SPI-6 gene transfer effects on a mouse model of SS
Sjögren's syndrome (SS) is an autoimmune disease characterized by a focal and diffuse lymphoid cell infiltration into the salivary glands. It has been hypothesized that these sequelae are due to apoptosis of the exocrine epithelial cells. Apoptosis can be induced by cytotoxic T-lymphocytes, containing Granzyme B (GrB) in cytoplasmic granules. GrB initiates a caspase-independent apoptosis pathway and is inhibited by serine proteinase inhibitor 6 (SPI-6) in the mouse. Objective: To evaluate the effect of SPI-6 cDNA produced in salivary glands after gene transfer to non-obese diabetic (NOD) mice, an SS model Methods: Two serotype 2 rAAV vectors, rAAVSPI-6 and rAAVLacZ, were constructed and administered into both submandibular glands (SMGs) of 8-week-old female NOD mice (n = 8) via retroductal delivery ( 1010 particles/gland). Salivary flow rates (SFR) were determined before vector delivery and at sacrifice (16-week-old). Blood glucose levels and body weight were measured weekly, and diabetic mice (blood glucose ≥ 400 mg/dL) were treated with insulin. After sacrifice, SMGs were harvested and analyzed for inflammatory infiltrates (focus score), apoptosis (TUNEL assay), and cytokine profile [mouse interleukins (IL) -2, 4, 6, 10, 12, 18, interferon (IFN)-γ, tumor necrosis factor-α and RANTES] in aqueous gland extracts. Results: At 8 weeks, SFR were not different between two groups. In contrast, at 16 weeks SFR were significantly higher in the rAAVSPI-6-treated group (p = 0.018). The frequency of apoptotic cells was lower in the rAAVSPI-6-treated group (p = 0.018). SMG IL-10 levels were significantly increased (p = 0.009), while IFN-γ levels were significantly decreased (p = 0.029), in the rAAVSPI-6-treated mice. There were no differences in focus scores, blood glucose levels or animal weights between two groups at 16 weeks. Conclusion: These results suggest inhibition of GrB may be beneficial for the autoimmune exocrinopathy of NOD mice and possibly SS.
Division: IADR General Session
Meeting:2006 IADR General Session (Brisbane, Australia) Location: Brisbane, Australia
Year: 2006 Final Presentation ID:286 Abstract Category|Abstract Category(s):Salivary Research
Authors
Mineshiba, Fumi
( NIH, Bethesda, MD, USA
)
Lodde, Beatrijs M.
( NIH, Bethesda, MD, USA
)
Cotrim, Ana P.
( NIH, Bethesda, MD, USA
)
Takahashi, Hiroshi
( NIH, Bethesda, MD, USA
)
Wang, Jianghua
( NIH, Bethesda, MD, USA
)
Schmidt, Michael
( NIH, Bethesda, MD, USA
)
Casciola-rosen, Livia
( Johns Hopkins University School of Medicine, Baltimore, MD, USA
)
Rosen, Antony
( Johns Hopkins University School of Medicine, Baltimore, MD, USA
)