维生素E对创伤小鼠淋巴细胞功能的调节作用及机制

研究了维生素Ｅ对创伤小鼠淋巴细胞功能的调节作用及机制。结果显示：ＶＥ体内应用（１００ｍｇ／ｋｇ·ｄ－１，ｉ·ｍ×４ｄ）对创伤小鼠淋巴细胞白介素２（ＩＬ－２）ｍＲＮＡ、ＩＬ－２受体（ＩＬ－２Ｒ）ｍＲＮＡ水平，ＩＬ－２的生成，ＩＬ－２Ｒ的表达以及Ｔ淋巴细胞转化具有明显的升高作用。可明显逆转创伤小鼠血清及淋巴组织中ＶＥ含量的降低，丙二醛（ＭＤＡ）含量的升高以及淋巴细胞膜流动性的降低。并可改善创伤小鼠淋巴组织的损害。结果表明：ＶＥ可通过降低创伤小鼠的脂质过氧化反应，保护淋巴细胞膜，进而纠正创伤后淋巴细胞功能的受抑状态。     

黄芪多糖对烧伤小鼠细胞免疫功能的作用

应用小鼠烧伤模型，对黄芪多糖（ＡＰＳ）的免疫增强作用进行了体内外研究。结果表明：体内应用ＡＰＳ（２５０ｍｇ·ｋｇ－１，ｑｄ，连续５ｄ），可明显提高烧伤小鼠Ｔ淋巴细胞转化，ＩＬ－２的产生及ＩＬ－２Ｒ的表达；体外分别应用５０、１００、２５０ｍｇ·Ｌ－１的黄芪多糖，发现其可纠正烧伤小鼠Ｔ淋巴细胞转化，ＩＬ－２的产生及ＩＬ－２Ｒ表达的受抑状态，并促进巨噬细胞产生ＩＬ－１，抑制ＰＧＥ２合成，且呈剂量依赖关系；体外去除烧伤小鼠脾细胞中的巨噬细胞后，ＡＰＳ对Ｔ淋巴细胞转化，ＩＬ－２产生及ＩＬ－２Ｒ表达的调节作用消失。提示ＡＰＳ对烧伤小鼠的免疫调节作用依赖于巨噬细胞，通过调节其分泌ＩＬ－１，抑制ＰＧＥ２合成，而促进ＩＬ－２产生及ＩＬ－２Ｒ表达，进而增强Ｔ淋巴细胞增殖。     

IL-2-PE40对免疫活性T细胞的影响

目的研究ＩＬ－２－ＰＥ４０对免疫活性Ｔ细胞的影响。方法采用ＣｏｎＡ刺激的淋巴细胞增殖试验、混合淋巴细胞培养（ＭＬＣ）及细胞毒试验。结果ＩＬ－２－ＰＥ４０对ＣｏｎＡ诱导的小鼠脾细胞有十分强的细胞毒性，能选择性地抑制ＭＬＣ中抗原活化的Ｔ细胞活性，保留未活化Ｔ细胞对ＣｏｎＡ诱导的丝裂原反应，在培养ｄ３加入ＩＬ－２－ＰＥ４０比培养开始时加入对ＭＬＣ抑制作用强。结论ＩＬ－２－ＰＥ４０能够高度选择性抑制免疫活性Ｔ细胞，是ＩＬ－２Ｒ靶向治疗中具有潜力的一种免疫抑制剂。     

白芍总甙治疗类风湿性关节炎的临床药理研究

对２９例类风湿性关节炎（ＲＡ）患者进行了白芍总甙（ＴＧＰ）的开放性临床试验．结果表明，大剂量ＴＧＰ（１．２～１．８ｇ·ｄ－１）服用８ｗｋ，对ＲＡ患者有明显疗效．不仅改善临床症状与体征以及降低血球沉降率与类风湿因子滴度，而且对ＲＡ患者的异常免疫功能，如外周血单个核细胞产生ＩＬ－１水平；外周血淋巴细胞的致分裂素反应与产生ＩＬ－２水平以及ＩＬ－２受体密度；抑制性Ｔ细胞的数目等均有机能依赖性恢复作用。与氨甲喋呤（ＭＴＸ）的比较试验表明．ＴＧＰ的抗关节炎作用起效较ＭＴＸ早．但疗效较温和，对ＲＡ患者异常免疫功能的影响也不完全相同，且ＴＧＰ的耐受性远较小剂量ＭＴＸ为优。本试验还表明．ＩＬ－１可作为监护ＴＧＰ疗效和调整剂量的一种灵敏而简便的指标。     

氨甲喋呤对类风湿性关节炎患者外周血单个核细胞产生细胞因子的影响

目的研究氨甲喋呤（ＭＴＸ）对类风湿性关节炎（ＲＡ）患者外周血单个核细胞（ＰＢＭＣ）产生细胞因子的影响。方法采用ＥＬＩＳＡ双抗夹心法，观察ＲＡ患者ＴＮＦ－α、ＩＬ－６的自发分泌及ＭＴＸ和ＬＰＳ的影响，以及ＭＴＸ和ＰＨＡ对ＩＬ－１０和ＩＦＮ－γ产生的影响。结果低浓度ＭＴＸ（５ｍｇ·Ｌ－１）有抑制ＲＡ患者ＰＢＭＣ自发分泌ＩＬ－６的作用，并对ＬＰＳ（１０ｍｇ·Ｌ－１）诱导ＩＬ－６的产生具有抑制作用，对ＴＮＦ－α的自发分泌及ＬＰＳ促分泌作用无明显影响；而高浓度ＭＴＸ（１５ｍｇ·Ｌ－１）对ＴＮＦ－α、ＩＬ－６和ＩＮＦ－γ均具有抑制作用；并能促进ＰＨＡ（１０ｍｇ·Ｌ－１）诱导ＩＬ－１０的产生；使ＩＬ－１０／ＩＮＦ－γ的比率上升。结论ＭＴＸ通过调节细胞因子网络（增高Ｔｈ２型细胞产生的细胞因子和降低Ｔｈ１型细胞产生的细胞因子）来发挥免疫调节作用和抑制炎症反应，这可能是其对ＲＡ产生治疗作用机制之一     

Fas与HIV感染

Ｆａｓ抗原（Ｆａｓ Ａｇ）表达与人类免疫缺陷症病毒（ＨＩＶ）感染引起的艾滋病（ＡＩＤＳ）进程有密切关系。随着ＨＩＶ感染的加重，细胞表面Ｆａｓ Ａｇ表达增加，主要表现在ＣＤ４＾＋和ＣＤ８＾＋细胞。通过Ｆａｓ Ａｇ介导的细胞程序死亡（ＰＣＤ）途径是ＨＩＶ感染引起的Ｔ淋巴细胞免疫缺陷的重要原因，白细胞介素２（ＩＬ－２），ＩＬ－１２等细胞因子以及ＩＬ－１β转化酶（ＩＣＥ）样蛋白酶抑制剂在体外能抑制由Ｆａｓ     

白芍总甙对佐剂性关节炎大鼠滑膜细胞功能和脾细胞增殖反应的影响

本文研究了白芍总甙（ＴＧＰ）对大鼠佐剂性关节炎（ＡＡ）滑膜细胞功能以及脾淋已细胞增殖反应的影响及其作用机理。结果表明，ＴＧＰ５０ｍｇ·ｋｇ－１·ｄ－１×１０ｄｉｇ可使ＡＡ大鼠滑膜细胞过度分泌白介素１，肿癌坏死因子（ＴＮＦ）和前列腺素Ｅ２（ＰＧＥ２）的功能恢复正常，继而下调滑膜成纤维细胞的增殖；吲哚美辛２ｍｇ·ｋｇ－１·ｄ－１×１０ｄｉｇ抑制ＰＧＥ２产生，但增加ＡＡ大鼠滑膜细胞分泌白介素１与ＴＮＦ，从而促进滑膜成纤维细胞的增殖。ＴＧＰ５０ｍｇ·ｋｇ－１·ｄ－１×１０ｄｉｇ恢复ＡＡ大鼠脾细胞过低的伴刀豆球蛋白Ａ（ＣｏｎＡ）增殖反应与其下调巨噬细胞产生一氧化氮和ＰＧＥ２有关；体外实验亦证明，高浓度（０．４——６．４ｍｇ·Ｌ－１）ＴＧＰ负调节脾细胞ＣｏｎＡ增殖反应与其促进巨噬细胞产生一氧化氮和ＰＧＥ２有关。     

白芍总甙对正常人与类风湿性关节炎患者单核细胞和淋巴细胞功能的影响

０．１～２．５ｍｇ·Ｌ－１白芍总甙（ＴＧＰ）对正常人的ＬＰＳ诱导外周血单个核细胞产生ＩＬ－１．ＰＨＡ－Ｐ诱导淋巴细胞增殖反应和ＩＬ－２产生均呈现浓度依赖性的双向作用；ＴＧＰ还可浓度（０．１～１２．５ｍｇ·Ｌ－１）依赖性地降低正常人淋巴细胞上ＩＬ－２Ｒ的密度．ＴＧＰ能使类风湿性关节炎（ＲＡ）患者低下的ＰＨＡ－Ｐ致分裂素反应与ＩＬ－２产生能力恢复正常，使外周血中减少的Ｔｓ细胞数目回到正常水平．但可使ＲＡ患者ＰＢＭＣ过度产生ＩＬ－１降低至正常范围．并能显著降低ＲＡ患者增高的淋巴细胞ＩＬ－２Ｒ的密度。上述结果表明．ＴＧＰ对ＲＡ患者有明显的机能依赖性免疫调节作用．ＴＧＰ对ＲＡ的治疗作用可能与其调整ＲＡ患者异常的免疫功能有关。     

白芍总甙对B淋巴细胞增殖和白介素1生成的调节作用

白芍总甙（ＴＧＰ）对脂多糖（ＬＰＳ）诱导的小鼠脾淋巴细胞增殖反应的量效曲线呈钟形，用贴壁法除去脾细胞中巨噬细胞（ＭΦ）或加入１０μｍｏｌ·Ｌ１吲哚美辛（Ｉｎｄ）可使ＴＧＰ量效曲线的下降支消失，再加５％同系小鼠腹腔ＭΦ中或前列腺素Ｅ２（ＰＧＥ２）０．０２２０μｍｏｌ·Ｌ１可使量效曲线下降支再现．同步检测ＴＧＰ对ＬＰＳ诱导大鼠腹腔ＭΦ产生ＰＧＥ２与白介素１（ＩＬ１）．结果表明，ＴＧＰ０．５－３ｌ２．５μｇ·ｍＬ１对ＬＰＳ诱导的ＩＬ－１产生曲线呈钟形．而ＴＧＰＬＰＳ的ＰＧＥ２产生曲线呈浓度依赖性地增高；在１２．５－３１２．５μｇ·ｍＬＴＧＰ范围内，１０μｍｏｌ·Ｌ１Ｉｎｄ可使高浓度ＴＣＰＬＰＳ的ＩＬ－１释放曲线明显抬高。提示ＴＧＰ对ＬＰＳ诱导的Ｂ细胞增殖反应和ＩＬ－１诱生的负调节作用都与其促进ＭΦ释放ＰＧＥ２有关．     

香菇多糖的免疫调节作用

检测香菇多糖（ＬＮＴ）对环磷酰胺（Ｃｙ）诱导的免疫功能低下的小鼠脾细胞溶血素抗体（ＩｇＭ）生成的影响和对ＣｏｎＡ诱导小鼠脾淋巴细胞增殖反应和ＩＬ－２生成的影响。结果表明，国产ＬＮＴ的３种剂量（０．５，１，２ｍｇ·ｋｇ－１·ｄ－１×５ｄ，ｉｐ）显著促进ＩｇＭ抗体的生成，且以１ｍｇ·ｋｇ－１·ｄ－１作用最佳。ＬＮＴ（１～１２５ｍｇ·Ｌ－１）可明显促进ＣｏｎＡ诱导的脾淋巴细胞增殖反应和ＩＬ－２的生成。量效曲线呈钟罩形。提示有浓度依赖性的双向免疫调节作用。     

Rottlerin inhibits human T cell responses

Rottlerin is a pharmacological inhibitor of protein kinase C (PKC) theta, a novel PKC selectively expressed in T lymphocytes. PKC theta is known to regulate T cell receptor (TCR)/CD28 signalling pathways in T lymphocytes, but the impact of PKC theta inhibition on human T cell responses remains undefined. In this work, we describe the effects of rottlerin on the responses of CD4+ and CD8+ human T lymphocytes upon polyclonal activation. We observed a dose-dependent inhibition of CD4+ and CD8+ T cell proliferation in response to anti-CD3/anti-CD28 antibodies stimulation in the presence of rottlerin. This inhibition was associated with impaired CD25 expression and decreased interleukin (IL)-2 production in activated T cells. In contrast, rottlerin did not alter IL-2-induced T cell proliferation. Furthermore, we demonstrated that rottlerin blocked interferon (IFN) gamma, IL-10 and IL-13 mRNA expression in TCR/CD28 activated CD4+ T cells. These findings place rottlerin as a potent immunosuppressive agent for the development of novel therapies in T cell mediated immune disorders.     

Effect of lipoteichoic acid on IL-2 and IL-5 release from T lymphocytes in asthma and COPD

Susceptibility to infections with gram-positive bacteria, which are an important trigger of exacerbations, is increased in COPD and asthma. Unraveling the underlying mechanisms may help developing therapeutic strategies to reduce exacerbation rates. The aim of this study was to evaluate the effects of lipoteichoic acid (LTA), a danger signal from gram-positive bacteria, on T cell cytokines related to bacterial infection defense in COPD and asthma. T cell populations within peripheral blood mononuclear cells (PBMCs) were ex-vivo activated towards T(H)2/T(C)2 subtypes and subsequently stimulated with LTA. IL-2 and IL-5 concentrations in cell culture supernatants were measured by ELISA comparative between non-smokers (NS), current smokers without airflow limitation (S), smokers with moderate to severe COPD and mild to moderate asthmatics (A) (each n=10). IL-2 and IL-5 baseline levels were without differences between the cohorts. After T cell activation, IL-2 and IL-5 releases were increased in all cohorts, however, for IL-2 this increase was significantly higher in S and by trend in COPD compared to the other groups. LTA time-dependently suppressed IL-2 release in NS, S and COPD but not in A. LTA reduced IL-5 release in COPD and A but not in NS and S. Summarized, LTA reduces T(H)2/T(C)2 cytokines indicating immunosuppressive effects, which are dysregulated in COPD and asthma. This implies a misguided response to gram-positive bacterial infections, which might help to explain the increased susceptibility to bacterial infections in COPD and asthma.     

Activation-induced T cell apoptosis by monocytes from stem cell products.

We recently found that mobilized peripheral blood stem cell (PSC) products (from both cancer patients and normal donors) contain high levels of CD14+ monocytes, which can inhibit the proliferation of allogeneic and autologous T cells. We found in our studies that using CD14+ monocytes from mobilized PSC products (from normal and cancer patient donors), normal apheresis products or normal peripheral blood (PB) can affect lymphocyte function and apoptosis-dependent T cell activation. However, it appears that the apoptosis is dependent on the frequency of monocytes, which is increased by both mobilization and apheresis. Both phytohemagglutinin (PHA)- and interleukin (IL)-2-induced proliferation of steady-state peripheral blood mononuclear cells (PBMC) were markedly inhibited by co-culture with irradiated CD14+ monocytes, although inhibition was significantly greater with PHA than with IL-2 stimulation. IL-2 (predominately CD56+ NK cells) or anti-CD3 monoclonal antibody (mAb) and IL-2-expanded lymphocytes (activated T cells) were inhibited by PSC monocytes to a significantly greater level as compared to steady-state lymphocytes. Indeed, no inhibition of T cell proliferation was observed when lymphocytes were co-cultured in the absence of mitogenic or IL-2 stimulation. In contrast, an increased proliferation was observed in co-cultures of CD14+ monocytes and steady-state or activated lymphocytes without mitogenic stimulation. Cell cycle analysis by flow cytometry revealed a significant increase in hypodiploid DNA, in a time-dependent manner, following co-culture of monocytes and PBMC in PHA, suggesting that T cell apoptosis occurred during PHA-induced activation. These results demonstrate that PSC-derived monocytes inhibit T cell proliferation by inducing the apoptosis of activated T cells and NK cells, but not steady-state cells. This suggests a potential role for monocytes in the induction of peripheral tolerance following stem cell transplantation.     

Suppressive effect of a novel water-soluble artemisinin derivative SM905 on T cell activation and proliferation in vitro and in vivo

Artemisinin and its derivatives exhibit potent immunosuppressive activity. The aim of this study was to investigate the suppressive effects of SM905, a new water-soluble artemisinin derivative, on T lymphocytes both in vitro and in vivo, and explore its potential mode of action. The results showed that SM905 had a high inhibitory activity in Concanavalin A (ConA)-induced splenocyte proliferation and mixed lymphocyte reaction, and a relatively low cytotoxicity in vitro. In ovalbumin-immunized mice, oral administration of SM905 dose-dependently suppressed T cell proliferative response to ovalbumin, and inhibited anti-ovalbumin interleukin-2 (IL-2) and interferon-gamma (IFN-gamma) production by T cells. Further studies showed that SM905 inhibited TCR (T cell receptor)/CD3 plus CD28-mediated primary T cell proliferation and cytokine production (IL-2 and IFN-gamma), and exerted an inhibitory action on the phosphorylation of mitogen-activated protein (MAP) kinases including extracellular signal-regulated kinase (ERK), p38 and Jun N-terminal kinase (JNK), and the activation of Ras. The results of this study provided experimental evidence that the new artemisinin derivative SM905 had immunosuppressive effects both in vitro and in vivo. SM905 suppressed T cell activation, which was associated with the inhibition of MAP kinases and Ras activation. Our results suggested a potential of SM905 to be developed as a new type agent for treating T cell-mediated immune disorder.     

PCP and analogs prevent the proliferative response of T lymphocytes by lowering IL2 production. An effect related to the blockade of mitogen-triggered enhancement of free cytosolic calcium concentration

The psychotomimetic drug PCP displays a vast array of known pharmacological effects, among them its capacity to affect cation transport in nervous and myocardiac tissues. Since increased movements of cations are essential for the immune responses, it has been mentioned that PCP could also depress immune functions by this mechanism. In order to check this hypothesis, we have investigated the effects of PCP and of many other structural derivatives on the blastogenic response of murine or human T lymphocytes. We find that all the drugs block an early event of T lymphocyte activation and prevent their further proliferation; conversely they do not affect primed lymphocytes. The compounds, which do not inhibit interleukin-1 (IL-1) production in stimulated macrophages, lower interleukin-2 (IL-2) synthesis in activated T helper cells. This negative action appears to be related to the inhibition of the rise of free cytosolic calcium concentration [Ca2+]i observed soon after the T receptor triggering and which is an essential message for IL-2 production. The lymphocyte membrane depolarization induced by the drugs could explain the blockade of the lectin-induced [Ca2+]i changes. The study of the structure-activity relationship shows that the PCP analogs which possess a quasi-rigid conformational structure express an inhibitory capacity of T lymphocyte proliferation higher than that of PCP (200 times for some products). Since these compounds interact poorly with the CNS tissues and have few behavioral effects, we suggest that PCP exerts its negative action on lymphocytes on cell components different from its receptor(s) in the CNS.     

Cardiotoxin-III selectively enhances activation-induced apoptosis of human CD8+ T lymphocytes

Cardiotoxin-III (CTX-III), a major cardiotoxin isolated from the venom of the Taiwan cobra (Naja naja atra), is a highly basic, hydrophobic, toxic protein, which can induce lysis of mononuclear cells by an unknown mechanism. This study was undertaken to investigate the effects of CTX-III on untreated and PHA-activated peripheral blood mononuclear cells (PBMCs) in vitro. The results show that treatment of PHA-activated lymphocytes with CTX-III (10 microg/ml) induced apoptosis and depletion of the CD8(+) population. In both untreated and PHA-treated lymphocytes, interferon-gamma production was dramatically reduced and interleukin-2 (IL-2) production was moderately reduced by CTX-III treatment. In PHA-activated lymphocytes, CD4 expression was increased, whereas CD8 and IL-2R beta chain (CD25) expression were decreased. In contrast, CTX-III had no effect on the viability of PHA-activated monocytes but significantly enhanced their tumor necrosis factor-alpha production. These results show that CTX-III selectively enhanced activation-induced apoptosis in CD8(+) T cells. CTX-III was found to bind to the cell membrane of PHA-stimulated PBMCs, and three CTX-III-binding proteins, with molecular weights of 92, 77, and 68 kDa, were identified. We therefore propose that CTX-III interacts with one or more cell surface proteins and initiates a signal pathway causing functional changes. These findings provide an insight into the immunomodulatory properties of CTX-III and suggest a novel method for the selective induction of apoptosis in CD8(+) T lymphocytes.