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1.
Background: During antigen capture and processing, mature dendritic cells (DC) express large amounts of peptide-MHC complexes and accessory molecules on their surface. DC are antigen-presenting cells that have an important role in tolerance and autoimmunity. The transforming growth factor-beta1 (TGF-Beta1) cytokine has a regulatory role on the immune and non-immune cells. The aim of this study is to evaluate the effect of TGF-Beta1 on the induction of human leukocyte antigen-G (HLA-G) expression on the DC which is derived from monocyte. Methods: In this study, we evaluated the effect of TGF-Beta1 in induction HLA-G expression on the monocyte-derived DC by flowcytometry and then CD4+ T cell proliferative responses in the presence of DC-treated TGF-Beta1 was studied. Results: The results of this study showed that DC bearing HLA-G down-regulated activation of CD4+ T cells and production of IL-6 and IL-17 in comparison with control (P<0.05). Conclusion: It is concluded that TGF-Beta1 has an important regulatory role in CD4+ T cell proliferation by increasing HLA-G on DC and these cells can probably prevent unexpected immune responses in vivo. 相似文献
2.
This study was conducted to investigate the effect of the environmental temperature on the immune response of exotic broiler chicks reared in arid-hot climate zone (the Sudan). Twenty eight broiler chicks (Lohman) were challenged with 1 mL of 10% sheep red blood cells suspension (10% SRBCs) at day 2 and day 13 during summer (June) and winter (January) seasons. At day 13 and day 20 sera were harvested and subjected to hemagglutination test to measure antibody titers against 10% SRBCs for primary and secondary immune response, respectively. In winter season the antibody titers (GMT) against 10% SRBCs for the secondary immune response was so high compared to that in summer season. Nevertheless, the antibody titers for primary immune response during winter and summer seasons were, somehow, identical although it was a little bit higher during winter season. The weights of the lymphoid organs (spleen, thymus and bursa of Fabricius) were significantly higher in the winter season compared to summer season irrespective of the age. 相似文献
3.
Kanneboyina Nagaraju Lisa G Rider Chenguang Fan Yi-Wen Chen Megan Mitsak Rashmi Rawat Kathleen Patterson Cecilia Grundtman Frederick W Miller Paul H Plotz Eric Hoffman Ingrid E Lundberg 《Journal of Autoimmune Diseases》2006,3(1):2
Background
While vascular and immune abnormalities are common in juvenile and adult dermatomyositis (DM), the molecular changes that contribute to these abnormalities are not clear. Therefore, we investigated pathways that facilitate new blood vessel formation and dendritic cell migration in dermatomyositis.Methods
Muscle biopsies from subjects with DM (9 children and 6 adults) and non-myositis controls (6 children and 7 adults) were investigated by immunohistochemistry using antibodies that recognize existing (anti-CD146) and newly formed blood vessels (anti-αVβ3) and mature dendritic cells (anti-DC-LAMP). Blood vessel quantification was performed by digitalized image analysis. Additional muscle biopsies from subjects with adult DM and non-myositis controls were used for global gene expression profiling experiments.Results
A significant increase in neovascularization was found in muscle biopsies of DM patients; neovascularization (αVβ3 positive capillaries and vessels per muscle fiber) was much higher in juvenile than in adult DM patients (control vs juvenile DM: Mean ± SE: 0.06 ± 0.01 vs 0.6 ± 0.05; p < 0.0001 and control vs adult DM: Mean ± SE: 0.60 ± 0.1 vs 0.75 ± 0.1; p = 0.051). Gene expression analysis demonstrated that genes that participate not only in angiogenesis but also in leukocyte trafficking and the complement cascade were highly up regulated in DM muscle in comparison to age matched controls. DC-LAMP positive dendritic cells were highly enriched at perivascular inflammatory sites in juvenile and adult DM patients along with molecules that facilitate dendritic cell transmigration and reverse transmigration (CD142 and CD31).Conclusion
These results suggest active neovascularization and endothelial cell activation in both juvenile and adult DM. It is likely that close association of monocytes with endothelial cells initiate rapid dendritic cell maturation and an autoimmune response in DM.4.
5.
BACKGROUND: The liver has been suggested as a suitable target organ for gene therapy of Type 1 diabetes. However, the fundamental issue whether insulin-secreting hepatocytes in vivo will be destroyed by the autoimmune processes that kill pancreatic beta cells has not been fully addressed. It is possible that the insulin secreting liver cells will be destroyed by the immune system because hepatocytes express major histocompatibility complex (MHC) class I molecules and exhibit constitutive Fas expression; moreover the liver has antigen presenting activity. Together with previous reports that proinsulin is a possible autoantigen in the development of Type 1 diabetes, the autoimmune destruction of insulin producing liver cells is a distinct possibility. METHODS: To address this question, transgenic Non-Obese Diabetic (NOD) mice which express insulin in the liver were made using the Phosphoenolpyruvate Carboxykinase (PEPCK) promoter to drive the mouse insulin I gene (Ins). RESULTS: The liver cells were found to possess preproinsulin mRNA, translate (pro)insulin in vivo and release it when exposed to 100 nmol/l glucagon in vitro. The amount of insulin produced was however significantly lower than that produced by the pancreas. The transgenic PEPCK-Ins NOD mice became diabetic at 20-25 weeks of age, with blood glucose levels of 24.1 +/- 1.7 mmol/l. Haematoxylin and eosin staining of liver sections from these transgenic NOD PEPCK-Ins mice revealed the absence of an infiltrate of immune cells, a feature that characterised the pancreatic islets of these mice. CONCLUSIONS: These data show that hepatocytes induced to produce (pro)insulin in NOD mice are not destroyed by an ongoing autoimmune response; furthermore the expression of (pro)insulin in hepatocytes is insufficient to prevent development of diabetes in NOD mice. These results support the use of liver cells as a potential therapy for type 1 diabetes. However it is possible that a certain threshold level of (pro)insulin production might have to be reached to trigger the autoimmune response. 相似文献
6.
BACKGROUND: Viral protein-1 (VP1) is a major capsid protein of Coxsakievirus B3 (CVB3) that plays an important role in directing viruses towards permissive cells and acts as a main antigenic site of the virus in eliciting of host immune response, hence it seems VP1 can be considered as a vaccine candidate against CVB3 infection. In this study, cDNA of VP1 was prepared, cloned into pET expression vector and the recombinant protein (VP1) was over expressed in E. coli. METHODS: The viruses were grown in suspension cultures of Vero cells with an input virus multiplicity of 10-50 plaque-forming units/cell. After observing complete cytopathic effect, the total RNA (cells and virus) was prepared for RT-PCR and by using specific primers, VP1 cDNA was amplified and ligated into pET vectors (32 a and 28 a). The recombinant vector was transferred into competent E. coli (BL-21) and after selection of proper colony, which carried correct cDNA within the vector; cells were cultured and induced with isopropyl B-D-thiogalactopyranoside, in order to express protein (VP1). The cultures were tested for presence of VP1 by SDS-PAGE and Western-Blotting analysis. RESULTS: Molecular techniques such as PCR which showed exact defined size of the VP1 (819 bp), restriction digestion and finally immunoblot analysis of over expressed protein; all confirmed the correct cloning and expression of VP1 in this research. CONCLUSION: In this research, full length of VP1 as major capsid protein of CVB3 was over expressed in E. coli which, can be used for further studies, including neutralizing antibody production against CVB3. 相似文献
7.
Yinyan Yin Nuo Xu Yi Shi Bangyue Zhou Dongrui Sun Bixia Ma Zhengzhong Xu Jin Yang Chunmei Li 《Marine drugs》2021,19(6)
Astaxanthin, originating from seafood, is a naturally occurring red carotenoid pigment. Previous studies have focused on its antioxidant properties; however, whether astaxanthin possesses a desired anti-inflammatory characteristic to regulate the dendritic cells (DCs) for sepsis therapy remains unknown. Here, we explored the effects of astaxanthin on the immune functions of murine DCs. Our results showed that astaxanthin reduced the expressions of LPS-induced inflammatory cytokines (TNF-α, IL-6, and IL-10) and phenotypic markers (MHCII, CD40, CD80, and CD86) by DCs. Moreover, astaxanthin promoted the endocytosis levels in LPS-treated DCs, and hindered the LPS-induced migration of DCs via downregulating CCR7 expression, and then abrogated allogeneic T cell proliferation. Furthermore, we found that astaxanthin inhibited the immune dysfunction of DCs induced by LPS via the activation of the HO-1/Nrf2 axis. Finally, astaxanthin with oral administration remarkably enhanced the survival rate of LPS-challenged mice. These data showed a new approach of astaxanthin for potential sepsis treatment through avoiding the immune dysfunction of DCs. 相似文献
8.
9.
《Journal of Cereal Science》2006,43(1):31-37
Transgene technology provides a powerful tool for developing traits that are otherwise difficult to achieve through conventional methods. The development of transgenic plants requires the use of selectable marker genes, as the efficiency of plant transformation is less than optimal for many important species, especially for monocots such as durum wheat (Triticum turgidum var. durum). Many concerns have been expressed about the persistence of currently used marker genes in plants used for field cultivation. To sustain further progress in this area, alternative efficient selection methods are desirable. A recent development is the use of selective genes that give transformed cells a metabolic advantage (positive selection) compared to untransformed cells, which are slowly starved with a concomitant reduction in growth and viability. This selection strategy is in contrast to traditional negative selections during which the transgenic cells are able to survive on a selective medium whereas the non-transgenic cells are actively killed by the selective agent. We compared the ‘selection efficiency’ of a commonly used negative selection method that employs the Streptomyces hygroscopicus bar gene to confer resistance to the herbicide bialaphos, to a positive selection employing the Escherichia coli phosphomannose isomerase (pmi) gene as the selectable gene and mannose as the selective agent. Calli derived from immature embryos of the durum wheat cultivar Svevo were bombarded separately with bar and pmi genes using a biolistic system. The integration and expression of the two genes in the T0 generation were confirmed by PCR analysis with specific primers for each gene and the chlorophenol red assay, respectively. The selection efficiency, calculated as the number of expressing plants divided by the number of total regenerants, was higher when pmi was used as the selectable marker gene (90.1%) than when bar was used (26.4%). Thus, an efficient selection method for durum wheat transformation was established that obviates the use of herbicide résistance genes. 相似文献
10.
叶绿素仪(SPAD)在茶树氮素营养诊断中的适用性研究 总被引：6，自引：0，他引：6
测定叶片氮素含量是诊断茶树氮素状况的一项重要方法。本文利用盆栽试验,通过不同的供氮水平,研究了利用叶绿素仪(SPAD-502)进行茶树氮素营养快速诊断的适用性。结果表明,茶树新梢产量与氮素用量、成熟叶氮素含量之间呈线性加平台的反应关系,成熟叶的SPAD值与其全氮含量呈显著线性正相关,并与茶树产量存在着比较明显的关系拐点,初步显示SPAD可以较好地表征茶树的氮素营养状况,有可能作为快速诊断方法用于指导茶树施肥,但是还需要通过大田试验进行进一步验证。本文还探讨了测定位点、叶位、天气状况、田间原位或离体测定方式、表面清洗以及样本量等因素对SPAD测试精度的影响。 相似文献
11.
为获得优质高效的肥料精量化施撒效果,本研究以橡胶专用颗粒肥为对象,采用响应面设计试验与分析方法,研究了橡胶专用颗粒肥在含水率、跌落高度和碰撞接触面3因素交互作用下对肥料跌落后反弹高度响应结果的影响。结果表明,3因素交互获取最佳的响应值组合为跌落高度49.36 cm,2 cm厚塑料板,8.93%的肥料湿度,经平行试验验证并获得橡胶专用颗粒肥与塑料板、钢板和肥料平铺面的恢复碰撞系数分别为0.72、0.64和0.41;各因素对肥料反弹高度的影响大小顺序为碰撞材料A>肥料含水率C>跌落高度B,AC的交互作用和二次项A2水平显著,随着碰撞材料A发生变化,反弹高度呈塑料板（-1）>钢板（1）>肥料平铺面（0）响应趋势。上述结果对于肥料颗粒运动仿真分析、适配的农机具原理分析、主要结构设计和用料选型以及橡胶专用颗粒肥的物化特性持续优化均具有重要的实际指导意义。 相似文献
12.
da Matta CB de Souza ET de Queiroz AC de Lira DP de Araújo MV Cavalcante-Silva LH de Miranda GE de Araújo-Júnior JX Barbosa-Filho JM de Oliveira Santos BV Alexandre-Moreira MS 《Marine drugs》2011,9(3):307-318
Marine natural products have been the focus of discovery for new products of chemical and pharmacological interest. The aim of this study was to evaluate the antinociceptive activity of the methanolic (ME), acetate (AE), hexanic (HE) and chloroform (CE) extracts obtained from Caulerpa mexicana, and ME, CE and HE obtained from Caulerpa sertularioides. These marine algae are found all over the world, mainly in tropical regions. Models such as the writhing test, the hot plate test and formalin-induced nociception test were used to evaluate antinociceptive activity in laboratory mice. In the writhing test, all the extracts were administered orally at a concentration of 100 mg/kg, and induced high peripheral antinociceptive activity, with a reduction in the nociception induced by acetic acid above 65%. In the hot plate test, treatment with extracts from C. sertularioides (100 mg/kg, p.o.) did not significantly increase the latency of response, although the ME, AE and HE from C. mexicana showed activity in this model. This result suggests that these extracts exhibit antinociceptive activity. In the formalin test, it was observed that ME, AE and HE obtained from C. mexicana reduced the effects of formalin in both phases. On the other hand only CE from C. sertularioides induced significant inhibition of the nociceptive response in the first phase. To better assess the potential anti-inflammatory activity of the extracts, the carrageenan-induced peritonitis test was used to test Caulerpa spp. extracts on cell migration into the peritoneal cavity. In this assay, all extracts evaluated were able to significantly inhibit leukocyte migration into the peritoneal cavity in comparison with carrageenan. These data demonstrate that extracts from Caulerpa species elicit pronounced antinociceptive and anti-inflamatory activity against several nociception models. However, pharmacological and chemical studies are continuing in order to characterize the mechanism(s) responsible for the antinociceptive action and also to identify the active principles present in the Caulerpa species. 相似文献
13.
为探明化学合成条件对聚酯型儿茶素A（Theasinensin A,TSA）得率的影响,通过单因素试验和Plackett-Burman Design（PBD）确定TSA化学合成关键因子,然后采用响应面法（Response surface methodology,RSM）,进一步优化TSA化学合成技术参数。结果表明,氯化铜用量、甲醇体积分数、温度对TSA得率的影响差异极显著,主因素效应为甲醇体积分数>氯化铜用量>温度,最优条件为氯化铜用量43%,甲醇体积分数26%,温度15℃,聚酯型儿茶素得率为59.12%,与模型预测值59.34%接近。PBD和RSM联用优化TSA化学合成工艺可行,预测性较好,可为其他种类儿茶素氧化聚合物的高效化学合成提供借鉴和理论依据。 相似文献
14.
Giuseppe Firrao Emanuela Torelli Emanuela Gobbi Steluta Raranciuc Gianluca Bianchi Romano Locci 《Journal of Cereal Science》2010
Mycotoxin contamination is a major concern to the maize industry worldwide. Despite the several strategies that have been exploited in an attempt to reduce the severity of this problem, during conducive years, severely contaminated lots are still introduced in the maize processing chain affecting the general quality and safety of the product. As chemical analysis is laborious, time consuming and equipment dependent, more convenient methods are needed for the early identification of contaminated lots. Here a novel approach based on image analysis that provides fast response with minimal equipment and effort is presented. Maize samples were grounded and imaged under 10 different LED lights with emission centered at wavelengths ranging from 720 to 940 nm. The digital images were converted into matrices of data to compute comparative indexes. A three layers feed-forward neural network was trained to predict mycotoxin content from the calculated indexes. The results showed a significant correlation between predictions from image analysis and the concentration of the mycotoxin fumonisin as determined by chemical analysis. The technique developed produces reliable contamination estimates within few minutes and can be readily used to assist lot selection in various steps of the maize processing chain. 相似文献
15.
ABSTRACT: BACKGROUND: Theory suggests that biodiversity can act as a buffer against disturbances and environmental variability via two major mechanisms: Firstly, a stabilising effect by decreasing the temporal variance in ecosystem functioning due to compensatory processes; and secondly, a performance enhancing effect by raising the level of community response through the selection of better performing species. Empirical evidence for the stabilizing effect of biodiversity is readily available, whereas experimental confirmation of the performance-enhancing effect of biodiversity is sparse. RESULTS: Here, we test the effect of different environmental regimes (constant versus fluctuating temperature) on bacterial biodiversity-ecosystem functioning relations. We show that positive effects of species richness on ecosystem functioning are enhanced by stronger temperature fluctuations due to the increased performance of individual species. CONCLUSIONS: Our results provide evidence for the performance enhancing effect and suggest that selection towards functionally dominant species is likely to benefit the maintenance of ecosystem functioning under more variable conditions. 相似文献
16.
Dragano NR de Venancio VP Paula FB Della Lucia F Fonseca MJ Azevedo L 《Plant foods for human nutrition (Dordrecht, Netherlands)》2010,65(4):319-325
Brazilian savanna constitutes a valuable ecoregion that contributes to the supply of fruit known worldwide for its nutritional
value and peculiar flavors. Among them, the Marolo (Annona crassiflora Mart.) fruit is known for its use in folk medicine. In order to establish the safety of Marolo for human consumption, this
study evaluated the following: the chemical composition of Marolo pulp; its mutagenic and antimutagenic activities using micronucleus
test; and the oxidative stress induced in the livers of mice fed a diet containing 1%, 10% or 20% pulp. It was observed that
the chemical composition of marolo pulp was similar to that of common fruit; nevertheless, its lipidic content and energetic
values were higher. In the mice fed experimental diets, the biochemical parameters of the blood serum showed normal levels
of glucose, triglycerides, and cholesterol. The micronucleus test indicated neither mutagenic nor antimutagenic effects of
Marolo consumption on bone marrow cells but showed potentialization of cyclophosphamide (CP). The oxidative stress levels
observed indicated that CP was not exerting a great influence on the induction of reactive oxygen species. As the whole fruit
is a complex matrix, the interactions between its components could be responsible for its negative and positive biological
effects. 相似文献
17.
Response to two cycles of divergent selection for grain yield under drought stress in four rice breeding populations 总被引：1，自引：0，他引：1
R. Venuprasad M.T. Sta Cruz M. Amante R. Magbanua A. Kumar G.N. Atlin 《Field Crops Research》2008,107(3):232-244
Drought is a major production constraint in rainfed rice (Oryza sativa L.). Lack of effective selection criteria is a major limitation hampering progress in breeding for drought tolerance. In an earlier report, we showed in two populations that one cycle of direct selection was effective in increasing grain yield under stress. In the present study, we retested the efficiency of direct selection for grain yield under drought stress in rice using four populations derived from crossing upland-adapted, drought-tolerant varieties (Apo, Vandana) to high-yielding, lowland-adapted, drought-susceptible varieties (IR64, IR72). Each population was subjected to two cycles of divergent selection either under drought stress in upland or under nonstress conditions in lowland conditions. Following selection, approximately 40 high-yielding lines selected under each protocol from each population, along with a set of unselected lines, were evaluated in a series of selection response trials over a range of moisture levels. Significant response to direct selection under stress was realized in 9 out of 15 combinations of populations and stress environments, and in 6 of the 7 severe stress trials. Averaging over all the populations and stress environments, the stress-selected lines had a yield advantage of 25 and 37% over nonstress-selected and random lines, respectively. In contrast to this, under nonstress, the nonstress-selected lines had an average yield advantage of only 7 and 13% over stress-selected and random lines, respectively. Direct selection in managed stress trials during dry seasons gave significant response (25% on average relative to indirect selection in nonstress conditions) under naturally occurring wet season stress. In addition, direct selection under stress in upland gave an average gain of 16 and 45% over nonstress-selected and random lines, respectively, under stress in lowland. The yield advantage of the stress-selected lines appears to result mainly from maintenance of higher harvest index. These results show that direct selection for grain yield under stress is effective and does not reduce yield potential. Overall, this is the first report in rice demonstrating that (a) selection under managed drought stress in the dry season can result in yield gains under natural stress in the wet season, and (b) that selection under upland drought stress can, at least under the conditions of the present study, result in gains under lowland drought conditions. 相似文献
18.
Ianora A Bentley MG Caldwell GS Casotti R Cembella AD Engström-Öst J Halsband C Sonnenschein E Legrand C Llewellyn CA Paldavičienë A Pilkaityte R Pohnert G Razinkovas A Romano G Tillmann U Vaiciute D 《Marine drugs》2011,9(9):1625-1648
Marine chemical ecology comprises the study of the production and interaction of bioactive molecules affecting organism behavior and function. Here we focus on bioactive compounds and interactions associated with phytoplankton, particularly bloom-forming diatoms, prymnesiophytes and dinoflagellates. Planktonic bioactive metabolites are structurally and functionally diverse and some may have multiple simultaneous functions including roles in chemical defense (antipredator, allelopathic and antibacterial compounds), and/or cell-to-cell signaling (e.g., polyunsaturated aldehydes (PUAs) of diatoms). Among inducible chemical defenses in response to grazing, there is high species-specific variability in the effects on grazers, ranging from severe physical incapacitation and/or death to no apparent physiological response, depending on predator susceptibility and detoxification capability. Most bioactive compounds are present in very low concentrations, in both the producing organism and the surrounding aqueous medium. Furthermore, bioactivity may be subject to synergistic interactions with other natural and anthropogenic environmental toxicants. Most, if not all phycotoxins are classic secondary metabolites, but many other bioactive metabolites are simple molecules derived from primary metabolism (e.g., PUAs in diatoms, dimethylsulfoniopropionate (DMSP) in prymnesiophytes). Producing cells do not seem to suffer physiological impact due to their synthesis. Functional genome sequence data and gene expression analysis will provide insights into regulatory and metabolic pathways in producer organisms, as well as identification of mechanisms of action in target organisms. Understanding chemical ecological responses to environmental triggers and chemically-mediated species interactions will help define crucial chemical and molecular processes that help maintain biodiversity and ecosystem functionality. 相似文献
19.
安吉白茶多糖抗肿瘤及免疫调节研究 总被引：2，自引：0，他引：2
选用MTT法研究了安吉白茶多糖的体外抗肿瘤活性;采用建立小鼠移植瘤模型,通过测定安吉白茶多糖对荷瘤小鼠抑瘤率和腹腔巨噬细胞吞噬能力,研究其体内抗肿瘤活性和免疫调节作用。结果表明,安吉白茶多糖体外能显著抑制S180细胞的生长,且具有剂量依赖关系。体内试验表明,与模型对照组相比,安吉白茶多糖对小鼠S180实体瘤和H22腹水型肝癌移植瘤的生长均有显著抑制作用(P<0.05),对荷瘤小鼠脾指数和胸腺指数也有较强增高作用。体内免疫调节试验结果显示,安吉白茶多糖可使荷S180实体瘤小鼠腹腔巨噬细胞吞噬能力显著升高(P<0.05)。 相似文献
20.
Pearl millet (Pennisetum glaucum) is cultivated across a wide range of environments ranging from extremely stressful to favourable. The objective of this research was to compare methods to identify productive cultivars for stress and non-stress conditions. Thirty pearl millet cultivars were evaluated at 22 locations that were grouped as stress, non-stress, or intermediate environments. Five selection indices viz., arithmetic mean (AM), geometric mean (GM), AM (standard units), stress susceptibility index (S) and drought response index (DRI) were calculated for each genotype to determine correlation between selection indices and yield under stress (YS), non-stress (YNS), and average conditions (YAV). Both cultivars and locations were significant sources of variation. Phenology of cultivars had different influence on yielding ability in contrasting environments. While earliness was advantageous for stress conditions, cultivars with longer duration tended to yield more under non-stress conditions. YS was only moderately determined by YNS. Both AM and GM were suitable indices for selection of cultivars that would perform well across stress, non-stress, and intermediate environments. Stress susceptibility index (S) was negatively correlated with YS (r=−0.62**) but should only be used as a selection criterion in combination with yield under stress (YS) to identify cultivars adapted to stress environments. DRI was positively correlated with YS but had no association with YNS. Results indicated that DRI might be useful for identifying cultivars with high performance under stress particularly when days to flower differ considerably among test entries. 相似文献