Purpose Dexamethasone (Dex) has long been used as a potent immunosuppressive agent in the treatment of inflammatory and autoimmune diseases, despite serious side effects. In the present study, Dex and model antigen ovalbumin (OVA) were encapsulated with poly(lactic-co-glycolic acid) to deliver Dex and OVA preferentially to phagocytic cells, reducing systemic side effects of Dex. The OVA-specific immune tolerance-inducing activity of the nanoparticles (NPs) was examined. Methods Polymeric NPs containing OVA and Dex (NP[OVA+Dex]) were prepared by the water-in-oil-in-water double emulsion solvent evaporation method. The effects of NP[OVA+Dex] on the maturation and function of immature dendritic cells (DCs) were examined in vitro. Furthermore, the OVA-specific immune tolerizing effects of NP[OVA+Dex] were confirmed in mice that were intravenously injected or orally fed with the NPs. Results Immature DCs treated in vitro with NP[OVA+Dex] did not mature into immunogenic DCs but instead were converted into tolerogenic DCs. Furthermore, profoundly suppressed generation of OVA-specific cytotoxic T cells and production of OVA-specific IgG were observed in mice injected with NP[OVA+Dex], whereas regulatory T cells were concomitantly increased. Feeding of mice with NP[OVA+Dex] also induced OVA-specific immune tolerance. Conclusion The present study demonstrates that oral feeding as well as intravenous injection of poly(lactic-co-glycolic acid) NPs encapsulating both antigen and Dex is a useful means of inducing antigen-specific immune tolerance, which is crucial for the treatment of autoimmune diseases.

The active form of vitamin D 3 , 1,25-dihydroxyvitamin D 3 (aVD 3 ), is known to exert beneficial effects in the treatment of autoimmune diseases because of its immunosuppressive effects. However, clinical application of aVD 3 remains limited because of the potential side effects, particularly hypercalcemia. Encapsulation of aVD 3 within biodegradable nanoparticles (NPs) would enhance the delivery of aVD 3 to antigen presenting cells, while preventing the potential systemic side effects of aVD 3 . In the present study, polymeric NPs containing ovalbumin (OVA) and aVD 3 (NP[OVA+aVD 3 ]) were prepared via the water-in-oil-in-water double emulsion solvent evaporation method, after which their immunomodulatory effects were examined. Bone marrow-derived immature dendritic cells (DCs) treated with NP(OVA+aVD 3 ) did not mature into immunogenic DCs but were converted into tolerogenic DCs, which express low levels of co-stimulatory molecules and MHC class II molecules, produce lower levels of pro-inflammatory cytokines while increasing the production of IL-10 and TGF-β, and induce the generation of Tregs. Intravenous injection with NP(OVA+aVD 3 ) markedly suppressed the generation of OVA-specific CTLs in mice. Furthermore, OVA-specific immune tolerance was induced in mice orally administered with NP(OVA+aVD 3 ). These results show that biodegradable NPs encapsulating both antigen and aVD 3 can effectively induce antigen-specific immune suppression.

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Thapsigargin (TGN) is a potent and selective inhibitor of sarco-endoplasmic Ca2+-ATPase, leading to rapid elevation of cytoplasmic Ca2+ concentration. Previous reports have shown that TGN increases the production of various cytokines from macrophages and dendritic cells. Here, we examine the effects of TGN on murine T cells. Nanomolar concentrations of TGN are a significant inducer of IL-2 production with full activity at 50 nM. Micromolar concentrations of TGN, however, are inhibitory to IL-2 production and T cell proliferation. The IL-2 production-inducing activity of TGN is much more prominent when T cells are primed with concanavalin A or anti-CD3 mAb, and is due to the increase of cytoplasmic Ca2+ concentration. TGN at 50 nM does not affect interferon-gamma or IL-4 production from T cells. Thus, the present study shows that low nanomolar concentrations of TGN could be useful in potentiating IL-2 production from antigen-primed T cells.

Trans-ε-viniferin is a naturally occurring polyphenol belonging to the stilbenoids family. Trans-ε-viniferin is isolated from Vitis amurensis, 1 of the most common wild grapes in Korea, Japan and China. We investigated the effects of trans-ε-viniferin on in vitro maturation (IVM) and developmental competence after IVF or parthenogenesis (PA). At the laboratory of Veterinary Pharmacology, College of Veterinary Medicine, Chungbuk National University, trans-ε-viniferin was purified from the leaves and stems of Vitis amurensis. Data were analyzed with SPSS 17.0 using Duncan's multiple range test. First, in total, 594 cumulus–oocyte complexes (COC) were used for the evaluation of nuclear maturation. The COC were matured in TCM-199 medium supplemented with various concentrations of trans-ε-viniferin (0, 0.1, 0.5, 1.0 and 5.0 μM) with 10% porcine follicular fluid, 10 IU mL–1 of eCG and 10 IU mL–1 of hCG. After 22 h in maturation culture, the COC were cultured in hormone-free medium supplemented with various concentrations of trans-ε-viniferin for an additional 22 h and then nuclear maturation was evaluated. Second, in total, 300 matured oocytes were used to examine the effects of different trans-ε-viniferin concentrations (0, 0.5 and 5.0 μM) on porcine oocyte intracellular glutathione (GSH) and reactive oxygen species (ROS) levels. Lastly, the developmental competence of oocytes matured with different concentrations of trans-ε-viniferin (0, 0.5 and 5.0 μM) was evaluated after IVF or PA. In total, 711 embryos were evaluated. As results, we observed that trans-ε-viniferin treatment during IVM did not improve the nuclear maturation of oocytes in any group (84.2, 86.6, 85.5, 83.3 and 79.2%, respectively), but significantly increased (P < 0.05) intracellular GSH levels in the 0.5 μM group (0 μM vs 0.5 μM; 14.6 vs 16.8 pmol oocyte–1) and reduced ROS levels (0 μM vs 0.5 μM and 50 μM; 174.6 vs 25.7 and 23.8 pixel oocyte–1). Oocytes treated with trans-ε-viniferin during IVM did not have significantly different cleavage rates or blastocyst formation rates after IVF, but total cell numbers were significantly higher (P < 0.05) in the 0.5 and 5.0 μM treatment groups (53.6 ± 4.0 and 47.9 ± 3.1) compared to the control group (36.4 ± 2.2). The PA embryos showed similar results; there were no significant differences in cleavage rates and blastocyst formation rates, but the total cell number significantly increased in the 0.5 and 5.0 μM treatment groups (59.6 ± 4.2 and 60.8 ± 4.6) compared to the control group (43.1 ± 2.1). In conclusion, these results indicate that trans-ε-viniferin treatment during porcine IVM increased total cell number of blastocysts, possibly through increasing intracellular GSH synthesis and reducing ROS levels. This work was supported by a grant from the Korea institute of Planning & Evaluation for Technology in Food, Agriculture, Forestry & Fisheries, Republic of Korea.