Purification of a novel B cell growth and differentiation factor associated with lupus syndrome.
We have previously reported that KML1-7 cells cloned from a lupus-prone MRL/l mice produced a soluble factor that preferentially expanded anti-DNA antibody production across the H-2 barrier. We purified this factor, a 55-kDa protein that we termed nucleobindin (Nuc). Nuc showed not only induction of anti-ssDNA IgG antibody in cultures of B cells from MRL/l mice (greater than 16 weeks old), but also growth activity. Furthermore, antibodies against existing cytokines have so far not been shown to block Nuc activity on these B cells. In view of the fact that Nuc did not boost anti-ssDNA IgG antibody production in cultures of spleen cells of comparable age from MRL/n mice, which develop a mild form of lupus after the age of one year, Nuc may act on pre-activated B cells to help IgG anti-DNA antibody production. Taken together, Nuc is a new kind of growth and differentiation factor associated with lupus syndrome.
Kanai
Y
Y
Department of Molecular Oncology, University of Tokyo, Japan.
Tanuma
S
S
D000818:Animals; D000974:Antibodies, Antinuclear / Q000096:biosynthesis; D001327:Autoimmune Diseases / Q000276:immunology / Q000378:metabolism*; D001402:B-Lymphocytes / Q000187:drug effects* / Q000276:immunology / Q000473:pathology; D002135:Calcium-Binding Proteins; D002454:Cell Differentiation / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D002460:Cell Line; D004247:DNA / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics / Q000302:isolation & purification* / Q000494:pharmacology; D005260:Female; D006133:Growth Substances / Q000235:genetics / Q000302:isolation & purification* / Q000494:pharmacology; D008180:Lupus Erythematosus, Systemic / Q000276:immunology / Q000378:metabolism*; D051379:Mice; D008807:Mice, Inbred BALB C; D008817:Mice, Mutant Strains / Q000276:immunology / Q000378:metabolism*; D009419:Nerve Tissue Proteins; D000080866:Nucleobindins; D013268:Stimulation, Chemical
D000974:Antibodies, Antinuclear; D002135:Calcium-Binding Proteins; D004268:DNA-Binding Proteins; D006133:Growth Substances; D009419:Nerve Tissue Proteins; D000080866:Nucleobindins; D004247:DNA