Adoptive cell therapy using antigen-specific CD4⁻CD8⁻T regulatory cells to prevent autoimmune diabetes and promote islet allograft survival in NOD mice

AIMS/HYPOTHESIS

A new differentiation pathway for CD4(-)CD8(-) (DN) T cells has recently been identified that exhibits the potent function of peripheral converted DN T cells in suppressing immune responses and provides the potential to treat autoimmune diseases. The aim of this study was to determine if the DN T cells converted from CD4(+) T cells of NOD mice retain the antigen-specific regulatory capacity and prevent autoimmune diabetes in vivo. We also sought to determine if the combination of DN T cells with rapamycin promotes islet allograft survival in autoimmune diabetic NOD recipients.

METHODS

NOD CD4(+) T cells were converted to DN T cells in an in vitro mixed-lymphocyte reaction, with or without GAD65 peptide, as previously reported. The antigen-specific DN T cells were adoptively transferred to NOD/SCID mice, new-onset diabetic NOD mice or islet-allograft-recipient NOD mice as the part of cell-based therapy. The development of diabetes and allograft survival was assessed by monitoring blood glucose levels.

RESULTS

NOD CD4(+) T cells were converted in vitro to DN T cells at a rate of 50% and expressed unique cell features. The DN T cells from NOD donors blocked autoimmunity and prevented diabetes in NOD models, and these effects were even greater for GAD65-peptide-primed DN T cells. DN T cells acted in conjunction with rapamycin to suppress alloantigen-triggered T cell proliferation, promoted apoptosis and prolonged islet allograft survival in NOD recipients.

CONCLUSIONS/INTERPRETATION

Administration of the islet beta cell antigen-specific DN T cells can prevent the development of autoimmune diabetes and promote islet allograft survival in NOD mice.

Three-electron interatomic Coulombic decay from the inner-valence double-vacancy states in NeAr

We have unambiguously identified interatomic Coulombic decay in NeAr from the inner-valence double-vacancy state Ne-Ar(2+)(3s(-2)) to outer-valence triple-vacancy states Ne(+)(2p(-1))-Ar(2+)(3p(-2)) by momentum-resolved electron-ion multicoincidence. This is the first observation of interatomic Coulombic decay where three electrons (3e) participate. The results suggest that this 3e interatomic Coulombic decay is significantly faster than other competing processes like fluorescence decay and charge transfer via curve crossing.

Public health services in Shenzhen: a case study

As one of the fastest growing cities in Pearl River Delta of southern China, Shenzhen accommodates a higher percentage and increasing number of internal migrants, mainly coming from the inland areas. The public health issues that challenge its local government include the special population structure, high incidence of infectious diseases, high prevalence of mental problems, rising chronic disease burdens, and maternal and children’s health issues, although progress has been made in the past years. The health authority of Shenzhen has realized that provision of high quality equitable public health services to its residents, including migrants is of high priority, and should be supported by innovations in the health insurance system and establishment of community-based primary care networks. Making changes within the national-level health reform framework and learning from international experiences are necessary and important.

Effect of insulin in combination with selenium on blood glucose and PI3K-mediated GLUT4 expression in skeletal muscle of streptozotocin-induced diabetic rats

OBJECTIVES

We evaluated the effect of low doses of insulin (1 U/kg/day) and selenium (180 microg/kg/day) in combination on general physiological parameters, and on PI3K and GLUT4 levels in skeletal muscle of streptozotocin (STZ)-induced diabetic rats.

MATERIALS AND METHODS

Diabetic rats were treated with insulin, selenium, and insulin and selenium in combination for four weeks. The levels of blood glucose and hemoglobin A1c were estimated, and the levels of P13K and GLUT4 in skeletal muscle were examined by immunoblotting and immunohistochemistry.

RESULTS

Insulin in combination with selenium could significantly lower blood glucose and HbAlc levels, and restore the disturbances in PI3K and GLUT4 levels in skeletal muscle. Treatment with insulin was only partially effective in the restoration of diabetic alterations.

CONCLUSION

We conclude that there was cooperation between insulin and selenium, and that treatment of diabetic rats with combined doses of insulin and selenium was effective in the normalization of blood glucose and correction of altered PI3K and GLUT4 distribution in skeletal muscle of diabetic rats.

Knockdown of the gene encoding Drosophila tribbles homologue 3 (Trib3) improves insulin sensitivity through peroxisome proliferator-activated receptor-γ (PPAR-γ) activation in a rat model of insulin resistance

AIMS/HYPOTHESIS

Insulin action is purportedly modulated by Drosophila tribbles homologue 3 (TRIB3), which in vitro prevents thymoma viral proto-oncogene (AKT) and peroxisome proliferator-activated receptor-γ (PPAR-γ) activation. However, the physiological impact of TRIB3 action in vivo remains controversial.

METHODS

We investigated the role of TRIB3 in rats treated with either a control or Trib3 antisense oligonucleotide (ASO). Tissue-specific insulin sensitivity was assessed in vivo using a euglycaemic-hyperinsulinaemic clamp. A separate group was treated with the PPAR-γ antagonist bisphenol-A-diglycidyl ether (BADGE) to assess the role of PPAR-γ in mediating the response to Trib3 ASO.

RESULTS

Trib3 ASO treatment specifically reduced Trib3 expression by 70% to 80% in liver and white adipose tissue. Fasting plasma glucose, insulin concentrations and basal rate of endogenous glucose production were unchanged. However, Trib3 ASO increased insulin-stimulated whole-body glucose uptake by ~50% during the euglycaemic-hyperinsulinaemic clamp. This was attributable to improved skeletal muscle glucose uptake. Despite the reduction of Trib3 expression, AKT2 activity was not increased. Trib3 ASO increased white adipose tissue mass by 70% and expression of Ppar-γ and its key target genes, raising the possibility that Trib3 ASO improves insulin sensitivity primarily in a PPAR-γ-dependent manner. Co-treatment with BADGE blunted the expansion of white adipose tissue and abrogated the insulin-sensitising effects of Trib3 ASO. Finally, Trib3 ASO also increased plasma HDL-cholesterol, a change that persisted with BADGE co-treatment.

CONCLUSIONS/INTERPRETATION

These data suggest that TRIB3 inhibition improves insulin sensitivity in vivo primarily in a PPAR-γ-dependent manner and without any change in AKT2 activity.

Modeling pathogenesis of Huntington's disease with inducible neuroprogenitor cells

Huntington's disease (HD) is caused by an abnormal expansion of CAG trinucleotide repeats encoding polyglutamine (polyQ) in the first exon of the huntingtin (htt) gene. Despite considerable efforts, the pathogenesis of HD remains largely unclear due to a paucity of models that can reliably reproduce the pathological characteristics of HD. Here, we report a neuronal cell model of HD using the previously established tetracycline regulated rat neuroprogenitor cell line, HC2S2. Stable expression of enhanced green fluorescence protein tagged htt exon 1 (referred to as 28Q and 74Q, respectively) in the HC2S2 cells did not affect rapid neuronal differentiation. However, compared to the cells expressing wild type htt, the cell line expressing mutant htt showed an increase in time-dependent cell death and neuritic degeneration, and displayed increased vulnerability to oxidative stress. Increased protein aggregation during the process of neuronal aging or when the cells were exposed to oxidative stress reagents was detected in the cell line expressing 74Q but not in its counterpart. These results suggest that the neuroprogenitor cell lines mimic the major neuropathological characteristics of HD and may provide a useful tool for studying the neuropathogenesis of HD and for high throughput screening of therapeutic compounds.