Inducible nuclear expression of NF-kappa B in primary B cells stimulated through the surface Ig receptor.
Constitutive expression of NF-kappa B has been associated with developmental maturity in B cells on the basis of studies using continuously growing cell lines and plasmacytomas; however, little is known about the behavior of NF-kappa B in primary, mature B cells. In the present work, the regulation of NF-kappa B expression was studied by analyzing subcellular fractions of adult murine splenic B cells with the electrophoretic mobility shift assay using a kappa B-containing oligonucleotide. Although nuclear extracts from resting B cells contained kappa B-binding activity, additional kappa B-binding activity was present in cytosolic fractions in a form that became apparent after treatment with detergent. Competition analysis indicated that the DNA binding activity detected by electrophoretic gel mobility shift assay was specific for the kappa B motif, and UV photo-cross-linking showed the molecular size of kappa B-binding protein to be similar to that of the DNA binding subunit of NF-kappa B. Nuclear expression of kappa B-binding activity was markedly induced by treatment of B cells with phorbol ester or with LPS. Most notably, kappa B-binding activity was induced after surface IgR cross-linking, and the mechanism of this induction involved PKC. Further, anti-Ig-induced activity was superinduced in the presence of cycloheximide. These results indicate that nuclear NF-kappa B is rapidly induced as a result of B cell stimulation, and further suggest that NF-kappa B may play a specific role in mature B cells after ligand binding to surface Ig distinct from its postulated developmental role as a stage-specific factor involved in kappa-enhancer function.
Liu
J L
JL
Department of Microbiology, Boston University Medical Center, MA 02118.
Chiles
T C
TC
Sen
R J
RJ
Rothstein
T L
TL
D000818:Animals; D001402:B-Lymphocytes / Q000378:metabolism*; D002467:Cell Nucleus / Q000378:metabolism; D003432:Cross-Linking Reagents; D004268:DNA-Binding Proteins / Q000096:biosynthesis; D004789:Enzyme Activation; D005786:Gene Expression Regulation; D008070:Lipopolysaccharides / Q000494:pharmacology; D008213:Lymphocyte Activation / Q000187:drug effects; D051379:Mice; D008807:Mice, Inbred BALB C; D016328:NF-kappa B / Q000096:biosynthesis*; D011493:Protein Kinase C / Q000502:physiology; D011947:Receptors, Antigen, B-Cell / Q000502:physiology; D011961:Receptors, Fc / Q000502:physiology; D015398:Signal Transduction / Q000276:immunology; D013154:Spleen; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
D003432:Cross-Linking Reagents; D004268:DNA-Binding Proteins; D008070:Lipopolysaccharides; D016328:NF-kappa B; D011947:Receptors, Antigen, B-Cell; D011961:Receptors, Fc; D011493:Protein Kinase C; D013755:Tetradecanoylphorbol Acetate