AAV8-mediated Gene Transfer of Interleukin-4 to Endogenous β-Cells Prevents the Onset of Diabetes in NOD Mice

Abstract

We have demonstrated the ability to deliver and express genes specifically in beta-cells for at least 6 months, using a murine insulin promoter (mIP) in a double-stranded, self-complementary AAV vector (dsAAV8-mIP). In this study, we evaluated the effects of dsAAV8-mIP-mediated delivery of interleukin 4 (mIL-4) to endogenous beta-cells in nonobese diabetic (NOD) mice. In 4-week-old NOD mice, the extent of gene transfer and expression in endogenous beta-cells after ip delivery of dsAAV8-mIP-enhanced green fluorescent protein (eGFP) was comparable to normal BALB/C mice. Further, after IP delivery of dsAAV8-mIP-IL4, expression of mIL-4 was detected in islets isolated from the treated mice and cultured. AAV8-mIP-mediated gene expression of mIL-4 in endogenous beta- cells of 4- and 8-week-old NOD mice prevented the onset of hyperglycemia in NOD mice and reduced the severity of insulitis. Moreover, expression of mIL-4 also maintained the level of CD4(+)CD25(+)FoxP3(+) cells, and adoptive transfer of splenocytes from nondiabetic dsAAV8-mIP-IL-4 mice to NODscid mice was able to block the diabetes induced by splenocytes co-adoptively transferred from nondiabetic dsAAV-mIP-eGFP mice. Taken together, these results demonstrate that local expression of mIL-4 in islets prevents islet destruction and blocks autoimmunity, partly through regulation of T-cell function.

DsAAV8-mediated expression of glucagon-like peptide-1 in pancreatic beta-cells ameliorates streptozotocin-induced diabetes

“…36,37 Our data indicate that AAV-mediated expression of GLP-1 in beta-cells following single intraperitoneal administration can mitigate the onset of diabetes in a model of type-1 diabetes. Targeted production of GLP-1 in beta-cells on its own, or coupled with a therapy designed to reduce autoimmune destruction, such as beta-cell expression of interleukin-4 as described by Rehman et al, 29 may represent a novel therapeutic strategy for type-1 diabetes.…”

“…Furthermore, it has been shown that therapeutic genes can be delivered to beta-cells through intraperitoneal injection of AAV8. 29 Therefore, we sought to generate and deliver a GLP-1 transgene, expressed under the control of the insulin-II promoter, to beta-cells using this novel viral vector. To test the utility of this method of GLP-1 administration, we induced beta-cell apoptosis through low-dose streptozotocin (STZ) administration.…”

Genetic vaccination for re-establishing T-cell tolerance in type 1 diabetes

“…to young NOD mice. 116 Diabetes is prevented in NOD mice receiving dsAAV8-mIP-IL4, which correlates with reduced islet infiltration and an increase in FoxP3 + Treg in the periphery. Interestingly, no effect on β cell autoimmunity is detected in dsAAV8-mIP-IL10-treated NOD mice.…”

“…Here, the use of an insulin II promoter (IP) has proven to be highly effective for tightlyregulated and stable β cell-specific expression of rAAV encoded transgenes. 105,116 Evidence that T1D can be manipulated by targeting β cells in vivo is provided by a study in which dsAAV8 recombinants encoding IL-4 and IL-10 transgenes driven by a mouse IP (mIP) were administered i.p. to young NOD mice.…”

dsAAV8-mediated gene transfer and β-cell expression of IL-4 and β-cell growth factors are capable of reversing early-onset diabetes in NOD mice

“…To bypass the need for systemic levels of immunomodulatory proteins to treat T1D, we have developed an approach for conferring long-term, local b-cell-specific expression by systemic gene transfer of self-complementary, double-stranded adeno-associated virus serotype 8 (dsAAV8) containing the murine preproinsulin-II promoter (MIP). 1 We have previously demonstrated that AAV gene transfer of interleukin-4 (IL-4) to endogenous b-cells in young, non-diabetic NOD mice prevented the onset of hyperglycemia in these mice and reduced the severity of insulitis. 1 However, although local expression of murine IL-4 in islets prevented islet destruction and blocked autoimmunity in NOD mice when administered before the onset of hyperglycemia, AAV-mediated gene transfer of IL-4 to b-cells of early-onset diabetic NOD mice was unable to reverse hyperglycemia (unpublished results).…”