title: In vitro immune response of human peripheral lymphocytes. VI. Distribution and characterization of precursors for PHA- and protein A-induced colony-forming B cells.
abstract: B cells from peripheral blood or cord blood formed colonies by stimulation with either PHA or protein A. On the other hand, tonsillar B cells did not form protein A-induced colonies, although PHA-induced colony formation was comparable to that observed in peripheral B cells. Lack of protein A-induced colony formation in tonsillar B cells was not due to the defect of helper T cells in preculture or to the presence of suppressor cells but was due to the absence of precursors for colony formation. The result showed that PHA- and protein A-induced colony-forming cells belonged to distinct subsets of B cells. Depletion of mu-bearing cells from peripheral B cells abrogated both PHA- and protein A-induced colony formation. Depletion of delta-bearing cells did not affect PHA- and protein A-induced colony formation and the population enriched with delta-bearing cells also showed colony formation. Depletion of complement receptor (CR)-positive cells removed precursors for both PHA- and protein A-induced colony formation. These results showed that precursor cells for PHA- and protein A-induced colony formation were IgM+, IgD+ and CR+ or IgM+, IgD- and CR+.
mesh_terms: D000818:Animals; D001402:B-Lymphocytes / Q000166:cytology / Q000276:immunology*; D002417:Cattle; D002454:Cell Differentiation; D003114:Colony-Forming Units Assay; D003176:Complement C3 / Q000276:immunology; D005260:Female; D006801:Humans; D007111:Immunity, Cellular; D014066:Palatine Tonsil / Q000166:cytology; D010835:Phytohemagglutinins / Q000494:pharmacology*; D011247:Pregnancy; D011817:Rabbits; D011947:Receptors, Antigen, B-Cell; D011951:Receptors, Complement / Q000276:immunology; D013205:Staphylococcal Protein A / Q000494:pharmacology*
chemical_list: D003176:Complement C3; D010835:Phytohemagglutinins; D011947:Receptors, Antigen, B-Cell; D011951:Receptors, Complement; D013205:Staphylococcal Protein A