Cyclosporin-A sensitive induction of NF-AT in murine B cells.
Primary B cells are induced to proliferate by cross-linking surface immunoglobulin or by its pharmacological equivalent, phorbol ester and calcium ionophore. However, nuclear responses that have been studied in activated B cells are typically inducible with phorbol esters alone. We show that a factor, indistinguishable from the nuclear factor of activated T cells (NF-AT), is induced in B cells in response to anti-immunoglobulin signals or the combined action of phorbol ester and ionomycin, but not in response to either reagent alone. The signals necessary for NF-AT induction in B cells, therefore, closely parallel those required to induce B cell proliferation. Transfection analysis shows that B cell NF-AT is a transcriptional activator. Furthermore, NF-AT induction in splenic cells is suppressed by cyclosporin A, suggesting a mechanism by which immunosuppressive agents act on the B cell compartment. We propose that NF-AT should be considered more generally as a nuclear factor of activated lymphoid cells.
Venkataraman
L
L
Rosenstiel Research Center, Brandeis University, Waltham, Massachusetts 02254-9110.
Francis
D A
DA
Wang
Z
Z
Liu
J
J
Rothstein
T L
TL
Sen
R
R
D000818:Animals; D001402:B-Lymphocytes / Q000187:drug effects* / Q000276:immunology / Q000378:metabolism*; D001483:Base Sequence; D002460:Cell Line; D016572:Cyclosporine / Q000494:pharmacology*; D017931:DNA Primers / Q000235:genetics; D004268:DNA-Binding Proteins / Q000096:biosynthesis* / Q000235:genetics; D015870:Gene Expression / Q000187:drug effects; D066298:In Vitro Techniques; D008213:Lymphocyte Activation; D051379:Mice; D008969:Molecular Sequence Data; D050778:NFATC Transcription Factors; D009687:Nuclear Proteins; D014157:Transcription Factors / Q000096:biosynthesis* / Q000235:genetics; D015533:Transcriptional Activation; D014162:Transfection
D017931:DNA Primers; D004268:DNA-Binding Proteins; D050778:NFATC Transcription Factors; D009687:Nuclear Proteins; D014157:Transcription Factors; D016572:Cyclosporine