Dietary intervention with sialylated lactulose affects the immunomodulatory activities of mice

Four sialylated lactuloses [N-acetylneuraminic acid-α2,3-lactulose (Neu5Acα2,3lactulose), N-acetylneuraminic acid-α2,6-lactulose (Neu5Acα2,6lactulose), deaminoneuraminc acid-α2,3-lactulose (Kdnα2,3lactulose), and deaminoneuraminc acid-α-2,6-lactulose (Kdnα2,6lactulose)] were reported to modulate the immunity of mice. The influences of cytokine expression, cell immunity, humoral immunity, and nonspecific immunity were investigated in our study using several techniques. Analysis via ELISA showed that cytokine expression was induced by sialylated lactulose treatment consistently in the serum and spleen. Among the 4 tested sialylated lactuloses, Neu5Acα2,6lactulose performed the best, simultaneously and appropriately promoting the expression of proinflammatory and anti-inflammatory factors in the serum and spleen. Kdnα2,3lactulose showed the best antioxidant activity according to detection of the activity of superoxide dismutase, myeloperoxidase, peroxidase, and alkaline phosphatase. Flow cytometry revealed that only Kdnα2,3lactulose significantly boosted the CD3⁺ T lymphocyte ratio similarly to that of lactulose. Analysis of the hemolysin content to characterize humoral immunity revealed that Kdnα2,3lactulose notably increased hemolysin content compared with that in the control group. To evaluate the nonspecific immune effects of the 4 sialylated lactuloses, a fluorescence microsphere phagocytosis assay was used to analyze the phagocytosis of macrophages. Kdnα2,3lactulose still performed the best in enhancing the phagocytosis of macrophages, showing markedly increased phagocytic percentage and phagocytic index values compared with those in the control and lactulose groups. Comparing the differences of these 4 sialylated lactuloses in affecting immunity in mice revealed that Kdnα2,3lactulose had the best overall performance in influencing cytokine expression, cell immunity, humoral immunity, and nonspecific immunity. This study provides critical support for use of sialylated lactuloses as potential immunomodulators in foods.     

初乳中生物活性物质的开发与应用

初乳不同于常乳，它是哺乳动物为自己的后代准备的第一份食品。牛初乳不仅含有哺乳动物所必需的各种营养物质、矿物元素和氨基酸，还含有很多具有生物活性的多肽、底聚糖类物质。其中研究较多的有：非肽类营养因子（nonpeptide trophic factors），激素（hormones），细胞因子（cytokines），生长因子（growth factors），表皮生长因子受体配基家族（epidermal growth factor receptor ligand family），表皮生长因子（epidermal growth factor），转移生长因子（transforming growth factor），转化生长因子β家族（transforming growth factor β family），胰岛素样生长因子（insulin-like growth factors），生长调节素及其结合蛋白（somatomedins，and their binding proteins），血小板衍生的生长因子（platelet-derived growth factor），（vascular endothelial growth factor），乳铁蛋白（lactoferrin），生长激素及其释放因子（growth hormone and its releasing factor）和抗体等。本文就初乳的特性、这些生理因子的作用、应用、分离提纯和研究进展进行系统综述，并从哺乳动物进化的角度分析初乳这些功在新生个体发育和分化和先天免疫中的作用。     

Immunomodulatory Activity of Recombinant Ricin Toxin Binding Subunit B (RTB)

Ricin toxin binding subunit B (RTB) is one of the subunits of the ricin protein. RTB has been used as adjuvant, but little is known about its mechanism. In this study, we found that RTB increased not only nitric oxide (NO) release, but also tumor necrosis factor (TNF)-α and interleukin (IL)-6 production in mouse macrophage cell line RAW264.7 cells. They subsequently exhibited enhanced ConA-induced T-cell and LPS-induced B-cell proliferative responses. We also examined the cytokines that were produced from splenocytes following in vitro RTB administration. Increased levels of IL-2, interferon (IFN)-γ and TNF-α were observed, while IL-4 and IL-5 were unaffected. These results demonstrate that recombinant RTB can act on the immune system and activate T-cells by introducing a Th1 immune response. Th1 cells might be the primary cellular target affected by RTB. Our results suggest that the recombinant RTB can promote the activation of macrophages and has a beneficial effect on immunomodulatory activity.     

Immunological Effects of Oenothein B,an Ellagitannin Dimer,on Dendritic Cells

Oenothein B is a unique macrocyclic ellagitannin dimer that has been found in various medicinal plants belonging to Onagraceae, Lythraceae, and Myrtaceae, with diverse biological activities. The immunological effects of tannins in terms of cytokine-release from macrophages and monocytes have been discussed, while the effects on other immunocompetent cells have been the subject of minimal investigation. We evaluated the immunomodulatory effects induced by tannin treatment in human dendritic cells (DCs), which play a critical role in the initial immune response, by measuring the changes in cytokine production, cell differentiation, and cell viability. Oenothein B showed significant down-regulation of the expression of cell surface molecules, CD1a and CD83, suggesting the inhibition of DC differentiation and/or maturation. The suppressive effect on DCs was associated with the induction of apoptosis without the activation of caspase-3/7, 8, and 9, and this was supported by the morphological features indicating significant nuclear condensation. Oenothein B also markedly suppressed the production of inflammatory cytokines, such as IL-1β and IL-6, in a dose-dependent manner. These data may, in part, be able to explain the traditional use of tannin-containing medicinal plants for the treatment of a variety of inflammatory diseases, including inflammatory bowel disease, celiac disease, and rheumatoid arthritis.     

Benefits in the Macrophage Response Due to Graphene Oxide Reduction by Thermal Treatment

Graphene and its derivatives are very promising nanomaterials for biomedical applications and are proving to be very useful for the preparation of scaffolds for tissue repair. The response of immune cells to these graphene-based materials (GBM) appears to be critical in promoting regeneration, thus, the study of this response is essential before they are used to prepare any type of scaffold. Another relevant factor is the variability of the GBM surface chemistry, namely the type and quantity of oxygen functional groups, which may have an important effect on cell behavior. The response of RAW-264.7 macrophages to graphene oxide (GO) and two types of reduced GO, rGO15 and rGO30, obtained after vacuum-assisted thermal treatment of 15 and 30 min, respectively, was evaluated by analyzing the uptake of these nanostructures, the intracellular content of reactive oxygen species, and specific markers of the proinflammatory M1 phenotype, such as CD80 expression and secretion of inflammatory cytokines TNF-α and IL-6. Our results demonstrate that GO reduction resulted in a decrease of both oxidative stress and proinflammatory cytokine secretion, significantly improving its biocompatibility and potential for the preparation of 3D scaffolds able of triggering the appropriate immune response for tissue regeneration.     

食品与机体中的移动通讯网络

在总结近年来有关食品胃肠黏膜信号通路研究的基础上,根据现代免疫学的研究成果,提出机体中存在着移动细胞之间的通讯网络的假说,该假说认为：细胞因子网络实际上就是移动通讯网络的信号传递系统;机体中的移动细胞可以依赖细胞因子,通过自分泌、旁分泌进行局部通讯;通过内分泌进行远距离全局性通讯;通过和固定细胞之间的信号交流和胃肠道黏膜、神经内分泌系统进行高密度的通讯联系,从而形成一个“无线”和“有线”之间相互协调的通讯网络;在这个通讯网络中,细胞通过受体及其信号传递、级联放大系统接受并通过基因表达与调控定量放大这些细胞信号,从而发挥生命活动;而细胞因子和趋化因子等信号分子则通过循环系统在固定和移动细胞之间传递信号,分子之间互不干涉,在极低的浓度下通过相应的细胞发挥通讯媒体的作用。作者通过研究发现：功能性食品正是通过改变这个复杂的通讯网络发挥其生物功能。这一理论和研究方法的建立将有可能从根本上改变功能性食品如何发挥生物功能的评价方法和标准。     

黄芪注射液对哮喘大鼠p38蛋白激酶和白细胞介素-5表达的影响

目的:探讨黄芪注射液对哮喘大鼠p38蛋白激酶(p38 MAPK)和白细胞介素-5(IL-5)表达的影响。方法:应用鸡卵清蛋白(OVA)腹腔注射致敏和反复超声雾化吸入复制大鼠哮喘模型。40只大鼠随机分成5组:正常对照组, 哮喘模型组和黄芪注射液低、中、高剂量组(2.5、5.0、10.0 mL/kg)。分别采用酶联免疫吸附法(ELISA)、原位分子杂交方法和蛋白质印迹检测支气管肺泡灌洗液(BALF)IL-5含量、肺组织IL-5 mRNA和磷酸化p38 MAPK 表达的变化, 并观察BALF 中炎症细胞计数、分类以及肺组织病理学变化。结果:哮喘模型组大鼠BALF 中炎症细胞计数、IL-5含量和肺组织中IL-5 mRNA及磷酸化p38 MAPK 表达均较正常对照组显著增加(P<0.01);黄芪干预组的上述改变较哮喘模型组显著降低(P<0.01), 肺组织病理学损伤程度明显减轻, 黄芪注射液低、中、高剂量组之间差异无统计学意义。肺组织磷酸化p38 MAPK 表达水平与BALF中嗜酸性粒细胞(EOS)计数和IL-5、IL-5 mRNA含量之间分别呈显著正相关(r=0.62、0.69、0.74, P<0.01)。结论:p38 MAPK 可能参与了支气管哮喘的发病过程。黄芪对哮喘的治疗作用可能部分与抑制p38 MAPK 的磷酸化活化、降低炎症介质释放、减轻炎症细胞浸润有关。