ISSN:
1365-3083
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Medicine
Notes:
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 Ca2+ -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.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1365-3083.1994.tb03430.x
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