Class-Switch Recombination in the Absence of the IgH 3' Regulatory Region.
J Immunol
; 197(7): 2930-5, 2016 10 01.
Article
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| MEDLINE
| ID: mdl-27559052
ABSTRACT
The â¼28-kb 3' regulatory region (3'RR), which is located at the most distal 3' region of the Ig H chain locus, has multiple regulatory functions that control IgH expression, class-switch recombination (CSR), and somatic hypermutation. In this article, we report that deletion of the entire 3'RR in a mouse B cell line that is capable of robust cytokine-dependent CSR to IgA results in reduced, but not abolished, CSR. These data suggest that 3'RR is not absolutely required for CSR and, thus, is not essential for targeting activation-induced cytidine deaminase to S regions, as was suggested. Moreover, replacing 3'RR with a DNA fragment including only its four DNase I hypersensitive sites (lacking the large spacer regions) restores CSR to a level equivalent to or even higher than in wild-type cells, suggesting that the four hypersensitive sites contain most of the CSR-promoting functions of 3'RR. Stimulated cells express abundant germline transcripts, with the presence or absence of 3'RR, providing evidence that 3'RR has a role in promoting CSR that is unique from enhancing S region transcription.
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Bases de datos:
MEDLINE
Asunto principal:
Inmunoglobulina G
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Región de Cambio de la Inmunoglobulina
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Cadenas Pesadas de Inmunoglobulina
Límite:
Animals
Idioma:
En
Revista:
J Immunol
Año:
2016
Tipo del documento:
Article