title: Heavy metal modulation of lymphocyte activities--II. Lead, an in vitro mediator of B-cell activation.
abstract: Investigation of the immunopotentiating effect(s) of Pb2+ on the humoral immune response has provided evidence that a heavy metal can alter the proliferation and differentiation of B-cells. Pb2+ interacted with B-cells to enhance both their proliferation and their differentiation into sheep red blood cell (SRBC)-specific PFC. Preincubation of B-cells with Pb2+ for only 1 h enhanced their activities. Enhancement of in vitro humoral immunity to SRBC was due to direct Pb2+ activation of B-cells and enhancement of T-cell help. Furthermore, Pb2+ and the cyclic nucleotides dibutyryl cyclic adenosine monophosphate (DBcAMP) or cyclic guanosine monophosphate (cGMP) worked in a synergistic manner to enhance the B-cell proliferation, and Pb2+ and DBcAMP synergistically enhanced PFC development. Ni2+, which had been shown to enhance PFC development in cultures of spleen cells in a manner equivalent to Pb2+, did not enhance PFC development in B-cell cultures as well as Pb2+ and did not produce synergistic effects with DBcAMP or cGMP. The possible mechanisms by which Pb2+ enhances B-cell activities and the implications of these effects are discussed.
mesh_terms: D000818:Animals; D000917:Antibody Formation; D001402:B-Lymphocytes / Q000276:immunology*; D003994:Bucladesine / Q000494:pharmacology; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D003995:Dibutyryl Cyclic GMP / Q000494:pharmacology; D005260:Female; D006462:Hemolytic Plaque Technique; D007854:Lead / Q000494:pharmacology*; D008213:Lymphocyte Activation / Q000187:drug effects*; D008211:Lymphocyte Cooperation; D051379:Mice; D008808:Mice, Inbred CBA / Q000276:immunology; D009532:Nickel / Q000494:pharmacology; D013154:Spleen / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology
chemical_list: D007854:Lead; D003995:Dibutyryl Cyclic GMP; D003994:Bucladesine; D009532:Nickel