Interaction between Cl- channels and CRAC-related Ca2+ signaling during T lymphocyte activation and proliferation.
OBJECTIVE
To test the hypothesis that Cl channel blockers affect T cell proliferation through Ca2+-release-activated Ca2+ (CRAC) signaling and examine the effects of the combination of a CRAC channel blocker and a Cl channel blocker on concanavalin A (ConA; 5 mg/mL)-induced Ca2+ signaling, gene expression and cellular proliferation in human peripheral T lymphocytes.


METHODS
[3H]Thymidine incorporation, Fura-2 fluorescent probe, RNase protection assay, and reverse transcription-polymerase chain reaction were used.


RESULTS
The Cl channel blocker 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid (DIDS) inhibited ConA-induced Ca2+ influx, interleukin-2 mRNA expression and T lymphocyte proliferation in a concentration-dependent manner, and also enhanced the inhibitory effects of 1-[beta-[3-(4-methoxyphenyl)propoxyl]-4-methoxyphenethyl]-1H-imidazole (SK&F96365) on the above key events during T cell activation. A combination of DIDS (1 micromol/L) and SK&F96365 (1 micromol/L) significantly diminished ConA-induced ClC-3 mRNA expression by 64%, whereas DIDS(1 micromol/L) or SK&F96365 (1 micromol/L) alone decreased ConA-induced ClC-3 mRNA expression by only 16% and 9%, respectively.


CONCLUSIONS
These results suggest that there is an interaction between CRAC-mediated Ca2+ signaling and DIDS-sensitive Cl channels during ConA-induced T cell activation and proliferation. Moreover, the DIDS-sensitive Cl channels may be related to the ClC-3 Cl channels.
Department of Pharmacology, Zhongshan Medical College, Sun Yat-Sen University, Guangzhou 510089, China.
Guan-Lei
GL
Wang
Yan
Y
Qian
Qin-Ying
QY
Qiu
Xiu-Jian
XJ
Lan
Hua
H
He
Yong-Yuan
YY
Guan
D017878:4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid / Q000008:administration & dosage / Q000494:pharmacology*; D000328:Adult; D002118:Calcium / Q000378:metabolism*; D002121:Calcium Channel Blockers / Q000494:pharmacology; D015220:Calcium Channels; D049109:Cell Proliferation / Q000187:drug effects; D018118:Chloride Channels / Q000037:antagonists & inhibitors* / Q000096:biosynthesis / Q000235:genetics; D003208:Concanavalin A / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D006801:Humans; D007093:Imidazoles / Q000494:pharmacology*; D007376:Interleukin-2 / Q000096:biosynthesis / Q000235:genetics; D008213:Lymphocyte Activation / Q000187:drug effects; D008565:Membrane Proteins; D000071740:ORAI1 Protein; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D013601:T-Lymphocytes / Q000166:cytology / Q000378:metabolism*
D002121:Calcium Channel Blockers; D015220:Calcium Channels; D018118:Chloride Channels; C115376:ClC-3 channel; D007093:Imidazoles; D007376:Interleukin-2; D008565:Membrane Proteins; D000071740:ORAI1 Protein; C510746:ORAI1 protein, human; D012333:RNA, Messenger; D003208:Concanavalin A; C063159:1-(2-(3-(4-methoxyphenyl)propoxy)-4-methoxyphenylethyl)-1H-imidazole; D017878:4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid; D002118:Calcium