Differential activation of NF-kappa B subunits in dendritic cells in response to Gram-negative bacteria and to lipopolysaccharide.
Dendritic cell (DC) maturation is essential for the initiation of T-dependent immune responses. Nuclear factor kappa B/Rel (NF kappa B/Rel) transcription factors are ubiquitously expressed signalling molecules, known to regulate the transcription of a large number of genes involved in immune responses, including cytokines such as IL-1, IL-6, TNF-alpha and cell surface molecules (MHC class I and II, B7.2). In this study, we have compared the activation of five members of the NF-kappa B family, p65, c-Rel, p50, RelB and p52, during DC maturation in response to lipopolysaccharide (LPS) and to Salmonella typhimurium. We have shown that although the translocation of NF-kappa B occurred very early, 30 min after treatment with both S. typhimurium and LPS, bacteria-induced NF-kappa B activation was more pronounced. Four out of five members, i.e. p65, c-Rel, p50 and RelB, were similarly activated upon the two stimuli but with different kinetics. Indeed, we have observed that p65, c-Rel and p50 were translocated early, whereas RelB was translocated later in DC activation. This differential regulation suggests that the various members of NF-kappa B family can mediate distinct functions of DC physiology.
Hofer
S
S
Department of Biotechnology and Bioscience, University of Milano-Bicocca, P.zza della Scienza 2, 20126 Milan, Italy.
Rescigno
M
M
Granucci
F
F
Citterio
S
S
Francolini
M
M
Ricciardi-Castagnoli
P
P
D000818:Animals; D002454:Cell Differentiation; D002467:Cell Nucleus / Q000378:metabolism; D003470:Culture Media; D003713:Dendritic Cells / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D005786:Gene Expression Regulation; D008070:Lipopolysaccharides / Q000276:immunology*; D051379:Mice; D016328:NF-kappa B / Q000378:metabolism*; D052002:NF-kappa B p50 Subunit; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D020569:Proto-Oncogene Proteins c-rel / Q000378:metabolism; D012486:Salmonella typhimurium / Q000276:immunology*; D015398:Signal Transduction; D051996:Transcription Factor RelA; D051841:Transcription Factor RelB; D014157:Transcription Factors / Q000378:metabolism; D014158:Transcription, Genetic
D003470:Culture Media; D008070:Lipopolysaccharides; D016328:NF-kappa B; D052002:NF-kappa B p50 Subunit; D011518:Proto-Oncogene Proteins; D020569:Proto-Oncogene Proteins c-rel; C497594:Relb protein, mouse; D051996:Transcription Factor RelA; D014157:Transcription Factors; D051841:Transcription Factor RelB