title: Differences in calcium requirements for B-cell tolerance and immunity.
abstract: Incubation of unprimed spleen B cells with high concentrations of hapten-conjugates resulted in the induction of specific unresponsiveness or tolerance to a subsequent encounter with the hapten on a potentially immunogenic carrier. This process of tolerance induction could occur in the absence of extracellular calcium. In contrast B-cell activation to both proliferation and subsequent antibody secretion is known to be calcium dependent. This means that either (1) the decisions which determine immunity and tolerance in B cells are mediated through totally distinct signalling pathways, or that (2) if tolerance and immunity depend on same common signalling events, then the commitment of B cells to switch on or off must be determined at a very early stage.
mesh_terms: D000818:Animals; D000917:Antibody Formation; D000921:Antibody-Producing Cells / Q000187:drug effects; D001402:B-Lymphocytes / Q000276:immunology*; D002118:Calcium / Q000494:pharmacology / Q000502:physiology*; D006462:Hemolytic Plaque Technique; D007108:Immune Tolerance; D051379:Mice; D008808:Mice, Inbred CBA; D013154:Spleen / Q000276:immunology
chemical_list: D002118:Calcium