B cells from p50/NF-kappa B knockout mice have selective defects in proliferation, differentiation, germ-line CH transcription, and Ig class switching.
To better understand the role of NF-kappaB in normal B cell physiology, we used a purified population of resting B cells from p50/NF-kappa B knockout (p50-/-) mice to determine their ability to proliferate, secrete Ig, express germ-line CHRNA, and undergo Ig isotype switching in vitro in response to a number of distinct stimuli. p50-/- B cells proliferated normally in response to dextran-anti-IgD Abs (alpha delta-dex) and membrane-bound, but not soluble, CD40 ligand (CD40), and they were virtually unresponsive to LPS when compared with control B cells. p50-/- B cells secreted markedly reduced Ig in response to alpha delta-dex or mCD40L in the presence of IL-4 + IL-5, despite their relatively normal proliferative rates, whereas normal Ig secretion was restored by the combination of alpha delta-dex and CD40L. p50-/- B cells expressed normal steady-state levels of germ-line CH gamma 1 and CH alpha RNA but markedly reduced germ-line CH gamma 3 and CH epsilon RNA upon appropriate stimulation. Although p50-/- B cells underwent substantial switching to IgG1, a marked reduction in the switch to IgG3 and IgE, as IgA, was observed. These data are the first to demonstrate key, independent roles for p50/NF-kappaB in normal B cell maturation to Ig secretion, germ-line CH gene activation, and Ig class switching, as well as mitogenesis, and provide a powerful and well-defined in vitro model system for studying the role of p50/NF-kappaB in a wide range of normal cellular functions.
Snapper
C M
CM
Department of Pathology, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA.
Zelazowski
P
P
Rosas
F R
FR
Kehry
M R
MR
Tian
M
M
Baltimore
D
D
Sha
W C
WC
D000818:Animals; D001402:B-Lymphocytes / Q000187:drug effects / Q000276:immunology; D001483:Base Sequence; D019013:CD40 Antigens / Q000276:immunology / Q000494:pharmacology; D023201:CD40 Ligand; D002454:Cell Differentiation / Q000235:genetics / Q000276:immunology; D003911:Dextrans / Q000494:pharmacology; D018095:Germ-Line Mutation / Q000187:drug effects / Q000276:immunology*; D017578:Immunoglobulin Class Switching / Q000235:genetics*; D007127:Immunoglobulin Constant Regions / Q000235:genetics*; D007143:Immunoglobulin Heavy Chains / Q000235:genetics*; D007075:Immunoglobulin M / Q000096:biosynthesis / Q000187:drug effects; D015847:Interleukin-4 / Q000494:pharmacology; D015848:Interleukin-5 / Q000494:pharmacology; D008070:Lipopolysaccharides / Q000494:pharmacology; D008213:Lymphocyte Activation / Q000187:drug effects / Q000235:genetics*; D008562:Membrane Glycoproteins / Q000494:pharmacology; D051379:Mice; D018345:Mice, Knockout; D008938:Mitosis / Q000187:drug effects / Q000276:immunology; D008969:Molecular Sequence Data; D016328:NF-kappa B / Q000172:deficiency / Q000235:genetics*; D052002:NF-kappa B p50 Subunit; D015398:Signal Transduction / Q000276:immunology; D014158:Transcription, Genetic / Q000276:immunology*
D019013:CD40 Antigens; D003911:Dextrans; D007127:Immunoglobulin Constant Regions; D007143:Immunoglobulin Heavy Chains; D007075:Immunoglobulin M; D015848:Interleukin-5; D008070:Lipopolysaccharides; D008562:Membrane Glycoproteins; D016328:NF-kappa B; D052002:NF-kappa B p50 Subunit; D023201:CD40 Ligand; D015847:Interleukin-4