Biochemical characterization of B cell stimulatory factors for lipopolysaccharide-preactivated B cell blasts: distinction from other known lymphokines.
We have performed a biochemical characterization of B cell stimulatory factors (BSF) produced by Con A-stimulated mouse spleen cells that stimulate growth of lipopolysaccharide (LPS)-preactivated B cells (designated BSF-LPS). Two biochemically distinct forms of BSF-LPS were identified in preparative isoelectric focusing, one acidic form having a pI of 3.9-4.4 and a more basic form with a pI 5.2-5.9. The biochemical heterogeneity of the BSF-LPS activity from Con A-stimulated spleen cells was further demonstrated by ion exchange chromatographies using a fast protein liquid chromatography (FPLC) system. The acidic and the basic forms of BSF-LPS could be totally separated from each other and both are distinct from interleukin-2 (IL-2). Moreover, extending the characterization of the BSF-LPS, together with the use of various murine assay systems for BSF, we could formally exclude that IL-4 or IL-5 accounted for the BSF-LPS activities. In summary, our data provide evidence for the existence of heterogeneous BSF-LPS which maintain growth of LPS-preactivated B cell blasts, and show that these factors can be distinguished from the other lymphokines which have been involved in the control of the cell growth of murine B lymphocytes.
Ruuth
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Institute for Applied Cell and Molecular Biology, University of Umeå, Sweden.
Praz
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Lundgren
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D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology*; D002852:Chromatography, Ion Exchange; D003208:Concanavalin A / Q000494:pharmacology; D005260:Female; D066298:In Vitro Techniques; D015847:Interleukin-4; D007378:Interleukins / Q000096:biosynthesis / Q000302:isolation & purification*; D007525:Isoelectric Focusing; D008070:Lipopolysaccharides / Q000494:pharmacology; D008213:Lymphocyte Activation; D008297:Male; D051379:Mice; D013154:Spleen / Q000276:immunology
D007378:Interleukins; D008070:Lipopolysaccharides; D003208:Concanavalin A; D015847:Interleukin-4