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11.
Antigen-specific clones of proliferating T lymphocytes. I. Methodology, specificity, and MHC restriction 总被引:14,自引:0,他引:14
B Sredni H Y Tse C Chen R H Schwartz 《Journal of immunology (Baltimore, Md. : 1950)》1981,126(1):341-347
In this report we describe in detail a new method for cloning antigen-specific, proliferating T lymphocytes directly from primed murine lymph nodes after 3 days of activation in vitro. After expansion in liquid culture the cells from the colonies were shown to be antigen specific and to require I-A histocompatible, irradiated spleen cells for stimulation. For hapten-carrier-type antigens, the T cells were shown to be carrier specific in their recognition but they were also capable of distinguishing the presence of the hapten. Recloning of small numbers of these cells in soft agar under conditions of high plating efficiency yielded true clones (i.e., populations derived from a single cell) whose antigen specificity was identical to that of cells from the original colony. The fact that a clone of T cells was I-A restricted in its antigen recognition demonstrates that suppressor T cell function cannot account for the phenomenon of major histocompatibility complex restriction. 相似文献
12.
A simple, rapid and sensitive method of determining cerebrospinal fluid IgG is presented. The procedure depends upon the fact that spinal fluid gamma globulin, and two of its components (IgG and IgM) will precipitate latex particles in proportion to their concentration, and that the optical density of the supernatant solution containing unprecipitated latex particles after centrifugation is inversely proportional to the concentration of these immunoglobulins. The method is sensitive to 50 nanograms, is inexpensive, requires 0.1 ml. or less of spinal fluid, and can be performed in minutes. Preliminary studies show that it compares favorably with results obtained by radial immunodiffusion. 相似文献
13.
Cytotoxic activities of Coriolus versicolor (Yunzhi) extract on human leukemia and lymphoma cells by induction of apoptosis 总被引:3,自引:0,他引:3
Coriolus versicolor (CV), also known as Yunzhi, is one of the commonly used Chinese medicinal herbs. Although recent studies have demonstrated its antitumour activities on cancer cells in vitro and in vivo, the exact mechanism is not fully elucidated. Hence, the objective of this study was to examine the in vitro cytotoxic activities of a standardized aqueous ethanol extract prepared from Coriolus versicolor on a B-cell lymphoma (Raji) and two human promyelocytic leukemia (HL-60, NB-4) cell lines using a MTT cytotoxicity assay, and to test whether the mechanism involves induction of apoptosis. Cell death ELISA was employed to quantify the nucleosome production resulting from nuclear DNA fragmentation during apoptosis. The present results demonstrated that CV extract at 50 to 800 microg/ml dose-dependently suppressed the proliferation of Raji, NB-4, and HL-60 cells by more than 90% (p < 0.01), with ascending order of IC50 values: HL-60 (147.3 +/- 15.2 microg/ml), Raji (253.8 +/- 60.7 microg/ml) and NB-4 (269.3 +/- 12.4 microg/ml). The extract however did not exert any significant cytotoxic effect on normal liver cell line WRL (IC50 > 800 microg/ml) when compared with a chemotherapeutic anticancer drug, mitomycin C (MMC), confirming the tumour-selective cytotoxicity. Nucleosome productions in HL-60, NB-4 and Raji cells were significantly increased by 3.6-, 3.6- and 5.6-fold respectively upon the treatment of CV extract, while no significant nucleosome production was detected in extract-treated WRL cells. The CV extract was found to selectively and dose-dependently inhibit the proliferation of lymphoma and leukemic cells possibly via an apoptosis-dependent pathway. 相似文献
14.
Cheuk-Yiu Law Chung-Wah Siu Katherine Fan Wing-Hon Lai Ka-Wing Au Yee-Man Lau Lai-Yung Wong Jenny C.Y. Ho Yee-ki Lee Hung-Fat Tse Kwong-Man Ng 《Biochemistry and Biophysics Reports》2016
Patients with Danon disease may suffer from severe cardiomyopathy, skeletal muscle dysfunction as well as varying degrees of mental retardation, in which the primary deficiency of lysosomal membrane-associated protein-2 (LAMP2) is considerably associated. Owing to the scarcity of human neurons, the pathological role of LAMP2 deficiency in neural injury of humans remains largely elusive. However, the application of induced pluripotent stem cells (iPSCs) may shed light on overcoming such scarcity.In this study, we obtained iPSCs derived from a patient carrying a mutated LAMP2 gene that is associated with Danon disease. By differentiating such LAMP2-deficient iPSCs into cerebral cortical neurons and with the aid of various biochemical assays, we demonstrated that the LAMP2-deficient neurons are more susceptible to mild oxidative stress-induced injury.The data from MTT assay and apoptotic analysis demonstrated that there was no notable difference in cellular viability between the normal and LAMP2-deficient neurons under non-stressed condition. When exposed to mild oxidative stress (10 μM H2O2), the LAMP2-deficient neurons exhibited a significant increase in apoptosis. Surprisingly, we did not observe any aberrant accumulation of autophagic materials in the LAMP2-deficient neurons under such stress condition.Our results from cellular fractionation and inhibitor blockade experiments further revealed that oxidative stress-induced apoptosis in the LAMP2-deficient cortical neurons was caused by increased abundance of cytosolic cathepsin L. These results suggest the involvement of lysosomal membrane permeabilization in the LAMP2 deficiency associated neural injury. 相似文献
15.
Jesus G. Cruz-Garza Zachery R. Hernandez Teresa Tse Eunice Caducoy Berdakh Abibullaev Jose L. Contreras-Vidal 《Journal of visualized experiments : JoVE》2015,(104)
Understanding typical and atypical development remains one of the fundamental questions in developmental human neuroscience. Traditionally, experimental paradigms and analysis tools have been limited to constrained laboratory tasks and contexts due to technical limitations imposed by the available set of measuring and analysis techniques and the age of the subjects. These limitations severely limit the study of developmental neural dynamics and associated neural networks engaged in cognition, perception and action in infants performing “in action and in context”. This protocol presents a novel approach to study infants and young children as they freely organize their own behavior, and its consequences in a complex, partly unpredictable and highly dynamic environment. The proposed methodology integrates synchronized high-density active scalp electroencephalography (EEG), inertial measurement units (IMUs), video recording and behavioral analysis to capture brain activity and movement non-invasively in freely-behaving infants. This setup allows for the study of neural network dynamics in the developing brain, in action and context, as these networks are recruited during goal-oriented, exploration and social interaction tasks. 相似文献
16.
A rapid, robust, sensitive and economic sensing method, based on a molecularly imprinted polymer (MIP) synthetic antibody mimic, and fluorescence polarization analysis, for the direct detection of UV-excited fluorescent analytes in food and environmental samples was developed. Fluoroquinolone (FQ) antibiotics were used as fluorescent model analytes. Water-compatible MIP nanoparticles were synthesized with enrofloxacin (ENRO) as the imprinting template. Fluorescence polarization measurements then allow the direct determination of the amount of ENRO and other structurally related piperazine-based fluoroquinolones that bind to the MIP. No separation step was required since this technique distinguishes in situ analyte molecules bound to the MIP from the free analyte in solution. This assay was successfully applied for the first time to determine FQs in real samples, i.e. tap water and milk, without any prior concentration step, by simply adding a known amount of MIP. No interference by the sample components was observed even though the excitation was in the UV region. In tap water, a low limit of detection of 0.1 nM for ENRO was achieved with 5 μg mL(-1) of MIP. In milk, ENRO and danofloxacin, whose MRLs have been fixed at 0.28 μM and 0.08 μM, respectively, could be selectively measured and distinguished from other families of antibiotics. The procedure is very easy and practical as it consists of simply precipitating the milk proteins with acetonitrile and adding buffer and MIP to the supernatant before reading the polarization values with a spectrofluorimeter. 相似文献
17.
N V Cheliapov I D Drynov I G Kharitonento L A Chucha N A Sololov P I Tse?tlin 《Biokhimii?a (Moscow, Russia)》1975,40(5):1099-1103
Deoxyribonucleoprotamine (DNPn) from sonicated nuclei of sturgeon sperm heads was studied by means of ring dichroism. A derivative analysis of DNA and DNPn melting curves in 1 mM Tris. HCl pH 8.0 revealed the fraction of protein-free DNA being about 30% and suggested the preferable binding of protamine molecules with AT-rich DNA regions. The latter is also confirmed by the data on ring dichroism of protein-poor soluble DNAPn fraction in 0,14 M NaCl. Ring dichroism of DNA and DNPn in 1 mM Tris coinsides at the wavelength of 310-240 nm at concentrations of 500-50 mkg/ml. Dilution of DNPn to 5 mkg-ml resulted in the decrease of the ellipticity at 275 nm and produced no effect at 260-210 nm. The effect observed is suggested to be due to a partial transition of DNA in DNPn into C-form under the dilution as a result of a higher molecule hydration and a destruction of some hydrogen bonds between guanidine residues of arginine and oxygen of phosphate groups, stabilyzing DNA in the B-form. Ring dichroism spectrum of protamine, calculated by the subtraction of DNA spectrum from DNPn spectrum at the region of 240-210 nm coinsides with that of free protamine and indicates the absence of an ordered structure in protamine molecules in DNPn. 相似文献
18.
Keng Po Lai Xiao Lin Nathan Tam Jeff Cheuk Hin Ho Marty Kwok-Shing Wong Jie Gu Ting Fung Chan William Ka Fai Tse 《Environmental microbiology》2020,22(9):3784-3802
Alteration of the gut microbiota plays an important role in animal health and metabolic diseases. However, little is known with respect to the influence of environmental osmolality on the gut microbial community. The aim of the current study was to determine whether the reduction in salinity affects the gut microbiota and identify its potential role in salinity acclimation. Using Oryzias melastigma as a model organism to perform progressive hypotonic transfer experiments, we evaluated three conditions: seawater control (SW), SW to 50% sea water transfer (SFW) and SW to SFW to freshwater transfer (FW). Our results showed that the SFW and FW transfer groups contained higher operational taxonomic unit microbiota diversities. The dominant bacteria in all conditions constituted the phylum Proteobacteria, with the majority in the SW and SFW transfer gut comprising Vibrio at the genus level, whereas this population was replaced by Pseudomonas in the FW transfer gut. Furthermore, our data revealed that the FW transfer gut microbiota exhibited a reduced renin–angiotensin system, which is important in SW acclimation. In addition, induced detoxification and immune mechanisms were found in the FW transfer gut microbiota. The shift of the bacteria community in different osmolality environments indicated possible roles of bacteria in facilitating host acclimation. 相似文献
19.
Wang Haili Xu Yuanyuan Xu Aiqing Wang Xinghua Cheng Lijun Lee Sharen Tse Gary Li Guangping Liu Tong Fu Huaying 《Journal of physiology and biochemistry》2020,76(4):637-653
Journal of Physiology and Biochemistry - Atrial remodeling in diabetes is partially attributed to NF-κB/TGF-β signal transduction pathway activation. We examined whether the... 相似文献
20.
Arjun Dhanoya Tse Wang Eli Keshavarz‐Moore Ariberto Fassati Benjamin M. Chain 《Traffic (Copenhagen, Denmark)》2013,14(2):165-175
Eukaryotic cells have the ability to uptake and transport endogenous and exogenous DNA in their nuclei, however little is known about the specific pathways involved. Here we show that the nuclear transport receptor importin 7 (imp7) supports nuclear import of supercoiled plasmid DNA and human mitochondrial DNA in a Ran and energy‐dependent way. The imp7‐dependent pathway was specifically competed by excess DNA but not by excess of maltose‐binding protein fused with the classical nuclear localizing signal (NLS) or the M9 peptides. Transport of DNA molecules complexed with poly‐l ‐lysine was impaired in intact cells depleted of imp7, and DNA complexes remained localized in the cytoplasm. Poor DNA nuclear import in cells depleted of imp7 directly correlated with lower gene expression levels in these cells compared to controls. Inefficient nuclear import of transfected DNA induced greater upregulation of the interferon pathway, suggesting that rapid DNA nuclear import may prevent uncontrolled activation of the innate immune response. Our results provide evidence that imp7 is a non‐redundant component of an intrinsic pathway in mammalian cells for efficient accumulation of exogenous and endogenous DNA in the nucleus, which may be critical for the exchange of genetic information between mitochondria and nuclear genomes and to control activation of the innate immune response . 相似文献