title: Reactivity of Leu-1+ tonsillar B cells to a high molecular weight B cell growth factor.
abstract: This work was focused on the responsiveness of B cells from blood and tonsils to typical B cell growth factors (BCGF) in the absence of anti-mu antibody. This direct responsiveness was not observed with small dense B cells from either organ. Large tonsillar B cells but not large blood B cells did respond directly to a high m.w. BCGF (m.w. 50,000 BCGF), whereas large B cells from both organs responded directly to the low m.w. BCGF (m.w. 20,000 BCGF). The tonsillar B cells directly responsive to the m.w. 50,000 BCGF express the 4F2 marker and thus belong to a population of in vivo-preactivated B cells. Moreover, this direct responsiveness to the m.w. 50,000 BCGF is localized in Leu-1+ tonsillar B cells. The Leu-1+ and Leu-1- tonsillar B cell subsets do not differ in their responsiveness to the m.w. 50,000 BCGF upon costimulation with anti-mu antibody and to the m.w. 20,000 BCGF regardless of the presence of anti-mu antibody. Thus, the Leu-1+ subset present in tonsils shows a particular reactivity to a high m.w. BCGF.
mesh_terms: D000293:Adolescent; D000328:Adult; D000888:Antibodies, Anti-Idiotypic / Q000276:immunology; D000945:Antigens, Differentiation, T-Lymphocyte; D000954:Antigens, Surface / Q000032:analysis*; D001402:B-Lymphocytes / Q000187:drug effects* / Q000276:immunology; D002455:Cell Division / Q000187:drug effects; D002648:Child; D002675:Child, Preschool; D006133:Growth Substances / Q000494:pharmacology*; D006801:Humans; D007075:Immunoglobulin M / Q000276:immunology; D015847:Interleukin-4; D008213:Lymphocyte Activation / Q000187:drug effects; D008222:Lymphokines / Q000494:pharmacology*; D008970:Molecular Weight; D014066:Palatine Tonsil / Q000473:pathology*
chemical_list: D000888:Antibodies, Anti-Idiotypic; D000945:Antigens, Differentiation, T-Lymphocyte; D000954:Antigens, Surface; D006133:Growth Substances; D007075:Immunoglobulin M; D008222:Lymphokines; C044203:anti-IgM; D015847:Interleukin-4