• Title/Summary/Keyword: T-cell inhibition

Search Result 615, Processing Time 0.023 seconds

Immunomodulatory Effect of cAMP-Elevating Agents on Macrophage- and T cell-Mediated Immune Responses (cAMP 증가 유도 약물의 대식세포- 및 T 세포-매개성 면역반응 조절작용)

  • Rhee, Man-Hee;Cho, Jae-Youl
    • YAKHAK HOEJI
    • /
    • v.51 no.1
    • /
    • pp.35-43
    • /
    • 2007
  • To investigate the immunomodulatory roles of cyclic AMP (CAMP) on macrophage- and T lymphocyte-mediated immune responses, CAMP elevating agents were employed and carefully re-examined under the activation conditions of the cells. Various inhibitors tested dose-dependently blocked tumor necrosis factor (TNF)-${\alpha}$ production with IC$_{50}$ values ranged from 0.04 to 300 ${\mu}$M. Of the inhibitors, cAMP-elevating agents showed lower cytotoxicity assessed by lactate dehydrogenase (LDH) release, suggesting less toxic and more selective. In particular co-treatment of dbcAMP with a protein kinase C inhibitor staurosporine displayed the synergistic inhibition of TNF-${\alpha}$ production. The modulatory effect of dbcAMP on TNF-${\alpha}$ and nitric oxide (NO) was significantly affected by treatment time of dbcAMP. Thus, post-treatment of dbcAMP (three hours before LPS) abrogated dbcAMP's inhibitory activity and rather enhanced TNF-${\alpha}$ level up to 60%. In contrast, additional NO production was shown at the co-treatment of dbcAMP with LPS. Unlike simultaneous treatment of phorbol 12-myristate 13-acetate (PMA) and interferon (IFN)-${\gamma}$co-treatment, the combination of dbcAMP with other NO-inducing stimuli did not show drastic overproduction of NO. cAMP elevating agents also diminished splenocyte proliferation stimulated by concanavalin (Con) A, phytohemaglutinin A (PHA) and lipopolysaccharide (LPS). In addition, dbcAMP but not rolipram strongly suppressed CD8$^+$ T cells (CTLL-2). Finally, cAMP elevating agents were differentially involved in regulating CD98-mediated cell-cell adhesion. Thus, dbcAMP and rolipram significantly enhanced the cell-cell adhesion, whereas forskolin blocked. Therefore, our results suggest that CAMP elevating agents participate in various immune responses mediated by macrophages and T cells with a different fashion depending on cellular environments and activation signals.

Swiprosin-1 Expression Is Up-Regulated through Protein Kinase $C-{\theta}$ and $NF-{\kappa}B$ Pathway in T Cells

  • Kim, Young-Dae;Kwon, Min-Sung;Na, Bo-Ra;Kim, Hye-Ran;Lee, Hyun-Su;Jun, Chang-Duk
    • IMMUNE NETWORK
    • /
    • v.13 no.2
    • /
    • pp.55-62
    • /
    • 2013
  • Swiprosin-1 exhibits the highest expression in $CD8^+$ T cells and immature B cells and has been proposed to play a role in lymphocyte biology through actin remodeling. However, regulation of swiprosin-1 gene expression is poorly understood. Here we report that swiprosin-1 is up-regulated in T cells by PKC pathway. Targeted inhibition of the specific protein kinase C (PKC) isotypes by siRNA revealed that $PKC-{\theta}$ is involved in the expression of swiprosin-1 in the human T cells. In contrast, down-regulation of swiprosin-1 by A23187 or ionomycin suggests that calcium-signaling plays a negative role. Interestingly, swiprosin-1 expression is only reduced by treatment with $NF-{\kappa}B$ inhibitors but not by NF-AT inhibitor, suggesting that the $NF-{\kappa}B$ pathway is critical for regulation of swiprosin-1 expression. Collectively, these results suggest that swiprosin-1 is a $PKC-{\theta}$-inducible gene and that it may modulate the late phase of T cell activation after antigen challenge.

Widdrol Blocks 3T3-L1 Preadipocytes Growth and Differentiation Due to Inhibition of Mitotic Clonal Expansion

  • Yun, Hee-Jung;Kim, Jeong-Hwan;Jeong, Hyun-Young;Ji, Hyang-Hwa;Nam, Soo-Wan;Lee, Eun-Woo;Kim, Byung-Woo;Kwon, Hyun-Ju
    • Journal of Microbiology and Biotechnology
    • /
    • v.22 no.6
    • /
    • pp.806-813
    • /
    • 2012
  • Adipocyte differentiation is strongly associated with obesity, which causes metabolic disorders. In this study, we investigated the inhibitory effects of widdrol on 3T3-L1 preadipocyte growth and differentiation. Widdrol decreased lipid droplet accumulation and down-regulated adipogenic transcription factors such as C/$EBP{\alpha}$, C/$EBP{\beta}$, and $PPAR{\gamma}$. Widdrol blocked preadipocyte proliferation and differentiation through the inhibition of mitotic clonal expansion, which was accompanied by the failure of degradation of p21, a cyclin-dependent kinase inhibitor. Cell-cycle analysis clearly indicated that widdrol actively induces cell-cycle arrest at the G1-S phage transition, causing cells to remain in the preadipocyte state. Moreover, widdrol increased p21 expression and inhibited Rb phosphorylation in preadipocyte incubated in a hormone medium. Therefore, these findings clearly suggest that widdrol blocks preadipocyte growth and differentiation through the inhibition of mitotic clonal expansion by p21-and Rb-dependent G1 arrest and can be developed as a potent anti-adipogenic agent for reducing obesity.

Inhibition of Adipogenesis in 3T3-L1 Adipocytes with Ethanol Extracts of Saururus chinensis (삼백초 추출물의 3T3-L1 세포에 대한 지방축적 억제효과)

  • Shin, Ok-Su;Shin, Youn-Ho;Lee, Kang-Hyun;Kim, Gun-Yong;Kim, Ki-Ho;Park, Jung-Keug;Ahn, Jae-Il;Song, Kye-Yong
    • KSBB Journal
    • /
    • v.27 no.6
    • /
    • pp.381-386
    • /
    • 2012
  • Obesity increases the risk of many adult diseases, such as atherosclerosis, diabetes, hypertension, ischemic heart disease and breast cancer. Inhibition of adipogenesis is an effective way in the anti-obesity management. Because of main components of Saururus chinensis is flavonoid, it has been showed some improvement by its antioxidant effects on the atherosclerosis, heart disease and diabetic hyperlipidemia. But mechanism of anti-obesity effect of S. chinensis is not clear. We investigated the effects of ethanol extracts of S. chinensis on adipogenesis in the 3T3-L1 pre-adipocyte. The 3T3-L1 cell line is commonly used to study adipogenesis in vitro. In this study, ethanol extracts of S. chinensis significantly decrease the lipid accumulation in the 3T3-L1 cells proved by measuring triglyceride contents and Oil red O staining. The proposed mechanism of inhibition of adipogenesis in the 3T3-L1 cells with ethanol extracts of S. chinensis is down-regulation of transcriptional factors and adipocyte-specific genes such CCAAT/enhancer binding protein ${\alpha}$ ($C/EBP{\alpha}$) and Peroxisome proliferator activated receptor ${\gamma}$ ($PPAR{\gamma}$) in concentration dependent pattern. These results suggest that ethanol extracts of S. chinensis inhibits adipognesis in the 3T3-L1 cells and can be used as a safe and efficient natural substance to manage anti-obesity.

The Effect of Gamisamryungbaekchul-san(加味蔘苓白朮散) on the Tumor and Immune Response in Mouse B16 Melanoma Tumor Model (가미삼령백출산(加味蔘苓白朮散)의 B16 흑색종 암모델에 대한 항종양효과(抗腫瘍效果)와 면역증강효과(免疫增强效果)에 관한 연구(硏究))

  • Iem Cheol-Hong;Keum Jong-Chul;Lee Sang-Jae;Kim Kwang-Ho
    • Journal of Society of Preventive Korean Medicine
    • /
    • v.5 no.1
    • /
    • pp.103-115
    • /
    • 2001
  • Background : Gamisamryungbaekchul-san(加味蔘?白朮散) is a herbal medicine which has been used for the traditional therapeutic agent of augmentation of the spleen and reinforcement of the Qi. Objective : This Study was performed to investigate the effect of Gamisamryungbaekchul-san on the tumor and immune response in the moose B16 melanoma tumor model. Materials and Methods : The tumor was induced by subcutaneous inoculation of B16BL6 melanoma cells in the shaved dorsal region of mice. Mice were orally administered with Gamisamryungbaekchul-san extract(26.3mg/mouse) for 14days after inoculation. For making examination of antitumor effect, the Increase of life span, Tumor growth inhibition rate, change of body weight were measured and evaluated. For the immune response increasing effect, the percentage of T lymphocyte and B Lymphocyte in the peripheral blood, the percentage of CD4+ T-cell, CD8+ T-cell and CD4+/CD8+ ratio in the peripheral blood and spleen, interleukin-2 productivity were measured and evaluated. Results : Gamisamryungbaekchul-san showed 16.59% increase of life span, 31.64% tumor growth inhibition rate and increase of body weight. Gamisamryungbaekchul-san increased the percentage of T lymphocyte in the peripheral blood, CD4+ T cell percentage of peripheral blood and spleen, and Interleukin-2 productivity as compared with the Control group. Whereas Gamisamryungbaekchul-san had no effect on the percentage of B lymphocyte in the peripheral blood, the percentage of CD8+ T cell, CD4+/CD8+ T-cell ratio in both of peripheral blood and spleen as compared with the Control group. Conclusion : This study shows that Gamisamryungbaekchul-san has anti-tumor effects and immunoregulatory effects on the B16 melanoma tumor model. It is suggested that Gamisarmyungbaekchul-san could be a useful immunomodulator and anti-tumor agent.

  • PDF

Antioxidant and Protective Effects of Palmul-tang on Ultraviolet B (UVB)-induced Damage in Human Keratinocytes (팔물탕의 항산화 효과와 자외선으로 유도된 각질형성세포 손상에 대한 보호효과)

  • Kim, Tae-Yeon;Bak, Jong-Phil
    • Journal of Society of Preventive Korean Medicine
    • /
    • v.19 no.3
    • /
    • pp.141-154
    • /
    • 2015
  • Objective : In this paper, we investigated the anti-oxidative capacities and protective effects of water extract of palmul-tang (PMT) against Ultraviolet B(UVB)-induced oxidative damage in human keratinocytes(HaCaT). Method : To evaluate the anti-oxidative activities of PMT, we measured scavenging activities on 1,1-diphenyl-2-picrylhydrazyl(DPPH) radical, hydroxyl radical, hydrogen peroxide, superoxide anion, lipid peroxidation and reducing power of PMT. To give an oxidative stress to HaCaT cells, UVB was irradiated with $40mJ/cm^2$ to HaCaT cells. To detect the protective effects of PMT against UVB, we measured cell viability, apoptotic bodies and reactive oxygen species(ROS) generation. Results : PMT showed the anti-oxidative activities by scavenging DPPH radical, hydroxyl radical, hydrogen peroxide, superoxide anion, lipid peroxidation. Also PMT showed high reducing values. The UVB-induced oxidative conditions led to the cell apoptosis. However, treatment with PMT reduced oxidative stress conditions, including inhibition of cell apoptosis and expression of ROS. Conclusion : PMT had anti-oxidative activities and exhibited protective effects against UVB on HaCaT cells. PMT would be useful for the development of cosmetics treating UVB-induced skin aging.

Natural Compounds from Danshen Suppress the Activity of Hepatic Stellate Cells

  • Oh, Seong-Hwan;Cho, Kyung-Hwan;Yang, Beom-Seok;Roh, Yong-Kyun
    • Archives of Pharmacal Research
    • /
    • v.29 no.9
    • /
    • pp.762-767
    • /
    • 2006
  • Danshen is an herbal medication frequently used in oriental medicine to treat liver or kidney malfunction. In the course of our studies, we observed that compounds purified from Danshen exhibit an inhibitory activity against Discoidin Domain Receptor 2 (DDR2) tyrosine kinase. Through this inhibition, these compounds also inhibited the growth of HSC T6 cells and suppressed the expression of alpha-smooth muscle actin and MMP2, as well as collagen synthesis, all of which are increased in activated liver stellate cells. Given that activation of liver stellate cells is the hallmark of liver fibrosis and that DDR2 plays a critical role in this activation, these results suggest that one of the pharmacological activities of Danshen extract that protects the liver is the inhibition of key cell-signaling kinases, such as DDR2, in liver stellate cells.

Growth Inhibition of Human Hepatoma and Bladder Carcinoma Cells by DNA Topoisomerae Inhibitor β-lapachone (DNA topoisomerase 억제제인 β-lapachone에 의한 인체 간암 및 방광암세포 증식억제에 관한 연구)

  • Choi Da Yean;Lee Jae Il;Chung Hyun Sup;Seo Han Gyeol;Woo Hyun Joo;Choi Yung Hyun
    • Journal of Life Science
    • /
    • v.15 no.3 s.70
    • /
    • pp.323-331
    • /
    • 2005
  • The objective of the present study was to investigate the effect of $\beta-lapachone$, a quinone obtained from the bark of the lapacho tree (Tabebuia avellanedae) in South America, on the cell growth of human hepatoma (HepG2) and bladder (T24) carcinoma cells. Exposure of cancer cells to $\beta-lapachone$ resulted in growth inhibition, morphological changes and apoptosis in a concentration-dependent manner, which could be proved by MTT assay and flow cytometry analysis. Reverse transcription-polymerase chain reaction (RT-PCR) and Western blot analyses revealed that $\beta-lapachone$ did not affect the levels of tumor suppressor p53 and cyclin-dependent kinase (Cdk) inhibitor p21 (WAFl/CIPl) expression. However, the transcriptional factor Sp-l and proliferating cell nuclear antigen (PCNA) protein levels were significantly down-regulated by $\beta-lapachone$ in both cell lines. Moreover, $\beta-lapachone$ treatment caused a dose-dependent inhibition of the expression of telomere regulatory gene products such as human telomere reverse transcriptase (hTERT) and telomerase-associated protein-l (TEP-l). Taken together, these findings suggest that $\beta-lapachone$-induced inhibition of human hepatoma and bladder carcinoma cell proliferation is associated with the induction of apoptotic cell death via modulation of several major growth regulatory gene products, and provide important new insights into the additional mechanisms of the anti-cancer activity of $\beta-lapachone$.

Fungistatic Activity of Kojic Acid Against Human Pathogenic Fungi and Inhibition of Melanin-production in Cryptococcus neoformans

  • Chee, Hee-Youn;Lee, Eun-Hee
    • Mycobiology
    • /
    • v.31 no.4
    • /
    • pp.248-250
    • /
    • 2003
  • Kojic acid was investigated for its antifungal activity against the human pathogenic fungi including Candida albicans, Cryptococcus neoformans and Trichophyton rubrum. For C. albicans, C. neoformans and T. rubrum, the MIC(minimum inhibitory concentration) of kojic acid was 640, 80 and 160 ${\mu}g/ml$, respectively. In C. neoformans, melanin-producing yeast, kojic acid-treated nonmelanized cell was more susceptible to magainin than melanized cell, suggesting melanin give a protective function against microbial peptide.