National surveillance of 2,3,7,8-substituted polychlorinated dibenzo-p-dioxins/furans in soil in Taiwan.

In this study, the polychlorinated dibenzo-p-dioxin/furan (PCDD/F) levels in 381 soil samples coming from different background areas (n = 238) and contaminated areas (n = 143) in Taiwan were investigated from 2011 to 2015 using high resolution gas chromatograph/high resolution mass spectrometry (HRGC/HRMS). The contaminated areas showed higher PCDD/F contamination as compared to the background areas (1230 vs 749 pg/g dry weight (dw)); 14.0 vs 6.25 pg WHO2005-TEQ/g dw). The lowest levels were recorded in the outlying islands (1.28 pg WHO2005-TEQ/g dw). PCDD/F congener distribution profiles in the background and contaminated areas as well as on the islands varied. OCDD was the dominant congener in almost all locations, including the northern background (87.7%) and central contaminated (74.2%) areas. Other dominant species included OCDF and 1,2,3,4,6,7,8-HpCDD. Levels of PCDD/F-TEQs in Taiwanese soils, including the background areas, were higher than in some developing countries and regions with global background levels due to high industrialization except for the contaminated areas. Geographic differences in dioxin-contaminated soils were also shown in this study. Higher soil dioxin-TEQs were observed in locations with high populations and population densities. Despite the limitations, the economic status of Taiwan represented by the annual averaged family income (AAFI) was positively correlated to soil dioxin-TEQs.

Two-stage face transplantation: a new concept in vascularized composite allotransplantation.

BACKGROUND: Animal models and clinical cases of facial allotransplantation have been performed as a single stage procedure. A staged surgery might offer some advantages in selected cases. In this study, a two-stage face transplantation approach was performed on rat and the feasibility and safety were evaluated. METHODS: Brown Norway rats were used as donors and Lewis rats as recipients in the allotransplantation groups. A total of 33 hemiface-scalp transplantations were performed. Syngeneic orthotopic transplantations were performed either in one-stage (one single stage surgery; N = 3), local two-stage [heterothopic transplantation to the neck during the first stage and graft rotation as a pedicled flap to cover the facial defect on postoperative day (POD) 2; N = 3], or distant two-stage approaches (heterothopic transplantation to the groin during the first stage and free graft transfer to the face on postoperative day 2; N = 3). In the allotransplantation groups using the same approaches, 12 received no treatment (N = 4 each subgroup) and 12 received the same tapering dose of cyclosporine (10 to 2 mg/Kg/day; N = 4 each subgroup). Graft survival and the rejection grades were assessed clinically and pathologically. RESULTS: All syngeneic transplants survived for the follow-up period of 180 days. The mean rejection-free survival and total survival of the allograft in the no treatment group was 6 ± 0.3 and 14.3 ± 4.5 days in the one-stage group, 6 ± 0.4 and 18.5 ± 1 days in the local two-stage group and 6 ± 0.2 and 14.3 ± 5.7 (P > 0.05). All allografts in the treatment groups did not develop rejection during the 42 days follow-up period. CONCLUSIONS: It is feasible, reliable, reproducible, and safe to perform a two-stage face transplantation in rats. This novel approach has the potential to be applied in research and eventually in selected clinical cases of facial allotransplantation.

Targeting tumour necrosis factor receptor 1 assembly reverses Th17-mediated colitis through boosting a Th2 response.

OBJECTIVE: The soluble preligand assembly domain (PLAD) of tumour necrosis factor receptor 1 (TNFR1) interferes with receptor trimerisation to block downstream signalling, and mediates Th17 suppression. We explored the therapeutic potential of recombinant PLAD.Fc protein on a spontaneous experimental colitis. DESIGN: A T-cell-specific BLIMP-1 knockout mouse model with mixed Th1/Th17 responses, resembling human Crohn's disease (CD) was established, and its colitogenic phenotype was characterised. Mice, 9 weeks old, were treated with PLAD.Fc protein at 5 mg/kg of body weight twice per week for 16 weeks, and presence of colitis was monitored by the appearance of diarrhoea, weight loss, and by histological colonic scoring. Activation status, cytokine profiles, and transcription factors in T cells were further analysed. RESULTS: The colitogenic phenotype in BLIMP-1 knockout mice was alleviated when an interleukin (IL)-23 knockdown transgene was introduced, indicating a therapeutic potential by downregulating IL-23-Th17 axis in these knockout mice. In PLAD.Fc-treated group, the mouse body weight remained stable and only mild disease scores were revealed. The percentage of naive CD4 T cells was increased and that of effector/memory CD4 T cells was decreased after PLAD.Fc-treatment. Moreover, the levels of IFN-γ, IL-17, IL-21, IL-22, IL-23R, granulocyte-macrophage colony-stimulating factor (GM-CSF) and TNF-α were diminished. Strikingly, Th2-associated cytokines (IL-4, IL-13 and IL-10) in sera, as well as percentages of Th2 cells, were increased in PLAD.Fc-treated mice. However, PLAD.Fc-mediated suppression of effector phenotypes in Th1/Th17 was abrogated after neutralising IL-10. CONCLUSIONS: The Th2 cytokine milieu induced by PLAD.Fc rebalanced T-helper cell subsets and conferred a protection against colitis in BLIMP-1 knockout mice.

A new rat model for orthotopic abdominal wall allotransplantation.

BACKGROUND: Abdominal wall, one of the most commonly transplanted composite tissues, is less researched and lacking animal models. Its clinical necessities were emphasized in multiple case series to reconstruct large abdominal defects. Previous animal models have only studied components of the abdominal wall transplant. We describe findings from a new model that more likely reflect clinical transplantation. METHODS: Full-thickness hemiabdominal wall flap was procured from Brown Norway (BN) rats and transplanted to an orthotopic defect on Lewis rats. Three groups were studied: group 1: Lewis to Lewis syngeneic; group 2: BN to Lewis control; and group 3: BN to Lewis with postoperative cyclosporine. Vascular imaging and cross vessel section were performed along with full-thickness abdominal wall. Immune cell profiling with flow cytometry at different time points was studied in all groups. RESULTS: Syngeneic group had no rejection. Control group consistently showed rejection around postoperative day 6. With cyclosporine treatment, however, transplant and recipient tissue integration was observed. Flow cytometry revealed that innate immunity is responsible for the initial inflammatory events following abdominal wall engraftment. Adaptive immunity cells, specifically interferon-γ-producing T helper (Th) 1 and interleukin-17-producing Th17 cells, dramatically and positively correlate with rejection progression of abdominal wall transplants. CONCLUSIONS: Technical, histological, and immunological aspects of a new rat model are described. These results give clues to what occurs in human abdominal wall transplantation. In addition, Th1, a proinflammatory cell, was found to be a potential biomarker for allograft rejection.

A novel rat full-thickness hemi-abdominal wall/hindlimb osteomyocutaneous combined flap: influence of allograft mass and vascularized bone marrow content on vascularized composite allograft survival.

Vascularized bone marrow transplantation (VBMT) appears to promote tolerance for vascularized composite allotransplantation (VCA). However, it is unclear whether VBMT is critical for tolerance induction and, if so, whether there is a finite amount of VCA that VBMT can support. We investigated this with a novel VCA combined flap model incorporating full-thickness hemiabdominal wall and hindlimb osteomyocutaneous (HAW/HLOMC) flaps. Effects of allograft mass (AM) and VBMT on VCA outcome were studied by comparing HAW/HLOMC VCAs with fully MHC-mismatched BN donors and Lewis recipients. Control groups did not receive treatments following transplantation. Treatment groups received a short course of cyclosporine A (CsA), antilymphocyte serum, and three doses of adipocyte-derived stem cells (POD 1, 8, and 15). The results showed that all flaps in control allogeneic groups rejected soon after VCAs. Treatment significantly prolonged allograft survival. Three of eight recipients in HLOMC treatment group had allografts survive long-term and developed donor-specific tolerance. Significantly higher peripheral chimerism was observed in HLOMC than other groups. It is concluded that the relative amount of AM to VBMT is a critical factor influencing long-term allograft survival. Accordingly, VBMT content compared with VCA mass may be an important consideration for VCA in humans.

Novel design strategy for checkpoint kinase 2 inhibitors using pharmacophore modeling, combinatorial fusion, and virtual screening.

Checkpoint kinase 2 (Chk2) has a great effect on DNA-damage and plays an important role in response to DNA double-strand breaks and related lesions. In this study, we will concentrate on Chk2 and the purpose is to find the potential inhibitors by the pharmacophore hypotheses (PhModels), combinatorial fusion, and virtual screening techniques. Applying combinatorial fusion into PhModels and virtual screening techniques is a novel design strategy for drug design. We used combinatorial fusion to analyze the prediction results and then obtained the best correlation coefficient of the testing set (r test) with the value 0.816 by combining the Best(train)Best(test) and Fast(train)Fast(test) prediction results. The potential inhibitors were selected from NCI database by screening according to Best(train)Best(test) + Fast(train)Fast(test) prediction results and molecular docking with CDOCKER docking program. Finally, the selected compounds have high interaction energy between a ligand and a receptor. Through these approaches, 23 potential inhibitors for Chk2 are retrieved for further study.

Donor age negatively affects the immunoregulatory properties of both adipose and bone marrow derived mesenchymal stem cells.

PURPOSE: Age negatively impacts the biologic features of mesenchymal stem cells (MSCs), including decreased expansion kinetics and differentiation potential. Clinically, donor-age may be within a wide spectrum; therefore, investigation of the role of donor's age on immunoregulatory potential is of critical importance to translate stem cell therapies from bench to bedside. METHODS: Adipose and bone marrow derived MSCs (ASCs and BMSCs) were isolated in parallel from Lewis and Brown Norway rats of young (less than 4-week old) and senior groups (older than 15-month). The presentation of cells and time required for growth to 90% confluence was recorded. FACS sorting based on the expression of CD90 and CD29 double positive and CD45 CD11 double negative quantified the proportions of MSCs. After expansion, ASCs and BMSCs from different age groups were co-cultured in mixed lymphocyte reaction (MLR; Lewis vs. Brown Norway) assays. The suppression of CD3(+)CD4(+) and CD3(+)CD8(+) T cell populations by different sources of MSCs were compared. RESULTS: The kinetics of cell growth was slower in old animals (17.3±2days) compared with young animals (8.8±3days), and cell morphology was irregular and enlarged in the senior groups. The yield of MSCs by FACS sorting was significantly higher in young groups compared to senior groups (p<0.02). With regard to immunoregulatory potential, senior ASCs failed to induce any CD3(+)CD4(+) T cell suppression (p>0.05). In addition, young BMSCs-induced suppression was more prominent than seniors (p<0.05). CONCLUSIONS: Donor age should be taken into consideration when using recipient MSC of either bone marrow or adipose origin in clinical applications.

Syngeneic adipose-derived stem cells with short-term immunosuppression induce vascularized composite allotransplantation tolerance in rats.

BACKGROUND AIMS: A clinically applicable tolerance induction regimen that removes the requirement for lifelong immunosuppression would benefit recipients of vascularized composite allotransplantation (VCA). We characterized the immunomodulatory properties of syngeneic (derived from the recipient strain) adipocyte-derived stem cells (ADSCs) and investigated their potential to induce VCA tolerance in rats. METHODS: ADSCs were isolated from Lewis (LEW, RT1A(l)) rats; their immunomodulatory properties were evaluated by means of mixed lymphocyte reactions in vitro and VCAs in vivo across a full major histocompatibility complex mismatch with the use of Brown-Norway (BN, RT1A(n)) donor rats. Two control and four experimental groups were designed to evaluate treatment effects of ADSCs and transient immunosuppressants (anti-lymphocyte globulin, cyclosporine) with or without low-dose (200 cGy) total body irradiation. Flow cytometry was performed to quantify levels of circulating CD4(+)CD25(+)FoxP3(+) regulatory T cells (Tregs). RESULTS: Cultured syngeneic ADSCs exhibited CD90.1(+)CD29(+)CD73(+)CD45(-)CD79a(-)CD11b/c(-) phenotype and the plasticity to differentiate to adipocytes and osteocytes. ADSCs dramatically suppressed proliferation of LEW splenocytes against BN antigen and mitogen, respectively, in a dose-dependent fashion, culminating in abrogation of allo- and mitogen-stimulated proliferation at the highest concentration tested. Accordingly, one infusion of syngeneic ADSCs markedly prolonged VCA survival in LEW recipients treated with transient immunosuppression; of these, 66% developed tolerance. Total body irradiation provided no additional VCA survival benefit. An important role for Tregs in tolerance induction/maintenance was suggested in vivo and in vitro. CONCLUSIONS: Treatment comprising syngeneic ADSCs and transient immunosuppression (i) increased levels of circulating Tregs and (ii) induced tolerance in 66% of recipients of major histocompatibility complex-mismatched VCAs.

Design checkpoint kinase 2 inhibitors by pharmacophore modeling and virtual screening techniques.

Damage to DNA is caused by ionizing radiation, genotoxic chemicals or collapsed replication forks. When DNA is damaged or cells fail to respond, a mutation that is associated with breast or ovarian cancer may occur. Mammalian cells control and stabilize the genome using a cell cycle checkpoint to prevent damage to DNA or to repair damaged DNA. Checkpoint kinase 2 (Chk2) is one of the important kinases, which strongly affects DNA-damage and plays an important role in the response to the breakage of DNA double-strands and related lesions. Therefore, this study concerns Chk2. Its purpose is to find potential inhibitors using the pharmacophore hypotheses (PhModels) and virtual screening techniques. PhModels can identify inhibitors with high biological activities and virtual screening techniques are used to screen the database of the National Cancer Institute (NCI) to retrieve compounds that exhibit all of the pharmacophoric features of potential inhibitors with high interaction energy. Ten PhModels were generated using the HypoGen best algorithm. The established PhModel, Hypo01, was evaluated by performing a cost function analysis of its correlation coefficient (r), root mean square deviation (RMSD), cost difference, and configuration cost, with the values 0.955, 1.28, 192.51, and 16.07, respectively. The result of Fischer's cross-validation test for the Hypo01 model yielded a 95% confidence level, and the correlation coefficient of the testing set (rtest) had a best value of 0.81. The potential inhibitors were then chosen from the NCI database by Hypo01 model screening and molecular docking using the cdocker docking program. Finally, the selected compounds exhibited the identified pharmacophoric features and had a high interaction energy between the ligand and the receptor. Eighty-three potential inhibitors for Chk2 are retrieved for further study.

Overexpression of galectin-9 in islets prolongs grafts survival via downregulation of Th1 responses.

The differential activation of T helper (Th) cells and production of cytokines contribute to graft rejection or tolerance. In general, the Th1-type cytokines and cytotoxic T-cells are detected consistently in a host who is undergoing rejection, whereas Th2 responses are linked to a tolerance condition. Galectin-9 modulates Th1 cell immunity by binding to the T-cell immunoglobulin mucin-3 (Tim-3) molecule expressed on the Th1 cells. We investigate whether overexpression of galectin-9 in islets prolongs grafts survival in diabetic recipients. Islets were transduced with lentiviruses carrying galectin-9 and were then transplanted to streptozotocin-induced diabetic NOD/SCID recipients. The normoglycemic recipients then received splenocytes from diabetic NOD mice. Blood glucose concentration was monitored daily after adoptive transfer. The histology of the islet grafts and flow cytometric analyses were assessed at the end of the study. Overexpression of galectin-9 in islets prolonged graft survival in NOD/SCID mice after challenge with diabetogenic splenocytes (mean graft survival, 38.5 vs. 26.0 days, n=10, respectively; p=0.0096). The galectin-9-overexpressed grafts showed decreased infiltration of IFN-γ-producing CD4(+) and CD8(+) T-cells, but not of IL-17-producing CD4(+) T-cells. Strikingly, this islet-specific genetic manipulation did not affect the systemic lymphocyte composition, indicating that galectin-9 may regulate T-cell-mediated inflammation in situ. We demonstrate that galectin-9 protects grafts from Th1 and Tc1 cell-mediated rejections, suggesting that galectin-9 has preventive and/or therapeutic benefit in transplant therapy for autoimmune diabetes and may be applied further to the transplantation of other organs or tissues.

Current status of the immunomodulation and immunomediated therapeutic strategies for multiple sclerosis.

Multiple sclerosis (MS) is an autoimmune disease of the central nervous system, and CD4(+) T cells form the core immunopathogenic cascade leading to chronic inflammation. Traditionally, Th1 cells (interferon-γ-producing CD4(+) T cells) driven by interleukin 12 (IL12) were considered to be the encephalitogenic T cells in MS and experimental autoimmune encephalomyelitis (EAE), an animal model of MS. Currently, Th17 cells (Il17-producing CD4(+) T cells) are considered to play a fundamental role in the immunopathogenesis of EAE. This paper highlights the growing evidence that Th17 cells play the core role in the complex adaptive immunity of EAE/MS and discusses the roles of the associated immune cells and cytokines. These constitute the modern immunological basis for the development of novel clinical and preclinical immunomodulatory therapies for MS discussed in this paper.

Targeting pre-ligand assembly domain of TNFR1 ameliorates autoimmune diseases - an unrevealed role in downregulation of Th17 cells.

The pre-ligand assembly domain (PLAD) of tumor necrosis factor receptors mediates specific ligand-independent receptor assembly and subsequent signaling. However, the physiological role of PLAD in the regulation of TNFR-mediated immune responses in autoimmunity is still unclear. By using the recombinant PLAD.Fc protein to block TNFR1 assembly, we demonstrated that PLAD.Fc treatment significantly reduced the TNFR1-driving proinflammatory cytokines and protected NOD mice from diabetes. Strikingly, Th17 differentiation was significantly inhibited in PLAD.Fc-treated NOD and TNFR1-deficient mice, indicating a TNFR1-dependent Th17 development. PLAD.Fc-modulated effects on DCs, in terms of the downregulation of Th17-inducing cytokines, IL-6 and TGF-ß, explained the potential mechanism for Th17 suppression. Finally, we provided an additional result that PLAD.Fc administration diminished the infiltration of Th17 cells in the central nervous system and ameliorated the experimental autoimmune encephalomyelitis in mice. Collectively, these data demonstrated that targeting PLAD of TNFR1 provides protection from autoimmune diseases through the downregulation of Th17 and suggested a therapeutic potential of PLAD-modulation in TNF-involved inflammatory diseases.

Erythropoietin enhances endogenous haem oxygenase-1 and represses immune responses to ameliorate experimental autoimmune encephalomyelitis.

Both erythropoietin (EPO) and haem oxygenase-1 (HO-1), an anti-oxidative stress protein, have proven protective roles in experimental autoimmune encephalomyelitis (EAE), a reliable animal model of multiple sclerosis. In this study, EPO delivered intraperitoneally could reduce disease severity in myelin oligodendrocyte glycoprotein (MOG)­EAE mice. To assess the effect of EPO on endogenous HO-1 in EAE, we investigated expression of HO-1 mRNA by real-time polymerase chain reaction (RT­PCR), protein expression centrally and peripherally by Western blot and immunohistochemistry and mean fluorescence intensity of splenic HO-1 by flow cytometry. A significantly higher expression of HO-1 in both the central nervous system (CNS) and spleen was shown in EPO-treated MOG­EAE mice than in controls.We further examined the immunomodulatory effect of EPO in EAE, and via RT­PCR demonstrated significantly lower expression of interferon-γ, interleukin (IL)-23, IL-6 and IL-17 mRNA, and significantly higher expression of IL-4 and IL-10 mRNA in CNS of EPO-treated MOG­EAE mice than in controls. Using flow cytometry, we also observed a significantly decreased ratio of both T helper type 1 (Th1) and Th17 lymphocyte subsets isolated from CNS and a significantly increased ratio of splenic regulatory CD4 T cells in EPO-treated MOG­EAE mice. In addition, we demonstrated that MOG-specific T cell proliferation was lower in the EPO-treated group than in controls and showed amelioration of EAE by adoptive transfer of splenocytes from EPO-treated MOG­EAE mice. Together, our data show that in EAE, EPO induction of endogenous HO-1 and modulation of adaptive immunity both centrally and peripherally may involve the repression of inflammatory responses.

Decoy receptor 3 protects non-obese diabetic mice from autoimmune diabetes by regulating dendritic cell maturation and function.

Decoy receptor 3 (DcR3), a member of the tumor necrosis factor receptor superfamily, regulates immune responses through competing with receptors of Fas ligand (FasL), LIGHT and TNF-like molecule 1A (TL1A). We have previously demonstrated that transgenic expression of DcR3 in a ß cell-specific manner significantly protects non-obese diabetic (NOD) mice from autoimmune diabetes. In this study, we further investigated the systemic effect of DcR3 in regulating lymphocytes and dendritic cells in NOD mice. Our results demonstrated that both DcR3 plasmid and protein treatments significantly inhibited insulitis and diabetes. Lymphocytes from DcR3.Fc-treated mice revealed less proliferative potential and transferred ameliorated diabetes. By administration of DcR3.Fc in T1 and T2 double transgenic NOD mice expressing human Thy1 or murine Thy1.1 surface marker under IFN-γ or IL-4 promoter control respectively, we observed a remarkable reduction of Th1 and an increase of Th2 immune responses in vivo. Strikingly, in vitro polarization experiments exhibited that not only Th1 but also Th17 cell differentiation was significantly inhibited in splenocytes treated with DcR3.Fc protein. However, this phenomenon was only observed in splenocytes, not in purified CD4(+) T cells, suggesting that DcR3-mediated inhibition of Th1 and Th17 differentiation is not T cell-autonomous and maybe through other cell types such as dendritic cells. Finally, our results demonstrated that DcR3 directly modulates the differentiation and maturation of dendritic cells and subsequently regulates the differentiation and effector function of T cells.