酵母多糖对机体免疫功能的影响

目的探讨酵母多糖对机体免疫功能的影响,从而为维护人体健康提供理论依据。方法每批20只小鼠随机分为酵母多糖组和正常对照组,每组10只。酵母多糖组每天灌服0.2 ml浓度为80 mg/ml的酵母多糖溶液,正常对照组每天灌服0.2 ml 0.9%氯化钠溶液,11 d后处死,测定小鼠各项免疫指标。(1)固有免疫:半体内法检测小鼠巨噬细胞吞噬功能;(2)细胞免疫:小鼠后足迟发型超敏反应强度;(3)体液免疫:血凝法测定小鼠血清中溶血素含量;(4)免疫系统:对脾脏和胸腺称重计算脾脏指数和胸腺指数。结果酵母多糖组小鼠巨噬细胞吞噬率和吞噬指数分别为(29.3±1.95)%、0.43±0.03,明显高于正常小鼠组的(25.7±2.05)%、0.39±0.18(P<0.01);酵母多糖组小鼠左右后足重量差为(22.1±2.4)g,与正常组小鼠的(17.9±3.3)g比较差异有统计学意义(P<0.01);酵母多糖组小鼠抗体积数为33±4,高于正常组小鼠的32±7(P<0.05);酵母多糖组小鼠脾脏指数和胸腺指数分别为5.50±0.20、2.21±0.35,分别较正常组小鼠的5.01±0.28、1.87±0.33有明显提高(P<0.01)。结论酵母多糖可以显著提高机体的免疫功能,长期食用发酵食品有助于身体健康。     

酵母多糖对免疫功能的影响

目的从酵母菌中提取其多糖成分,探讨酵母多糖对小鼠免疫功能的影响,为酵母多糖的临床应用提供实验依据。方法取小鼠脾脏淋巴细胞,置于96孔细胞培养板中,加入酵母多糖为酵母多糖组和细胞培养液为空白对照组,测定小鼠脾细胞的增殖活性;取细胞上清液,测定细胞因子白细胞介素-2(IL-2)、干扰素-γ(IFN-γ);用流式细胞术(FCM)检测细胞表型,观察酵母多糖对细胞免疫和体液免疫作用。结果实验组细胞增殖活性显著高于对照组(P<0.01);实验组IL-2,IFN-γ的浓度与酵母多糖在一定浓度范围内成剂量依赖关系;酵母多糖即能刺激B淋巴细胞,也能刺激T细增殖。结论酵母多糖可提高小鼠免疫功能,它不仅能提高体液免疫功能,而且能提高细胞免疫功能。     

多糖多相脂质体的药理作用

本文对分别装载环磷酰胺、5-氟脲嘧啶、丝裂霉素C和顺铂等四类化疗药的多糖多相脂质体的抗小鼠移植肿瘤作用,及其对小鼠免疫器官、外周血白细胞和蛋白质合成的影响进行了初步研究。同时测定了装载丝裂霉素的该类脂质作的LD_(50)。证明了多糖多相脂质体具有增强化疗药的抗肿瘤作用。降低药物毒性,促进蛋白质合成等作用。     

酵母多糖对小鼠腹腔巨噬细胞产生一氧化氮和白细胞介素-1的影响

目的探讨酵母多糖对小鼠腹腔巨噬细胞产生一氧化氮 (NO)和白细胞介素 1(IL 1)的影响。方法将不同剂量的酵母多糖加入体外培养的小鼠腹腔巨噬细胞中 ,取细胞培养上清液根据Griess反应检测NO-2 的量 ,间接反映巨噬细胞产生NO的生成量 ,并用溴化四唑蓝 (MTT)比色法检测上清液中IL 1的生成量。结果酵母多糖可明显促进小鼠腹腔巨细胞产生NO和IL 1,NO的生成量呈现剂量依赖关系。结论酵母多糖可诱导小鼠腹腔巨噬细胞产生NO和IL 1,可能是酵母多糖调节机体免疫功能、杀伤病原微生物和抗肿瘤的重要途径     

酵母多糖诱导小鼠流产模型的建立及巨噬细胞表型和功能改变的实验研究

目的 建立酵母多糖诱导小鼠流产的模型并初步探讨巨噬细胞表型及功能的变化.方法 利用腹腔注射酵母多糖建立小鼠模型.采用流式细胞术及ELISA检测巨噬细胞表型及细胞因子和共刺激分子的表达.结果 通过腹腔静脉注射酵母多糖250 μg/g是理想的小鼠流产建模剂量.在体内试验中,酵母多糖组子宫替代活化的巨噬细胞(M2)比例明显低于对照组,差异有统计学意义(P＜0.05),对经典活化的巨噬细胞(M1)无明显差别;在体外实验中,酵母多糖组刺激的子宫巨噬细胞M1比例均明显增多,M2比例明显均减少,差异有统计学意义(P＜0.05).血清检测出酵母多糖组的IL-4减少,IL-2,IL-6和IFN增加,差异有统计学意义(P＜0.05).酵母多糖组子宫巨噬细胞表面CD80和CD86增多,差异有统计学意义(P＜0.05).结论 酵母多糖可在小鼠诱导流产,该模型可应用于感染相关流产的研究;酵母多糖注射后孕鼠流产可能与巨噬细胞相关的抑制性免疫功能减弱有关.     

人参多糖多相脂质体对免疫功能的影响及抗癌作用

以巨噬细胞ＥＡ花环形成率为指标，证明了人参多糖多相脂质体（ＺＭＩ，ＺＭ２）可激活正常或荷瘤小鼠腹腔巨噬细胞ＦＣ受体，将有助于改善机体的免疫功能，增强巨噬细胞对肿瘤的攻击能力．同时还证明，ＺＭ１单用对小鼠Ｓ－１８０肿瘤有轻度抑制作用，作为化疗辅助剂与环磷酰胺、环己基亚硝脲合用有协同作用．与氨甲喋呤合用可明显提高抗癌效果．     

具有活性羧基末端的长循环脂质体的制备和分布

目的　研究长循环免疫脂质体(immunoliposomes,IML)的制备方法, 体外靶细胞杀伤活性和在小鼠体内的组织分布。方法　合成和纯化了1个带末端羧基的磷脂酰乙醇胺(PE)的聚乙二醇衍生物(DPPE-PEG3000-COOH),掺入脂质体中制成长循环脂质体;通过羧基活泼酯化,将膀胱癌单克隆抗体BDI-1或小鼠IgG共价连接到该脂质体表面制成免疫脂质体,体外肿瘤细胞杀伤实验检测载阿霉素免疫脂质体(ADM-BDI-1-IML)特异杀伤靶细胞的能力。用同位素氚示踪法测量免疫脂质体在小鼠的组织分布。结果　抗体在脂质体上的结合率可达30％。体外肿瘤细胞杀伤实验证明载阿霉素免疫脂质体有选择性杀伤靶细胞人膀胱癌细胞EJ的能力。和普通脂质体相比,免疫脂质体在血中的滞留时间明显延长,并减少了在肝、脾的聚集。结论　长循环免疫脂质体在血中有较长的滞留时间,在体外有特异寻靶活性,载阿霉素免疫脂质体有选择性杀伤靶细胞的活性,这些性质为其在体内主动寻靶和选择性杀伤靶肿瘤细胞提供了必要条件。     

荆豆凝集素修饰的牛血清白蛋白脂质体的免疫学性质

目的对荆豆凝集素修饰的牛血清白蛋白脂质体进行免疫学评价。方法 3组小鼠分别于0、7、14、21 d口服免疫牛血清白蛋白溶液(bovine serum albumin,BSA)、BSA脂质体及荆豆凝集素修饰的BSA脂质体,建立ELISA法测定小鼠在7、14、21、28、35及42 d时体内产生的系统及黏膜免疫应答。结果与BSA溶液组相比,将抗原包裹于脂质体、尤其是荆豆凝集素修饰的脂质体中免疫小鼠后,可在小鼠血清及小肠分泌液中检测到较高的IgG及IgA水平。其中,免疫后42 d,凝集素修饰脂质体组的IgG和IgA水平分别为BSA溶液组产生相应抗体值的4.33倍和4.74倍。结论荆豆凝集素修饰脂质体口服免疫小鼠后可同时诱导机体产生黏膜及系统免疫应答,可以作为口服疫苗的载体。     

人参皂苷脂质体对小鼠低温力竭游泳试验的初步研究

目的考察人参皂苷脂质体对低温力竭游泳运动小鼠的影响及机制。方法 40只小鼠随机分为生理盐水组、人参皂苷脂质体低浓度组、中浓度组、高浓度组,灌胃21 d,考察各组小鼠低温力竭游泳运动的时间,并通过免疫器官脏器系数研究其机制。结果人参皂苷脂质体低浓度组能显著延长小鼠低温力竭游泳运动时间(P<0.05),且胸腺系数具显著性差异(P<0.05)。结论低浓度组人参总皂苷脂质体能够提高小鼠低温力竭游泳运动的时间。     

不同磷脂组成莪术油包合物脂质体的抗肿瘤作用比较

目的:考察不同磷脂组成莪术油包合物脂质体的抗肿瘤药效。方法:采用乙醇注入法制备了莪术油包合物脂质体。KM小鼠接种H22瘤株造成移植性荷瘤小鼠模型,比较莪术油不同制剂[包括莪术油溶液,莪术油包合物(ZTO-HPCD)、莪术油包合物SPC脂质体(ZTO-HPCD-SL)及莪术油包合物复合磷脂脂质体(ZTO-HPCD-SHL)]给药后荷瘤小鼠的抑瘤效果,比较给药后各组荷瘤小鼠的体质量和免疫器官(脾和胸腺)指数。并且还考察了对腹水癌模型小鼠生命延长率的影响。结果:磷脂组成对莪术油包合物脂质体的抗肿瘤效果具有显著影响。相同剂量下的莪术油溶液、ZTO-HPCD、ZTO-HPCD-SL、ZTO-HPCD-SHL的抑瘤率分别为17.90%、17.49%、39.77%、59.42%,与莪术油溶液相比,莪术油包合物脂质体制剂给药后未发现对免疫器官存在明显的抑制作用,具有一定的生命延长作用。结论:采用包合物脂质体与复合磷脂脂质体技术可以显著提高莪术油的抗肝癌效果。     

Amygdaloid Signature of Peripheral Immune Activation by Bacterial Lipopolysaccharide or Staphylococcal Enterotoxin B

Activated immune cells produce soluble mediators that not only coordinate local and systemic immune responses but also act on the brain to initiate behavioral, neuroendocrine and metabolic adaptations. Earlier studies have shown that the amygdala, a group of nuclei located in the medial temporal lobe, is engaged in the central processing of afferent signals from the peripheral immune system. Here, we compared amygdaloid responses to lipopolysaccharide (LPS) and staphylococcal enterotoxin B (SEB), two prototypic bacterial products that elicit distinct immune responses. Intraperitoneal administration of LPS (0.1 mg/kg) or SEB (1 mg/kg) in adult rats induced substantial increases in amygdaloid neuronal activity as measured by intracerebral electroencephalography and c-fos gene expression. Amygdaloid neuronal activation was accompanied by an increase in anxiety-related behavior in the elevated plus-maze test. However, only treatment with LPS, but not SEB, enhanced amygdaloid IL-1β and TNF-α mRNA expression. This supports the view of the immune system as a sensory organ that recognizes invading pathogens and rapidly relays this information to the brain, independent of the nature of the immune response induced. The observation that neuronal and behavioral responses to peripheral immune challenges are not necessarily accompanied by increased brain cytokine expression suggests that cytokines are not the only factors driving sickness-related responses in the CNS.     

Enhancement by muramyldipeptides of the activities of early-type inducers of interferon

A synthetic muramyldipeptide (MDP) and two analogues, B30-MDP and MDP-Lys(L18), augmented serum interferon (IFN) production in mice by the inducers lipopolysaccharide (LPS) and polyinosinic acid:polycytidylic acid (poly I:C), and also augmented immune IFN production induced by purified protein derivative (PPD) in mycobacteria-sensitized mice. These compounds were most effective when administered to mice one day before the interferon inducer. By contrast, IFN production in mice by either oral tilorone or virus infection was not enhanced with these compounds. Since LPS and poly I:C are well known as early-type IFN inducers, and tilorone and virus infection are late-type inducers, we presume that MDP and its analogues are able to augment only early-type IFN production. This enhancing effect may be mediated by macrophage activation. In vivo antiviral activity of MDP and its analogues was further tested in mice infected with vaccinia virus (VV) using early-type inducers. When mice previously treated with MDP or its analogues were stimulated for IFN production with a low dose of LPS, protective activity against VV infection was markedly enhanced.     

Effects of swainsonine on the humoral immune response of lipopolysaccharide

Effects of swainsonine (SW; 8α, β-indolizidine-1α, 2α, 8-triol from Locoweed) on the humoral immune responses of lipopolysaccharide (LPS) were studied in ICR mice. Mice were divided into 4 groups (10mice/group), and LPS was given to each mouse 1 hr after i.p. injection with 3.7 mg/kg of swainsonine, by i.p. injection twice a week for 14 days at a dose of 2 mg/kg. Humoral immune responses were evaluated by hemagglutination (HA) titer and splenic plaque forming cells (PFC). The results of this study were summarized as follows: Mice administrated each of LPS and SW showed significant enhancement of the weight ratios of spleen to body, HA titer, 2-mercaptoethanol-resistant HA (MER-HA) titer and PFC compared with those in controls. However, the LPS plus SW treatment decreased HA titer, MER-HA titer and PFC corresponding to humoral immunity, as compared with those in the mice treated with LPS alone. These findings indicated that LPS significantly enhanced humoral immune responses, but their enhancement effects were lowered somewhat by SW.     

Bacterial DNA does not increase serum corticosterone concentration or prevent increases induced by other stimuli

Bacterial DNA containing unmethylated CpG motifs (CpG DNA) and other microbial molecules such as lipopolysaccharide (LPS) have a broad range of immune stimulatory effects, which may include many shared cell signaling pathways leading to enhanced cytokine production. Some cytokines activate the hypothalamic-pituitary-adrenal (HPA) axis, and their production is downregulated by products of the HPA axis (glucocorticoids). Because such interactions have practical implications in the clinical use of CpG DNA, the present study was done to examine the effects of CpG DNA and LPS on serum corticosterone concentrations. In contrast to LPS, administration of CpG DNA (DNA from Escherichia coli) (30-300 microg) alone did not significantly increase serum corticosterone concentrations 1 or 4 h after administration. Administration of CpG DNA to mice prior to LPS caused a synergistic increase in serum tumor necrosis factor-alpha (TNF-alpha), indicative of an immune stimulatory effect. LPS and TNF-alpha, however, induced similar levels of corticosterone with or without concomitant CpG DNA. Increasing doses of LPS caused peak corticosterone levels similar to those induced by LPS in combination with CpG DNA. Exogenous TNF-alpha administered in vivo induced comparable concentrations of corticosterone with or without CpG DNA. An alternative stressor (restraint) yielded similar levels of corticosterone with or without CpG DNA. These results indicate that CpG DNA does not induce corticosterone release or alter its release by other stimuli, indicating biologically important differences in its immune effect compared to those of LPS, and possibly reduced toxicity.     

Histamine produced by macrophage and T lymphocyte: a new type of signal transducer

Macrophages (M phi) produce histamine (Hm) when activated by bacterial endotoxin (LPS) through induced histidine decarboxylase (HDC). Among the cytokines tested, GM-CSF or IL-3 specifically augmented the LPS-dependent HDC induction by M phi. Hm formed by M phi regulates synthesis of cytokines such as IL-1, IL-6, G-CSF and M-CSF by the cells per se and may modulate immune reactions and division and differentiation of various hematopoietic cells. Kupffer cells, M phi-like cells in the liver, also synthesize Hm in mice injected with hepatotoxins such as tetradecanoylphorbol acetate or LPS. Hm thus produced by Kupffer cells may participate in the regeneration of the injured liver through induction of hepatocyte growth factor. Concanavalin A (Con A) enhanced Hm formation by T lymphocytes. GM-CSF or IL-3 also enhanced the Hm synthesis by CD4+ and CD8+ T cells. Hm formed by T cells regulates immune reactions such as lymphocyte blastogenesis. In animals infected with gram(-) bacteria Hm is produced by the M phi-T cell system and may regulate immune competence to the bacteria. In addition, Hm may act as a signal transducer between the peripheral immune system and hypothalamus-pituitary-adrenal system, leading to GC secretion, in order to prevent occurrence of tissue injury caused by excess immune reactions.     

In Vivo Morphine Treatment Synergistically Increases LPS-Induced Caspase Activity in Immune Organs

Caspases are a family of proteins important for the elimination of infected cells through the induction of apoptosis as well as the initiation of inflammatory cytokines including IL-1β and IL-18. Morphine exposure to animals and/or cells has been associated with the induction of apoptosis. The most common practices of apoptosis detection have involved removing tissues from animal or humans and the analysis of apoptosis on cells or tissues. These methods can potentially induce spontaneous apoptosis that is unrelated to the actual treatment. The objective of this study was to develop an in vivo detection method for assessing caspase activity induced both by morphine directly and by morphine combined with lipopolysaccharide (LPS)–immune activation. Mice were administered saline, morphine, LPS, or a combination of morphine and LPS. Prior to sacrifice, mice were injected with a poly-caspase-specific apoptosis detection probe to detect internal caspase activity in vivo. Results revealed that morphine alone did not directly induce caspase activity. However, morphine significantly enhanced the LPS-induced caspase activity in spleen, thymus, and bone marrow-derived immune cells. The use of a poly-caspase detection probe methodology to label caspase activity in vivo provides a powerful quantitative tool for the in vivo analysis of caspase activity.     

Prenatal lipopolysaccharide treatment enhances MK-801-induced psychotomimetic effects in rats

The aim of this study was to evaluate the effect of prenatal lipopolysaccharide (LPS) treatment, which is an animal developmental model of schizophrenia, on MK-801-induced psychotomimetic behavioral changes and brain aminergic system activity in adult offspring. Repeated LPS (1 mg/kg) injection in rats, that had started from 7th day of pregnancy and was continued every second day till delivery, resulted in a long-lasting disruption of prepulse inhibition (PPI) and elevation of locomotor activity in their offspring. The prenatally LPS-treated rats showed hypersensitivity to MK-801 (0.1 and 0.4 mg/kg) as evidenced by the enhancement of acoustic startle amplitude, reduced PPI, and enhanced locomotor activity.These behavioral changes were accompanied by a decrease in the dopamine and its metabolite, DOPAC concentration in the frontal cortex, enhanced dopaminergic system activity in the striatum and no changes in noradrenaline (NA) level. Furthermore, the significant augmentation of 5-HT and 5-HIAA content in the frontal cortex of females only was detected. No changes in the cortical NA tissue level were found. Summing up, the present study demonstrated that the activation of the immune system in prenatal period led to persistent behavioral hypersensitivity to psychotomimetic action of a non-competitive NMDA receptor antagonist, and attention/information processing deficits. The foregoing data indicate that prenatal administration of LPS model some of the clinical aspects of schizophrenia and these behavioral effects are connected with neurochemical changes.     

Effect of endocrine disrupting chemicals on lipopolysaccharide-induced tumor necrosis factor-alpha and nitric oxide production by mouse macrophages

Little is known about the development of infectious diseases during exposure to endocrine disrupting chemicals (EDCs), although several studies have reported on the effect of EDCs on the immune function of the human body. To assess the effect of EDCs on the development of infectious disease, we investigated the effect of eighteen possible EDCs on mouse macrophage production of tumor necrosis factor-alpha (TNF-alpha) and nitric oxide (NO) in response to bacterial endotoxin in vitro and ex vivo. Of chemicals we examined, simazine, nitrofen, and benzyl butyl phthalate inhibited lipopolysaccharide (LPS)-induced TNF-alpha production by mouse macrophage cell line RAW 264 in vitro. Carbaryl, alachlor, nonylphenol, octylphenol, tributyltin, and triphenyltin inhibited LPS-induced NO production in vitro, whereas 2,4-dichlorophenoxy acetic acid and bisphenol A enhanced its production. Zineb and alachlor, on the other hand, enhanced LPS-induced TNF-alpha production by mouse peritoneal macrophages ex vivo, while alachlor inhibited LPS/interferon-gamma-induced NO production ex vivo. These results indicate that some EDCs exert modulatory activity on endotoxin-induced macrophage activation either positively or negatively, suggesting that these compounds may affect the development of infectious diseases. This is the first report that systematically compared the effect of EDCs on LPS action.     

In vivo and in vitro effects of 1,1-dimethylhydrazine on selected immune functions

The in vivo phase of the experiments reported here include the evaluation of immune function after short-or long-term treatment of mice with 1,1-dimethylhydrazine (UDMH). Long-term exposure (3 injections/week for 14 weeks) resulted in increased numbers of Jerne plaque-forming cells, a trend toward decreased induction of suppressor cell activity by concanavalin A (Con A), and no effects on mitogen-induced lymphocyte blast transformation (LBT), compared to saline-treated control mice. These effects were greatest at doses of 10 or 50 mg/kg, while higher doses had less of an effect. In vitro experiments were performed by adding UDMH to normal murine splenocytes in the LBT assay and con A-induced suppressor cell assay. The UDMH induced a significant enhanced response to lipopolysaccharide (LPS) at 10 and 50 micrograms/ml, and a suppressed response to both Con A and LPS at higher concentrations. The UDMH also caused a decrease in suppressor cell activity at 25 micrograms/ml. Selective abrogation of suppressor activity or alteration of the suppressor cell-helper ratio were suggested as possible mechanisms for the enhancement effect associated with UDMH.