Transcriptional regulation of the germline immunoglobulin C sub( alpha ) and C sub( epsilon ) genes: Implications for commitment to an isotype switch

Lymphokine directed isotype switching is preceded by the induced expression of the corresponding germline Ig heavy chain constant region (C sub(H)) gene. This association favors a model in which lymphokine induced germline C sub(H) gene expression promotes switch recombination by increasing the acce...

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Bibliographic Details
Published in:International immunology 1992-01, Vol.4 (10), p.1145-1151
Main Authors: Gaff, C, Grumont, RJ, Gerondakis, S
Format: Article
Language:English
Online Access:Get full text
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Summary:Lymphokine directed isotype switching is preceded by the induced expression of the corresponding germline Ig heavy chain constant region (C sub(H)) gene. This association favors a model in which lymphokine induced germline C sub(H) gene expression promotes switch recombination by increasing the accessibility of the switch region to a recombinase(s). An important prediction of this model is that the induction of germline C sub(H) RNAs represents increased specific de novo transcription. To test if this prediction is fulfilled by the switch commitment factors, IL-4 and transforming growth factor- beta (TGF- beta ), we have utilized a B cell line, 1.29, that switches from IgM to IgE and IgA in vitro. In this cell line, IL-4 and TGF- beta increase germline C sub( epsilon ) and C sub( alpha ) RNA levels respectively, predominantly by elevating transcription of these genes. Transcription of germline C sub( epsilon ) and C sub( alpha ) genes appears to be independently regulated and is not affected by lipopolysaccharide or IL-5.
ISSN:0953-8178