The cytosolic free Ca2+ in ectromelia (mousepox) virus stimulated cytotoxic T lymphocytes.
The objective of these studies was to assess the intracellular calcium (Ca2+) signal involved in the activation of ectromelia virus (EV)-specific cytotoxic T lymphocytes (CTL) upon stimulation with EV-sensitized (A20) target cells or concanavalin A (Con A). The CTL originated from mice previously infected with EV. The level of cytosolic Ca2+ in EV-specific CTL was measured using Fluo-3 AM. In both cases transient [Ca2+]i rise and a sustained plateau (1723 nM) were observed in buffer with 1 mM extracellular calcium. The [Ca2+]i response of EV-specific CTL to EV-sensitized target cells or Con A in extracellular calcium free buffer consisted of only one peak at 852 nm. The cytotoxic activity EV-specific CTL assessed in normal medium was 53.0%, but significantly reduced to 15% when verapamil was added to the buffer. No enhancement of [Ca2+]i response in EV-specific CTL was observed upon costimulation with PMA. Association of the level of intracellular [Ca2+]i in EV-specific CTL and the percentage of their cytotoxicity was found. These results show partial dependence of EV-specific CTL killing on extracellular calcium.
Toka
F N
FN
Department of Microbiology and Immunology, Faculty of Veterinary Medicine, Warsaw Agricultural University (SGGW), Poland.
De Faundez
I S
IS
Gierynska
M
M
Niemiałtowski
M G
MG
D000818:Animals; D002118:Calcium / Q000276:immunology*; D002478:Cells, Cultured; D003600:Cytosol / Q000276:immunology; D003601:Cytotoxicity Tests, Immunologic; D004481:Ectromelia virus / Q000276:immunology*; D004482:Ectromelia, Infectious / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D013602:T-Lymphocytes, Cytotoxic / Q000166:cytology / Q000276:immunology* / Q000821:virology; D014407:Tumor Cells, Cultured
D002118:Calcium