In some experiments the compounds were incubated with either nitrites or H₂O₂.Results: In our experimental set-up TauBr and HOCl exerted strong bactericidal effects on E. coli (MBC = 110 M and 8 M, respectively), while TauCl (< 1000 M) did not kill test bacteria. However, both, TauBr and TauCl, at noncytotoxic concentrations (< 300 M) inhibited the cytokine and nitric oxide production by macrophages. H₂O₂ completely abolished the biological activities of TauBr but not those of TauCl. Nitrites did not affect any activity of TauBr or TauCl while they diminished the HOCl^– mediated bacterial killing.Conclusion: TauBr, despite very low concentration of Br^– in body fluids, may support TauCl and HOCl in the regulation of inflammatory response and in killing of bacteria by neutrophils. However, TauBr activity in vivo will depend on the presence of H₂O₂ and possible other mediators of inflammation which can compete with target molecules for TauBr.Received 16 August 2004; returned for revision 16 September 2004; accepted by A. Falus 13 October 2004     

SOCS1与T细胞分化发育及功能调控的研究进展

细胞因子参与介导了机体天然免疫和获得性免疫应答反应，SOCS家族是近年来发现的通过JAK／STAT途径抑制细胞因子信号转导通路的负性调控蛋白。目前SOCS家族成员中以SOCS1的研究最为深入。SOCS1的缺失会导致T细胞胸腺选择受阻，以IFNγ为主的多种细胞因子的过量分泌，T细胞表面活化分子表达增加等等。因此，SOCS1的正常表达对于T细胞的分化发育和自身稳定发挥了重要作用。     

人α2（I）型胶原基因启动子活性研究

目的 探索器官纤维化形成中调控I型胶原基因高水平转录的启动片段及TGF-β、PDGF－BB、IGF－1等细胞因子对其活性的影响。方法 从人α2（I）胶原基因转录起始点上游－2.4kb至＋58bp的片段中，取长度不等的片段作为启动子与含氯霉素乙酰基转移酶（CAT）报告基因的质粒组成5个重组体，转染上述重组体至正常人原代培养皮肤成纤维细胞，测定细胞CAT表达水平以比较各重组体的启动子活性，同时加入细胞因子，以测定其对I型胶原启动序列的影响。结果 除－129～＋58bp序列外，其余4个重组体CAT表达水平均较高，其中－2292～＋58bp、－1476～ 58bp序列具较强启动CAT表达活性，－339～ 58bp、－616～ 58bp片段次之。TGF－β、IGF－1均能在一定程度上调人α2（I）胶原基因启动活性。结论 人α2（I）胶原基因片段－2292～ 58bp、－1476～ 58bp、－339～ 58bp有高启动活性，是进一步研究纤维化相关DNA结合蛋白的重要调控靶序列。TGF－β、IGF－1促进胶原表达，与其上调胶原基因启动活性有关。     

T cell activation correlates with an increased proportion of antigen among the materials acquired from target cells

We have investigated the density of peptides required to elicit different biological responses in cytotoxic T lymphocytes (CTL), including trogocytosis (i.e., the phenomenon whereby the lymphocytes actively capture fragments of plasma membrane from those cells with which they establish an immune synapse). We have used two separate mouse models of CTL recognising defined peptides presented by MHC class I molecules. In both systems, triggering of cytotoxicity and capture of membrane components reached saturation with low densities of ligand. On the other hand, down-modulation of cell-surface levels of TCR, induction of IFN-gamma production and detection of peptide captured required much higher ligand densities. Interestingly, fratricide (i.e., killing between CTL sharing the same specificity), a mechanism proposed to account for CTL exhaustion, was detected only at antigen concentrations still well above that second threshold leading to full blown activation. Taken together, our results show that the different thresholds that govern the elicitation of different CTL functions correlate with different proportions of antigen among the target cell components being captured via trogocytosis.     

Peptides derived from IgE heavy chain constant region induce profound IgE isotype-specific tolerance

(BALB/c × SJL)F1 mice, perinatally injected with peptide-N-glyconase F-treated, deglycosylated IgE heavy chain or recombinant IgE heavy chain (CH?2-CH?4), were profoundly inhibited in antigen-specific IgE production. There exist minimally two tolerogenic IgE peptides, residing in the CH?2 and CH?4 domains. Peptide I, generated by V8 protease, comprises 39 amino acids within CH?2, beginning at amino acid 103. Peptide E begins at amino acid 312 of the CH?4 domain and extends through the CH?4 domain. The total lack of antigen-specific IgE responses in IgE peptide-treated mice was not due to overproduction of interferon-γ, nor lack of interleukin (IL)-4, as predicted by the Th2/IL-4 paradigm for IgE production. IgE-tolerant mice exhibited comparable levels of circulating anti-IgE antibodies to those of PBS-treated control mice. IgG obtained from sera of both sources failed to inhibit IgE responses in vitro. Moreover, IgE responses of spleen cells from IgE peptides-treated mice were restored by CD4⁺ T cells from PBS-treated control mice. We hypothesize that regulation of antigen-specific IgE responses is mediated by CD4⁺ T cells which normally recognize IgE peptides on IgE precursor B cells, and can be rendered tolerant by perinatal IgE peptide treatment.     

Adult Still's disease reflects a Th2 rather than a Th1 cytokine profile

Adult Still's disease (ASD) is a chronic multisystemic disease. Extraordinarily high serum levels of IL-18 in ASD patients have been described, whereas the mechanism remains to be clarified. This study aimed to evaluate proinflammatory cytokines and to consider their pathological roles. In patients with rheumatic diseases (n = 151), blood samples were taken at the active phase and the serum levels of IL-18 and other proinflammatory cytokines were measured by ELISA. The extra-high levels of IL-18 were confirmed selectively in ASD patients (n = 10). In the active phase of ASD patients, the levels of IL-6 were elevated accordingly, but IL-1beta and TNF-alpha were undetectable. As to Th1-Th2 cytokines, the levels of IL-4 and IL-13, but not INF-gamma, IL-12, or IL-2, were elevated in all ASD patients examined. Moreover, the serum levels of IL-18 showed a good correlation with those of IL-4, suggesting that ASD reflects a Th2 rather than a Th1 cytokine profile.     

Lack of intermediate-affinity interleukin-2 receptor in mice leads to dependence on interleukin-2 receptor α, β and γ chain expression for T cell growth

An interleukin (IL)-4 dependant mouse T cell clone 8.2 derived from an IL-2-dependent T cell line was characterized. As measured by flow cytometric analysis and Northern blotting, it expresses IL-2 receptor β (IL-2Rβ) and γ (IL-2Rγ) chains, but has lost expression of IL-2 receptor α chain (IL-2Rα). To investigate the properties of the mouse IL-2Rβγ complex and the role of IL-2Rα gene expression, this clone was further studied. T cell clone 8.2 has lost the capacity to bind ¹²⁵I-labeled human IL-2 under experimental conditions able to detect intermediate-affinity IL-2R in human cells. Mouse IL-2 is unable to block the binding of mAb TMβ1 to 8.2 cells. Under the same experimental conditions, mouse IL-2 blocks the binding of TMβ1 to C30-1 cells expressing the IL-2αβγ complex. Since TMβ1 recognizes an epitope related to the IL-2 binding site of IL-2Rβ, these results can be taken as a demonstration that mouse IL-2Rβγ does not bind mouse IL-2. Furthermore, T cell clone 8.2 does not proliferate in response to recombinant mouse or human IL-2. On the other hand, T cell transfectant lines expressing heterospecific receptors made of the human IL-2Rβ and mouse IL-2Rγ chains bind ¹²⁵I-labeled human IL-2 and proliferate in response to IL-2. This establishes the difference between mouse and human IL-2Rβ chains. Transfection of T cell clone 8.2 with human IL-2Rα genes restores their capacity to proliferate in response to IL-2. In addition, all transfectants grown in IL-2 express the endogeneous mouse IL-2Rα chain. When grown in IL-4, the endogeneous mouse IL-2Rα gene remains silent in all these transfectants. These results show that, contrary to the human, the mouse does not express an intermediate-affinity IL-2R. Expression of the IL-2Rα gene is therefore required for the formation of the functional IL-2R in mice.