• Animal cells and systems
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• v.3 no.3
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• pp.331-336
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• 1999

p56$^{Ick}$, a cytoplasmic protein tyrosine kinase of the src family, is non-covalently associated with the cell surface coreceptors CD4 and CD8, which are expressed on thymocytes and mature T cells. The coreceptor protein plays an important role during the differentiation of thymocytes and the activation of T cells. DNA constructs were designed to study the roles of CD4 and CD8 during the differentiation of thymocytes. One is a chimeric cDNA which consists of coding regions for the extracellular domain of CD8a and the transmembrane and cytoplasmic domain of CD4. The other is the same chimeric cDNA but with a point mutation converting Cys to Ala in the Ick-binding site to disrupt the association. We confirmed that the CD8a/CD4 chimeric molecule bound to Ick more efficiently than the wild type CD8a protein. However, the chimeric protein with the Cys$leftrightarro$Ala mutation did not associate with Ick. The results suggest a possibility that the CD8a/CD4 chimeric protein may behave like a CD4 protein in associating with Ick and that it may deliver a signal inside the cell in a similar manner, Analysing effects of the mutant CD8a/CD4 chimeric protein expression in developing thymocytes will elucidate the role of Ick during the determination of CD4/CD8 cell lineages.

• Journal of Ginseng Research
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• v.21 no.3
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• pp.160-168
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• 1997

The present study was carried out to investigate the effects of Panax ginseng saponin extracts on the dexamethasone-induced apoptosis of mouse thymus in vivo and mouse thymocytes in vitro. The saponin fractions of red ginseng (R-SAP) and white ginseng (Wl-SAP) were provided by the Korea Ginseng & Tobacco Research Institute, and the other saponin fraction of white ginseng (W2-SAP) was extracted in our laboratory. 1. The male ICR mice (3~4 wk old; weighing 15$\pm$2 g) were given by each saponin fraction of 5 mg/kg/ day for 4 days, and at one hour after the last treatment, they were injected by deuamethasone (5 mg/kg : DX). The mouse thymus was extracted at 6 hours after DX injection, and they were stained with hematoxylin-eosin reagents and an Apop-Tag kit, respectively, and the thymocytes prepared from it were labelled with anti-mouse FITC-anti-CD4 and anti-mouse PE-anti-CD8 and then analyzed by fluorescence activated cell sorter (FACS). DX-induced reduction of thymus weight was significantly attenuated by W2- SAP but was not affected by other saponin fractions. And DX-induced apoptotic death of thymocytes, appeared in the histologic findings of the thymus, was inhibited by the saponin fractions and the order of these inhibitory potencies was R-SAP》W2-SAP>Wl-SAP. However, in respect of T cell receptors, the differentiation of thymocytes seems not to be changed by treatments with DX or/and the saponin fractions. 2. In the primary thymocyte culture, the DX-induced reduction of thymocyte MTT values was rather greater in RPMI 1640 medium of IWc fetal bovine serum (FBS) or horse serum (HS). In addition, the DX-Induced MTT reduction was significantly inhibited by R-SAP or W2-SAP, in the culture using that medium of 5% FBS or HS. But these saponin fraction did not effected the DX-induced reduction of thymocyte MTT value in primary culture of 10% FBS or 10% HS. These results suggest that R-SAP and some W-SAP fractions may protect thymocyte from stress or glucocorticoisteroid-induced death of them.

• Toxicological Research
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• v.13 no.1_2
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• pp.39-48
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• 1997

Cyclophosphamide(25, 50 or 100 mg/kg), orally administered to male Sprague-Dawley rats, caused a time- and dose-dependent thymic atrophy. In the light microscopic examination of the atrophic thymus, thymocytes with condensed or fragmented nucleus were multifocally observed in the cortical region, started to increase 8 hr after CPA treatment and reached to the maximal level at 16 hr, although such cells were not seen after 48 hr when the severe depletion of thymocytes were marked. In agarose gel electrophoresis to analyze the DNA changes, DNA extracted from atrophic thymus showed a oligonucleosomal laddering at the corresponding time to morphological changes. In an additional supportive experiment, thymocytes showing morphological changes, nuclear condensation or apoptotic body, exhibited a positive reaction to immunoperoxidase staining using in situ apoptosis detection kit. Separately, agarose gel electrophoresis of DNA from bone .marrow cells was performed to investigate the involvement of bone marrow cells in the process of thymocyte apoptosis. Although DNA laddering was slightly increased 2 and 4 hr after treatment, no clear correlation was inferred. Taken togather, it is concluded that thymocytes showing morphological changes in thymic atrophy induced by cyclophosphamide administration represent an apoptosis having biochemical nature of programmed cell death.

• Animal cells and systems
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• v.1 no.4
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• pp.657-663
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• 1997

The CD4 and CDS coreceptors, in conjunction with the T cell receptor (TCR) , make important contributions to the differentiation of thymocytes. They have been shown to be involved in the clonal deletion and positive selection processes during T cell development in thymus. To further analyze the role of CD4 and CDS proteins during T cell differentiation, we have generated transgenic mice constitutively expressing high levels of a native CD4 and a CD4{CDSa hybrid protein. The hybrid protein is composed of CD4 extracellular domain linked to the CD8a transmembrane region and cytoplasmic tail. The transgenes were driven by human beta-actin promoter, and therefore, they were expressed in all tissues examined including thymus, spleen, and lymph nodes. The resulting CD4 and CD4{CD8${\alpha}$transgenic mice were found to express the CD4 and CD4{CD8${\alpha}$ respectively, in developing thymocytes and peripheral T cells. The expression levels of transgenic proteins were 5-10 times higher than that of endogenous CD4 in thymus. However, total surface CD4 expression (CD4 or CD4{CD8${\alpha}$ transgenic protein plus endogenous CD4) of the transgenic mice were main. tained at similar levels compared to control littermates. Surface CD4 expression on CDS T cells, however, was significantly lower than that on cells expressing endogenous CD4. These results suggest that a total avidity between developing thymocytes and thymic stromal cells is impor. tant for differentiation of thymocytes.

• The Korea Journal of Herbology
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• v.23 no.3
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• pp.141-147
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• 2008

Objectives : The cortex and root of Acanthopanax sessiliflorus (AR), a herbal medicine, have been used for several diseases including cancer in Oriental countries. Recently, we reported that AR has an immune-potentiating action. Oga-Power(OP) was made using extract from AR. For these reasons, we hypothesized that OP can potentiate the immune system in terms of accelerating proliferation rates of immune cells such as thymocytes and splenocytes. Methods : In this experiment, proliferation rates of thymocytes and splenocytes were measured using modified 3-[4,5-dimethy -lthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT). No production levels in macrophages isolated from normal mice were measured using Griess method. Results : In our results, treatment with OP accelerated proliferation rates of splenocytes, but did not affect those of thymocytes in vitro. On the other hand, proliferation rates of thymocytes was elevated in vivo. In addition, level of NO production from macrophage separated from abdominal cavity of normal mice was elevated by treatment with OP. Conclusions : In conclusion, OP has immune-potentiating action, by acceleration of splenocyte proliferation and elevation of NO production level from macrophages.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.19 no.1
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• pp.55-64
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• 2006

Objective : The purpose of this study was to investigate effect of Gungguitakli-San(GTS) on the anti-tumor, immunocytes. Methods : This study estimated the proliferation of L1210 and S-180 cell lines, mouse splenocytes and thymocytes in vitro, and estimated the proliferation of L1210 cell, S-180 cell, thymocytes and splenocytes and body weight in S-180 cells-transplanted mice. The cytotoxicity and proliferation of cells were tested using a colorimetric tetrazoliun assay(M1T assay). Results : The results of this study were obtained as follow ; 1. GTS was significantly increased in the proliferation of thymocytes and splenocytes In vitro. 2. GTS was significantly showed cytotoxicity on the L1210 cell lines and 8-180 cell lines in vitro. 3. GTS was significantly showed cytotoxicity on the L1210 cell lines in vivo. 4. GTS was significantly increased in the weight of mice and decreased weight of sarcoma, in S-180 cells transplanted mice. 5. GTS was significantly increased in the period of survive, in S-180 cells transplanted mice. Conclusions : The author thought that GTS had action of anti-cancer by becoming immunocytes activity and by cytotoxicity of cancer cells.

• Journal of Physiology & Pathology in Korean Medicine
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• v.21 no.5
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• pp.1219-1225
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• 2007

Immunological activities of Ginseng Radix water extract (GE) were compared with theirs of Insamhodo-tang water extract (IHT). GE and IHT (500 mg/kg) were administered p.o. twice a day for 5 days to C57BL/6 mice, respectively. IHT decreased the cell viability of murine thymocytes and splenocytes, but increased the population of $CD4^+$ cells in thymocytes, and the population of $Thy1^+$ cells and $CD4^+$ cells in splenocytes in contrast to GE. In addition, IHT decreased the phagocytic activity of peritoneal macrophages, but increased the production of nitric oxide from peritoneal macrophages in contrast to GE. These results suggest that IHT decrease a specific- and nonspecific immune reaction in comparison with GE.

• The Journal of Pediatrics of Korean Medicine
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• v.15 no.2
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• pp.15-30
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• 2001

The purpose of this research was to investigate the effects of BITG on immune response in the young mice. BITG(500mg/kg) was administerd per orally once a day for 7 days to the young BALB/C(4 wks old)mice. The administrationo of BITG enhanced the cell viability of splenocytes, but did not affect that of thymocytes. In vitro system, BITG decreased the cell viability of thymocytes and splenocytes at the concentration of $100{\mu}g/m{\ell}$. The administration of BITG did not affect DNA fragmentation of thymocytes, but decreased that of splenocytes. The administration of BITG increased the population of Thy1+ cell and CD4+CD8- cell in splenocytes. In addition, BITG decreased the production of NO and increased the lucigenin chemiluminescence from peritoneal macrophages. These results suggest that BITG enhances the specific-immune and nonspecific-immune response via increase of cell viability in splenocytes and of phagocytic activity in peritoneal macrophages.

• Journal of Physiology & Pathology in Korean Medicine
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• v.17 no.3
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• pp.656-661
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• 2003

The specific immune response of unripened fruits and ripened fruits of Rubus coreanus Miquel was examined in BALB/C mice. The 70% ethyl alcohol extracts (20 or 100 mg/kg) of unripened fruits (RCE-I) and of ripened fruits (RCE-II) were administered p.o. once a day for 7 days. RCE-I and RCE-II decreased the viability of thymocytes, but increased the viability of splenocytes. Also, RCE-I enhanced the population of helper T and cytotoxic T cells in thymocytes and RCE-II enhanced the population of helper T cells. Furthermore, RCE-I and RCE-II decreased the population of B220/sup +/ cells and Thy1/sup +/ cells and helper T cells in splenocytes. In a general way, the immunosuppressive action of RCE-I was more potent than those of RCE-II. These results suggest that RCE-I and RCE-II have a regulative action of immune response via decrease the viability of thymocytes and increase the viability of splenocytes.

• Korean Journal of Veterinary Research
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• v.39 no.6
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• pp.1112-1118
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• 1999

Galectin-3 plays an important role in cell development, differentiation and cancer metastasis, including cell-cell/extracellular matrix (ECM) interactions and is supposed to have an effect of apoptosis on T-cells in thymic clonal selection. In this study, to know the effect of galectin-3 on thymocyte development, we used recombinant human galectin-3 (rHgal-3) from Escherichia coli, JM105, which was inserted with human gal-3 gene-transformed plasmid vector (prGal-3) to express human galectin-3. Expressed rHgal-3 was confirmed by western blot using the culture supernant of hybridoma (M3/38) producing monoclonal antibody to human galectin-3. Sepharose gel affinity chromatography was used to purify the expressed rHgal-3. Thymocytes and hepatocytes from 6-week-old male BALB/c mice were incubated with rHgal-3 and showed marked increase of apoptotic population on analysis using flow cytometry with 7-AAD in a dosedependent manner. However, rHgal-3 failed to induce apoptosis on hepatocytes. Interestingly, this apoptotic effect was not inhibited by lactose, a specific lectin domain inhibitor. From these results, we concluded that extrinsic -3 induces apoptosis on mouse thymocytes, and galectin-3 may have an apoptotic effect on T-cells in thymic clonal selection.