title: Development of a human T-cell hybridoma secreting separate B-cell growth and differentiation factors.
abstract: A cloned human T-cell hybridoma (7D5) secreting B-cell growth factor (BCGF) and B-cell differentiation factor (BCDF) was established. Supernatant from this hybrid was capable of maintaining proliferation in anti-IgM-activated normal human B cells. In addition, the hybridoma supernatant induced differentiation and antibody secretion in Staphylococcus aureus Cowan I-stimulated B cells. No interleukin 2 was present in supernatant from this hybridoma. Molecular size of the hybridoma-derived BCGF and BCDF was determined by gel filtration chromatography. BCGF activity was present in the 20-kDa fractions, and BCDF activity eluted in the 30- to 35-kDa fractions. The isoelectric points of the factors, determined by chromatofocusing, were 6.6 for BCGF and 5.9 for BCDF. Finally, absorption experiments were performed using specific target cells. Phytohemagglutinin-stimulated T-cell blasts did not remove either BCGF or BCDF activity. Anti-IgM-activated B cells absorbed BCGF but not BCDF. In contrast, CESS cells removed BCDF but not BCGF. Thus, a human T-cell hybridoma secreting two distinct B-cell lymphokines was developed. Further immunochemical and functional studies of these immunoregulatory molecules should greatly enhance our understanding of the regulation of human B-cell function in normal and disease states.
mesh_terms: D001402:B-Lymphocytes / Q000276:immunology*; D002454:Cell Differentiation; D002455:Cell Division; D002478:Cells, Cultured; D002999:Clone Cells; D006133:Growth Substances / Q000302:isolation & purification / Q000378:metabolism*; D006801:Humans; D006825:Hybridomas / Q000276:immunology*; D007075:Immunoglobulin M / Q000276:immunology; D015847:Interleukin-4; D008213:Lymphocyte Activation; D008222:Lymphokines / Q000302:isolation & purification / Q000378:metabolism*; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D006133:Growth Substances; D007075:Immunoglobulin M; D008222:Lymphokines; D015847:Interleukin-4