Arthritis & Rheumatism, Volume 62,
November 2010 Abstract Supplement

Abstracts of the American College of
Rheumatology/Association of Rheumatology Health Professionals
Annual Scientific Meeting
Atlanta, Georgia November 6-11, 2010.


A Role of Autoimmune Response to M3 Muscarinic Acethylcholine Receptor in the Pathogenesis of Sjogren's Syndrome Like Autoimmune Sialoadenitis.

Iizuka2,  Mana, Tsuboi2,  Hiroto, Nakamura2,  Yumi, Matsuo2,  Naomi, Matsumoto2,  Isao, Sumida1,  Takayuki

Univ of Tsukuba/Inst Clin Med, Tsukuba City, Japan
Univ of Tsukuba/Inst Clin Med

Objective:

Sjögren's syndrome (SS) is a chronic autoimmune disease characterized by lymphocytic infiltration of salivary glands, in which CD4+ T cells are predominant. These infiltrating T cells play a crucial role in the generation of SS. Previous studies showed that autoantibodies and auto-reactive T cells against M3 muscarinic acethylcholine receptor (M3R) were detected in patients with SS. In this study, to reveal the pathological role of M3R immune response in SS, we tried to induce SS like sialoadenitis by autoimmune response to M3R.

Methods:

(1) C57BL/6J (M3R+/+) mice and M3R knockout (M3R-/-) mice were immunized intradermaly with synthesized peptides encoding the extracellular domains of murine M3R (N-terminus, 1st, 2nd, and 3rd extracellular loops) in CFA. On day 10, these mice were boosted with intradermal injection. Ten days after booster immunization, spleens were isolated, the immune response to M3R was examined in vitro, and then the splenocytes were transferred to Rag1 knockout mice (Rag1-/-) (M3R-/-®Rag1-/-). (2) Anti-M3R antibodies and the amount of saliva flow M3R-/-®Rag1-/- were measured on day 0, 15, 45. (3) In M3R-/-® Rag1-/- mice, salivary glands were investigated histologically by H&E staining and evaluated immunohistochemically using anti-Thy1, anti-B220, anti-CD4 and anti-CD8 antibodies. Infiltrating lymphocytes derived from salivary glands were co-cultured with M3R peptides in vitro and cytokine (IFN-g, IL-17, IL-4) in the supernatant was measured by ELISA. (4) CD3+ T cells purified from M3R-/- mice immunized with M3R were transferred to Rag1-/- mice (M3R-/-CD3+®Rag1-/-) and salivary glands were examined by histological analysis. (5) The splenocytes from IFN- g -/-/M3R-/- mice immunized with M3R were transferred to Rag1-/- mice (IFN- g -/-/M3R-/-®Rag1-/-).

Results:

(1) IL-17 and IFN- g were highly produced in splenocytes of immunized M3R-/- mice compared with M3R+/+ mice. (2) In M3R-/-® Rag1-/- mice, anti-M3R antibodies was significantly increased and saliva flow were decreased. (3) On day 45, the sialoadenitis with remarkable mononuclear infiltration was observed and Thy1+CD4+ cells predominantly infiltrated in salivary glands of M3R-/-®Rag1-/- mice. IL-17 was preferentially produced from M3R reactive infiltrated T cells. (4) The moderate sialoadenitis with T cell infiltration was also detected in M3R-/-CD3+®Rag1-/- mice. (5) The obvious sialoadenitis was also observed in IFN- g -/-/M3R-/-®Rag1-/- mice as well as M3R-/-®Rag1-/- mice.

Conclusion:

These findings support the notion that M3R reactive Th17 cells might play a crucial role in the generation of autoimmune sialoadenitis such as SS.

To cite this abstract, please use the following information:
Iizuka, Mana, Tsuboi, Hiroto, Nakamura, Yumi, Matsuo, Naomi, Matsumoto, Isao, Sumida, Takayuki; A Role of Autoimmune Response to M3 Muscarinic Acethylcholine Receptor in the Pathogenesis of Sjogren's Syndrome Like Autoimmune Sialoadenitis. [abstract]. Arthritis Rheum 2010;62 Suppl 10 :2176
DOI: 10.1002/art.29940

Abstract Supplement

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