54 results
Search Results
2. Fault self-healing: A biological immune heuristic reinforcement learning method with root cause reasoning in industrial manufacturing process.
- Author
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Tian, JiaYi, Yin, Ming, and Jiang, Jijiao
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REINFORCEMENT learning , *MANUFACTURING processes , *T helper cells , *T cells , *HEALING , *CONVOLUTIONAL neural networks , *INDUSTRIALISM - Abstract
Stable fault self-healing ensures the smooth operation of intelligent industrial manufacturing processes. However, current research, while capable of inferring fault propagation paths or individually controlling manufacturing processes, still faces some challenges and limitations in addressing issues within manufacturing processes. In particular, it is easy to overlook the impact of fault variables on normal causal relationships in the manufacturing process and how to achieve adaptive fault repair from the source of faults. The biological immune system possesses sensitive nodes and a neuro-endocrine-immune network with interconnected functionalities, bearing remarkable resemblance to the sensor arrays, information networks, and intelligent controller systems in modern self-healing control systems. These problem domains have significant practical implications in industrial manufacturing processes and urgently require new methods and technologies to address them. To address the issue of root cause fault self-healing in intelligent industrial manufacturing processes, this paper proposes an innovative method that utilizes root cause inference and bio-inspired heuristic reinforcement learning models to achieve fault self-healing in industrial processes. First, innovatively introduce the Variational Autoencoder (VAE) into the Time Convolutional Network (TCN) to construct the TCN-VAE network. By performing feature reconstruction, the network's feature extraction capability is enhanced, further exploring the relationships between latent variables, and consequently building a causal graph of faults. A multi-head attention mechanism is introduced into the network, and the inference process is quantitatively evaluated, thereby improving the generalization and accuracy of root cause inference. Root cause determination rules are established to identify the fundamental reasons for fault occurrence, ensuring self-healing from the source of faults. Next, we developed for the first time a fault self-healing model based on reinforcement learning, utilizing the immune repair process of effector T cells to characterize the fault self-healing process. It effectively adapts to eliminate various levels of faults based on the state transition process of antigens in T helper cells. Additionally, stability control analysis is performed on the proposed model. The average reward function curve and Sobol sensitivity index demonstrates the model's strong robustness in practical applications. The validation results from case studies on the Tennessee Eastman (TE) and Continuous Stirred Tank Reactor (CSTR) show that the average improvement in fault repair F1 score was 0.0941 and 0.105 respectively, and the fastest improvement in fault repair response time was 0.266s and 0.258s respectively. It was confirmed that the root cause inference and fault repair results align with the actual mechanisms of the manufacturing processes. The proposed method has been verified to achieve stable and accurate root cause fault repair in real-world intelligent industrial manufacturing systems, making a significant contribution to achieving stable and accurate root cause fault repair in intelligent industrial manufacturing systems. • TCN-VAE enables feature reconstruction and latent variable exploration for root cause reasoning. • Multi-head attention enhances generality and accuracy in root cause reasoning. • Effector T-cell immune-inspired RL adapts to eliminate faults effectively. • The fault self-healing model exhibits strong reliability and robustness. • Method validated on Tennessee Eastman and continuous stirred-tank reactor datasets. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
3. Optimization of polydimethylsiloxane (PDMS) surface chemical modification and formulation for improved T cell activation and expansion.
- Author
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Zeng, Qiongjiao, Xu, Bowen, Deng, Jiewen, Shang, Kun, Guo, Zhenhong, and Wu, Shuqing
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T cells , *MECHANICAL chemistry , *POLYDIMETHYLSILOXANE , *YOUNG'S modulus , *SURFACE chemistry , *T cell receptors , *BIOCHEMICAL substrates - Abstract
Adoptive T cell therapy has undergone remarkable advancements in recent decades; nevertheless, the rapid and effective ex vivo expansion of tumor-reactive T cells remains a formidable challenge, limiting their clinical application. Artificial antigen-presenting substrates represent a promising avenue for enhancing the efficiency of adoptive immunotherapy and fostering T cell expansion. These substrates offer significant potential by providing flexibility and modularity in the design of tailored stimulatory environments. Polydimethylsiloxane (PDMS) silicone elastomer stands as a widely utilized biomaterial for exploring the varying sensitivity of T cell activation to substrate properties. This paper explores the optimization of PDMS surface modification and formulation to create customized stimulatory surfaces with the goal of enhancing T cell expansion. By employing soft PDMS elastomer functionalized through silanization and activating agent, coupled with site-directed protein immobilization techniques, a novel T cell stimulatory platform is introduced, facilitating T cell activation and proliferation. Notably, our findings underscore that softer modified elastomers (Young' modulus E∼300 kPa) exhibit superior efficacy in stimulating and activating mouse CD4+ T cells compared to their stiffer counterparts (E∼3 MPa). Furthermore, softened modified PDMS substrates demonstrate enhanced capabilities in T cell expansion and Th1 differentiation, offering promising insights for the advancement of T cell-based immunotherapy. [Display omitted] • Chemically modified layers and Protein A enhance antibody density and stability. • Softer elastomers better stimulate CD4+ T cells compared to stiffer ones. • Softened PDMS substrates enhance T cell expansion and Th1 differentiation. • Study shows surface chemistry and mechanical cues influence T cell behavior. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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4. Tracking down tumor-specific T cells.
- Author
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Reading, James, Foster, Kane, Joshi, Kroopa, and Chain, Benny
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CANCER cells , *T cells - Abstract
Two papers published in this edition of Cancer Cell (Zheng et al., 2022 and Veatch et al., 2022) provide an elegant illustration of how single-cell sequencing can be used to define a molecular phenotype which identifies tumor-specific T cells. Two papers published in this edition of Cancer Cell (Zheng et al., 2022 and Veatch et al., 2022) provide an elegant illustration of how single-cell sequencing can be used to define a molecular phenotype which identifies tumor-specific T cells. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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5. Azo-based hypoxic-activated 6-diazo-5-oxo-L-norleucine (DON) prodrug combined with vascular disrupting agent nanoparticles for tumor-selective glutamine metabolism blockade.
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Xu, Hang, Zheng, Mengfei, Yang, Chenguang, Wang, Kun, Lv, Zheng, Liu, Zhilin, Tang, Zhaohui, and Chen, Xuesi
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GLUTAMINE , *TUMOR microenvironment , *CELL metabolism , *METABOLISM , *T cells , *COLON cancer , *WEIGHT loss , *NANOMEDICINE - Abstract
Highly expressed azo-reductase (AZOR) selectively reduces Azo-DON to DON in hypoxic tumor environments, impair glutamine metabolism in cancer cells, and promote tumor cell death without affecting T cell metabolism and proliferation, thereby generating strong antitumor immune responses. CB-PLG nanoparticles (CBP) mentioned in the paper can enhance the degree of hypoxia in normoxic tumors, which is conducive to efficient reduction of Azo-DON at tumor sites. [Display omitted] • Azo-DON is a novel hypoxia-active prodrug of glutamine antagonist. • Azo-DON selectively blocks tumor glutamine metabolism after reducing to DON. • T cells continue to proliferate and remain active when Azo-DON is reduced to DON. • CBP nanoparticles increase tumor hypoxia and facilitate the reduction of Azo-DON. Glutamine antagonists, such as 6-diazo-5-oxo-L-norleucine (DON), have demonstrated remarkable anti-tumor effects by blocking tumor glutamine metabolism, but their use is frequently causing toxicity. Despite the existence of multiple glutamine antagonist prodrug designs, a tumor-selective prodrug has yet to be developed. Herein, a novel prodrug of DON, Azo-DON, has been developed, which remains stable and inactive in normal tissues with sufficient oxygen levels, while can be selectively reduced to DON by highly expressed azo-reductase in hypoxic tumor environments. This leads to blockade of glutamine metabolism in cancer cells and promotes cell death without affecting T cell proliferation. In a high-hypoxic H22 hepatoma cancer model, Azo-DON showed a 1.8-fold enhancement in glutamine blockade compared to the control group, resulting in a tumor suppression rate (TSR) of 84.2% in vivo with no significant weight loss. In a low-hypoxic CT26 colon cancer model, when combined with vascular disrupting agent nanoparticles (CBP) to induce a hypoxic environment, Azo-DON exhibited a 4.6-fold enhancement in glutamine blockade over the control group, resulted in a remarkable TSR of 96.6% in vivo. This innovative approach represents a promising strategy for the application of broad-spectrum metabolic inhibitors in the field of precision cancer treatment. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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6. Biophysiology of in ovo administered bioactive substances to improve gastrointestinal tract development, mucosal immunity, and microbiota in broiler chicks.
- Author
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Ayalew, Habtamu, Wang, Jing, Wu, Shugeng, Qiu, Kai, Tekeste, Ayalsew, Xu, Changchun, Lamesgen, Dessalegn, Cao, Sumei, Qi, Guanghai, and Zhang, Haijun
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CHICKS , *GASTROINTESTINAL system , *PHAGOCYTOSIS , *CELL receptors , *LYMPHOCYTE count , *T cells , *IMMUNITY , *PROBIOTICS - Abstract
Early embryonic exogenous feeding of bioactive substances is a topic of interest in poultry production, potentially improving gastrointestinal tract (GIT) development, stimulating immunization, and maximizing the protection capability of newly hatched chicks. However, the biophysiological actions and effects of in ovo administered bioactive substances are inconsistent or not fully understood. Thus, this paper summarizes the functional effects of bioactive substances and their interaction merits to augment GIT development, the immune system, and microbial homeostasis in newly hatched chicks. Prebiotics, probiotics, and synbiotics are potential bioactive substances that have been administered in embryonic eggs. Their biological effects are enhanced by a variety of mechanisms, including the production of antimicrobial peptides and antibiotic responses, regulation of T lymphocyte numbers and immune-related genes in either up- or downregulation fashion, and enhancement of macrophage phagocytic capacity. These actions occur directly through the interaction with immune cell receptors, stimulation of endocytosis, and phagocytosis. The underlying mechanisms of bioactive substance activity are multifaceted, enhancing GIT development, and improving both the innate and adaptive immune systems. Thus summarizing these modes of action of prebiotics, probiotics and synbiotics can result in more informed decisions and also provides baseline for further research. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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7. An intimate encounter: DC3s empower anti-tumor CTLs.
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Stojanovic, Ana and Cerwenka, Adelheid
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CELL survival , *HOMEOSTASIS , *CELL physiology , *CELL communication , *CYTOTOXIC T cells , *CELL proliferation , *T cells - Abstract
Discrete tissue niches are emerging as essential prerequisites enabling cell communication and function in both homeostasis and disease. In a recent Cell paper, Di Pilato et al. identify a unique dendritic cell-cytotoxic T cell crosstalk within the perivascular space that facilitates T cell survival and proliferation and drives anti-tumor activity. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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8. Grouped gene selection and multi-classification of acute leukemia via new regularized multinomial regression.
- Author
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Li, Juntao, Wang, Yanyan, Jiang, Tao, Xiao, Huimin, and Song, Xuekun
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ACUTE leukemia , *GENE expression , *B cells , *T cells , *MOLECULAR genetics - Abstract
Diagnosing acute leukemia is the necessary prerequisite to treating it. Multi-classification on the gene expression data of acute leukemia is help for diagnosing it which contains B-cell acute lymphoblastic leukemia (BALL), T-cell acute lymphoblastic leukemia (TALL) and acute myeloid leukemia (AML). However, selecting cancer-causing genes is a challenging problem in performing multi-classification. In this paper, weighted gene co-expression networks are employed to divide the genes into groups. Based on the dividing groups, a new regularized multinomial regression with overlapping group lasso penalty (MROGL) has been presented to simultaneously perform multi-classification and select gene groups. By implementing this method on three-class acute leukemia data, the grouped genes which work synergistically are identified, and the overlapped genes shared by different groups are also highlighted. Moreover, MROGL outperforms other five methods on multi-classification accuracy. [ABSTRACT FROM AUTHOR]
- Published
- 2018
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9. Ultrasensitive photoelectrochemical biosensor for the detection of HTLV-I DNA: A cascade signal amplification strategy integrating λ-exonuclease aided target recycling with hybridization chain reaction and enzyme catalysis.
- Author
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Shi, Xiao-Mei, Fan, Gao-Chao, Tang, Xueying, Shen, Qingming, and Zhu, Jun-Jie
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PHOTOELECTROCHEMICAL cells , *BIOSENSORS , *ENZYMES , *CATALYSIS , *T cells - Abstract
Sensitive and specific detection of DNA is of great significance for clinical diagnosis. In this paper, an effective cascade signal amplification strategy was introduced into photoelectrochemical (PEC) biosensor for ultrasensitive detection of human T-cell lymphotropic virus type I (HTLV-I) DNA. This proposed signal amplification strategy integrates λ-exonuclease (λ-Exo) aided target recycling with hybridization chain reaction (HCR) and enzyme catalysis. In the presence of target DNA (tDNA) of HTLV-I, the designed hairpin DNA (h 1 DNA) hybridized with tDNA, subsequently recognized and cleaved by λ-Exo to set free tDNA. With the λ-Exo aided tDNA recycling, an increasing number of DNA fragments (output DNA, oDNA) were released from the digestion of h 1 DNA. Then, triggered by the hybridization of oDNA with capture DNA (cDNA), numerous biotin-labeled hairpin DNAs (h 2 DNA and h 3 DNA) could be loaded onto the photoelectrode via the HCR. Finally, avidin-labeled alkaline phosphatase (avidin-ALP) could be introduced onto the electrode by specific interaction between biotin and avidin. The ALP could catalyze dephosphorylation of phospho-L-ascorbic acid trisodium salt (AAP) to generate an efficient electron donor of ascorbic acid (AA), and thereby greatly increasing the photocurrent signal. By utilizing the proposed cascade signal amplification strategy, the fabricated PEC biosensor exhibited an ultrasensitive and specific detection of HTLV-I DNA down to 11.3 aM, and it also offered an effective strategy to detect other DNAs at ultralow levels. [ABSTRACT FROM AUTHOR]
- Published
- 2018
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10. Application of the feature-detection rule to the Negative Selection Algorithm
- Author
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Poggiolini, Mario and Engelbrecht, Andries
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FEATURE selection , *T cells , *COMPUTER algorithms , *THYMUS , *LYMPHOCYTES , *IMMUNE system , *PERFORMANCE evaluation - Abstract
Abstract: The Negative Selection Algorithm developed by Forrest et al. was inspired by the way in which T-cell lymphocytes mature within the thymus before being released into the blood system. The mature T-cell lymphocytes exhibit an interesting characteristic, in that they are only activated by non-self cells that invade the human body. The Negative Selection Algorithm utilises an affinity matching function to ascertain whether the affinity between a newly generated (NSA) T-cell lymphocyte and a self-cell is less than a particular threshold; that is, whether the T-cell lymphocyte is activated by the self-cell. T-cell lymphocytes not activated by self-sells become mature T-cell lymphocytes. A new affinity matching function termed the feature-detection rule is introduced in this paper. The feature-detection rule utilises the interrelationship between both adjacent and non-adjacent features of a particular problem domain to determine whether an antigen is activated by an artificial lymphocyte. The performance of the feature-detection rule is contrasted with traditional affinity matching functions, currently employed within Negative Selection Algorithms, most notably the r-chunks rule (which subsumes the r-contiguous bits rule) and the hamming distance rule. This paper shows that the feature-detection rule greatly improves the detection rates and false alarm rates exhibited by the NSA (utilising the r-chunks and hamming distance rule) in addition to refuting the way in which permutation masks are currently being applied in artificial immune systems. [Copyright &y& Elsevier]
- Published
- 2013
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11. A fractional-order differential equation model of HIV infection of CD4+ T-cells
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Ding, Yongsheng and Ye, Haiping
- Subjects
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BIOLOGICAL mathematical modeling , *DIFFERENTIAL equations , *FRACTIONAL calculus , *HIV infections , *T cells , *POPULATION dynamics , *NUMERICAL analysis , *SIMULATION methods & models - Abstract
Abstract: In this paper, we introduce fractional-order into a model of HIV infection of CD4+ T-cells. We show that the model established in this paper possesses non-negative solutions, as desired in any population dynamics. We also carry out a detailed analysis on the stability of equilibrium. Numerical simulations are presented to illustrate the results. [Copyright &y& Elsevier]
- Published
- 2009
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12. proffered papers.
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ONCOLOGY , *TUMOR growth , *BEVACIZUMAB , *T cells - Abstract
This section presents abstracts of oncology-related topics including the kinetics of tumor growth, the effectiveness of bevacizumab in reducing the growth rate of renal carcinoma and the role of beta-catenin in regulating acute adult T cell leukemia/lymphoma.
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- 2008
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13. CD38: An important regulator of T cell function.
- Author
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Li, Wentao, Liang, Lin, Liao, Qianjin, Li, Yanling, and Zhou, Yanhong
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T cells , *CELL physiology , *CD38 antigen , *EXTRACELLULAR enzymes , *CHIMERIC antigen receptors - Abstract
Cluster of differentiation 38 (CD38) is a multifunctional extracellular enzyme on the cell surface with NADase and cyclase activities. CD38 is not only expressed in human immune cells, such as lymphocytes and plasma cells, but also is abnormally expressed in a variety of tumor cells, which is closely related to the occurrence and development of tumors. T cells are one of the important immune cells in the body. As NAD consuming enzymes, CD38, ART2, SIRT1 and PARP1 are closely related to the number and function of T cells. CD38 may also influence the activity of ART2, SIRT1 and PARP1 through the CD38-NAD+ axis to indirectly affect the number and function of T cells. Thus, CD38-NAD+ axis has a profound effect on T cell activity. In this paper, we reviewed the role and mechanism of CD38+ CD4+ T cells / CD38+ CD8+ T cells in cellular immunity and the effects of the CD38-NAD+ axis on T cell activity. We also summarized the relationship between the CD38 expression level on T cell surface and disease prediction and prognosis, the effects of anti-CD38 monoclonal antibodies on T cell activity and function, and the role of anti-CD38 chimeric antigen receptor (CAR) T cell therapy in tumor immunity. This will provide an important theoretical basis for a comprehensive understanding of the relationship between CD38 and T cells. [Display omitted] • As a NAD consuming enzyme, CD38 is closely related to the number and function of T cells. • The expression of CD38 in CD4+ T cells and CD8+ T cell affects the function of CD4+T cell. • The expression level of CD38 on T cell surface is associated with disease prediction and prognosis. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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14. Characterisation of CD4 T cells in healthy and diseased koalas (Phascolarctos cinereus) using cell-type-specific monoclonal antibodies.
- Author
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Mangar, Chandan, Armitage, Charles W., Timms, Peter, Corcoran, Lynn M., and Beagley, Kenneth W.
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CD4 antigen , *T cells , *KOALA , *MONOCLONAL antibodies , *HABITATS , *LYMPHOCYTES , *PHYSIOLOGY - Abstract
The koala ( Phascolarctos cinereus ) is an arboreal herbivorous marsupial that is an Australian icon. Koalas in many parts of Australia are under multiple threats including habitat destruction, dog attacks, vehicular accidents, and infectious diseases such as Chlamydia spp. and the koala retrovirus (KoRV), which may contribute to the incidence of lymphoma and leukaemia in this species. Due to a lack of koala-specific immune reagents and assays there is currently no way to adequately analyse the immune response in healthy, diseased or vaccinated animals. This paper reports the production and characterisation of the first anti-koala CD4 monoclonal antibody (mAb). The koala CD4 gene was identified and used to develop recombinant proteins for mAb production. Fluorochrome-conjugated anti-CD4 mAb was used to measure the levels of CD4 + lymphocytes collected from koala spleens (41.1%, range 20–45.1%) lymph nodes (36.3%, range 19–55.9%) and peripheral blood (23.8%, range 17.3–35%) by flow cytometry. Biotin-conjugated anti-CD4 mAb was used for western blot to determine an approximate size of 52 kDa for the koala CD4 molecule and used in immunohistochemistry to identify CD4 + cells in the paracortical region and germinal centres of spleen and lymph nodes. Using the anti-CD4 mab we showed that CD4 cells from vaccinated, but not control, koalas proliferated following in vitro stimulation with UV-inactivated Chlamydia pecorum and recombinant chlamydial antigens. Since CD4 + T cells have been shown to play a pivotal role in clearing chlamydial infection in both human and mouse infections, using this novel antibody will help determine the role CD4 + T cells play in protection against chlamydial infection in koalas and also enhance our knowledge of how KoRV affects the koala immune system. [ABSTRACT FROM AUTHOR]
- Published
- 2016
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15. The use and abuse of immune indices in nutritional immunology studies.
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Selvaraj, Ramesh K., Shanmugasundaram, Revathi, and Rengasamy, Ravikumar
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IMMUNE system , *NUTRITIONAL immunology , *POULTRY feeding , *PHOSPHORYLATION , *CYTOKINES , *T cells - Abstract
The immune system is complex, with redundant and overlapping functions. Identifying the correct immune parameters to study the immune status of an animal is challenging. Nutritional immunologists often measure different isotypes of antibodies, hematological parameters, parasite loads, functional assays of macrophages and T cells, pro- and anti-inflammatory cytokines, phosphorylation status of proteins involved in signaling pathways, and several other parameters to identify the immune status of birds. Papers in which authors misinterpret immune parameters are common. This article discusses the drawbacks of some of the common interpretations of several immunological assays available for nutritional immunologists. [ABSTRACT FROM AUTHOR]
- Published
- 2016
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16. Panoptic clinical review of the current and future treatment of relapsed/refractory T-cell lymphomas: Cutaneous T-cell lymphomas.
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Zinzani, Pier Luigi, Bonthapally, Vijayveer, Huebner, Dirk, Lutes, Richard, Chi, Andy, and Pileri, Stefano
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LYMPHOMAS , *T cells , *CANCER relapse , *CANCER chemotherapy , *INTERFERONS , *MYCOSIS fungoides - Abstract
Primary cutaneous T-cell lymphomas (CTCLs), such as mycosis fungoides and Sézary syndrome, are a rare group of non-Hodgkin lymphomas, usually treated using a multimodal approach. Unfortunately, many patients go on to develop relapsed/refractory disease. Systemic treatment for relapsed/refractory CTCL has historically relied on chemotherapies and interferons, and while active, responses are often short-lived. Three drugs are now approved in the US to treat relapsed/refractory CTCL including the oral retinoid, bexarotene, and histone deacetylase inhibitors, romidepsin and vorinostat. Although response rates are typically <35%, romidepsin and vorinostat can induce some durable responses in heavily pretreated patients and alleviate bothersome symptoms, such as pruritus. New studies indicate that the anti-CD30 antibody-drug conjugate brentuximab vedotin, anti-CCR4 antibody mogamulizumab, and fusion protein immunotoxin A-dmDT390-bisFv(UCHT1) may be particularly active in this setting. In this paper, we present an exhaustive review of the clinical data on current and possible future drug treatment options for relapsed/refractory CTCL. [ABSTRACT FROM AUTHOR]
- Published
- 2016
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17. Abstracts for the ESDR Clinically Oriented Symposium.
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CONFERENCES & conventions , *LYMPHOMAS , *T cells , *IMMUNOGLOBULINS , *B cells , *LYMPHOCYTES - Abstract
This article presents abstracts for various research papers to be presented in the European Society for Dermatological Research's symposium on September 26-28, 1997. These research papers pertain to subjects like the eortic classification for primary cutaneous lymphomas, different prognosis between cutaneous and systemic lymphoproliferative disorders, parapsoriasis and early cutaneous T cell lymphoma, immunoglobulin gene rearrangement of pseudo B-cell lymphomas and prognostic significance of polymerase chain reaction detectable dominant T lymphocyte clones.
- Published
- 1997
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18. Abstracts for the 27th Annual Meeting of the European Society for Dermatological Research.
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MEETINGS , *CYTOKINES , *PROSTAGLANDINS , *DENDRITIC cells , *T cells , *MELANOMA - Abstract
This article presents abstracts for various research papers to be presented in the 27th Annual Meeting of the European Society for Dermatological Research. These research papers pertain to subjects like proinflammatory cytokines and prostaglandins' inducing maturation of potent immunostiumlatory dendritic cells, mediators that mobilize langerhans cells, antigens for the activation of T lymphocytes by skin dendritic cells and vaccination of melanoma patients with peptide-pulsed dendritic cells.
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- 1997
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19. Global stability and periodic oscillations for an SIV infection model with immune response and intracellular delays.
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Song, Haitao, Liu, Shengqiang, Jiang, Weihua, and Wang, Jinliang
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SIMIAN immunodeficiency virus , *IMMUNE response , *T cells , *CYTOTOXIC T cells , *HOPF bifurcations - Abstract
In this paper, we consider the combined effects of cytotoxic T lymphocyte (CTL) responses on the competition dynamics of two Simian immunodeficiency virus (SIV) strains model. One of strains concerns a relatively slowly replicating and mildly cytopathic virus in the early infection (SIVMneCL8), the other is faster replicating and more cytopathic virus at later stages of the infection (SIVMne170). It is shown that the global dynamics of the ordinary differential equations can be determined by several threshold parameters, and we prove the global stability of the equilibria by rigorous mathematical analysis. To account for a series of infection mechanism leading to viral production, we incorporate time delays in the infection term. Using the methods of constructing suitable Lyapunov functionals and LaSalle’s invariance principle, we obtain the sufficient conditions for the global attractiveness of infection-free equilibrium with both virus strains going extinct, single-infection equilibrium with one of two virus strains out-competing the other one and the two strains coexisting infection equilibrium. We establish that the intracellular delays can destabilize the single-infection equilibrium leading to Hopf bifurcation and periodic oscillations. We show that introduction of immune responses is responsible for the coexistence of two virus strains and the intracellular delays may alter the two-strain competition results. Numerical simulations are presented to illustrate the theoretical conclusions. [ABSTRACT FROM AUTHOR]
- Published
- 2014
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20. Global analysis of HIV-1 dynamics with Hill type infection rate and intracellular delay.
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Bairagi, N. and Adak, D.
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HIV infections , *GLOBAL analysis (Mathematics) , *VIRAL transmission , *ENDEMIC diseases , *T cells - Abstract
The mass action infection law, the most frequently used transmission process in the theoretical studies of disease dynamics, has been challenged in various ways. Hill type infection rate is supposed to be a better alternative to mass action law. In the first phase of this paper, we study a basic HIV model with Hill type infection rate. In the second phase, we modify our basic model with intracellular delay τ that measures the time between the first effective contact between a virus and a healthy CD4 + T cell and the latter becomes productively infective. Mathematical results like well-posedness, permanence, local stability and global stability of both the delayed and non-delayed systems are studied. It is observed that the endemic equilibrium is locally and globally asymptotically stable if the virus replication factor is greater than a threshold value and unstable otherwise. In the latter case, the disease-free steady state occurs and is proved to be globally asymptotically stable. Our simulation results shed different insights on drug therapy when various perturbations are given to the system. It is shown that multi-blockers drug therapy is more appropriate in the treatment of HIV patients in comparison to any mono-blocker drug therapy. [ABSTRACT FROM AUTHOR]
- Published
- 2014
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21. Characteristics of the somatic hypermutation in the Camelus dromedarius T cell receptor gamma (TRG) and delta (TRD) variable domains.
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Ciccarese, Salvatrice, Vaccarelli, Giovanna, Lefranc, Marie-Paule, Tasco, Gianluca, Consiglio, Arianna, Casadio, Rita, Linguiti, Giovanna, and Antonacci, Rachele
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GENETIC mutation , *SOMATIC cells , *CAMELS , *T cells , *CELL receptors - Abstract
In previous reports, we had shown in Camelus dromedarius that diversity in T cell receptor gamma (TRG) and delta (TRD) variable domains can be generated by somatic hypermutation (SHM). In the present paper, we further the previous finding by analyzing 85 unique spleen cDNA sequences encoding a total of 331 mutations from a single animal, and comparing the properties of the mutation profiles of dromedary TRG and TRD variable domains. The transition preference and the significant mutation frequency in the AID motifs (dgyw/wrch and wa/tw) demonstrate a strong dependence of the enzymes mediating SHM in TRG and TRD genes of dromedary similar to that of immunoglobulin genes in mammals. Overall, results reveal no asymmetry in the motifs targeting, i.e. mutations are equally distributed among g:c and a:t base pairs and replacement mutations are favored at the AID motifs, whereas neutral mutations appear to be more prone to accumulate in bases outside of the motifs. A detailed analysis of clonal lineages in TRG and TRD cDNA sequences also suggests that clonal expansion of mutated productive rearrangements may be crucial in shaping the somatic diversification in the dromedary. This is confirmed by the fact that our structural models, computed by adopting a comparative procedure, are consistent with the possibility that, irrespective of where (in the CDR-IMGT or in FR-IMGT) the diversity was generated by mutations, both clonal expansion and selection seem to be strictly related to an enhanced structural stability of the γδ subunits. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
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22. Molecular characterization and expression of CD2BP2 in Nile tilapia (Oreochromis niloticus) in response to Streptococcus agalactiae stimulus.
- Author
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Zhen Gan, Bei Wang, Yishan Lu, Shuanghu Cai, Jia Cai, JiChang Jian, and Zaohe Wu
- Subjects
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GENE expression , *MOLECULAR genetics , *NILE tilapia , *STREPTOCOCCUS agalactiae , *CARRIER proteins , *CD2 antigen , *T cells , *RNA splicing - Abstract
CD2BP2 (CD2 cytoplasmic tail binding protein 2), one of several proteins interacting with the cytoplasmic tail of CD2, plays a crucial role in CD2-triggered T cell activation and nuclear splicing. The studies on CD2BP2 have tended to be confined to a few mammals, and little information is available to date regarding fish CD2BP2. In this paper, a CD2BP2 gene (On-CD2BP2) was cloned from Nile tilapia, Oreochromis niloticus. Sequence analysis showed that the full length of On-CD2BP2 cDNA was 1429 bp, containing a 5'untranslated region (UTR) of 111 bp, a 3'-UTR of 193 bp and an open reading frame of 1125 bp which is encoding 374 amino acids. Two important structural features, a GYF domain and a consensus motif GPFXXXXMXXWXXXGYF were detected in the deduced amino acid sequence of On-CD2BP2, and the deduced genomic structure of On-CD2BP2 was similar to the known CD2BP2. The mRNA expression of On-CD2BP2 in various tissues of Nile tilapia was analyzed by fluorescent quantitative real-time PCR. In healthy Nile tilapia, the On-CD2BP2 transcripts were mainly detected in the head kidney and spleen. While vaccinated with inactivated Streptococcus agalactiae, the On-CD2BP2 mRNA expression was significantly up-regulated in the head kidney, spleen and brain 48 h post immunization. Moreover, there was a clear time-dependent expression pattern of On-CD2BP2 after immunization and the expression reached the highest level at 24 h in the brain and 48 h in the head kidney and spleen. This is the first report of proving the presence of a CD2BP2 ortholog in fish, and investigating its tissue distribution and expression profile in response to bacterial stimulus. These findings indicated that On-CD2BP2 may play an important role in the immune response to bacteria in Nile tilapia. [ABSTRACT FROM AUTHOR]
- Published
- 2014
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23. Intelligent photothermal dendritic cells restart the cancer immunity cycle through enhanced immunogenic cell death.
- Author
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Sun, Zhihong, Deng, Guanjun, Peng, Xinghua, Xu, Xiuli, Liu, Lanlan, Peng, Jiaofeng, Ma, Yifan, Zhang, Pengfei, Wen, Austin, Wang, Yifan, Yang, Zhaogang, Gong, Ping, Jiang, Wen, and Cai, Lintao
- Subjects
- *
DENDRITIC cells , *CELL death , *T cells , *CANCER cells , *IMMUNITY , *HEAT shock proteins , *IMMUNOLOGICAL tolerance - Abstract
Dendritic cells (DCs) play a pivotal role in initiating antigen-specific tumor immunity. However, the abnormal function of DCs owing to the immunosuppressive tumor microenvironment (TME) and the insufficient number of tumor infiltrating DCs could promote immune tolerance and tumor immune escape. Thus, there is great potential to employ DCs to induce efficient antitumor immunity. In this paper, we developed intelligent DCs (iDCs), which consist of nanoparticles loaded with photothermal agents (IR-797) and coated with a mature DC membrane. The DC cell membrane on the surface of iDCs preserves the ability to present antigens and prime T cells. The iDCs can also enter the lymph node and stimulate T cells. The activated T cells reduced the expression of heat shock proteins (HSPs) in tumor cells, rendering them more sensitive to heat stress. Subsequently, we used mild photothermal therapy (42–45 °C) to induce immunogenic cell death and contribute to a synergistic antitumor effect. iDCs as a refined and precise system in combination with DC-based immunotherapy and thermal therapy can be stored long-term and on a large scale, so they can be applied in many patients. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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- View/download PDF
24. Immune inspired Fault Detection and Diagnosis: A fuzzy-based approach of the negative selection algorithm and participatory clustering
- Author
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Costa Silva, Guilherme, Palhares, Reinaldo Martinez, and Caminhas, Walmir Matos
- Subjects
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IMMUNE response , *FUZZY systems , *ALGORITHMS , *CLUSTER analysis (Statistics) , *ANTIGENS , *T cells , *DECISION making - Abstract
Abstract: This paper describes an immune-inspired system based on an alternate theory about the self–nonself distinction theory, which defines the negative selection process as a mechanism of a fuzzy system based on the affinity between antigen and T-cells. This theory may provide a decision making tool which improves the generation of detectors or even define new data monitoring in order to detect an extreme variation of the system behavior, which means anomalies occurrences. Through these algorithms, tests are performed to detect faults of a DC motor. Upon detection of faults, a participatory clustering algorithm is used to classify these faults and tested to obtain the best set of parameters to achieve the most accurate clustering for these tests in the application being discussed in the article. [Copyright &y& Elsevier]
- Published
- 2012
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25. Anti-cytomegalovirus effects of tricin are dependent on CXCL11
- Author
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Murayama, Tsugiya, Li, Ying, Takahashi, Takashi, Yamada, Rie, Matsubara, Keiko, Tuchida, Yuuzo, Li, Zhuan, and Sadanari, Hidetaka
- Subjects
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CYTOMEGALOVIRUSES , *CHEMOKINES , *FIBROBLASTS , *INTERFERONS , *T cells , *VIRUS diseases , *HERPESVIRUSES , *LYMPHOCYTES , *ANTIVIRAL agents - Abstract
Abstract: It has been reported that treatment with tricin (4′,5,7-trihydroxy-3′,5′-dimethoxyflavone), a derivative of Sasa albo-marginata, after human cytomegalovirus (HCMV) infection significantly suppressed both infectious virus production and HCMV replication in the human embryonic fibroblast cell line MRC-5. In this paper, we examined the mechanisms for the anti-HCMV effects of tricin in MRC-5 cells. Exposure of fibroblasts to tricin inhibited infectious HCMV production, with concomitant decreases in levels of transcripts of the CXC chemokine IFN-inducible T cell alpha chemoattractant (I-TAC or CXCL11) gene. We also found that the transcripts of the HCMV immediate early (IE) gene and replication of HCMV were lower in CXCL11 gene-knockdown cells. These results suggest that tricin is a novel compound with potential anti-HCMV activity and that CXCL11 is one of the chemokines involved in HCMV replication. In addition, it is possible that CXCL11 is the one of the targets of tricin. [Copyright &y& Elsevier]
- Published
- 2012
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26. TLT-1s, Alternative Transcripts of Triggering Receptor Expressed on Myeloid Cell-like Transcript-1 (TLT-1), Inhibits the Triggering Receptor Expressed on Myeloid Cell-2 (TREM-2)-mediated Signaling Pathway during Osteoclastogenesis.
- Author
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Soo-Hyun Yoon, Yong Deok Lee, Jeongim Ha, Youngkyun Lee, and Hong-Hee Kim
- Subjects
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CELL receptors , *OSTEOCLASTS , *CELL membranes , *T cells , *HOMOLOGY (Biology) , *MEMBRANE proteins - Abstract
Triggering receptor expressed on myeloid cells (TREM)-like transcript-1 (TLT-1) is an immunoreceptor tyrosine-based inhibitory motif (ITIM)-baring TREM family protein. In this study, we identified an alternative transcript form of TLT-1, namely TLT-1s, which has very short extracellular immunoglobulin domain consisting of only 202 amino acids. TLT-1s was mainly expressed in macrophages and osteoclast precursor cells. Upon receptor activator of nuclear factor-κB ligand stimulation, TLT-1s mRNA and protein levels were gradually decreased in BMMs. We also showed the TLT-1s is localized to the cytoplasmic membrane in osteoclast precursor cells. TLT-1s silencing strongly enhanced the formation and resorption activity of osteoclast. In addition, forced expression of TLT-1s showed reduced formation of osteoclast. Because ITIM-baring proteins inhibit immunoreceptor tyrosine-based activation motif (ITAM)-mediated receptor signaling, we tested whether TLT-1s physically interacted with TREM-2, the ITAM-associated co-stimulatory receptor essential for osteoclast differentiation. We showed that TLT-1s is associated with TREM-2 in osteoclast precursor cells. TLT-1s is also associated with tyrosine Src homology 2 domain-containing phosphatase-1 andSH2 domain-containing inositol phosphatase-1 and recruited them to the TREM2-ITAM signaling complex. In addition, knockdown of TLT-1s markedly elevated the intracellular calcium concentration and oscillation in osteoclast precursor cells. In addition, calcium-mediated induction of nuclear factor of activated T cells was also increased by TLT-1s silencing. Furthermore, TREM-2-mediated Akt activation and proliferation of osteoclast precursor cells were also enhanced in TLT-1s silenced cells. In this paper, we found the noble ITIM-baring inhibitory membrane protein; TLT-1s, which regulates ITAMmediated signaling on osteoclastogenesis. [ABSTRACT FROM AUTHOR]
- Published
- 2012
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27. Peripheral human γδ T cells control growth of both avirulent and highly virulent strains of Francisella tularensis in vitro
- Author
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Rowland, Caroline A., Hartley, M. Gill, Flick-Smith, Helen, Laws, Thomas R., Eyles, Jim E., and Oyston, Petra C.F.
- Subjects
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T cells , *MICROBIAL virulence , *FRANCISELLA tularensis , *BACTERIAL diseases , *IMMUNOGLOBULINS , *LYMPHOCYTES , *PATHOGENIC microorganisms , *COMMUNICABLE diseases - Abstract
Abstract: In this paper we evaluate the role of human γδ T cells in control of Francisella tularensis infection. Using an in vitro model of infection, a reduction in bacterial numbers was detected in the presence of human γδ T cells for both attenuated LVS and virulent SCHU S4 strains of F. tularensis. Antibody neutralisation of IFN-γ caused an increase in survival of F. tularensis LVS suggesting that γδ T cell-mediated control of F. tularensis infection is partially mediated by IFN-γ. [Copyright &y& Elsevier]
- Published
- 2012
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28. Application of the homotopy analysis method for solving a model for HIV infection of CD4+ T-cells
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Ghoreishi, M., Ismail, A.I.B.Md., and Alomari, A.K.
- Subjects
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HIV infections , *CD antigens , *T cells , *MATHEMATICAL models in medicine , *HOMOTOPY theory , *DIFFERENTIAL equations , *STOCHASTIC convergence , *INFINITE series (Mathematics) - Abstract
Abstract: In this paper, the homotopy analysis method (HAM) is investigated to give an approximate solution of a model for HIV infection of CD4+ T-cells. This method allows for the solution of the governing differential equation to be calculated in the form of an infinite series with components which can be easily calculated. The HAM utilizes a simple method to adjust and control the convergence region of the infinite series solution by using an auxiliary parameter. The results obtained are presented, and six terms are sufficient to obtain an approximation solution that is very accurate. [Copyright &y& Elsevier]
- Published
- 2011
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29. Solving a fractional order model of HIV infection of CD4+ T cells
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Gökdoǧan, Ahmet, Yildirim, Ahmet, and Merdan, Mehmet
- Subjects
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HIV infections , *T cells , *NUMERICAL solutions to differential equations , *MATHEMATICAL transformations , *APPROXIMATION theory , *MATHEMATICAL models - Abstract
Abstract: In this paper, a multi-step differential transform method (MsDTM) is performed to give approximate and analytical solutions of nonlinear fractional order ordinary differential equation systems such as a model for HIV infection of CD4+ T cells. The numerical solutions obtained from the proposed method indicate that the approach is easy to implement and accurate when applied to systems of fractional differential equations. Some figures are presented to show the reliability and simplicity of the methods. [Copyright &y& Elsevier]
- Published
- 2011
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30. An approximate solution of a fractional order differential equation model of human T-cell lymphotropic virus I (HTLV-I) infection of T-cells
- Author
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Ertürk, Vedat Suat, Odibat, Zaid M., and Momani, Shaher
- Subjects
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NUMERICAL solutions to differential equations , *HTLV , *MATHEMATICAL models , *FRACTIONAL calculus , *T-cell lymphoma , *VIRUS diseases , *T cells , *APPROXIMATION theory , *ALGORITHMS - Abstract
Abstract: In this paper, a fractional order differential system for modeling human T-cell lymphotropic virus I (HTLV-I) infection of CD4+ T-cells is studied and its approximate solution is presented using a multi-step generalized differential transform method. The method is only a simple modification of the generalized differential transform method, in which it is treated as an algorithm in a sequence of small intervals (i.e. time step) for finding accurate approximate solutions to the corresponding systems. The solutions obtained are also presented graphically. [Copyright &y& Elsevier]
- Published
- 2011
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31. Global dynamics of a mathematical model for HTLV-I infection of CD4+ T-cells
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Cai, Liming, Li, Xuezhi, and Ghosh, Mini
- Subjects
- *
HTLV-I infections , *T cells , *MATHEMATICAL models , *MATHEMATICAL analysis , *MATHEMATICAL functions , *EQUILIBRIUM - Abstract
Abstract: In this paper, a mathematical model for HILV-I infection of CD4+ T-cells is investigated. The force of infection is assumed be of a function in general form, and the resulting incidence term contains, as special cases, the bilinear and the saturation incidences. The model can be seen as an extension of the model [Wang et al. Mathematical analysis of the global dynamics of a model for HTLV-I infection and ATL progression, Math. Biosci. 179 (2002) 207-217; Song, Li, Global stability and periodic solution of a model for HTLV-I infection and ATL progression, Appl. Math. Comput. 180(1) (2006) 401-410]. Mathematical analysis establishes that the global dynamics of T-cells infection is completely determined by a basic reproduction number . If , the infection-free equilibrium is globally stable; if , the unique infected equilibrium is globally stable in the interior of the feasible region. [Copyright &y& Elsevier]
- Published
- 2011
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32. Detecting interferon-gamma release from human CD4 T-cells using surface plasmon resonance
- Author
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Stybayeva, Gulnaz, Kairova, Markhabat, Ramanculov, Erlan, Simonian, Aleksandr L., and Revzin, Alexander
- Subjects
- *
INTERFERONS , *T cells , *SURFACE plasmon resonance , *ANTIGEN-antibody reactions , *IMMUNOASSAY , *CYTOKINES , *BIOSENSORS , *LEUCOCYTES - Abstract
Abstract: Cytokine secretion by leukocytes is an important indicator of immune response to pathogens and therefore has significant implications in disease diagnostics. Given heterogeneity of leukocyte subsets and the ability of multiple cell subsets to secrete the same cytokines, connecting cytokine production to a specific leukocyte subset is a distinct challenge. In the present paper we describe a strategy combining antibody (Ab)-based affinity cell separation and surface plasmon resonance (SPR) for capturing human CD4 T-cells and for label-free detection of cell-secreted interferon (IFN)-γ – an important inflammatory cytokine. Human blood was introduced into a flow chamber modified with anti-CD4 Abs resulting in capture of CD4+ T-cells. After mitogenic activation of cells inside the flow chamber, culture medium was routed onto an SPR chip modified with monoclonal IFN-γ Abs. SPR signal observed in this experiment correlated with cytokine production by T-cells. The strategy of combining SPR detection with cell purification may be used in the future for label-free, sensitive detection of multiple cytokines or proteins secreted by the desired cell subset. [Copyright &y& Elsevier]
- Published
- 2010
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33. A study of latency, reactivation and apoptosis throughout HIV pathogenesis
- Author
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Capistrán, Marcos A.
- Subjects
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APOPTOSIS , *HIV infections , *T cells , *STOCHASTIC systems , *IMMUNE system , *MATHEMATICAL models , *PRINCIPAL components analysis - Abstract
Abstract: The capability of the HIV to persist latent inside CD4+ T-cells is currently regarded as a barrier to recovery from infection. On the other hand, immune activation, which is a normal immune reaction to pathogens, is now recognized as a key ingredient to sustaining the HIV caused infection. Further, it has been shown that activation of infected memory T-cells indirectly promotes apoptosis (programmed cell death) of bystander CD4+ and CD8+ T-cells. In this paper we use standard modeling techniques to develop a model compliant with the above mentioned mechanisms. Our farthest goal is to study how the long-term depletion of T-cells that characterizes HIV pathogenesis depends on these mechanisms. Consequently, we conduct parameter estimation, and apply standard results of sensitivity analysis and principal component analysis of the state variables with respect to the parameters. [ABSTRACT FROM AUTHOR]
- Published
- 2010
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34. MRI-visible polymeric vector bearing CD3 single chain antibody for gene delivery to T cells for immunosuppression
- Author
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Chen, Guihua, Chen, Wenjie, Wu, Zhuang, Yuan, Renxu, Li, Hua, Gao, Jinming, and Shuai, Xintao
- Subjects
- *
GENETIC vectors , *IMMUNOGLOBULINS , *GENE therapy , *T cells , *GENE targeting , *IMMUNOSUPPRESSION , *NANOPARTICLES , *MAGNETIC resonance imaging - Abstract
Abstract: Gene therapy mediated by nonviral vectors provides great advantages over conventional drug therapy in inducing immunosuppression after organ transplantation, yet it was rarely reported because T cells are normally difficult to transfect. In this paper, a nonviral vector that effectively transports genes into T cells is developed by attaching a T cell specific ligand, the CD3 single chain antibody (scAbCD3), to the distal ends of poly(ethylene glycol)-grafted polyethylenimine (scAbCD3-PEG-g-PEI). This polymer was first complexed with superparamagnetic iron oxide nanoparticles (SPIONs) and was then used to condense plasmid DNA into nanoparticles with an ideally small size and low cytotoxicity. Based on a reporter gene assay, targeting ligand functionalization of the delivery agent leads to 16 fold of enhancement in the gene transfection level in HB8521 cells, a rat T lymphocyte line. This targeting event in cell culture was successfully imaged by MRI scan. Inspiringly, delivery of a therapeutic gene DGKα with our MRI-visible delivery agent was likewise efficient, resulting in a 43% inhibition in the stimulated proliferation of HB8521 cells as well as a 38% inhibition in the expression of a major functional cytokine interleukin-2 (IL-2), indicating the effective T cell anergy induced by gene therapy. [Copyright &y& Elsevier]
- Published
- 2009
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35. Influenza virus-specific cytotoxic T lymphocytes: a correlate of protection and a basis for vaccine development
- Author
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Rimmelzwaan, Guus F, Fouchier, Ron AM, and Osterhaus, Albert DME
- Subjects
- *
INFLUENZA A virus , *INFLUENZA vaccines , *VACCINES , *VIRUS diseases , *T cells , *PREVENTIVE medicine - Abstract
Since influenza A viruses of the H5N1 subtype continue to circulate in wild and domestic birds and cause an ever increasing number of human cases, it is feared that H5N1 viruses may cause the next influenza pandemic. Therefore, there is considerable interest in the development of vaccines that confer protection against infections with these viruses or ideally, protection against influenza viruses of different subtypes. For the development of broad-protective vaccines the induction of virus-specific cytotoxic T lymphocytes (CTL) may be an important target, since it has been demonstrated that CTL contribute to protective immunity and are largely directed to epitopes shared by influenza viruses of various subtypes. In the present paper, the possibility to develop (cross-reactive) CTL-inducing vaccines is discussed. [Copyright &y& Elsevier]
- Published
- 2007
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36. Dietary fish oil increases the number of splenic macrophages secreting TNF-alpha and IL-10 but decreases the secretion of these cytokines by splenic T cells from mice.
- Author
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Petursdottir, Dagbjort H. and Hardardottir, Ingibjorg
- Subjects
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MACROPHAGES , *CYTOKINES , *ENZYME-linked immunosorbent assay , *IMMUNOREGULATION , *FISH oils , *MARINE animal oils , *CELLULAR immunity , *T cells , *BIOLOGICAL transport , *ANIMAL experimentation , *COMPARATIVE studies , *CORN oil , *FAT content of food , *INTERLEUKINS , *RESEARCH methodology , *MEDICAL cooperation , *MICE , *PLANT proteins , *RESEARCH , *SPLEEN , *TUMOR necrosis factors , *EVALUATION research , *LIPOPOLYSACCHARIDES - Abstract
Dietary fish oil has immunomodulatory effects that are partly mediated by its effects on cytokine secretion. In this paper, we examine whether dietary fish oil has different effects on cytokine secretion by T cells and macrophages. Female BalbC mice were fed diets supplemented with 18% fish oil + 2% corn oil or 20% corn oil. Concanavalin A (ConA)- and LPS-induced TNF-alpha and IL-10 secretion by splenocytes was examined using ELISA. Dietary fish oil decreased ConA induced-, but increased LPS-induced, TNF-alpha and IL-10 secretion by total murine splenocytes. Dietary fish oil increased the number of splenocytes secreting TNF-alpha and IL-10, following stimulation with LPS, by 123 and 38%, respectively, but did not affect cytokine secretion by each cell, as determined using enzyme-linked immunospot. Spleens from mice fed the fish oil diet had over 2-fold higher proportion of macrophages with high expression of CD11b than spleens from mice fed the corn oil diet. In addition, fish oil increased the proportion of total and CD11b(+) splenocytes that expressed the LPS receptor complex molecules, CD14 and toll-like receptor (TLR)4/myeloid differentiation factor-2 (MD-2), by 85 and 28%, respectively. The increased proportion of macrophages expressing the LPS receptor complex molecules, CD14 and TLR4/MD-2, in spleens from mice fed the fish oil diet may explain the increased number of cells that secreted the cytokines after LPS stimulation. [ABSTRACT FROM AUTHOR]
- Published
- 2007
- Full Text
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37. Identification of 9-Hydroxyoctadecadienoic Acid and Other Oxidized Free Fatty Acids as Ligands of the G Protein-coupled Receptor G2A.
- Author
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Obinata, Hideru, Hattori, Tomoyasu, Nakane, Shinji, Tatei, Kazuaki, and Izumi, Takashi
- Subjects
- *
PROTEINS , *LYMPHOID tissue , *MACROPHAGES , *CONNECTIVE tissue cells , *B cells , *T cells , *CELL cycle , *ATHEROSCLEROSIS - Abstract
G2A is a G protein-coupled receptor that is predominantly expressed in lymphoid tissues and macrophages. G2A can be induced by diverse stimuli to cause cell cycle arrest in the G2/M phase in pro-B and T cells. G2A is also expressed in macrophages within atherosclerotic lesions, suggesting G2A involvement in atherosclerosis. Recently, G2A was discovered to possess proton-sensing ability. In this paper, we report another function of G2A, that is, as a receptor for 9-hydroxyoctadecadienoic acid (9-HODE) and other oxidized free fatty acids. G2A, expressed in CHO-K1 or HEK293 cells, showed 9-HODE-induced intracellular calcium mobilization, inositol phosphate accumulation, inhibition of cAMP accumulation, [35S]guanosine 5′-3-O-(thio)triphosphate binding, and MAP kinase activation. Furthermore, G2A was activated by various oxidized derivatives of linoleic and arachidonic acids, but it was weakly activated by cholesteryl-9-HODE. Oxidized phosphatidylcholine (1-palmitoyl-2-linoleoyl) when hydrolyzed with phospholipase A2 also evoked intracellular calcium mobilization in G2A-expressing cells. These results indicate that G2A is activated by oxidized free fatty acids produced by oxidation and subsequent hydrolysis of phosphatidylcholine or cholesteryl linoleate. Thus, G2A might have a biological role in diverse pathological conditions including atherosclerosis. [ABSTRACT FROM AUTHOR]
- Published
- 2005
- Full Text
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38. Modeling and analysis of early events in T-lymphocyte antigen-activated intracellular-signaling pathways
- Author
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Zheng, Yanan, Balakrishnan, Venkataramanan, Buzzard, Greg, Geahlen, Robert, Harrison, Marietta, and Rundell, Ann
- Subjects
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T cells , *IMMUNE response , *MATHEMATICAL models , *DIFFERENTIAL equations - Abstract
Abstract: The T-cell antigen-activated signaling pathway is a highly regulated intracellular biochemical system that is crucial for initiating an appropriate adaptive immune response. To improve the understanding of the complex regulatory mechanisms controlling the early events in T-cell signaling, a detailed mathematical model was developed that utilizes ordinary differential equations to describe chemical reactions of the signaling pathway. The model parameter values were constrained by experimental data on the activation of a specific signaling intermediate and indicated an initial rapid cascade of phosphorylation events followed by a comparatively slow signal downregulation. Nonlinear analysis of the model suggested that thresholding and bistability occur as a result of the embedded positive and negative feedback loops within the model. These nonlinear system properties may enhance the T-cell receptor specificity and provide sub-threshold noise filtering with switch-like behavior to ensure proper cell response. Additional analysis using a reduced second-order model led to further understanding of the observed system behavior. Moreover, the interactions between the positive and negative feedback loops enabled the model to exhibit, among a variety of other feasible dynamics, a sustained oscillation that corresponds to a stable limit cycle in the two-dimensional phase plane. Quantitative analysis in this paper has helped identify potential regulatory mechanisms in the early T-cell signaling events. This integrated approach provides a framework to quantify and discover the ensemble of interconnected T-cell antigen-activated signaling pathways from limited experimental data. [Copyright &y& Elsevier]
- Published
- 2005
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- View/download PDF
39. T cell activation: Kinetic proofreading, serial engagement and cell adhesion
- Author
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Coombs, Daniel and Goldstein, Byron
- Subjects
- *
T cells , *CELL adhesion , *MATHEMATICAL models , *MATHEMATICAL statistics - Abstract
Abstract: There is a fundamental difference in complexity between signaling initiated by ligands on the surface of one cell binding to receptors on the surface of another cell and ligands in solution binding to these receptors. The fact that two cells must approach each other and form a number of intercellular bonds of different types, all within the restricted geometry of the intercellular contact region, introduces the possibility of complex spatio-temporal dynamics of surface receptors that is not present otherwise. Mathematical modelling of these dynamics is in its early stages. However, useful tools have emerged. The purpose of this paper is to describe some of these mathematical tools, indicating their strengths and shortcomings, and suggest some directions for future theoretical studies. [Copyright &y& Elsevier]
- Published
- 2005
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40. Functional Characterization of JMJD2A, a Histone Deacetylase- and Retinoblastoma-binding Protein.
- Author
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Gray, Steven G., Iglesias, Antonio H., Lizcano, Fernando, Villanueva, Raul, Camelo, Sandra, Jingu, Hisaka, Teh, Bin T., Koibuchi, Noriyuki, Chin, William W., Kokkotou, Efi, and Dangond, Fernando
- Subjects
- *
HISTONE deacetylase , *RETINOBLASTOMA , *ZINC-finger proteins , *T cells , *CELL lines , *BIOCHEMISTRY - Abstract
To effectively direct targeted repression, the class I histone deacetylases (HDACs) associate with many important regulatory proteins. In this paper we describe the molecular characterization of a member of the Jumonji domain 2 (JMJD2) family of proteins, and demonstrate its binding to both class I HDACs and the retinoblastoma protein (pRb). JMJD2 proteins are characterized by the presence of two leukemia-associated protein/plant homeodomain (LAP/PHD) zinc fingers, one JmjN, one JmjC (containing an internal retinoblastoma-binding protein 2 (RBBP2)-like sequence), and two Tudor domains. The first member of this group, JMJD2A, is widely expressed in human tissues and cell lines, and high endogenous expression of JMJD2A mRNA was found in several cell types, including human T-cell lymphotropic virus 1 (HTLV-1)-infected cell lines. JMJD2A and JMJD2B exhibit cell type-specific responses to the HDAC inhibitor trichostatin A. We show that the JMJD2A protein associates in vivo with pRb and class I HDACs, and mediates repression of E2F-regulated promoters. In HTLV-1 virus-infected cells, we find that JMJD2A binds to the viral Tax protein. Antibodies to JMJD2A recognize the native protein but also a half-sized protein fragment, the latter up-regulated in THP-1 cells during the G2/M phase of the cell cycle. The ability of JMJD2A to associate with pRb and HDACs and potentiate pRb-mediated repression of E2F-regulated promoters implies an important role for this protein in cell proliferation and oncogenesis. [ABSTRACT FROM AUTHOR]
- Published
- 2005
- Full Text
- View/download PDF
41. Overexpression of a mutant CTLA4 inhibits T-cell activation and homeostasis-driven expansion
- Author
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Mao, Yifan, Brigham, Dan, and Chen, Dan
- Subjects
- *
CELLS , *LYMPHOCYTES , *PHYSIOLOGICAL control systems , *T cells , *PHYSIOLOGY , *BONE marrow - Abstract
Interaction of B7 with CD28 and CTLA4 plays an important function in T-cell activation and homeostasis. Disruption of CD28, CTLA4, or both has shown impact on T-cell biology. This paper examined the consequences of overexpressing a tailless mutant form of CTLA4 on T-cell activation and in vivo expansion.Retroviral gene transfer was used to infect bone marrow progenitor cells with either a control vector or a cytoplasmic domain-deleted mutant of CTLA-4 (ΔCTLA4). The cells were subsequently adoptively transferred to RAG-/- mice and allowed to repopulate. The T cells derived from the reconstituted RAG-/- mice were analyzed functionally in vitro and in vivo.The T cells were defective in their ability for IL-2 secretion, survival, and proliferation in response to Ag/APC stimulation in vitro. Addition of exogenous IL-2 or normal T cells was able to rescue the survival defect and allow cell-cycle progression. In adoptive transfer studies, the naïve T cells expressing ΔCTLA4 exhibited compromised capability to expand in RAG-/- mice. Memory ΔCTLA4T cells, however, were capable of proliferating in lymphopenic hosts to a similar extent as control memory T cells, but showed reduced survival.Surface ΔCTLA4 has similar tolerogenic/regulatory activity as CTLA4-Ig. In contrast to CTLA4-Ig, the effect of ΔCTLA-4 is autonomous. The inhibition of in vivo expansion by ΔCTLA4 indicates developmental and/or activation stage dependency of costimulation in T cells. [Copyright &y& Elsevier]
- Published
- 2004
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- View/download PDF
42. Modelling the interaction of T-Cells, antigen presenting cells, and HIV-1 in vivo
- Author
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Lou, Jie and Shao, Yiming
- Subjects
- *
T cells , *LYMPHOCYTES , *ANTIGENS , *IMMUNITY , *BIOLOGY - Abstract
Abstract: We develop and analyze a model for the interactions of T-cells, antigen presenting cells (APCs), and HIV-1. Our model consists of five components: APCs, resting helper T-cells, activated uninfected helper T-cells, activated and infected helper T-cells, and the free virus. We emphasize the impact of APCs during HIV infection and the cell-to-cell contact manner in the transference of HIV-1 in vivo. The existence and stability of the uninfected steady state and those of the infected steady states are discussed. The uniform persistence of the system is also obtained. As a novel approach, multiple exposures of HIV-1 are illustrated and discussed in the paper. Through numerical stimulations, we check the sensitivity of APCs and helper T-cells in impacting the infection outcome and obtain some relevant results. We also give the lowest infectioe dose for certain individuals. [Copyright &y& Elsevier]
- Published
- 2004
- Full Text
- View/download PDF
43. ORIGINAL ARTICLE Novel Immunotherapies for Psoriasis: Clinical Research Delivers New Hope for Patients and Scientific Advances.
- Author
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Gottlieb, Alice B.
- Subjects
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PSORIASIS , *IMMUNITY , *IMMUNOTHERAPY , *IMMUNOLOGIC diseases , *T cells , *IMMUNE response - Abstract
Immunobiologics provide the hope for safe and effective long-term management of psoriasis, a life-disabling condition. The use of targeted immunotherapies as pathogenic probes has led to scientific discoveries that help uncover new information on the pathogenesis of psoriasis and on the control of cutaneous immunity. The research described in this paper employs targeted immunotherapies as pathogenic probes of T1-mediated immune disorders, using psoriasis as the primary disease model. This approach has wide applicability to other immune-mediated inflammatory isorders. [ABSTRACT FROM AUTHOR]
- Published
- 2004
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44. CD103+ Dendritic Cells Producing Interleukin-12 in Anticancer Immunosurveillance.
- Author
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Zitvogel, Laurence and Kroemer, Guido
- Subjects
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DENDRITIC cells , *INTERLEUKIN-12 , *ANTINEOPLASTIC agents , *T cells , *CANCER chemotherapy - Abstract
The mechanisms through which tumor antigen-specific T cells are elicited in natural or chemotherapy-induced immunosurveillance have been elusive. In this issue of Cancer Cell , two papers by Broz and colleagues and Ruffell and colleagues delineate an important role for a specific dendritic cell subset characterized by CD103 expression, dependence on transcription factors Batf3 and Irf8, and interleukin-12 production. [ABSTRACT FROM AUTHOR]
- Published
- 2014
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45. The Role of Adhesion Molecules in Epithelial-T-Cell Interactions in Thymus and Skin.
- Author
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Singer, Kay H., Le, Phong T., Denning, Stephen M., Whichard, Leona P., and Haynes, Barton F.
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CELL adhesion molecules , *T cells , *THYMUS , *SKIN , *EPITHELIUM , *CELL adhesion - Abstract
Interaction of T lymphocytes with other cell types is important for normal T-cell development and function. Recently, a number of adhesion molecules important in T-cell interactions with other cell types have been defined. In this paper we review the role of two adhesion pathways, CD2/LFA-3 and LFA-1/ICAM-1, in T-cell interactions with epithelial cells of the thymus and skin. While thymic epithelium-T-cell interactions were mediated by both the LFA-1/ICAM-1 pathway and the CD2/LFA-3 pathway, epidermal-T-cell interactions were mediated primarily by the LFA-1/ICAM-1 pathway. Although ICAM-1 was not expressed in vivo on epidermal keratinocytes in normal skin, ICAM-1 was expressed by epidermal keratinocytes at the site of T-cell infiltration in inflammatory dermatitis. ICAM-1 was expressed in vivo on thymic epithelium. Both LFA-3 and ICAM-1 were expressed on epithelial cells of thymus and skin early on in fetal ontogeny. These antigen-independent adhesion molecules play an important role in the cell-cell interactions associated with T-cell differentiation and function. [ABSTRACT FROM AUTHOR]
- Published
- 1990
- Full Text
- View/download PDF
46. A Novel Method to Construct Dual-targeted Magnetic Nanoprobes by Modular Assembling.
- Author
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Bai, Chen, Hu, Pengcheng, Liu, Di, Chen, Yi, Ma, Ming, Gu, Ning, and Zhang, Yu
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FERRIC oxide , *NANOPARTICLES , *IRON oxides , *MAGNETIC resonance , *T cells , *MAGNETIC properties , *IRON oxide nanoparticles - Abstract
Magnetic nanoparticle is an important branch of nanomaterials, especially magnetic iron oxide (Fe 3 O 4) nanoparticles have attracted widespread attention due to the fact that they can be used not only as high-sensitivity magnetic resonance contrast agents, but also as carriers for the construction of multifunctional and intelligent nanoprobes. The functional ligands modified on the surface of nanoprobes always provide the effective targeting ability. However, during the coupling process, the competitive inhibition of different modified ligands probably affects the construction of nanoprobes. Therefore, a modular designed method to construct magnetic nanoprobes is proposed in this paper and this method provides the favorable coupling efficiency and activity of the modified ligands as well as the inconspicuous competitive coupling effect between different ligands. The nanoprobes are composed of streptavidin modified Fe 3 O 4 nanoparticles and the biotinylated functional ligands assembled on the nanoparticles. Due to the specific binding between streptavidin and biotin, the functional ligands are coupled on the Fe 3 O 4 nanoparticles and the different ligands could be simply replaced to construct the nanoprobes with different function. Two types of dual-targeted nanoprobes including CD20&CD3@Fe 3 O 4 and E5&CD3@Fe 3 O 4 are synthesized. These nanoprobes have the appropriate hydrodynamic size (∼20 nm) and desirable magnetic properties (about 240 mM-1s-1 for r 2 relaxivity). In cell experiments, CD20&CD3@Fe 3 O 4 and E5&CD3@Fe 3 O 4 showed strong cytotoxicity for Raji cells and HL60 cells respectively and enhanced the T cell mediated immunotherapy which provided dual-targeted ability in vitro. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
47. Early Epigenetic Immune Quantification Following Alpha/Beta T-Cell/CD19 B-Cell Depleted Haploidentical Stem Cell Transplant Correlates with CD4+ T Cell Recovery at Day +100.
- Author
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Mavers, Melissa, Schulze, Janika, Barbarito, Giulia, Lakshmanan, Uma, Parkman, Robertson, Weinberg, Kenneth I., Chu, Julia, Agarwal, Rajni, Roncarolo, Maria Grazia, Sachsenmaier, Christoph, Bacchetta, Rosa, and Bertaina, Alice
- Subjects
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STEM cell transplantation , *T cells , *HEMATOPOIETIC stem cell transplantation , *CYTOTOXIC T cells , *EPIGENETICS , *LYMPHOCYTE count - Abstract
Patients who fail to adequately reconstitute the donor-derived immune system after allogeneic hematopoietic stem cell transplantation (HSCT) are at increased risk for infections and leukemia relapse. In the past, pan T-cell depleted haploidentical grafts were associated with delayed immune reconstitution (IR). Recently, the majority of patients receiving αβ T-cell/B-cell depleted haploidentical HSCT (αβhaplo-HSCT) reach a threshold of 200 CD3+ T cells/mcl by 100 days after HSCT (Bertaina A et al. Blood 2014 Jul 31;124(5):822-6). However, a proportion of patients experience a slower IR with consequent higher morbidity and mortality. Early prediction of delayed IR may permit prompt clinical intervention such as infusion of donor lymphocytes or of virus-specific cytotoxic T cells. Flow cytometry, the most widely applied approach for IR analysis, suffers from intrinsic limitations, such as high lymphocyte number requirement, degradation of samples, and insufficient standardization due to technical and operator variability. To overcome these limitations, we used a DNA methylation-based quantitative PCR that detects the epigenetic signature of different peripheral blood immune cell subsets (epigenetic quantification). This technique provides relative and absolute immune cell counts applicable to fresh, frozen, or paper-spotted dried blood. Epigenetic measurements are based on a per cell DNA copy number and provide a clear positive or negative signal rather than arbitrarily defined thresholds for "positivity" as in flow cytometry. We hypothesize that epigenetic quantification at day 15 after αβhaplo-HSCT could predict flow-based IR at day 100. Patients were consented at Lucile Packard Children's Hospital (Stanford, CA). Blood was collected between days 10-17 for epigenetic quantification and days 82-124 for flow cytometry. Bisulfite treated DNA underwent qPCR quantification of cell type-specific DNA regions of de-methylation (Baron U et al. Sci Transl Med 2018 Aug 1;10(452):eaan3508). Flow cytometry was performed using directly conjugated antibodies. Absolute cell counts were determined, plotted, and then analyzed using a linear regression model. In the first 5 αβhaplo-HSCT patients evaluated, we found a direct correlation between the epigenetic quantification at day 15 and flow cytometry at day 100 for CD4+ T cells (P=0.01), while the early epigenetic quantification of CD3+ and CD8+ T cells was not informative (Fig. 1). Preliminary data suggest that the use of epigenetic quantification early after αβhaplo-HSCT can predict the IR of CD4+ T cells at day 100 in αβhaplo-HSCT recipients. Ongoing analysis on a larger cohort of both αβhaplo-HSCT and unmanipulated HSCT recipients, will confirm if epigenetic quantification results obtained early post-HSCT can be used as a clinical biomarker of delayed IR and guide physicians in the use of post-HSCT adoptive immunotherapy. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
48. T-CELL MEMBRANE CHARACTERISTICS OF "MYCOSIS CELLS" IN THE SKIN AND LYMPH NODE.
- Author
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Van Leeuwen, A. W. F. M., Meijer, C. J. L. M., and De Man, J. C. H.
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MYCOSIS fungoides , *LYMPHOPROLIFERATIVE disorders , *MYCOSES , *T cells , *LYMPH nodes , *ELECTRON microscopy - Abstract
In some patients with mycosis fungoides atypical cells ("mycosis cells") are found in the blood. Recently the T-cell membrane characteristics of these atypical cells have been described. In this paper the results of a study of the atypical cells isolated from the lymph nodes and the skin lesions of three patients with mycosis fungoides are presented. Using electron microscopy, it could be demonstrated that the atypical cells formed rosettes with uncoated sheep red blood cells, but not with antibody-complement-coated sheep erythrocytes, indicating the T-cell membrane characteristics of the atypical cells. [ABSTRACT FROM AUTHOR]
- Published
- 1975
- Full Text
- View/download PDF
49. The Role of Langerhans Cells in Antigen Presentation.
- Author
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Katz, Stephen I., Cooper, Kevin D., Iijima, Masafumi, and Tsuchida, Tetsuo
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LANGERHANS cells , *ANTIGENS , *BONE marrow , *DENDRITIC cells , *T cells , *GRAFT versus host disease - Abstract
Epidermal Langerhans cells are dendritic bone marrow-derived cells which synthesize and express Ia antigens. During the past decade, in vitro studies have demonstrated that they play a critical role in the induction of many types of T-cell responses. Specifically, Langerhans cells are effective antigen-presenting cells in allogeneic and antigen specific proliferative and cytotoxic T-cell responses. This paper reviews these functions and suggests areas of future investigations into the mechanisms involved in T-cell activation by Langerhans cells. [ABSTRACT FROM AUTHOR]
- Published
- 1985
- Full Text
- View/download PDF
50. Clinical Snippets.
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MEDICAL research , *DERMATOLOGY , *T cells , *VITILIGO , *MEDICINAL plants , *PATIENTS - Abstract
This section offers news briefs on research papers on dermatology as of June 1, 2015. A study reveals a decrease in regulatory T cells in skin of patients with the autoimmune depigmentation disease vitiligo. A study has identified lupeol via activity-guided purification following screening tests from extracts of medicinal plants, such as Solanum melongena. A research paper reveals the crucial role of ceramides in skin barrier function.
- Published
- 2015
- Full Text
- View/download PDF
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