ZINC-INDUCED APOPTOSIS IN BONE-MARROW AND SPLENIC B-LINEAGE LYMPHOCYTES OF THE MOUSE

Recently, our lab discovered that moderate concentrations of zinc coul d induce apoptosis in CD4(+)CD8(+)TCR(1o) murine thymocytes. To determ ine if B-lineage lymphocytes demonstrated similar sensitivity, bone ma rrow and splenic B-lymphocytes were treated with zinc at a concentrati on range of 100 to 200 mu M for 8 hrs and analyzed by flow cytometry f or apoptotic death in the B220(+)IgM(-) and B220(+)IgM(+) subsets of t he bone marrow and the IgM(+) and IgG(+) subsets of the spleen. B220()IgM(+) B-lineage cells in the bone marrow and IgM(+) B-cells in the s pleen were found to be most susceptible exhibiting 38% and 25% levels of zinc-induced apoptosis. B220(+)IgM(-) bone marrow B-lineage cells a nd IgG(+) B-cells in the spleen were found to be less sensitive to zin c treatment than IgM-bearing cells. Thus, it is possible that zinc mig ht initiate apoptosis in some cells of the immune System due to fluxes of the metal in cells or the presence of intracellular pools of zinc. (C) 1998 Elsevier Science Inc.