Previous Article | Next Article ![]()
Molecular and Cellular Biology, October 1999, p. 7264-7275, Vol. 19, No. 10
Integrated Program in Cellular,
Received 28 December 1998/Returned for modification 19 February
1999/Accepted 20 July 1999
The BCL-6 proto-oncogene encodes a POZ/zinc-finger transcription
factor that is expressed in B cells and a subset of CD4+ T
cells within germinal centers. Recent evidence suggests that BCL-6 can
act as a sequence-specific repressor of transcription, but the target
genes for this activity have not yet been identified. The binding site
for BCL-6 shares striking homology to the sites that are the target
sequence for the interleukin-4 (IL-4)-induced Stat6 (signal transducers
and activators of transcription) signaling molecule. Electrophoretic
mobility shift assays demonstrate that BCL-6 can bind, with different
affinities, to several DNA elements recognized by Stat6. Expression of
BCL-6 can repress the IL-4-dependent induction of immunoglobulin (Ig)
germ line
0270-7306/99/$04.00+0
Copyright © 1999, American Society for Microbiology. All rights reserved.
Transcriptional Repression of Stat6-Dependent
Interleukin-4-Induced Genes by BCL-6: Specific Regulation of I
Transcription and Immunoglobulin E Switching
transcripts, but does not repress the IL-4 induction of
CD23 transcripts. Consistent with the role of BCL-6 in modulating
transcription from the germ line
promoter, BCL-6
/
mice display an increased ability to class switch to IgE in response to
IL-4 in vitro. These animals also exhibit a multiorgan inflammatory disease characterized by the presence of a large number of
IgE+ B cells. The apparent dysregulation of IgE production
is abolished in BCL-6
/
Stat6
/
mice,
indicating that BCL-6 regulation of Ig class switching is dependent
upon Stat6 signaling. Thus, BCL-6 can modulate the transcription of
selective Stat6-dependent IL-4 responses, including IgE class switching
in B cells.
*
Corresponding author. Mailing address: Department of
Medicine/Microbiology, Columbia University, 630 W. 168th St., New York, NY 10032-3702. Phone: (212) 305-6982. Fax: (212) 305-1870. E-mail: pbr3{at}columbia.edu.
Molecular and Cellular Biology, October 1999, p. 7264-7275, Vol. 19, No. 10
0270-7306/99/$04.00+0
Copyright © 1999, American Society for Microbiology. All rights reserved.
This article has been cited by other articles:
| J. Bacteriol. | J. Virol. | Eukaryot. Cell |
|---|
| Microbiol. Mol. Biol. Rev. | Clin. Vaccine Immunol. | All ASM Journals |
|---|