Constitutive nuclear NF-kappa B in cells of the monocyte lineage.
In monocytes, the nuclear factor NF-kappa B has been invoked as an important transcription factor in the expression of cytokine genes, of cell-surface receptors and in the expression of human immunodeficiency virus. In such cells, DNA binding activity of NF-kappa B can be detected without intentional stimulation. In our studies, cells of the human monocytic line Mono Mac 6, cultured in medium containing fetal-calf serum and low levels of lipopolysaccharide (LPS), also exhibit such 'constitutive' NF-kappa B, as demonstrated by mobility-shift analysis of nuclear extracts. This nuclear NF-kappa B was still present when contaminant LPS was removed by ultrafiltration and when serum was omitted. Protein-DNA complexes of constitutive NF-kappa B are similar in mobility to the LPS-induced NF-kappa B and both are recognized by an antibody specific to the p50 subunit of NF-kappa B. By contrast, treatment of cells with pyrrolidine dithiocarbamate (PDTC) will only block LPS-induced NF-kappa B, but not the constitutive binding protein. Using LPS-free and serum-free conditions, constitutive NF-kappa B can be detected in different cell lines of the monocytic lineage (HL60, U937, THP-1, Mono Mac 1 and Mono Mac 6), but not in Molt 4 T cells or K562 stem cells. When ordered according to stage of maturation, the amount of constitutive NF-kappa B was not increased in more mature cell lines. Furthermore, when inducing differentiation in Mono Mac 6 cells, with vitamin D3, no change in constitutive or inducible NF-kappa B can be detected. Analysis of primary cells revealed substantial constitutive NF-kappa B-binding activity in blood monocytes, pleural macrophages and alveolar macrophages. The constitutive NF-kappa B appears to be functionally active, since a low level of tumour necrosis factor (TNF) transcript is detectable in monocytes, and this level can be increased by blocking transcript degradation using cycloheximide. The level of constitutive NF-kappa B in these cells is variable and is frequently found to be lower in the more mature macrophages. Constitutive NF-kappa B was not maintained by autocrine action of cytokines TNF, interleukin 6, interleukin 10, granulocyte-macrophage colony-stimulating factor or macrophage colony-stimulating factor, since neutralizing antibodies did not reduce constitutive DNA-binding activity. Furthermore, blockade of prostaglandin or leukotriene biosynthesis did not affect constitutive NF-kappa B.(ABSTRACT TRUNCATED AT 400 WORDS)
Frankenberger
M
M
Institute for Immunology, University of Munich, Germany.
Pforte
A
A
Sternsdorf
T
T
Passlick
B
B
Baeuerle
P A
PA
Ziegler-Heitbrock
H W
HW
D001483:Base Sequence; D002454:Cell Differentiation; D016895:Culture Media, Serum-Free; D006801:Humans; D016753:Interleukin-10 / Q000096:biosynthesis; D015850:Interleukin-6 / Q000096:biosynthesis; D008070:Lipopolysaccharides / Q000494:pharmacology; D008969:Molecular Sequence Data; D009000:Monocytes / Q000378:metabolism*; D016328:NF-kappa B / Q000096:biosynthesis*; D009841:Oligonucleotides; D012333:RNA, Messenger / Q000096:biosynthesis; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis
D016895:Culture Media, Serum-Free; D015850:Interleukin-6; D008070:Lipopolysaccharides; D016328:NF-kappa B; D009841:Oligonucleotides; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha; D016753:Interleukin-10