Phorbol myristate acetate inhibits increases in membrane fluidity induced by anti-IgM in B cells.
Anti-IgM or anti-IgD stimulates B cells to induce increases in inositol phospholipid metabolism and intracellular free calcium concentration [( Ca2+]i). Anti-IgM also causes increases in membrane fluidity that occur more promptly than those in [Ca2+]i in resting B cells as well as BAL17 B lymphoma cells. However, other B cell activators such as LPS or PMA did not induce the membrane fluidity changes. Furthermore, sodium fluoride, which is considered to be an activator of the guanine nucleotide-binding protein, caused increases in membrane fluidity as well as increased [Ca2+]i or inositol phospholipid metabolism. Anti-IgM- or sodium fluoride-induced increases in membrane fluidity were inhibited by 20-min pretreatment of cells with PMA, but not by 24-h pretreatment. These results indicate that membrane fluidity changes are closely associated with increased [Ca2+]i after cross-linkage of membrane Ig and are regulated by protein kinase C in B cells.
Mizuguchi
J
J
Department of Applied Immunology, National Institute of Health, Tokyo, Japan.
Utsunomiya
N
N
Nakanishi
M
M
Arata
Y
Y
D000818:Animals; D000888:Antibodies, Anti-Idiotypic / Q000276:immunology*; D001402:B-Lymphocytes / Q000187:drug effects* / Q000276:immunology / Q000648:ultrastructure; D002118:Calcium / Q000502:physiology; D005260:Female; D007072:Immunoglobulin D / Q000276:immunology; D007075:Immunoglobulin M / Q000276:immunology*; D008070:Lipopolysaccharides / Q000494:pharmacology; D008213:Lymphocyte Activation / Q000187:drug effects; D008223:Lymphoma / Q000473:pathology; D008560:Membrane Fluidity / Q000187:drug effects*; D051379:Mice; D008811:Mice, Inbred DBA; D011493:Protein Kinase C / Q000502:physiology; D012969:Sodium Fluoride / Q000494:pharmacology; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*; D014407:Tumor Cells, Cultured / Q000187:drug effects / Q000276:immunology / Q000648:ultrastructure
D000888:Antibodies, Anti-Idiotypic; D007072:Immunoglobulin D; D007075:Immunoglobulin M; D008070:Lipopolysaccharides; C039951:anti-IgD; C044203:anti-IgM; D012969:Sodium Fluoride; D011493:Protein Kinase C; D013755:Tetradecanoylphorbol Acetate; D002118:Calcium