Insulin B chain 9–23 gene transfer to hepatocytes protects from type 1 diabetes by inducing Ag-specific FoxP3 ⁺ T _regs

Abstract

Antigen (Ag)-specific tolerance in type 1 diabetes (T1D) in human has not been achieved yet. Targeting lentiviral vector (LV)-mediated gene expression to hepatocytes induces active tolerance toward the encoded Ag. The insulin B chain 9-23 (InsB9-23) is an immunodominant T cell epitope in nonobese diabetic (NOD) mice. To determine whether auto-Ag gene transfer to hepatocytes induces tolerance and control of T1D, NOD mice were treated with integrase-competent LVs (ICLVs) that selectively target the expression of InsB9-23 to hepatocytes. ICLV treatment induced InsB9-23-specific effector T cells but also FoxP3(+) regulatory T cells (Tregs), which halted islet immune cell infiltration, and protected from T1D. Moreover, ICLV treatment combined with a single suboptimal dose of anti-CD3 monoclonal antibody (mAb) is effective in T1D reversal. Splenocytes from LV.InsB9-23-treated mice, but not from LV.OVA (ovalbumin)-treated control mice, stopped diabetes development, demonstrating that protection is Ag-specific. Depletion of CD4(+)CD25(+)FoxP3(+) T cells led to diabetes progression, indicating that Ag-specific FoxP3(+) Tregs mediate protection. Integrase-defective LVs (IDLVs).InsB9-23, which alleviate the concerns for insertional mutagenesis and support transient transgene expression in hepatocytes, were also efficient in protecting from T1D. These data demonstrate that hepatocyte-targeted auto-Ag gene expression prevents and resolves T1D and that stable integration of the transgene is not required for this protection. Gene transfer to hepatocytes can be used to induce Ag-specific tolerance in autoimmune diseases.

Characterization of proinsulin‐specific regulatory T cells in type 1 diabetes at different ages of onset

“…Besides, studies have also shown that Tregs in subjects with T1D has defects in their immunosuppressive function . Tregs, especially beta cell‐specific Tregs have been shown to preserve the beta cell mass, delay progression of diabetes and have been explored during the past few years for cellular therapy of T1D . To the best of our knowledge, this is first report that shows the characteristics of islet‐associated (PI‐specific) Tregs in human subjects with T1D.…”

“…12,42 Tregs, especially beta cell-specific Tregs have been shown to preserve the beta cell mass, delay progression of diabetes and have been explored during the past few years for cellular therapy of T1D. [43][44][45][46][47] To the best of our knowledge, this is first report that shows the characteristics of islet-associated (PI-specific) Tregs in human subjects with T1D. In this study, we first observed a higher frequency of polyclonal Tregs in AOT1D subjects with better preservation of beta cell mass that had a positive correlation with age.…”

Paroxetine alleviates T lymphocyte activation and infiltration to joints of collagen-induced arthritis

“…However, these two kinds of T cells have totally opposite functions. CD25 low expression T cells are named as activated T cells (Thact) which promote the inflammatory immune response, while CD25 high expression Th cells defined as regulatory Th cells (Threg) are involved in inhibiting the immune system and retaining immune tolerance16. To precisely distinguish these two subpopulations, we stained CD4, CD25 and foxp3, a recognized transcription factor for analyzing Threg cells.…”

Complexity of immune responses to AAV transgene products – Example of factor IX

“…This strategy represents one potential solution to prevent immune responses to acid α-glucosidase (GAA) in systemic gene therapy for glycogen storage disorder II (Pompe disease). Other opportunities for this tolerogenic gene therapy lie in the treatment of autoimmune disease (at least those with know target antigens) and allergies [105, 106]. For human translation, the approach should benefit from the development of AAV capsids with superior transduction of human hepatocytes [107].…”