• IMMUNE NETWORK
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• v.2 no.3
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• pp.133-136
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• 2002

Background: The costimulatory molecule 4-1BB, a member of nerve growth factor receptor/tumor necrosis factor (NGFR/TNFR) super family, is involved in cell survival and death. Methods: In this study, female C57BL/6 ($H-2^b$) mice were used as a recipient, and DBA/2 ($H-2^d$) as a donor to assess a mixed lymphocyte reaction (MLR) and CTL response in vitro, and skin graft survival. IL-2, IFN level was measured by ELISA. Results: Mixed lymphocyte reaction (MLR) analysis showed that 4-1BB-deficient responder cells showed enhanced cellular proliferation over littermate controls. In contrast, IL-2 production was diminished only in 4-1BB knockout cultures. The IFN expression, on the other hand, was comparable between the groups. When female C57BL/6 ($H-2^b$) mice were grafted with the trunk skin of DBA/2 ($H-2^d$) mice, the in vivo tissue destruction of 4-1BB-deficient mice was not distinct from the normal littermates. Conclusion: These data suggest that 4-1BB is critical for the induction of alloreactive responses in vitro but 4-1BB alone could not change the course of skin rejection in vivo.

• Toxicological Research
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• v.11 no.1
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• pp.15-21
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• 1995

Several populations of lymphocytes possess receptors for autonomic neurotransmitter, which make lymphocytes susceptible to autonomic stimulation. This study was to evaluate the functional alternation of effector cells of the immune system. Female Balb/C mice, 15-20 g, were injected with MA subcutaneously under various conditions. Mixed lymphocyte reaction (MLR) showed certain T cell subsets were affected by MA. The level of interleukin-2 (IL-2) production was inhibited due to a defect in expression of the IL-2 receptor. In mice injected with 20 mg MA/kg, 1 day before assay, phagocytosis of peritoneal macrophages showed $14.07\pm3%$, which was similar degree to 5 mg MA/kg treatment for 4 consecutive days. Phagocytosis was almost recovered to that of control after 4 day in 20 mg/kg injected mice. Maximum inhibition of plaque forming cell (PFC) occurred when MA was given early, indicating the inductive time point of antibody production was affected. The cortisol level increased in the MA treated group (0.05, 0.20, and $0.08{\mu}g$/dl for control, low, and high dose-MA treated mice, respectively). Based on these results, MA has general suppression effects on the immune systems by functional alteration of effector cells. Considering the increment of serum cortisol levels, MA partially impacts the neuroendocrine system to lead to failure of immune response.

• YAKHAK HOEJI
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• v.38 no.6
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• pp.715-720
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• 1994

${\alpha}2-macroglobulin$ $({\alpha}2-M)$ has been shown to have a variety of activities. One of those activities is the suppression of immune response. Characterization of the immunosuppressive factor secreted by a T cell hybridoma showed that ${\alpha}2-M$ was produced and secreted from the T cell hybridoma. ${\alpha}2-M$ was produced abundantly from the T cell hybridoma when cultured as ascites. The isolation and identification of the ${\alpha}2-M$ were studied using affinity chromatography and N-terminal amino acid sequencing. The extended observations were that the ${\alpha}2-M$ produced by the T cell hybridoma suppresses mixed lymphocyte reaction.

• Journal of Microbiology and Biotechnology
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• v.18 no.8
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• pp.1431-1438
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• 2008

Immunomodulating activities of water-soluble exopolysaccharides (LL-EX) obtained from submerged mycelial culture of Lentinus lepideus were studied and their effectiveness was compared with lipopolysaccharide (LPS). The influence of the LL-EX on macrophage cellular lysosomal enzyme activity was to stimulate up to 267%, 392%, and 464% at the level of 10, 50, and $100{\mu}g/ml$, respectively. When the LL-EX was further fractionated into LL-Fr.I and Fr.II by Sepharose CL-6B gel chromatography, the cellular lysosomal enzyme activity of LL-Fr.II (2.1-fold) was higher than Fr.I (1.2-fold). Moreover, both LL-Fr.I and Fr.II stimulated the cytokines IL-1$\beta$, TNF-$\alpha$, and IL-6 in macrophages. In mixed lymphocyte reaction, LL-Fr.I and Fr.II enhanced the splenocyte proliferation up to 1.2-fold and 1.4-fold ($50{\mu}g/ml$), respectively, stimulating only T lymphocytes. The fractions of LL-EX not show any direct toxicity against human gastric adenocarcinoma cell (AGS). The molecular masses of LL-Fr.I and Fr.II were estimated to be about 1,986 kDa and 21 kDa, respectively. The total sugar and protein contents of the two fractions were 84.97% and 69.88%, and 15.03% and 30.12%, respectively. The sugar and amino acid compositions of the LL-Fr.I and Fr.II were also analyzed in detail.

• Journal of Microbiology and Biotechnology
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• v.18 no.10
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• pp.1709-1716
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• 2008

The porcine reproductive and respiratory syndrome Virus (PRRSV) is an infectious disease that causes abortions and respiratory disorders in swine. In this study, the interaction between PRRSV and porcine dendritic cells generated from $CD14^{+}$ monocytes in the presence of GM-CSF and IL-4 was examined. As a result, it was shown that immature and mature dendritic cells can be productively infected with PRRSV. When the expression of surface MHC molecules on infected dendritic cells was determined, MHC classes I and II were found to be downregulated when compared with un infected dendritic cells. With the exception of the IL-4 and IFN-$\gamma$ cytokines, the induction of the IL-10, IL-12, and TNF-$\alpha$ cytokines all increased in dendritic cells infected with PRRSV. A mixed lymphocyte reaction showed that peripheral blood mononuclear cells cocultured with PRRSV-infected dendritic cells were less stimulated than peripheral blood mononuclear cells cocultured with dendritic cells treated with PBS, LPS, or UV-inactivated PRRSV. Therefore, these results suggest that PRRSV would appear to modulate the immune stimulatory function of porcine dendritic cells.

• Toxicological Research
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• v.17
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• pp.217-218
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• 2001

In a series of our screening for immunomodulating substances, we isolated prodigiosin from the culture broth qf Serratia marcescens B-1231. This compound inhibited the T cell-mediated immune responses such as concanavalin A-induced proliferation, mixed lymphocyte response, local graft versus host reaction and T-dependent antibody response at nontoxic concentrations. However. prodigiosin did not effect B cell-mediated immune functions such as lipopolysaccharide-induced proliferation and -activated polyclonal antibody production at the same concentrations. Prodigiosin did not cause death in vitro to lymphocytes at effective concentrations (＜100 nM) and also did not show toxicity in vivo to lymphoid organs at effective dos-ages (10 and 30 mg/kg). The pharmacological potencies were comparable to the activities of well-known T-cell specific immunosuppressants such as cyclosporin A. In our continuing study, mechanism of action of PDG is investigated with respect to the effect of PDG on IL-2/IL-2R pathway and transcription factor.

• Journal of Microbiology and Biotechnology
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• v.14 no.1
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• pp.15-21
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• 2004

The immunomodulating activities and chemical characteristics of a water-soluble exopolymer from submerged mycelial culture of Phellinus pini were studied. Anticomplementary activity of this polymer was found to be $73.2\%$, and its activation system occurred through both classical and alternative pathways, where the classical pathway was detected to be the major one by crossed immunoelectrophoresis. Nitric oxide (NO) release ability and acid phosphatase activity of macrophage were increased by 1.6-fold ($100{\mu}g/ml$) and 3.4-fold ($500{\mu}g/ml$), respectively, and splenocyte proliferation in mixed lymphocyte reaction (MLR) was also increased by 2.6-fold ($200{\mu}g/ml$), compared to the control. The molecular weight of this polymer, determined by HPLC, was under 5 kDa. Total sugar and protein contents were 89.7 and 10.3%, respectively. Both sugar and amino acid compositions of the exopolymer were also analyzed.

• IMMUNE NETWORK
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• v.13 no.1
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• pp.16-24
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• 2013

CTLA-4Ig is regarded as an inhibitory agent of the T cell proliferation via blocking the costimulatory signal which is essential for full T cell activation. To improve applicability, we developed the CTLA-4Ig-CTKC in which the c-terminal lysine had been replaced by cysteine through single amino acid change. The single amino acid mutation of c-terminus of CTLA-4Ig was performed by PCR and was checked by in vitro transcription and translation. DNA construct of mutant form was transfected to Chinese hamster ovary (CHO) cells by electroporation. The purified proteins were confirmed by Western blot and B7-1 binding assay for their binding ability. The suppressive capacity of CTLA-4Ig-CTKC was evaluated by the mixed lymphocyte reaction (MLR) and in the allogeneic pancreatic islet transplantation model. CTLA-4Ig-CTKC maintained binding ability to B7-1 molecule and effectively inhibits T cell proliferation in MLR. In the murine allogeneic pancreatic islet transplantation, short-term treatment of CTLA-4Ig-CTKC prolonged the graft survival over 100 days. CTLA-4Ig-CTKC effectively inhibits immune response both in MLR and in allogeneic islet transplantation model, indicating that single amino acid mutation does not affect the inhibitory function of CTLA-4Ig. CTLA-4Ig-CTKC can be used in vehicle-mediated drug delivery system such as liposome conjugation.

• IMMUNE NETWORK
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• v.3 no.4
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• pp.302-309
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• 2003

Background: CTLA4 (CD152), which is expressed on the surface of T cells following activation, has a much higher affinity for B7 molecules comparing to CD28, and is a negative regulator of T cell activation. In contrast to stimulating and agonistic capabilities of monoclonal antibodies specific to CTLA-4, CTLA4Ig fusion protein appears to act as CD28 antagonist and inhibits in vitro and in vivo T cell priming in variety of immunological conditions. We've set out to confirm whether inhibition of the CD28-B7 costimulatory response using a soluble form of human CTLA4Ig fusion protein would lead to persistent inhibition of alloreactive T cell activation. Methods: We have used CHO-$dhfr^-$ cell-line to produce CTLA4Ig fusion protein. After serum free culture of transfected cell line we purified this recombinant molecule by using protein A column. To confirm characterization of fusion protein, we carried out a series of Western blot, SDS-PAGE and silver staining analyses. We have also investigated the efficacy of CTLA4Ig in vitro such as mixed lymphocyte reaction (MLR) & cytotoxic T lymphocyte (CTL) response and in vivo such as experimental autoimmune encephalomyelitis (EAE), graft versus host disease (GVHD) and skin-graft whether this fusion protein could inhibit alloreactive T cell activation and lead to immunosuppression of activated T cell. Results: In vitro assay, CTLA4Ig fusion protein inhibited immune response in T cell-specific manner: 1) Human CTLA4Ig inhibited allogeneic stimulation in murine MLR; 2) CTLA4Ig prevented the specific killing activity of CTL. In vivo assay, human CTLA4Ig revealed the capacities to induce alloantigen-specific hyporesponsiveness in mouse model: 1) GVHD was efficiently blocked by dose-dependent manner; 2) Clinical score of EAE was significantly decreased compared to nomal control; 3) The time of skin-graft rejection was not different between CTLA4Ig treated and control group. Conclusion: Human CTLA4Ig suppress the T cell-mediated immune response and efficiently inhibit the EAE, GVHD in mouse model. The mechanism of T cell suppression by human CTLA4Ig fusion protein may be originated from the suppression of activity of cytotoxic T cell. Human CTLA4Ig could not suppress the rejection in mouse skin-graft, this finding suggests that other mechanism except the suppression of cytotoxic T cell may exist on the suppression of graft rejection.

• Archives of Plastic Surgery
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• v.32 no.4
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• pp.533-538
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• 2005

Due to its safety and softness, autologous fat transplantation has been commonly performed for soft tissue correction. However, the injected fat is absorbed resulting in the reduction of volume of the graft by 40-60% within a few months. Thus, there was an attempt to use adipocytes differentiated from preadipocytes in vitro for transplantation. Differentiated adipocytes were biocompatible and matured with gradual volume increase at transplantation site in clinical study(unpublished data). In addition, they did not induce immune rejection in response to nonself lymphocytes in a mixed lymphocyte reaction(MLR)(unpublished data). The purpose of this study is to differentiate mouse preadipocytes following labeling into adipocytes to establish an animal model for allogenic transplantation. Preadipocytes isolated from inguinal and retroperitoneal fat pad of C57BL/6 mice were proliferated with growth medium by passage 3 and differentiated into adipocytes with different culture conditions after labeled with BrdU. At most suitable conditions, above 90% of preadipocytes were differentiated and BrdU labeling did not affect differentiation rate and function of differentiated adipocytes. These results demonstrate that BrdU-labeled adipocytes resulting from this in vitro differentiation protocol are useful for allogenic transplantation study.