Purification to homogeneity of a novel human B cell differentiation factor.
By immunization with a partially purified form of a novel human B cell differentiation factor, 446-BCDF, we generated a series of mAbs that inhibit the functional activity of this cytokine (induction of Ig secretion by Staphylococcus aureus Cowan I strain organisms-activated B cells). Two mAbs, 929 and 204, were shown to be specific for 446-BCDF in that they failed to inhibit B cell differentiation in response to other known cytokines (IL-2, IL-6) or mitogens (PWM). More importantly, passage of crude 446-BCDF over a mAb 929-Sepharose 4B column resulted in the depletion of 446-BCDF activity, which could be recovered after elution with 0.1 M glycine, pH 2.8. Finally, TCA precipitation of column-eluted fractions was run on SDS-PAGE. Two bands corresponding to the previously described m.w. range of 446-BCDF were detected in the eluate, but not in the effluent column fractions. Furthermore, protein eluted from these bands resolved with nondenaturing gels also demonstrated 446-BCDF activity. Thus, together these data further support the existence of a novel human B cell differentiation factor that has been purified to homogeneity.
De Kuang
Y
Y
Mount Sinai Medical Center, Division of Clinical Immunology, New York, NY 10029, USA.
Cidon
M
M
Mayer
L
L
D000911:Antibodies, Monoclonal / Q000302:isolation & purification; D001402:B-Lymphocytes / Q000737:chemistry* / Q000166:cytology; D002454:Cell Differentiation / Q000187:drug effects; D016207:Cytokines / Q000276:immunology / Q000302:isolation & purification* / Q000494:pharmacology; D006801:Humans; D007376:Interleukin-2 / Q000276:immunology; D015850:Interleukin-6 / Q000276:immunology
D000911:Antibodies, Monoclonal; D016207:Cytokines; D007376:Interleukin-2; D015850:Interleukin-6