PRIMARY B-CELLS ESSENTIALLY LACK CONSTITUTIVE NF-KAPPA-B ACTIVITY

Based primarily on the analysis of B cell lines, mature B cells are co nsidered distinct from non-B cells and immature B cells by having cons titutive nuclear NF-kappa B activity. By their comparison to splenic n on-B cells or activated B cells we show here that primary resting B ce lls lack cell-autonomous NF-kappa B activity. This finding indicates t hat the role of the transcription factor in B cells is similar to that in other cells, namely a common mediator of activation and stress sig nals. Whereas the absence of constitutive NF-kappa B activity in matur e B cells does not argue against a role of NF-kappa B in B cell develo pment, it does not support the notion of the essential function of the factor in maintaining the unique transcriptional activities in B cell s.