• Asian-Australasian Journal of Animal Sciences
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• v.20 no.6
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• pp.954-961
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• 2007

The experiments were conducted to determine effects of a mixture of conjugated linoleic acid (CLA) isomers on T cell subpopulations and responsiveness to mitogen of splenocytes in male broiler chicks. In experiment 1, birds (8-d old) were fed basal, CLA-(CLA) and safflower oil-supplemented (SA) diets which were formulated by supplementary 10 g CLA or safflower oil/kg to the basal diet for 14 d. Broiler starter diet, which mainly consisted of corn and soybean meal, was served as the basal diet. Proliferative response and interleukin (IL)-2-like activity stimulated by concanavalin (Con) A at a concentration of $10{\mu}g/ml$ of splenocytes in chicks fed the CLA diet were greater than in chicks fed the SA diet, but not at $20{\mu}g$ Con A/ml. Percentage of CD3-positive T cells in splenocytes did not differ between chicks fed the SA diet and CLA. Ratio of CD4-positive T cells to CD8- positive T cells was significantly affected by dietary fat source. In experiment 2, broiler chicks (1-d old) were fed the same diets as in experiment 1 for 14 d. Results of splenocyte proliferation to Con A were similar to those in experiment 1, but phytohemaggulutinin (PHA)- or pokeweed mitogen (PWM)- induced splenocyte proliferation did not differ between the CLA and SA fed groups. Supplementation with SA or CLA to the basal diet tended to have a depressive effect on the proliferation, with the greater effect being that of SA. In experiment 3, effect of an addition of CLA to splenocyte culture medium on splenocyte proliferation was determined. An addition of CLA to the culture medium resulted in reduction of the splenocyte proliferation to Con A, but an addition of linoleic acid. When PWM and PHA were used as mitogen, the inhibitory effect of CLA and linoleic acid on the proliferation did not differ. The results suggested that the effect of dietary CLA on splenocyte proliferation was similar to that of SA, although the effect of dietary CLA on sub-populations was slightly different from that of dietary SA. Further studies are needed to clarify whether use of CLA would be beneficial for maintaining or enhancing T cell immunity in chicks.

• BMB Reports
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• v.49 no.7
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• pp.370-375
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• 2016

Ras oncoproteins are small molecular weight GTPases known for their involvement in oncogenesis, which operate in a complex signaling network with multiple effectors. Approximately 25% of human tumors possess mutations in a member of this family. The Raf1/MEK/Erk1/2 pathway is one of the most intensively studied signaling mechanisms. Different levels of regulation account for the inactivation of MAP kinases by MAPK phosphatases in a cell type- and stimuli-dependent manner. In the present study, using three inducible Ras-expressing NIH/3T3 cell lines, we demonstrated that MKP3 upregulation requires the activation of the Erk1/2 pathway, which correlates with the shutdown of this pathway. We also demonstrated, by applying pharmacological inhibitors and effector mutants of Ras, that induction of MKP3 at the protein level is positively regulated by the oncogenic Ras/Raf/MEK/Erk1/2 signaling pathway.

• Proceedings of the Korea Environmental Mutagen Society Conference
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• 2003.10a
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• pp.175-175
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• 2003

• The Microorganisms and Industry
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• v.17 no.1
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• pp.29-31
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• 1991

B 세포이 가장 중요한 기능은 항체를 생산하여 체액성 면역반응을 조절하는 일이다. B 세포가 항체를 생산해 내는 형질세포(plasma cell)로 분화하기 위해서는 다음의 몇 가지 단계를 거쳐야 한다. 즉 resting 상태에서 mitogen이나 항원의 자극에 의한 활성화(activation)가 첫번째 단계이고 두번째로는 증식(proliferation)이며 마지막 단계가 분화(differentiation)이다. B 세포가 일단 mitogen이나 항원에 의해 활성화가 되면 활성화 된 clone의 증식과 분화는 T 세포에서 생산되는 여러 종류의 림포카인(lymphokine)의 영향하에서 이루어진다. 따라서 B 세포 기능에 영향을 미치는 림포카인의 종류를 알아내고 최근 새롭게 발견되는 림포카인의 B 세포에 대한 영향을 연구함이 중요하리라 생각된다. 여기에서는 B 세포 기능에 영향을 미치는 여러 림포카인의 종류의 그 기능에 관해서 간략하게 기술하고자 한다.

• Journal of fish pathology
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• v.13 no.2
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• pp.103-110
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• 2000

The immunostimulatory effects of quaternary ammonium compounds(QACs) were investigated in leucocytes of eel(Anguilla japonica) in vitro. Proliferation of peripheral blood lymphocytes(PBLs) was no significantly affected by QACs, regardless of mitogen(PHA, ConA and LPS) and the concentration of QACs added. QACs heightened the leucocytes function such as respiratory burst activity, phagocytosis and pinocytosis, resulting in significantly increased the bactericidal activity of macrophages. These results suggested that QAC might modulate the immune responses by activation of leucocytes function but not by increment of immunocompetent cell numbers.

• Parasites, Hosts and Diseases
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• v.25 no.1
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• pp.1-6
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• 1987

This study was to observe the changes of blastogenic responses of splenic Iymphocytes to T-cell mitogens, N. fcwleri Iysate and concanaualin A, and serum antibody titer during the course of experimental PAM in mice. Naegleria fcwleri, strain 0359, was cultured in the CGVS medium axenically and inoculated intranasally with $7{\times}10^4$ trophozoites for the development of experimental PAM in mice. The amoebae were subjected to ultrasonication and centrifuged at 20,000g for 60 minutes, and filtered through $0.2{\mu\textrm{m}}$ filter membrane. The supernatant, N. fcwleri Iysate, was used as T-cell mitogen, and antigen for ELISA. The serum antibody was examined by ELISA using peroxidase conjugate. Two hundred ${\mi}l$ of $10^6$ splenocytes in RPMI 1640 containing 0% fetal calf serum were added to each well of a microtiter plate. To each well was added T-cell mitogens, $100{\mu}g/ml$ of N. fowleri Iysate or $4{\mu}g/ml$ of con. A, and the plates were incubated for 42 hours at $37^{\circ}C$ in 5% $CO_2$ incubator. Cultures were pulsed with of $methyl-(^3H)-thymidine$ 6 hour before harvesting. The mean blastogenic response of the splenocytes to N. fewleri Iysate was reduced, whereas that to con. A was also reduced up to on day 11 after infection. Both of these results were statistically significant compared with those of uninfected control group. The serum antibody titers were increased gradually up to day 15. The results indicated that there was an impairment of the blastogenic response of splenocytes to N. fowleri Iysate during the acute course of experimental PAM in mice.

• Archives of Pharmacal Research
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• v.15 no.4
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• pp.275-282
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• 1992

The present work was designed to investigate the effects of barzilin on ConAinducedd TCGF release, responsiveness to standardd IL-2, and mitogens-induced proliferation of splenocyte when administered intraperitoneally to 8 week-old C57BL/6 mice for 2 consecutive days. Immunological tests were performed 72 hours after the treatment of brailin. The administration of 50 mg/kg brazilin caused a noticeable increase in TCGF release and responsiveness to standard II-2 but inhibited mitogens-induced proliferation of splenocyte. These results that brazilin is able to modular immunological functions despite of its inhibitory effect on mitogen induced cell proliferation.

• YAKHAK HOEJI
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• v.43 no.2
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• pp.208-213
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• 1999

The effects of five lupane-triterpenoids from leaves of two Acanthopanax spp., chiisanogenin, chisanoside and $22{\alpha}-hydroxychiisanogenin$, acakoreoside A and acantrifoside A on the mitogen-induced proliferation were investigated in vitro. T cell proliferation (TCP) to concanavalin A (Con A) and the B cell proliferation (BCP) to lipopolysaccharide (LPS) were increased by chiisanogenin. TCP to Con A was significantly increased by chiisanoside and acankoreoside A, but not affected by chiisanogenin, $22{\alpha}-hydroxychiisanogenin$ and acantrifoside A, BCP to LPS was significantly increased by acankoreoside A and acantrifoside A, and slightly increased by chiisanoside, chiisanogenin and $22{\alpha}-hydroxychiisanogenin$.

• Animal cells and systems
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• v.4 no.4
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• pp.341-345
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• 2000

It has been very difficult to develop and evaluate efficient fish vaccines because fish immune cells have not been properly characterized. In this study, we investigated the cell-mediated immunological properties of B- and T-like cells in Nile tilapia (Oreochromis nilotica). Surface immunoglobulin negative ($slg^{-}$) cell population proliferated in response to mammalian T-cell mitogens PHA and Con A, while surface immunoglobulin positive ($slg^{+}$) cells responded to the B-cell mitogen LPS. The slg$^{[-10]}$ cells from hemocyanin (HC)-immunized Tilapia, compared to the non-immunized control, reacted more to PHA than to Con A. Unexpectedly, antigen (Ag)-specific response was observed in both $slg^{-}$ and $slg^{-}$cells. Regardless of HC immunization, whole leukocytes from 8 head kidney of fish showed natural killer (NK)cell activity. Especially, NK cell activity was much higher in slg$^{[-10]}$ cells than in slg$^{+}$cells, indicating the possibility that fish NK cells were not at least associated with slg$^{+}$ cell population and not activated by Ag. Further understanding of functional fish immune cells will help to evaluate and develop effective vaccines for fishes and to monitor the course of therapy In infected fishes.hes.

• Archives of Pharmacal Research
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• v.18 no.4
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• pp.267-270
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• 1995

We examined the chronic effect of dextromethorphan(DM) on the cellular immune responses in mice. T cell simulator, phytohemagglutinin did not show singificant effect on lymphocyte proliferation. Costimulator of T and B cell, pokeweed mitogen, and B cell stimulator, lipopolysaccharide exhibited DM-induced decreased lymphocyte proliferation. Singificantly suppressed natural killer (NR) cell cytotoxicity was evidenced following 6 months DM exposure. These results suggest that chronic DM administration pertub B cell functioning and NK cell cytotoxicity. In addition, prenatal DM exposure did not potentiate the immunomodulation in postnatal effect induced by chronic DM.