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The increased expression of the activating Fc receptors in systemic lupus erythematosus
Author(s) -
Su Kaihong,
Zhou Huaxin,
Rockwell Nicholas A,
Chambers James G,
Zhang Yan,
Zhou Tong,
Edberg Jeffrey C,
Kimberly Robert P
Publication year - 2008
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.22.1_supplement.667.11
Subject(s) - receptor , immunology , antibody , myeloid , immune system , monoclonal antibody , fc receptor , downregulation and upregulation , dendritic cell , plasmacytoid dendritic cell , chemistry , microbiology and biotechnology , biology , biochemistry , gene
The immunoglobulin G Fc receptors (FcγRs) play an important role in mediating the effector function of IgG. The expression ratio of activating and inhibitory FcγRs determines the threshold for cellular activation. Previous studies have suggested dysregulation of FcγR expression on monocytes and B cells in patients with systemic lupus erythematosus (SLE). However, there is no systematic examination of both activating and inhibitory receptors to determine the activation/inhibition ratio. Using receptor specific monoclonal antibodies, we have examined the cell surface expression levels of the activating FcγRI, FcγRIIa, and FcγRIII and the inhibitory FcγRIIb on circulating monocytes, neutrophils, myeloid dendritic cells and plasmacytoid dendritic cells in SLE patients. Compared to healthy controls, monocytes and myeloid dendritic cells from active SLE patients have increased expression of FcγRI with similar levels of FcγRIIa and FcγRIIb. Plasmacytoid dendritic cells from SLE patients have increased expression of FcγRIIa with no detectable expression of the inhibitory FcγRIIb. We conclude that the upregulation of the activating FcγRs in SLE patients alters the activation/inhibition ratio and may contribute to the immune overactivation in SLE.