Premium
Intravenous Immunoglobulins Suppress Immunoglobulin Productions by Suppressing Ca2+ ‐Dependent Signal Transduction Through Fc γ Receptors in B Lymphocytes
Author(s) -
KONDO N.,
KASAHARA K.,
KAMEYAMA T.,
SUZUKI Y.,
SHIMOZAWA N.,
TOMATSU S.,
NAKASHIMA Y.,
HORI T.,
YAMAGISHI A.,
OGAWA T.,
IWATA H.,
TAKAHASHI Y.,
TAKENAKA R.,
WATANABE K.,
HAGA M.,
ORII T.
Publication year - 1994
Publication title -
scandinavian journal of immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.934
H-Index - 88
eISSN - 1365-3083
pISSN - 0300-9475
DOI - 10.1111/j.1365-3083.1994.tb03430.x
Subject(s) - antibody , receptor , immunology , immunoglobulin g , intracellular , microbiology and biotechnology , immunoglobulin e , signal transduction , medicine , biology , pharmacology , biochemistry
A high dose intravenous immunoglobulin (IVIG) therapy is used in the treatment of a wide range of autoimmune disorders. However, the mechanisms of the action of IVIGs remain poorly understood. To analyse the mechanisms of effects of IVIGs on immunoglobulin (Ig) production of B cells, the effects of IVIGs on B lymphoblastoid cell lines transformed by Epstein‐Barr virus (LCLs) were investigated. The productions of IgG or IgM of LCLs were dose‐dependently suppressed by polyethylene glycol (PEG)‐treated IVIG or pH 4‐treated 1VIG though the productions were not or only slightly suppressed by pepsin‐treated IVIG. The suppression by IVIGs was blocked by anti‐human IgG Fc or anti‐Fc γ RII. C μ gene expression and μ s C terminal gene expression of LCLs were suppressed by PEG‐treated IVIG, whereas neither C μ gene expression nor μ s C terminal gene expression of LCLs were suppressed by pepsin‐treated IVIG. Although the increase in intracellular calcium concentration in LCLs was not suppressed by pepsin‐treated IVIG, the increase was suppressed by PEG‐treated IVIG. This suppressing effect of PEG‐treated IVIG on intracellular calcium concentration of LCLs was blocked by anti‐human IgG Fc or anti‐ Fc γ RII. Our results suggest that IVIGs suppressed the Ca 2+ ‐dependent signal transduction through Fc γ R on B‐cell membrane, consequently, the transcription of C γ mRNA, especially secreted γ mRNA was suppressed in the B cells.