Allergy inhibitory receptor‐1 inhibits autoantibody production via upregulation of apoptotic debris clearance by macrophages

Abstract

Aim

Allergy inhibitory receptor‐1 (Allergin‐1) is a newly identified immune regulatory molecule thought to influence autoantibody production. Autoantibody production, like that observed in Allergin‐1‐deficient mice, is crucial in the pathogenesis of several autoimmune diseases such as systemic lupus erythematosus. The purpose of this study is to clarify the regulatory role of Allergin‐1‐mediated autoantibody production using a murine model of thymocytic anaphylaxis.

Methods

C57BL/6 (WT) and Allergin‐1‐deficient mice were treated with apoptotic cells from naive thymocytes stimulated by dexamethasone. Antibody titers of total or immunoglobulin G (IgG) subclass of anti‐double‐stranded DNA (anti‐dsDNA) and anti‐histone antibody from serum were measured using an enzyme‐linked immunosorbent assay. Macrophages from wild‐type (WT) or Allergin‐1‐deficient mice were co‐cultured with fluorescence‐labeled apoptotic thymocytes or fluorogenic reagent and resultant phagocytic activity was quantified by with flow cytometry.

Results

After apoptotic cells injection, antibody titers of total and IgG3 anti‐dsDNA and total anti‐histone from serum were significantly increased in Allergin‐1‐deficient versus WT mice. Phagocytic activity was significantly lower in macrophages from Allergin‐1‐deficient mice versus WT mice.

Conclusion

Allergin‐1 might play an inhibitory role in autoantibody production via upregulation of macrophage phagocytosis.