Abstract
Purpose: Th-cytokines play important roles in dacryoadenitis associated with Sjögren’s syndrome (SS). The aims of this study were to (i) investigate whether interleukin (IL)-17, a newly identified Th-cytokine, participates in autoimmune dacryoadenitis of MRL/lpr mice and (ii) examine the relationships among IL-17, IL-4, and interferon (IFN)-γ in these mice.
Methods: Three-month-old MRL/lpr mice with lacrimal gland inflammation and 3-month-old control BALB/c mice were used. Frozen sections of lacrimal glands and submandibular lymph nodes were stained with monoclonal antibodies to cytokines IL-17, IL-4, and IFN-γ. Concentrations of IL-17 in serum and 48-h splenocyte culture supernatants were detected by ELISA.
Results: Marked lacrimal gland inflammation was observed in all MRL/lpr mice but not in any BALB/c control mice. In the lacrimal glands of MRL/lpr mice, the proportions of cells that stained were 5 ± 3% for IL-17, 32 ± 14% for IL-4, and 4 ± 2% for IFN-γ. In the submandibular lymph nodes of MRL/lpr mice, expression of IL-17 and IL-4 was significantly higher than that of IFN-γ, and all three cytokines were significantly higher in MRL/lpr mice than in BALB/c mice. Concentrations of IL-17 in both serum and splenocyte culture supernatants of MRL/lpr mice were elevated compared to BALB/c controls.
Conclusions: Since expression of IL-17 is elevated in 3-month-old MRL/lpr mice, we suggest that it plays a role in the pathophysiology of autoimmune dacryoadenitis in these mice.
ACKNOWLEDGMENT
We would like to thank the Department of Pathology, EENT Hospital for histopathological analysis of biopsies and the central laboratory for technical support.
Declaration of interest: The authors report no conflict of interest. The authors alone are responsible for the content and writing of the paper.