High Levels of SOX5 Decrease Proliferative Capacity of Human B Cells, but Permit Plasmablast Differentiation

Language
en
Document Type
Article
Issue Date
2014-07-01
Issue Year
2014
Authors
Rakhmanov, Mirzokhid
Sic, Heiko
Kienzler, Anne-Kathrin
Fischer, Beate
Rizzi, Marta
Seidl, Maximilian
Melkaoui, Kerstina
Unger, Susanne
Moehle, Luisa
Schmit, Nadine E.
Editor
Abstract

Currently very little is known about the differential expression and function of the transcription factor SOX5 during B cell maturation. We identified two new splice variants of SOX5 in human B cells, encoding the known L-SOX5B isoform and a new shorter isoform L-SOX5F. The SOX5 transcripts are highly expressed during late stages of B-cell differentiation, including atypical memory B cells, activated CD21low B cells and germinal center B cells of tonsils. In tonsillar sections SOX5 expression was predominantly polarized to centrocytes within the light zone. After in vitro stimulation, SOX5 expression was downregulated during proliferation while high expression levels were permissible for plasmablast differentiation. Overexpression of L-SOX5F in human primary B lymphocytes resulted in reduced proliferation, less survival of CD138neg B cells, but comparable numbers of CD138+CD38hi plasmablasts compared to control cells. Thus, our findings describe for the first time a functional role of SOX5 during late B cell development reducing the proliferative capacity and thus potentially affecting the differentiation of B cells during the germinal center response.

Journal Title
PLoS ONE
Volume
9
Issue
6
Citation
DOI
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