• Asian Pacific Journal of Cancer Prevention
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• v.14 no.1
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• pp.309-314
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• 2013

Aim: Brain tumors almost universally have fatal outcomes; new therapeutics are desperately needed and will only come from improved understandins of glioma biology. Methods: Exosomes are endosomally derived 30~100 nm membranous vesicles released from many cell types. Examples from GL26 cells were here purified using density gradient ultracentrifugation and monitored for effects on GL26 tumor growth in C57BL/6j mice (H-2b). Lactate dehydrogenase release assays were used to detect the cytotoxic activity of CD8+T and NK cells. Percentages of immune cells producing intracellular cytokines were analyzed by FACS. Results: In this study, exosomes from murine-derived GL26 cells significantly promoted in vivo tumor growth in GL26-bearing B6 mice. Then we further analyzed the effects of the GL26 cells-derived exosomes on immune cells including CD8+T, CD4+T and NK cells. Inhibition of CD8+T cell cytotoxic activity was demonstrated by CD8+T cell depletion assays in vivo and LDH release assays in vitro. The treatment of mice with exosomes also led to a reduction in the percentages of CD8+T cells in splenocytes as determined by FACS analysis. Key features of CD8+T cell activity were inhibited, including release of IFN-gamma and granzyme B. There were no effects of exosomes on CD4+T cells and NK cells. Conclusion: Based on our data, for the first time we demonstrated that exosomes from murine derived GL26 cells promote the tumor growth by inhibition of CD8+T cells in vivo and thus may be a potential therapeutic target.

• Korean Journal of Animal Reproduction
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• v.27 no.3
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• pp.225-231
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• 2003

Transgenic mice containing Diphtheria Toxin-A (DT-A) gene fused to proximal lck promoter sequences was used for analysis of DT-A gene expression and thymocyte development. The diphtheria toxin gene was expressed in thymus, spleen and liver of transgenic mice confirmed by RT-PCR and Northern blotting. A FACS analysis with thymocyte cell surface antigens antibodies (CD4 and CD8) showed that the number of peripheral mature single positive thymocytes ($CD4^{+}\;and\;CD8^{+}$ cells) T-cells was severely reduced in transgenic mice compared to that in the non-transgenic littermates. A relative portion of $CD8^{+}$ single positive thymocytes was about 33.2% in transgenic peripheral T-cells while 50.6% in wild type. Reduction of $CD4^{+}$ cell numbers in transgenic mice was observed (5.9% in transgenic versus 10.3% in non-transgenic). The data from analysis of these transgenic mice indicate that the proximal lck promoter regulated the expression of DT-A gene at high level in developing thymocytes and the DT-A disrupted developing thymocytes in transgenic mice.

• Korean Journal of Poultry Science
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• v.28 no.3
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• pp.231-237
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• 2001

To examine the effects of feed additives on the expression of perpheral blood cell surface molecules, phagocytosis and antigen specific antibody formation, broilers were randomly assigned to $T_{1}$ , $T_{2}$ , $T_{3}$ , and $T_{4}$ groups. $T_{1}$ group was fed diet without any additives for 13 weeks, $T_{2}$ was fed diet with full fat flax, $T_{3}$ was fed diet with full fat flax containing $\alpha$-tocopherol, and $T_{4}$ was fed diet with full- fat flax containing $\alpha$-tocopherol and selenium. Since 5 weeks feeding the data were examined by flow cytometry using a panel of monoclonal antibodies. The expression of monocyte in all treated groups was significantly increased, in which the ratio of expression in $T_{3}$ group was especially evident. B cell expression of all treated groups was increased more than 2 fold. The expression of CD4+(helper T cell) cell and CD8+(cytotox$ic^pressor T cell) cell of all treated groups also was increased.ed.

• Journal of Preventive Medicine and Public Health
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• v.25 no.2 s.38
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• pp.157-161
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• 1992

To assess the immunological function of toluene exposed group, the proportions of T lymphocyte, B lymphocyte, CD4 cell, CD8 cell, the ratio of CD4 to CD8(CD4/CD8) in peripheral blood were measured on twenty-one toluene exposed workers and twelve healthy workers who did not have previous history of toluene exposure. In addition, to evaluate the present status of toluene exposure, urinary hippuric acid concenturations were measured in exposed group. The mean concenturation of urinary hippuric acid was 2.84 g/creatinine g in exposed group. The proportions of T lymphocyte, B lymphocyte, CD8 cell and CD4/CD8 of exposed group were slightly lower than non-exposed group except the proportion of CD4 cell which was similar in both groups. But these differences were not statistically different in both groups. The proportions of T lymphocyte and CD4 cell were significantly correlated with the length of duration in exposed group(P<0.05).

• IMMUNE NETWORK
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• v.14 no.4
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• pp.219-225
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• 2014

We examined the immunogenicity of H-2 class I-restricted and HLA-A2-restricted epitopes through peptide immunization of HLA-A2-transgenic mice that also express mouse H-2 class I molecules. All four of the tested epitopes restricted by H-2 class I robustly elicited T-cell responses, but four of seven epitopes restricted by HLA-A2 did not induce T-cell responses, showing that HLA-A2-restricted peptide epitopes tend to be poorly immunogenic in HLA-A2-transgenic mice. This finding was confirmed in HLA-A2-transgenic mice infected with a recombinant vaccinia virus expressing hepatitis C virus proteins. We examined the precursor frequency of epitope-specific naïve $CD8^+$ T cells in HLA-A2-transgenic and conventional C57BL/6 mice and found that the poor immunogenicity of HLA-A2-restricted peptide epitopes is related to the paucity of naïve $CD8^+$ T-cell precursors in HLA-A2-transgenic mice. These results provide direction for the improvement of mouse models to study epitope repertoires and the immunodominance of human T-cell responses.

• Biomedical Science Letters
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• v.1 no.1
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• pp.27-35
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• 1995

Several studies showed that the immunological factors such as CD4+ cell number, CD4%, CD8+ cell number and CD4/CD8 ratio and the serological factors such as, ${\beta}^2$-microglobulin(${\beta}^2$-MG), neopterin, soluble CD4, and soluble CD8 are related to the risk of development of AIDS. Especially, the CD4+ cell counts have been used to monitor progresson of HIV disease, to stratify, and to follow patients in clinical trials. Recently, the Centers for Disease Control and Prevention(CDCP) in USA has made the CD4+ cell count as a part of the classification of HIV disease. It is composed of 3 categories such as 1, 2, and 3 which asr $\geq$ 500/$mm^3$, 200/$mm^{3} $\geq$ and < 500/$mm^3$, and < 200/$mm^3$, respectively. In this study, to estimate the differences of immunological factors between HIV-infected and normal human groups in Korea, CD4+ T and CD8+ T cells, and the CD4/CD8 ratio were measured in 185 HIV-infected subjects and 140 healthy adult subjects. The lymphocyte subsets such as CD4+ T and CD8+ T were analysed by flow cytometer(FACStar) with two-color immunofluorescent stain using monoclonal antibodies such as anti-CD4 and anti-CD8 antibodies. The absolute numbers and percentages of CD4+ T and CD8+ T and the CD4/CD8 ratio of HIV infected persons were $462\pm{277}/mm^3$, $18.2\pm7.7%$, $1,170\pm{534}/mm^3$, $47.0\pm10.6%$ and $0,43\pm0.26 whereas those of uninfected persons were $886\pm{299}mm^3$, $32.9\pm{7.0%}, 730{\pm}259/mm^3$, $26.8\pm6.4%$ and $1.31\pm0.46$(P<0.01). In addition, estimating the reference values of peripheral blood lymphocyte subsets of Korean, the absolute numbers and percentages of CD4+ T and CD8+ T and the CD4/CD8 ratio of 140 healthy adults persons were measured and compared with those of foreigners. The reference ranges of CD4+ T cells, CD8+ T cells, CD4％, CD8%, and the CD4/CD8 ratio and 1.31$\pm$0.46, respectively. The significant differences were not observed when compared with those of foreigners. However a little difference was observed in the percentages of CD4+ T and the absolute numbers of CD8+ T between the normal values of Korean and those of foreigners were $43.6\pm8.9%$, $560\pm{230}/mm^3$. This result can also be useful as a basic data for the treatment and surveillance of HIV-infected patients in Korea.

• IMMUNE NETWORK
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• v.23 no.1
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• pp.9.1-9.15
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• 2023

Cancer immunotherapies continue to face numerous obstacles in the successful treatment of solid malignancies. While immunotherapy has emerged as an extremely effective treatment option for hematologic malignancies, it is largely ineffective against solid tumors due in part to metabolic challenges present in the tumor microenvironment (TME). Tumor-infiltrating CD8⁺ T cells face fierce competition with cancer cells for limited nutrients. The strong metabolic suppression in the TME often leads to impaired T-cell recruitment to the tumor site and hyporesponsive effector functions via T-cell exhaustion. Growing evidence suggests that mitochondria play a key role in CD8⁺ T-cell activation, migration, effector functions, and persistence in tumors. Therefore, targeting the mitochondrial metabolism of adoptively transferred T cells has the potential to greatly improve the effectiveness of cancer immunotherapies in treating solid malignancies.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.24 no.4
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• pp.377-383
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• 2021

Purpose: We investigated the association of effector memory (EM) CD8⁺ T cell and CD4⁺ T cell immunity with metabolic syndrome (MS). Methods: Surface and intracellular staining of peripheral blood mononuclear cells was performed. Anti-interleukin-7 receptor-alpha (IL-7Rα) and CX3CR1 antibodies were used to stain the subsets of EM CD8⁺ T cells, while anti-interferon-gamma (IFN-γ), interleukin-17 (IL-17), and forkhead box P3 (FOXP3) antibodies were used for CD4⁺ T cell subsets. Results: Of the 47 obese children, 11 were female. Children with MS had significantly higher levels of serum insulin (34.8±13.8 vs. 16.4±6.3 µU/mL, p<0.001) and homeostasis model assessment of insulin resistance (8.9±4.1 vs. 3.9±1.5, p<0.001) than children without MS. Children with MS revealed significantly higher frequencies of IL-7Rα^low CD8⁺ T cells (60.1±19.1% vs. 48.4±11.5%, p=0.047) and IL-7Rα^lowCX3CR1⁺ CD8⁺ T cells (53.8±20.1% vs. 41.5±11.9%, p=0.036) than children without MS. As the serum triglyceride levels increased, the frequency of IL-7Rα^lowCX3CR1⁺ and IL-7Rα^highCX3CR1^- CD8⁺ T cells increased and decreased, respectively (r=0.335, p=0.014 and r=-0.350, p=0.010, respectively), in 47 children. However, no CD4⁺ T cell subset parameters were significantly different between children with and without MS. Conclusion: In obese children with MS, the changes in immunity due to changes in EM CD8⁺ T cells might be related to the morbidity of obesity.

• Journal of Physiology & Pathology in Korean Medicine
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• v.20 no.6
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• pp.1576-1583
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• 2006

In order to investigate the effect of Goamshimshinhwan(GASSW) on SD rats with deteriorated immunity caused by methotrexate. Methotrexate was fed to the SD rats once a day for 4 days. After the immune responses of the at a dosage 1,000, 500 and 250mg/kg/10ml. and the changes on body weight and gains, spleen weight, total blood leukocyte numbers, total lymphocyte numbers, the percentage of B-cell, T-cell, CD3+CD+4 T-cell, CD3+CD8+ T-cell and CD4+/CD8+ T-cell ratios in the bolld and spleen were observed. In addition, the serum IL-2 levels and productivity of IL-2 of splenic cells were also demonstrated in this study. The changes on body weight were increased significantly in 100 and 500mg/kg of GASSW groups and the changes on body gain were increased significantly in 1000mg/kg of GASSW groups as compared with control group. The changes on the spleen weight (absolutely or relatively) were increased significantly in all GASSW groups as compared with control group. The total blood leukocyte numbers were increased significantly in 1000 and 500mg/kg of GASSW groups as compared with control group. The total lymphocyte numbers were increased significantly in all GASSW groups in the blood and increased significantly in 1000 and 500mg/kg of GASSW goups in spleen as compared with control group. The percentage of B-cell and T-cell were increased significantly in 1000mg/kg of GASSW groups in the blood and increased significantly in 1000 and 500mg/kg of GASSW groups in spleen as compared with control group. The percentage of CD3+CD4+ T-cell and the serum IL-2 levels and productivity of IL-2 of splenic cells were increased significantly in 100 and 500 mg/kg of GASSW groups in the blood and spleen as compared with control group. The percentage of CD3+CD8+ T-cell were increased significantly in 1000mg/kg of GASSW groups only in spleen as compared with control groups. The CD4+/CD8+ T-cell ratios were increased significantly in 1000 and 500mg/kg of GASSW groups only in the blood as compared with control group. Goamshimshinhwan(GASSW) has immuno-stimulating effect on SD rats with deteriorated immunity caused by methotrexate.

• IMMUNE NETWORK
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• v.5 no.2
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• pp.89-98
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• 2005

Background: DNA vaccination represents an anticipated approach for the control of numerous infectious diseases. Used alone, however, DNA vaccine is weak immunogen inferior to viral vectors. In recent, heterologous prime-boost vaccination leads DNA vaccines to practical reality. Methods: We assessed prime-boost immunization strategies with a DNA vaccine (minigene, $gB_{498-505}$ DNA) and recombinant vaccinia virus $(vvgB_{498-505})$ expressing epitope $gB_{498-505}$ (SSIEF ARL) of CD8+ T cells specific for glycoprotein B (gB) of herpes simplex virus (HSV). Animals were immunized primarily with $gB_{498-505}$ epitope-expressing DNA vaccine/recombinant vaccinia virus and boosted with alternative vaccine type expressing entire Ag. Results: In prime-boost protocols using vvgBw (recombinant vaccinia virus expressing entire Ag) and $vvgB_{498-505}$, CD8+ T cell-mediated immunity was induced maximally at both acute and memory stages if primed with vvgBw and boosted with $vvgB_{498-505}$ as evaluated by CTL activity, intracellular IFN-staining, and MHC class I tetramer staining. Similarly $gB_{498-505}$ DNA prime-gBw DNA (DNA vaccine expressing entire Ag) boost immunization elicited the strongest CD8+ T cell responses in protocols based on DNA vaccine. However, the level of CD8+ T cell-mediated immunity induced with prime-boost vaccination using DNA vaccine expressing epitope or entire Ag was inferior to those based on vvgBw and $vvgB_{498-505}$. Of particular interest CD8+ T cell-mediated immunity was optimally induced when $vvgB_{498-505}$ was used to prime and gB DNA was used as alternative boost. Especially CD7+ T cell responses induced by such protocol was longer lasted than other protocols. Conclusion: These facts direct to search for the effective strategy to induce optimal CD8+ T cell-mediated immunity against cancer and viral infection.