Developmental regulation of Fc epsilon RII/CD23 expression in B-lineage cells: evidence for transcriptional and post-transcriptional levels of control.
The present studies show that the expression of cell surface Fc epsilon RII/CD23, detected with the monoclonal anti-Fc epsilon RII/CD23 antibody B3B4 or by the binding of IgE, is not restricted to the stage of resting mature virgin B lymphocytes. Murine CD23 was detected as a cell surface protein on two sIgG+ B-cell lines. Moreover, we detected full-length transcripts for Fc epsilon RII/CD23 in several members of a panel murine B lymphoid lineage cell lines representative of all stages of murine B lymphocyte development. Our findings suggest that regulation of CD23 translation may differ between B-cell lines at various stages of differentiation. The detection of mRNA transcripts for Fc epsilon RII/CD23 was not restricted to transformed cell lines. Fc epsilon RII/CD23 transcripts were amplified by RT-PCR from peritoneal and splenic B lymphocyte subpopulations that were sorted by flow cytometry into populations that did not express surface Fc epsilon RII/CD23. Our findings suggest that Fc epsilon RII/CD23 transcription and translation are not necessarily restricted to the narrow developmental window of murine B lymphocyte differentiation as previously thought. Our findings imply that Fc epsilon RII/CD23 may be expressed at the protein level at various stages of murine B lymphocyte differentiation. Investigations into the expression patterns and potential mechanisms of regulation of Fc epsilon RII/CD23 could provide insight into the basis for the wide range of immunological functions that have been proposed for Fc epsilon RII/CD23.
Hagen
M
M
University of Iowa College of Medicine, Iowa City 52242, USA.
Sandor
M
M
Lynch
R G
RG
D000818:Animals; D016175:B-Lymphocyte Subsets / Q000378:metabolism*; D002454:Cell Differentiation; D002460:Cell Line; D018076:DNA, Complementary / Q000235:genetics; D005786:Gene Expression Regulation; D015723:Gene Library; D051379:Mice; D014176:Protein Biosynthesis; D012323:RNA Processing, Post-Transcriptional; D012333:RNA, Messenger / Q000032:analysis; D017455:Receptors, IgE / Q000096:biosynthesis* / Q000235:genetics; D014158:Transcription, Genetic
D018076:DNA, Complementary; D012333:RNA, Messenger; D017455:Receptors, IgE