Biochemical characterization and biological effects of partially purified B cell-activating factor (BCAF).
B cell-activating factor (BCAF) has been characterized and partially purified from the supernatant of the murine tumor T cell line 373. BCAF has an apparent molecular mass of 15 to 20 kDa when analyzed by Superose 12 fast protein liquid chromatography (FPLC) gel filtration and a pI of 4.5 to 5.0 when analyzed by FPLC chromatofocusing. Concentrated supernatant was applied to a nickel chelating column and unadsorbed active material was further purified by two sequential C4 reverse-phase high-performance liquid chromatography steps. This purification procedure allowed a complete separation of interleukin 2 and interleukin 4 activities from BCAF. This partially purified BCAF induces Ia expression, cell size increase and proliferation of small resting B cells. Furthermore, we have shown that the activity of partially purified BCAF is insensitive to treatment by monoclonal antibodies specific for interleukin 4 and interleukin 5.
Roth
C
C
Unité d'Immunogénétique Cellulaire, Institut Pasteur, Paris, France.
Moreau
J L
JL
Korner
M
M
Jankovic
D
D
Thèze
J
J
D000818:Animals; D001402:B-Lymphocytes / Q000166:cytology / Q000502:physiology*; D000949:Histocompatibility Antigens Class II / Q000096:biosynthesis; D007376:Interleukin-2 / Q000096:biosynthesis; D015847:Interleukin-4; D015848:Interleukin-5; D007378:Interleukins / Q000096:biosynthesis / Q000302:isolation & purification*; D007526:Isoelectric Point; D008213:Lymphocyte Activation; D051379:Mice; D008970:Molecular Weight; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
D000949:Histocompatibility Antigens Class II; D007376:Interleukin-2; D015848:Interleukin-5; D007378:Interleukins; D015847:Interleukin-4; D013755:Tetradecanoylphorbol Acetate