ISSN:
1744-313X
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Biology
,
Medicine
Notes:
Human IgE synthesis requires the presence of both interleukin 4 (IL-4) and T-cells. However, it is not clear what role IL-4 and T-cells play in the induction of IgE synthesis at the level of gene regulation. B cells that were obtained from patients with a high level of serum IgE and from healthy donors were immortalized by Epstein-Barr virus. We examined IgE production of these B cells stimulated with IL-4. Supernatant IgE levels of patient's B cells cultured with or without IL-4 were higher than those of healthy donor's B cells. Our results indicated that B cells stimulated with IL-4 from patients produced IgE, germline C ε transcript, and S μ S ε recombination. The germline C e transcript was dose-dependently induced in the presence of IL-4 and related to the supernatant IgE level. In B cells stimulated with IL-4 that were obtained from patients, (some of the) DNA near or within the I e region was (already partly) unmethylated, unlike those from healthy donors, and there was a loss of methyl groups of the DNA upon the addition of IL-4 in B cells from both patients and normal donors. IgE synthesis of B cells stimulated with IL-4 in patients with a high level of serum IgE is due to an accessibility in the immunoglobulin heavy-chain isotype switch, and this may reflect the accessibility in synthesis of germline C ε transcript, which may be caused by the increase of opening chromatin structures because of their unmethylation in the I ε region.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1744-313X.1995.tb00241.x
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