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ABSTRACT: To analyze the drift of T cell receptor (TCR) Vα and Vβ gene family CDR3 spectratype in response to ovarian carcinoma cells mediated by an anti-human ovarian carcinoma/CD3 bispecific single-chain antibody (BHL-1), and explore the mechanism of the bispecific single-chain antibody-mediated T cell immune response.
Immunoscopic spectratyping technique was used to analyze the TCR repertoire diversity (CDR3 spectratype distribution) of the T cells from 6 healthy donors before and after stimulation of the cells with human ovarian carcinoma in the presence of BHL-1. The predominant usage of TCR α and Vβ chain CDR3 was analyzed after the stimulation, and sequence analysis was performed for the CDR3 region of the monoclonal T cells.
The spectratypes of Vα and Vβ gene family TCR CDR3 region showed a Gaussian distribution before stimulation of the T cells from the 6 donors. After stimulation of the T cells, CDR3 spectratype drift occurred in the T cells, and some TCR Vα and Vβ families showed an anomalous and oligoclonal expansion. Different CDR3 sequences of the Vα and Vβ gene family TCR were found in the monoclonal T cells stimulated with BHL-1.
CDR3 spectratype drift occurs in TCR α and Vβ chains of T cells after stimulation with human ovarian carcinoma cells and BHL-1, indicating that the predominant usage of TCR Vα and Vβ families is associated with the specific T cell immune response mediated by BHL-1.
Nan fang yi ke da xue xue bao = Journal of Southern Medical University 07/2012; 32(7):919-23.
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ABSTRACT: Secondary rearrangements of the T cell receptor (TCR) represent a genetic correction mechanism which changes T cell specificity by re-activating V(D)J recombination in peripheral T cells. Murine T-cell hybridoma A1.1 was employed to investigate whether antigenic stimulation induced re-expression of recombinase genes and altered TCR Vβ expression. Following repeated antigenic stimulation, A1.1 cells were induced to re-express recombination activating gene (RAG)1 and terminal deoxynucleotidyl transferase (TdT) which are generally considered prerequisite to TCR gene rearrangement. Accompanied with the significant changes in TCR mRNA levels over time, it is suggested that secondary rearrangements may be induced in A1.1 cells, which represent a mature T cell clone capable of re-expressing RAG genes and possesses the prerequisite for secondary V(D)J rearrangement.
Cellular Immunology 03/2012; 274(1-2):19-25. · 1.97 Impact Factor
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ABSTRACT: Osteonecrosis of the femoral head (ONFH) is generally characterized as an irreversible disease and tends to cause permanent disability. Therefore, understanding the pathogenesis and molecular mechanisms of ONFH and developing effective therapeutic methods is critical for slowing the progress of the disease.
In this study, an experimental rabbit model of early stage traumatic ONFH was established, validated, and used for an evaluation of therapy. Computed tomography (CT) and magnetic resonance (MR) imaging confirmed that this model represents clinical Association Research Circulation Osseous (ARCO) phase I or II ONFH, which was also confirmed by the presence of significant tissue damage in osseous tissue and vasculature. Pathological examination detected obvious self-repair of bone tissue up to 2 weeks after trauma, as indicated by revascularization (marked by CD105) and expression of collagen type I (Col I), osteocalcin, and proliferating cell nuclear antigen. Transplantation of hepatocyte growth factor (HGF)-transgenic mesenchymal stem cells (MSCs) 1 week after trauma promoted recovery from ONFH, as evidenced by a reversed pattern of Col I expression compared with animals receiving no therapeutic treatment, as well as increased expression of vascular endothelial growth factor.
These results indicate that the transplantation of HGF-transgenic MSCs is a promising method for the treatment for ONFH and suggest that appropriate interference therapy during the tissue self-repair stage contributes to the positive outcomes. This study also provides a model for the further study of the ONFH etiology and therapeutic interventions.
PLoS ONE 01/2012; 7(5):e37503. · 4.09 Impact Factor
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Wei Luo,
Jin Su,
Xiao-Bing Zhang,
Zhi Yang,
Ming-Qian Zhou,
Zhen-Min Jiang,
Pei-Pei Hao,
Su-Dong Liu,
Qian Wen,
Qi Jin,
Li Ma
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ABSTRACT: The importance of CD4(+) and CD8(+) T cells in protection against tuberculosis (TB) is well known, however, the association between changes to the T cell repertoire and disease presentation has never been analyzed. Characterization of T-cells in TB patients in previous study only analyzed the TCR β chain and omitted analysis of the Vα family even though α chain also contribute to antigen recognition. Furthermore, limited information is available regarding the heterogeneity compartment and overall function of the T cells in TB patients as well as the common TCR structural features of Mtb antigen specific T cells among the vast numbers of TB patients.
CDR3 spectratypes of CD4(+) and CD8(+) T cells were analyzed from 86 patients with TB exhibiting differing degrees of disease severity, and CDR3 spectratype complexity scoring system was used to characterize TCR repertoire diversity. TB patients with history of other chronic disease and other bacterial or viral infections were excluded for the study to decrease the likely contribution of TCRs specific to non-TB antigens as far as possible. Each patient was age-matched with a healthy donor group to control for age variability. Results showed that healthy controls had a normally diversified TCR repertoire while TB patients represented with restricted TCR repertoire. Patients with mild disease had the highest diversity of TCR repertoire while severely infected patients had the lowest, which suggest TCR repertoire diversity inversely correlates with disease severity. In addition, TB patients showed preferred usage of certain TCR types and have a bias in the usage of variable (V) and joining (J) gene segments and N nucleotide insertions.
Results from this study promote a better knowledge about the public characteristics of T cells among TB patients and provides new insight into the TCR repertoire associated with clinic presentation in TB patients.
PLoS ONE 01/2012; 7(10):e48117. · 4.09 Impact Factor
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ABSTRACT: Mesenchymal stem cells (MSCs) play a crucial role in tissue repair by secretion of tissue nutrient factors such as hepatocyte growth factor (HGF). However, studies examining the effects of HGF on the proliferation and differentiation of MSCs used different concentrations of HGF and reported conflicting conclusions. This study aimed to determine the mechanisms by which different concentrations of HGF regulate MSC proliferation and osteogenic differentiation, and validate the mechanism in an animal model of early stage avascular necrosis of femoral head (ANFH). Our results demonstrate that a low concentration of HGF (20 ng/ml) preferentially promotes MSC osteogenic differentiation through increased c-Met expression and phosphorylation, Akt pathway activation, and increased expression of p27, Runx2 and Osterix. In contrast, a high concentration of HGF (100 ng/ml) strongly induced proliferation by inducing strong activation of the ERK1/2 signalling pathway. As validated by animal experiments, high localized expression of HGF achieved by transplantation of HGF transgenic MSCs into ANFH rabbits increased the number of MSCs. Subsequently, 2 weeks after transplantation, HGF levels decreased and MSCs differentiated into osteoblasts and resulted in efficient tissue repair. Our results demonstrate that sequential concentration changes in HGF control the proliferation and osteogenic differentiation of MSCs in vivo. This phenomenon can be exploited therapeutically to induce bone regeneration and, in turn, improve the efficacy of pharmacological intervention for ANFH treatment.
Journal of Cellular and Molecular Medicine 08/2011; 16(6):1260-73. · 4.13 Impact Factor
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ABSTRACT: Cell-mediated immunity is critical to the clearance of Mycobacterium tuberculosis due to the primarily intracellular niche of this pathogen. Adoptive transfer of M. tuberculosis-specific effector T cells has been shown to confer immunity to M. tuberculosis-infected recipients resulting in M. tuberculosis clearance. However, it is difficult to generate sufficient numbers of M. tuberculosis antigen-specific T cells in a short time. Recent studies have developed T cell receptor (TCR) gene-modified T cells that allow for the rapid generation of large numbers of antigen-specific T cells. Many TCRs that target various tumor and viral antigens have now been isolated and shown to have functional activity. Nevertheless, TCRs specific for intracellular bacterial antigens (including M. tuberculosis antigens) have yet to be isolated and their functionality confirmed. We isolated M. tuberculosis 38-kDa antigen-specific HLA class I and class II-restricted TCRs and modified the TCR gene C regions by substituting nine amino acids with their murine TCR homologs (minimal murinization). Results showed that both wild-type and minimal murinized TCR genes were successfully cloned into retroviral vectors and transduced into primary CD4(+) and CD8(+) T cells and displayed anti-M. tuberculosis activity. As expected, minimal murinized TCRs displayed higher cell surface expression levels and stronger anti-M. tuberculosis activity than wild-type TCRs. To the best of our knowledge, this is the first report describing TCRs targeting M. tuberculosis antigens and this investigation provides the basis for future TCR gene-based immunotherapies that can be designed for the treatment of immunocompromised M. tuberculosis-infected patients.
Journal of Molecular Medicine 05/2011; 89(9):903-13. · 4.67 Impact Factor
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ABSTRACT: We investigated the influence of tumor tissue differentiation on the diversity of TCR repertoire. CDR3 spectratypes of CD4(+) and CD8(+) T cell subsets were analyzed from 27 patients with gastrointestinal tract tumors exhibiting varying degrees of differentiation. A CDR3 spectratype complexity scoring system was used to quantify the diversity of TCR repertoire. Each patient was matched with an age-matched healthy group to control for age variability. Results show that the complexity scores (TCR repertoire diversity) have a significant correlation with the degree of tumor differentiation, which provides useful information for understanding immune response in cancer patients.
Cellular Immunology 03/2011; 270(1):47-52. · 1.97 Impact Factor
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ABSTRACT: To investigate the correlation between normalization of T cell receptor (TCR) repertoire and remission of advanced colorectal cancer. Forty-one patients were randomly assigned to receive either folinic acid/fluorouracil/irinotecan alone (n = 20) or folinic acid/fluorouracil/irinotecan in combination with recombinant human endostatin (n = 21). Efficacy and toxicity were evaluated, and changes in TCR repertoire diversity were assessed by detecting the spectratypes of TCR complementarity-determining region three before and after several cycles of therapy. A scoring system was used to quantify changes in the TCR repertoire over time. The results demonstrated that the TCR repertoire exhibited a higher degree of normalization among patients undergoing remission relative to patients experiencing tumor progression. The results of the current study showed a positive correlation between TCR repertoire normalization and remission of colorectal cancer, suggesting that dynamic monitoring of TCR repertoire diversity may have potential prognostic value in the clinical setting.
Cancer Science 01/2011; 102(4):706-12. · 3.33 Impact Factor
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ABSTRACT: The combination of IL-2 (interleukin-2) and GM-CSF (granulocyte/macrophage colony-stimulating factor) has been broadly studied in antitumour immune therapy, but its efficacy is uncertain. To better exert the activities of the two cytokines and study them in a mouse model, we have constructed a bifunctional protein, hIL-2–mGM-CSF (human IL-2–mouse GM-CSF), fused to a C-terminal tag of six histidine residues (His6). The fusion protein was expressed in Escherichia coli as IBs (inclusion bodies). After extracting and clarifying the IBs, four methods of protein purification and refolding were compared in order to optimize the preparation technique. Of these methods, the best result was obtained with a four-step process consisting of (1) purification with denaturing affinity chromatography, (2) followed by fully denaturing the protein with system conversion, (3) then refolding by isovolumetric ultrafiltration and (4) finally, purification by anion-exchange chromatography. The purity of the hIL-2–mGM-CSF was approx. 95%, yielding approx. 20 mg of protein/l of culture. The fusion protein retained the natural activities of IL-2 and GM-CSF, with specific activities of 8.7×106 and 1.1×107 i.u./mg respectively. Flow-cytometric analysis indicated that hIL-2–mGM-CSF could specifically bind to the corresponding receptor-positive cells. The present study provides important preliminary information for studying the antitumour activity of hIL-2–mGM-CSF in vivo, which will facilitate future clinical research into the use of hIL-2/hGM-CSF in immune therapy.
Biotechnology and Applied Biochemistry 12/2010; 50(1):41 - 48. · 1.53 Impact Factor
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ABSTRACT: An efficient slope-deterministic facet model for the computation of the radar scattering cross section from electrically large sea surface is presented. As a facet-based theory, it is a more comprehensive model which can adequately reflect the specular and diffuse configurations, as well as the mono- and bistatic features. Significant computational efficiency and good agreement with experimental data are observed, which make the proposed facet model well suitable for fast simulation on ocean synthetic aperture radar (SAR) imagery. Base on the facet model, a hybrid scheme is developed to analyze the high frequency composite scattering from the model of a ship at sea, in which the method of equivalent currents (MEC) and a hybrid frame which combines the four path model with the quasi-image method are employed to investigate the scattering characteristics of large ship-like target and its interactions with sea surface respectively. Finally, applications to SAR imagery simulation of marine scene are discussed with the help of the proposed sea and ship-sea scattering mechanism in detail.
IEEE Transactions on Antennas and Propagation 12/2010; · 2.15 Impact Factor
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Xueqin Yang,
Jiacong You, Wei Luo,
Jiao Yue,
Li Ma,
Wen Xiao,
Daxing Zhu,
Zhihao Wu,
Dong Wang,
Nagalakshmi Nadiminty,
Allen C. Gao,
Qinghua Zhou
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ABSTRACT: Introduction: An increasing number of studies have proven that the kinase suppressor of Ras (KSR1) functions as a scaffolding protein that coordinates the assembly of a multiprotein complex containing mitogen-activated protein kinase and its upstream regulators. However, a few studies have reported that KSR1 can activate c-Raf-1. Therefore, whether KSR1 possesses a kinase activity has been an unresolved issue until now.Materials and Methods: pCMV-Tag2b-KSR plasmids were transfected into 293T cells. In vitro autophosphorylation was assayed by autoradiography and in vitro kinase was assayed by reversed-phase high performance liquid chromatography.Results: We observed that wild-type KSR1 (WT-KSR) and N-terminal KSR1 (N-KSR) were phosphorylated, but the C-terminal KSR1 (C-KSR) and vector proteins were not. The high performance liquid chromatography profile showed not only the adenosine diphosphate peak but also the uridine triphosphate peak in the WT-KSR and N-KSR groups; both peaks were considerably more significant in these groups than in the others. The WT-KSR and N-KSR groups exhibited transphosphorylation and autophosphorylation activities, while the other groups revealed almost no activity.Discussion: Here, we demonstrate the nucleoside diphosphate kinase activity of the KSR1 complex and that this activity can be independent of the C-terminus of KSR1. Additionally, we found the autophosphorylation activity of the KSR1 complex to be extremely weak, suggesting that the KSR1 complex possesses an extremely weak kinase activity irrespective of whether it is nucleoside diphosphate kinase activity or serine/threonine protein kinase activity. These data suggest that the kinase activity of the KSR1 complex is derived from its associated proteins.
Thoracic Cancer. 09/2010; 1(3):109 - 115.
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ABSTRACT: To examine the differentiation of 5-azacytidine-induced bone marrow stromal stem cells (BMSCs) into cardiomyocyte-like cells and hepatocyte growth factor (HGF) gene expression after HGF gene transfection.
5-azacytidine was used to induce beagle dog BMSCs to differentiate into cardiomyocyte-like cells. Morphological observation and immunohistochemistry were performed to detect the expression of the markers of cardiomyocyte-like cells including beta-myosin heavy chain (beta-MHC) and alpha-sarcometric actin. The cells were then transfected with Ad-HGF, and the mRNA and protein expressions of HGF gene were detected by RT-PCR and ELISA, respectively.
After 4 weeks of induction with 5-azacytidine, the BMSCs differentiated into cardiomyocyte-like cells. The expressions of HGF at the mRNA and protein levels were confirmed in the cells after transfection with Ad-HGF. The peak HGF protein secretion was 10(3) ng/ml at 48 h after transfection.
Ad-HGF can efficiently transfect BMSCs induced with 5-azacytidine, and this result provides basic experimental evidence for biotherapy of ischemic heart disease using BMSCs.
Nan fang yi ke da xue xue bao = Journal of Southern Medical University 07/2010; 30(7):1537-40.
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ABSTRACT: Numerical modeling of an overhead transmission line section and the digital simulation of stochastic wind field, to which the transmission line section is exposed, are presented. Time-domain analyses of typical transmission line sections in stochastic wind fields are carried out by ABAQUS software. It is discovered that the numerically determined dynamic swing angles of the suspension insulator strings in the transmission line sections are larger than those calculated with the formulas proposed in the technical code for designing overhead transmission lines. A dynamic wind load factor is suggested to be introduced into the formulas proposed in the design code.
IEEE Transactions on Power Delivery 02/2010; · 1.35 Impact Factor
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ABSTRACT: Pertinent laws and statutes are more mature and perfect in the digital library construction in the USA. Compared with that, we lack rigorous and clear intellectual property right laws and specific legal provisions aiming at the digital library construction clearly in China. The intellectual property main issues in the processing, organization and dissemination of information in the construction are as follows: digitalization of literature information resources and the problem of copying, intellectual property rights in the development and utilization of database and in network communication. Because of these problems, some measures to protect intellectual property in building digital library in China are necessary such as strengthening legislation and popularization of law, giving full consideration to investment funds in copyright protection and raising funds required through various channels and measures for legal acquisition to intellectual property or use right of resources required, introducing communion calculating mechanism while sharing information resources, taking effective measures.
Knowledge Acquisition and Modeling, 2009. KAM '09. Second International Symposium on; 01/2010
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ABSTRACT: A quantitative multishell structure model of the grain size effect of nano-BaTiO3 ceramics is proposed on the basis of Ginsburg–Landau–Devonshire thermodynamic theory. The existence of surface defects is considered by assuming that surface energy varies inversely with the distance to the grain surface. The surface effects lead to the multishell structure in BaTiO3 nanoparticles consisting of a surface paraelectric layer and inner ferroelectric core. It is found that the ferroelectric–paraelectric phase boundary moves to the center of the grain with decreasing grain size. When the grain size is less than 5 nm, our model predicts that the ferroelectric phase disappears, leaving only one stable cubic structure. The dielectric constant of nano-BaTiO3 ceramics with multishell structure was then calculated using an iterative method. The results show that the dielectric constant of BaTiO3 ceramics is reduced at room temperature with decreasing grain size. The three temperature-dependent dielectric peaks are depressed and diffuse in the nano-BaTiO3 ceramics. The two low dielectric peaks move to higher temperatures, while the higher dielectric peak moves to lower temperature with decreasing grain size. The results of the calculation are also compared with experimental data and discussed in detail.
physica status solidi (b) 11/2009; 247(1):219 - 224. · 1.32 Impact Factor
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ABSTRACT: A hybrid high-frequency method is proposed to analyze the bistatic
electromagnetic scattering of the ship target on a very large
two-dimensional randomly rough sea surface. The scattering of the
ship-sea model is evaluated with the method of equivalent currents
(MEC). The iterative physical optics method (IPO) is utilized to study
the electromagnetic coupling effect caused by the hull and rough
surface. The shadowing correction based on the Z-Buffer technology is
introduced to eliminate the effects of the irrelevant scattering
resources. The validity of the hybrid method is confirmed by the SAR
simulation results and the scattering property of the ship-sea model is
discussed.
Chinese Physics Letters 10/2009; 26(11):4101. · 0.73 Impact Factor
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ABSTRACT: This paper discusses the implementation of the terrain openness parameter as a Web Service. Terrain Openness is a new morphology parameter that emphasizes surface concavities and convexities (Yokoyama et al., 2002) and can be derived directly from a digital elevation model (DEM). It is essentially an angular measure of the relation between surface relief and horizontal distance and can be used as a proxy for topographic curvature. It is not sensitive to noise in the data and has spatial scale built in its definition. However, the Terrain Openness parameter has not been widely used, perhaps because of limited software availability. Implementing it as a Web Service will ensure widest possible accessibility, because the only requirement for the user is an Internet connection and a standard web browser. This is made possible with recent advances in Service-Oriented Architecture (SOA), geospatial Web Services, and interoperability technologies. It is implemented within the framework of GeoBrain, an open, interoperable, distributed, standard-compliant, multi-tier web-based geospatial information services and knowledge building system.
Geoinformatics, 2009 17th International Conference on; 09/2009
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ABSTRACT: In the present study, either modified IFL regimen (modified irinotecan, fluorouracil and leucovorin, mIFL) alone or in combination with bevacizumab was used to treat patients with metastatic colorectal cancer (CRC). Treatment efficacy was assessed using coupled tomography imaging diagnosis. The toxicity accompany with treatment was evaluated, as well as T cell receptor (TCR) repertoire before and several cycles after therapy was dynamically monitored by analyzing the complementarity-determining region 3 (CDR3) length distribution within CD4(+) and CD8(+) T cell subsets. The degrees of normalization of the T cell repertoire in CRC patients treated with the two methods were compared. The results showed that mIFL combined with bevacizumab was more effective in treating patients with metastatic CRC, and was accompanied by an increase in side effects such as proteinuria and hematuria. An even more restricted CDR3 profile in patients with metastatic CRC compared with healthy control has been detected. A prominent usage of TCR beta chain variable (BV) gene BV12 and BV16 families within the CD4(+) T cell subset and BV19 and BV21 families within the CD8(+) T cell subset have been found before treatment. Moreover, CD8(+) T cells showed more restricted patterns than CD4(+) T cells, especially in patients before treatment. For patients with stable disease (SD) or partial remission (PR) after treatment, a less restricted CDR3 profile in post-treatment compared with pre-treatment has been found, but the opposite result was observed for patients with progressive disease (PD). The less restricted CDR3 pattern suggested a trend toward normalization of the TCR repertoire. The normalization of TCR repertoire significantly increased in patients treated with mIFL in combination with bevacizumab, but slightly in patients treated with mIFL alone. The results demonstrate a positive correlation between post-therapy TCR repertoire normalization and remission of metastatic CRC.
Cancer Immunology and Immunotherapy 09/2009; 59(2):247-56. · 3.70 Impact Factor
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ABSTRACT: Parallel disk systems consume a significant amount of energy due to the large number of disks. To design economically attractive and environmentally friendly parallel disk systems, in this paper we design and evaluate an energy-aware prefetching strategy for parallel disk systems consisting of a small number of buffer disks and large number of data disks. Using buffer disks to temporarily handle requests for data disks, we can keep data disks in the low-power mode as long as possible. Our prefetching algorithm aims to group many small idle periods in data disks to form large idle periods, which in turn allow data disks to remain in the standby state to save energy. To achieve this goal, we utilize buffer disks to aggressively fetch popular data from regular data disks into buffer disks, thereby putting data disks into the standby state for longer time intervals. A centrepiece in the prefetching mechanism is an energy-saving prediction model, based on which we implement the energy-saving calculation module that is invoked in the prefetching algorithm. We quantitatively compare our energy-aware prefetching mechanism against existing solutions, including the dynamic power management strategy. Experimental results confirm that the buffer-disk-based prefetching can significantly reduce energy consumption in parallel disk systems by up to 50 percent. In addition, we systematically investigate the energy efficiency impact that varying disk power parameters has on our prefetching algorithm.
Network Computing and Applications, 2009. NCA 2009. Eighth IEEE International Symposium on; 08/2009
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ABSTRACT: In this paper, we present an image retrieval method that integrates the color, textural and spatial information of images to facilitate the retrieval effect. Nine parameters are extracted based on the HSV, GLCM, LRE models, and wavelet, fractal algorithms, which include: hue, saturation, value, contrast, angular second moment, sum of variances, long run emphasis, fractal dimension, and wavelet horizontal energy proportion. Then with a maximal similarity measure, the nine parameters are used to retrieve wood species, and the results show that the retrieval effectiveness can be improved by combining these features.
Information and Automation, 2009. ICIA '09. International Conference on; 07/2009
