• Journal of Microbiology and Biotechnology
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• v.22 no.8
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• pp.1066-1076
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• 2012

Previous observations demonstrated that various immunosuppressive agents and their combination therapies can increase allograft survival rates. However, these treatments may have serious side effects and cannot substantially improve or prolong graft survival in acute graft-versus-host disease (GVHD). To improve the therapeutic potency of divalent immunoadhesins, we have constructed and produced several tetravalent forms of immunoadhesins comprising each of cytotoxic T-lymphocyte-associated antigen-4 (CTLA4), CD2, and lymphocyte activation gene-3 (LAG3). Flow cytometric and T cell proliferation analyses displayed that tetravalent immunoadhesins have a higher binding affinity and more potent efficacy than divalent immunoadhesins. Although all tetravalent immunoadhesins possess better efficacies, tetravalent forms of CTLA4-Ig and LAG3-Ig revealed higher inhibitory effects on T cell proliferation than tetravalent forms of TNFR2-Ig and CD2-Ig. In vitro mixed lymphocytes reaction (MLR) showed that combined treatment with tetravalent CTLA4-Ig and tetravalent LAG3-Ig was highly effective for inhibiting T cell proliferation in both human and murine allogeneic stimulation. In addition, both single tetravalent-form and combination treatments can prevent the lethality of murine acute GVHD. The results of this study demonstrated that co-blockade of the major histocompatibility complex class (MHC)II:T cell receptor (TCR) and CD28:B7 pathways by using tetravalent human LAG3-Ig and CTLA4-Ig synergistically prevented murine acute GVHD.

• YAKHAK HOEJI
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• v.49 no.1
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• pp.92-96
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• 2005

In order to investigate the effects of bisphenol A (BPA) on cell mediated immune reaction in vitro we examined the allogenic mixed lymphocyte reaction (MLR), splenocytes proliferation (SP) to T cell mitogens and IFN-${\gamma}\;production$. Splenocytes of Balb/c mice ($1.5{\times}10^5$ cells/well) were co-cultured with different numbers of mitomycin C-treated mature dentritic cells (DCs) in presence of BPA (25, 50, 100 ${\mu}M$) and $[^{3}H]$thymidine incorporation (cpm) was measured by scintilation counting. Splenocytes ($2{\times}10^6$ cells/well) were cultured with mitogens, Con A ($2\;{\mu}g/ml$), PHA ($5\;{\mu}g/ml$) and IL-2 ($0.1\;{\mu}g/ml$), or PMA ($5\;{\mu}g/ml$) and INO ($1\;{\mu}g/ml$) in presence of BPA (1, 10, 25, 50, 100 ${\mu}M$) and SP was assessed by MTT assay. $IFN-{\gamma}$ levels in culture supernant were determined by ELISA. At low concentration, BPA slightly increased MLR, SP and $IFN-{\gamma}$ levels, but at higher concentration it showed significant inhibitory effects on these immunological parameters. These results indicate that BPA is able to alternate cell-mediated immune reaction.

• Archives of Pharmacal Research
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• v.17 no.4
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• pp.236-239
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• 1994

The suppressive activity of isoflavonoids against lymphocyte proliferation in vitro was examined. Isoflabvonoid derivatives tested were isflavones isolated from Pueraia radix and synthesized 7-O-substituted biochanin A derivatives. The certain isoflavones such as biochanin A and 2-carbethoxybiochainin A were found to possess the suppressive activity against concanavaline A (Con A)-induced lymphocyte proliferation from mouse spleen. Against mixed lymphocyte culture reaction, biochanin A, 2-carbethoxybiochainin A, daidzein, formononetin, genistein and 7-O-isopropylbiochaninl A showed the suppressive activity at $10^{-5}$ M. However, all isoflavones tested did not show the suppressive activity against lymphocyte proliferation induced by B-cell mitogen, lipopolysaccharide (LPS). In general, isoflavones were revealed to be less active than flavones/flavonols.

• Archives of Pharmacal Research
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• v.23 no.6
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• pp.626-632
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• 2000

Brazilin, an active principle of Caesalprenia sappan, was examined for its immunopotentiating effects in multiple low dose streptozotocin (MLD-STZ) induced type diabetic mice. Brazilin was intraperitoneally administered for 5 consecutive days to MLD-STZ induced type 1 diabetic mice. Delayed type hypersensitivity, Con A-induced proliferation of splenocytes and mixed lymphocyte reaction, which had been decreased in diabetic mice, were significantly recovered by the administration of brazilin. Brazilin increased IL-2 production without affecting suppressor cell activity. Con A-induced and IL-2-induced expression of high affinity IL-2 receptors were also enhanced by brazilin. These results indicate that brazilin augments cellular immune responses, which are suppressed in the MLD-STZ induced type I diabetic mice, by increasing IL-2 production and responsiveness of immune cells to IL-2.

• BMB Reports
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• v.30 no.6
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• pp.385-389
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• 1997

Many cell types are known to stimulate $CD8^+$ T cells in allogeneic recognition such as mixed lymphocyte reaction (MLR). Whereas dendritic cells are most potent among them. T cells are usually considered very poor in stimulating $CD8^+$ T cells although there are some tumor cells that are weakly stimulatory. T cells, as a stimulator, cultured in the presence of concanavalin A that were otherwise nonstimulatory to $CD8^+$ T cells appeared to stimulate $CD8^+$ T cells strongly when they were pretreated with neuraminidase. The enhancement of MLR by neuraminidase could be achieved by treating either the stimulators or responders with neuraminidase. Removal of negatively-charged sialic acid moieties from the cell surface, which reduced electrostatic repulsion between responders and stimulators to give better cell-cell contact might be responsible for the enhanced MLR. In addition, neuraminidase treatment also appeared to deliver activation signal to responding T cells since it could activate $CD8^+$ T cells in synergy with phorbol myristate acetate. The maximal responses were observed when both responders and stimulators were treated with neuraminidase.

• Archives of Pharmacal Research
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• v.26 no.3
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• pp.192-196
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• 2003

This study describes the synthesis of novel enol esters (3) and triketones (4) as analogues of succinylacetone (SA) (Ed- this abbreviation is introduced here based on your use of it in the body of the paper) and the evaluation on the mouse allogeneic mixed lymphocyte reaction (MLR) and the murine model of antigen-induced paw edema formation for immunosuppressive activity. Enol esters (3a-f) were about 2-4 fold more potent than SA in in vitro activity.

• Proceedings of the PSK Conference
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• 2003.04a
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• pp.166.1-166.1
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• 2003

We investigated the effects of bisphenol A (BPA), endocrine disruptor, on the mixed lymphocyte reaction and TNF-$\alpha$ production of antigen presenting cells in mice. Cells from mouse (C57BL/6) bone marrow were cultured with GM-CSF for 8 days and mature dendritic cells (DCs) were prepared. These DCs proliferation in response to Balb/c splenocytes was measured at 72 h of culture with BPA by tritiated thymidine incorporation ([3H]TdR) and [3H]TdR incorporation was determined by scintilation counting. (omitted)

• The Journal of the Korean Society for Microbiology
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• v.16 no.1
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• pp.65-70
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• 1981

A microculture technique for the mixed lymphocyte culture test(MLC) in the sheep is described. The optimal incubation periods for the MLC are varied from 4 to 6 days depending on the sources of lymphocytes. It is found that a 2.5:1 stimulator-responder cell ratio and the responder cell concentration of $1{\times}10^5$ cells/well produce the highest($^3H$)-thymidine incorporation. Moreover cryopreservation of bovine lymphocytes results in satisfactory and reproducible MLC reaction. It is also evident that the MLC reactions of the sheep are under the control of histocompatibility matching between the stimulator cells and the responder cells. Significance of the technique as a too! for study on cell mediated immunity in sheep system, either normal or squamous cell carcinoma-bearing, are discussed.

• Journal of Veterinary Clinics
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• v.28 no.4
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• pp.399-402
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• 2011

In recent years, the mesenchymal stem cells (MSC) derived from various tissues have been widely tested for developing cell therapies, tissue repair and transplantation. Although there has been much interest in the immunomodulatory properties of MSC and their immunologic reactions following autologous, allogeneic and xenogenic transplantation of MSC in vivo, up to date, the expression of immunogenic markers, such as class I and II human leukocyte antigens (HLA), after differentiation of human umbilical cord blood (hUCB)-derived MSC has been poorly investigated and require extensive in vitro and in vivo testing. In this experiment, the expression of the HLA-ABC and HLA-DR on hUCB-derived MSC have been tested by immunocytochemical staining. The undifferentiated MSC were moderately stained for HLA-ABC but very weakly for HLA-DR. In order to investigate the inhibitory effect of allogeneic lymphocytes on proliferation of MSC, the MSC were cultured in the presence or absence of peripheral allogeneic lymphocytes stimulated with concanavalin A. The allogeneic lymphocytes did not significantly inhibit MSC proliferation. We conclude that hUCB-MSC expressed moderately class I HLA antigen while almost negatively class II HLA antigen. The MSC have an immunomodulatory effect which can suppress the allogeneic response of lymphocytes. These in vitro data suggest that allogeneic MSC derived from cord blood can be useful candidate for allogeneic cell therapy and transplantation without a major risk of rejection.

• Biomolecules & Therapeutics
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• v.1 no.2
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• pp.236-243
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• 1993

Immunologic potential of DA-125, a new anthracycline antitumor antibiotic, was investigated using guinea pigs and mice. In antigenicity experiments, guinea pigs were sensitized subcutaneously with DA-125 or DA-125 incorporated in complete Freund's adjuvant (CFA) once a week for three weeks. No systemic anaphylaxis was induced by intravenous injection of DA-125 or DA-125 incubated with guinea pig serum after 3 weeks from the last sensitization. None of sera of these animals showed any passive cutaneous anaphylactic reaction (PCA) when DA-125 or DA-125 incubated with guinea pig serum was used as a challenging antigen in homologous PCA experiment. On the other hand the treatment of guinea pigs with ovalbumin Incorporated in CFA induced systemic anaphylactic reaction when challenged by intravenous injection of 5 mg/body of ovalbumin. Immunodiffusion test revealed no precipitating antibodies as detected in guinea pigs sensitized with DA-125. In 24-hour heterologous PCA reaction with sera of C57BL/6 mice immunized with DA-125 or DA-125 mixed with aluminum hydroxide gel (Alum), None of sera showed positive reaction when DA-125 or DA-125 incubated with rat serum was used as a challenging antigen. Sera of animals immunized with a mixture of ovalbumin and alum showed positive PCA reaction when 5 mg/body of ovalbumin was injected as a challenging antigen. In lymphocyte proliferation tests, spleen lymphocyte proliferation to PHA and LPS was similarly impaired by 12 mg/kg of DXR or 36 mg/kg of DA-125, and the immunodepressive activity of DA-125 showed a dose-dependent manner. From these results, it could be concluded that immunosupression of DA-125 would be comparable to that of DXR and that DA-125 would not induce systemic allergic reaction in its clinical use.