• Title/Summary/Keyword: lymphocyte activation

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IQGAP1, a signaling scaffold protein, as a molecular target of a small molecule inhibitor to interfere with T cell receptor-mediated integrin activation

  • Li, Lin-Ying;Nguyen, Thi Minh Nguyet;Woo, Eui Jeon;Park, Jongtae;Hwang, Inkyu
    • Korean Journal of Agricultural Science
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    • v.47 no.2
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    • pp.361-373
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    • 2020
  • Integrins such as lymphocyte function-associated antigen -1 (LFA-1) have an essential role in T cell immunity. Integrin activation, namely, the transition from the inactive conformation to the active one, takes place when an intracellular signal is generated by specific receptors such as T cell receptors (TCRs) and chemokine receptors in T cells. In an effort to explore the molecular mechanisms underlying the TCR-mediated LFA-1 activation, we had previously established a high-throughput cell-based assay and screened a chemical library deposited in the National Institute of Health in the United States. As a result, several hits had been isolated including HIKS-1 (Benzo[b]thiophene-3-carboxylic acid, 2-[3-[(2-carboxyphenyl) thio]-2,5-dioxo-1-pyrrolinyl]-4,5,6,7-tetrahydro-,3-ethyl ester). In an attempt to reveal the mode of action of HIKS-1, in this study, we did drug affinity responsive target stability (DARTS) assay finding that HIKS-1 interacted with the IQ motif containing GTPase activating protein 1 (IQGAP1), a 189 kDa multidomain scaffold protein critically involved in various signaling mechanisms. Furthermore, the cellular thermal shift assay (CETSA) provided compelling evidence that HIKS-1 also interacted with IQGAP1 in vivo. Taken together, it can be concluded that HIKS-1 interferes with the TCR-mediated LFA-1 activation by interacting with IQGAP1 and thereby disrupting the signaling pathway for LFA-1 activation.

Human Activated Lymphocyte Treated with Anti-CD3, CD16, CD56 Monoclonal Antibody and IL-2 (Anti-CD3, CD16과 CD56 단일항체와 IL-2를 사용하여 활성화시킨 사람의 림프구)

  • Hong, Seon-Min;Lee, Dong-Wook;Kang, Jin-Gu;Kim, Han-Soo;Cho, Sung-Hoon
    • IMMUNE NETWORK
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    • v.5 no.1
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    • pp.11-15
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    • 2005
  • Background: Throughtout the last three decades, the therapy of leukemias and lymphoma has set the stage for curative cancer therapy in systemic malignant disease. This was the result of an integrated work of basic reaserch and clinical investigators leading to more aggressive albeit tolerable protocol of chemotherapy and radiotherapy. High dose therapy marks the most elaborated strategies in this field today. However, intensification of conventional therapeutic modalities as mentioned has to be based on new approaches and the exploration of new antineoplastic mechanisms. This insight has resulted in immune therapy of cancer. Among the cells of the immune system, natural killer (NK) cells and T cells are of major interest for the development of therapeutic strategies. Methods: Cytotoxicity to target cells was measured by LDH release method, Characterization of activated lymphocyte was measured by Flow cytometry analysis. Anti-CD3, 16, 56 monoclonal antibody and IL-2 were used for the activation of NK and T cell. The analysis of effect of activated lymphocyte, in vivo, were used by Balb/c nude mouse. Results and Conclusion: Cytotoxicity to K562 cells was significantly higher in the mixture group of NK and T cells than that of a group of activating T cells. The survivors and the rate of reduction of size of tumor craft of nude mouse group treatment with activated lymphocyte was higher than that of the group without treatment with activated lymphocyte. Therefore, this results are suggested that the activated lymphocytes by anti-CD3, CD16 and CD56 can reduce the malignancy effect of lymphoma.

A Study on the Relationship between the Obstetric Variables and Granulocyte/Lymphocyte Ratio in Some Postpartum Women (일부 산모의 산과적 지표와 과립구/림프구 비와의 관계)

  • Cho, Seung-Hee;Kim, Gun-Hee;Shim, Gye-Seon;Seo, Yun-Jung;Cho, Han-Baek;Choi, Chang-Min;Kim, Song-Baek
    • The Journal of Korean Obstetrics and Gynecology
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    • v.26 no.4
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    • pp.82-93
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    • 2013
  • Purpose: The aim of this study was to investigate the relation between peripheral blood leukocyte differential - Granulocyte rate, Lymphocyte rate and its calculated Granulocyte/Lymphocyte ratio - and the obstetric variables. Methods: From 270 cases of women who were in the postpartum care center attached to Won-Kwang Korean Medical Hospital, 36 cases met exclusion criteria. On the obstetric variables of 234 cases, peripheral blood leukocyte differential - Granulocyte rate, Lymphocyte rate and its calculated Granulocyte/Lymphocyte ratio - was analyzed. In the postpartum care center, the obstetric variables were asked of 234 cases of women, and who measured leukocyte differential. Results: Mean granulocyte rate and lymphocyte rate of peripheral blood leukocyte differential showed statistically significant difference from those in healthy people and was high. There was statistically significant difference in granulocyte/lymphocyte ratio according to mood of delivery, parity and period passed from childbirth. But whether postpartum women with anemia or not, maternal age and gender of neonate were not associated with granulocyte/lymphocyte ratio, and which was not significantly correlated with gestational age and neonatal birth weight. Conclusions: These findings suggest that activation of the sympathetic nervous system in postpartum women is higher than in healthy people. And granulocyte/lymphocyte ratio was influenced by mood of delivery, parity and period passed from childbirth. In future, more studies or surveys, with less bias, for the relation between peripheral blood leukocyte differential and the obstetric variables are required.

Comparison of Linarin and Its Acetylated linarin for the Cytotoxicity on the Proliferation of Lymphocytes and Activation of Macrophages (림포사이트의 증식과 대식세포의 활성화에 관한 린나린과 아세칠 린나린의 비교 연구)

  • 한신하;신지혜;소명아;한혜란;김민준;임동술;김경제
    • YAKHAK HOEJI
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    • v.47 no.4
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    • pp.234-238
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    • 2003
  • Linarin is a main compound from Chrysanthemum zawadskii var, latilobum. However, the biological mechanisms of these activities are unclear. Because of this wide diversity of effects, it is believed that they may be exerted through pluripotent effectors of linarin. In our previous screening study, the effects of linarin on the mouse macrophages cell line, RAW 264.7 cells, were investigated. It was found that linarin could stimulate macrophages activation by the production of tumor necrosis factor (TNF). The linarin (6.25∼12.5 $\mu\textrm{g}$/mι) inhibited the production of NO in LPS-activated RAW 264.7 cells and linarin became an useful candidates for the development of new drug to treat endotoxemia and inflammation accompanied by the overproduction of NO. However, linarin-treated total lymphocyte showed cytotoxicity in a dose dependent manner between 20 $\mu\textrm{g}$/mι and 40 $\mu\textrm{g}$/mι. In this study, linarin derivative (acetylated linarin) was synthesized in order to obtain less-cytotoxicity of linarin and evaluated for their in vitro cytotoxic activity aganist mouse total lymphocyte. There was no cytotoxic activity in a dose dependent manner (20∼40 $\mu\textrm{g}$/mι) of acetylated linarin whereas linarin showed. The production of NO, however, was not the case by this modified linarin. The cell morphological change was not significantly changed in response to acetylated linarin alone and these effects were potentiated by the addition of LPS. These results suggest that acetylated linarin may be developed to be a promising new drug candidate without cytotoxicity on the basis of its activity of macrophage activation.

Interactions among Measles Virus Hemagglutinin, Fusion Protein and Cell Receptor Signaling Lymphocyte Activation Molecule (SLAM) Indicating a New Fusion-trimer Model

  • Zhang, Peng;Li, Lingyun;Hu, Chunlin;Xu, Qin;Liu, Xin;Qi, Yipeng
    • BMB Reports
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    • v.38 no.4
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    • pp.373-380
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    • 2005
  • For measles viruses, fusion on the cell membrane is an important initial step in the entry into the infected cells. The recent research indicated that hemagglutinin firstly leads the conformational changes in the fusion protein then co-mediates the membrane fusion. In the work, we use the co-immunoprecipitation and pull-down techniques to identify the interactions among fusion protein, hemagglutinin and signaling lymphocyte activation molecule (SLAM), which reveal that the three proteins can form a functional complex to mediate the SLAM-dependent fusion. Moreover, under the confocal microscope, fusion protein and hemagglutinin protein can show the cocapping mediated by the SLAM. So fusion protein not only is involved in the fusion but also might directly interact with the SLAM to be a new fusion-trimer model, which might account for the infection mechanism of measles virus.

Immune Checkpoint Inhibitors: Therapeutic Tools for Breast Cancer

  • Su, Min;Huang, Chun-Xia;Dai, Ai-Ping
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.3
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    • pp.905-910
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    • 2016
  • Breast cancer is one of the major threats to female health, and its incidence is rapidly increasing in many countries. Currently, breast cancer is treated with surgery, followed by chemotherapy or radiation therapy, or both. However, a substantial proportion of breast cancer patients might have a risk for local relapse that leads to recurrence of their disease and/or metastatic breast cancer. Therefore searching for new and potential strategies for breast cancer treatment remains necessary. Immunotherapy is an attractive and promising approach that can exploit the ability of the immune system to identify and destroy tumors and thus prevent recurrence and metastatic lesions. The most promising and attractive approach of immunotherapeutic research in cancer is the blockade of immune checkpoints. In this review, we discuss the potential of certain inhibitors of immune checkpoints, such as antibodies targeting cytotoxic T-lymphocyte antigen 4 (CTLA-4), programmed death 1 (PD-1) and lymphocyte activation gene-3 (LAG-3), in breast cancer therapeutics. Immune checkpoint inhibitors may represent future standards of care for breast cancer as monotherapy or combined with standard therapies.

Extracts from Polypodium ferns upregulate the expression of CD95 in human peripheral blood lymphocytes

  • Lombardi, Valter R.M.;Etcheverria, I.;Fernandez-Novoa, L.;Blanco, A.;Diaz, J.;Cacabelos, R.
    • Advances in Traditional Medicine
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    • v.3 no.2
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    • pp.90-99
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    • 2003
  • There are several data in the literature indicating a great variety of pharmacological activities of Polypodium genus, which exhibit antiinflammatory and immunomodulatory activities. Since one of our main interests is to obtain natural immunoregulatory agents devoid of pharmacological adverse effects, we used flow cytometry analysis to highlight relative contributions of a water-soluble fraction of different concentrations of Polypodium rhizome extracts on lymphocyte subpopulations, NK and LAK activity. To measure their potential immunoregulatory activity a T cell proliferation assay in response to phytohemaglutinin (PHA) and mixed lymphocyte reactions were chosen. As a confirmatory bioassay we studied the effect of our extracts on CD45RO and CD95 antigen expressions. The results indicate that CD95 expression dramatically increases after peripheral blood lymphocyte activation and treatment with Polypodium leucotomus, cambricum and vulgare extracts, suggesting a powerful intrinsic pro-apoptotic effect.

Role of CAGE, a Novel Cancer/Testis Antigen, in Various Cellular Processes, Including Tumorigenesis, Cytolytic T Lymphocyte Induction, and Cell Motility

  • Kim, Young-Mi;Jeoung, Doo-Il
    • Journal of Microbiology and Biotechnology
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    • v.18 no.3
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    • pp.600-610
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    • 2008
  • A cancer-associated antigen gene (CAGE) was identified by serological analysis of a recombinant cDNA expression library (SEREX). The gene was identified by screening cDNA expression libraries of human testis and gastric cancer cell lines with sera from patients with gastric cancer. CAGE was found to contain a D-E-A-D box domain and encodes a putative protein of 630 amino acids with possible helicase activity. The CAGE gene is widely expressed in various cancer tissues and cancer cell lines. Demethylation plays a role in the activation of CAGE in certain cancer cell lines where the gene is not expressed. The functional roles of CAGE in tumorigenesis, the molecular mechanisms of CAGE expression, and cell motility are also discussed.

Neuraminidase Treatment Enhances Allogeneic Stimulation of Unprimed $CD8^+$ T Cells

  • Kim, Kil-Hyoun
    • BMB Reports
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    • v.30 no.6
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    • pp.385-389
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    • 1997
  • Many cell types are known to stimulate $CD8^+$ T cells in allogeneic recognition such as mixed lymphocyte reaction (MLR). Whereas dendritic cells are most potent among them. T cells are usually considered very poor in stimulating $CD8^+$ T cells although there are some tumor cells that are weakly stimulatory. T cells, as a stimulator, cultured in the presence of concanavalin A that were otherwise nonstimulatory to $CD8^+$ T cells appeared to stimulate $CD8^+$ T cells strongly when they were pretreated with neuraminidase. The enhancement of MLR by neuraminidase could be achieved by treating either the stimulators or responders with neuraminidase. Removal of negatively-charged sialic acid moieties from the cell surface, which reduced electrostatic repulsion between responders and stimulators to give better cell-cell contact might be responsible for the enhanced MLR. In addition, neuraminidase treatment also appeared to deliver activation signal to responding T cells since it could activate $CD8^+$ T cells in synergy with phorbol myristate acetate. The maximal responses were observed when both responders and stimulators were treated with neuraminidase.

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Altered Frequency, Activation, and Clinical Relevance of Circulating Innate and Innate-Like Lymphocytes in Patients With Alcoholic Liver Cirrhosis

  • Ki-Jeong Park;Hye-Mi Jin;Young-Nan Cho;Jae Hyun Yoon;Seung-Jung Kee;Hyo-Sin Kim;Yong-Wook Park
    • IMMUNE NETWORK
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    • v.23 no.3
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    • pp.22.1-22.15
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    • 2023
  • Alcoholic liver cirrhosis (ALC) is caused by chronic alcohol overconsumption and might be linked to dysregulated immune responses in the gut-liver axis. However, there is a lack of comprehensive research on levels and functions of innate lymphocytes including mucosal-associated invariant T (MAIT) cells, NKT cells, and NK (NK) cells in ALC patients. Thus, the aim of this study was to examine the levels and function of these cells, evaluate their clinical relevance, and explore their immunologic roles in the pathogenesis of ALC. Peripheral blood samples from ALC patients (n = 31) and healthy controls (HCs, n = 31) were collected. MAIT cells, NKT cells, NK cells, cytokines, CD69, PD-1, and lymphocyte-activation gene 3 (LAG-3) levels were measured by flow cytometry. Percentages and numbers of circulating MAIT cells, NKT cells, and NK cells were significantly reduced in ALC patients than in HCs. MAIT cell exhibited increased production of IL-17 and expression levels of CD69, PD-1, and LAG-3. NKT cells displayed decreased production of IFN-γ and IL-4. NK cells showed elevated CD69 expression. Absolute MAIT cell levels were positively correlated with lymphocyte count but negatively correlated with C-reactive protein. In addition, NKT cell levels were negatively correlated with hemoglobin levels. Furthermore, log-transformed absolute MAIT cell levels were negatively correlated with the Age, Bilirubin, INR, and Creatinine score. This study demonstrates that circulating MAIT cells, NKT cells, and NK cells are numerically deficient in ALC patients, and the degree of cytokine production and activation status also changed. Besides, some of their deficiencies are related to several clinical parameters. These findings provide important information about immune responses of ALC patients.