Slow and persistent increase of [Ca2+]c in response to ligation of surface IgM in WEHI-231 cells.
WEHI-231 and Bal 17 B cell lines are representative models for immature and mature B cells, respectively. Their regulation of cytosolic Ca(2+) concentration ([Ca(2+)](c)) was compared using fura-2 fluorescence ratiometry. The ligation of B cell antigen receptor (BCR) by anti-IgM antibody induced a slow but large increase of [Ca(2+)](c) in WEHI-231 cells while not in Bal 17 cells. The thapsigargin-induced store-operated Ca(2+) entry (SOCE) of Bal 17 cells reached a steady state which was blocked by 2-aminoethoxydiphenyl borate (2-APB). On the contrary, the thapsigargin-induced SOCE of WEHI-231 cells increased continuously, which was accelerated by 2-APB. The increase of [Ca(2+)](c) by BCR ligation was also enhanced by 2-APB in WEHI-231 cells while blocked in Bal 17 cells. The Mn(2+) quenching study showed that the thapsigargin-, or the BCR ligation-induced Ca(2+) influx pathway of WEHI-231 was hardly permeable to Mn(2+). The intractable increase of [Ca(2+)](c) may explain the mechanism of BCR-driven apoptosis of WEHI-231 cells, a well-known model of clonal deletion of autoreactive immature B cells.
Nam
Joo Hyun
JH
Department of Physiology, Sungkyunkwan University School of Medicine, Changan-Gu, Cheoncheon-Dong, Suwon 440-746, Republic of Korea.
Yoon
Sang Soon
SS
Kim
Tae Jin
TJ
Uhm
Dae-Yong
DY
Kim
Sung Joon
SJ
D000818:Animals; D000888:Antibodies, Anti-Idiotypic / Q000494:pharmacology; D001402:B-Lymphocytes / Q000166:cytology / Q000378:metabolism*; D001896:Boron Compounds / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism*; D002460:Cell Line; D003600:Cytosol / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D007075:Immunoglobulin M / Q000378:metabolism*; D008024:Ligands; D051379:Mice; D011947:Receptors, Antigen, B-Cell / Q000037:antagonists & inhibitors / Q000378:metabolism*; D019284:Thapsigargin / Q000494:pharmacology
D000888:Antibodies, Anti-Idiotypic; D001896:Boron Compounds; D004791:Enzyme Inhibitors; D007075:Immunoglobulin M; D008024:Ligands; D011947:Receptors, Antigen, B-Cell; C044203:anti-IgM; D019284:Thapsigargin; C109986:2-aminoethoxydiphenyl borate; D002118:Calcium