The cell cycle block and lysis of an activated T cell hybridoma are distinct processes with different Ca2+ requirements and sensitivity to cyclosporine A
| Autor: | M Merćep, P D Noguchi, J D Ashwell |
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| Rok vydání: | 1989 |
| Předmět: | |
| Zdroj: | The Journal of Immunology. 142:4085-4092 |
| ISSN: | 1550-6606 0022-1767 |
| Popis: | Stimulation of transformed T cells leads to both lymphokine secretion and inhibition of spontaneous growth. Studies performed with an Ag-specific T cell hybridoma demonstrated that growth inhibition is an early (within 1 h) manifestation of activation. Experiment in which extracellular Ca2+ was chelated or in which cyclosporine A was included indicated that activation-associated growth inhibition is a two-step process. The first phase is the establishment of a G1/S cell cycle block; it does not require extracellular Ca2+ and is not prevented by the addition of cyclosporine A. The second phase is cell lysis. It can be detected 4 to 6 h after activation, requires the presence of extracellular Ca2+, and is prevented when stimulation occurs in the presence of cyclosporine A. The observation that both Ca2+ depletion and cyclosporine A prevented IL-2 secretion at all time points indicates that the pathways leading to lymphokine secretion and the G1/S block diverge early in the course of the cellular response, and establish the cell cycle block as a distinct activation event with unique characteristics. |
| Databáze: | OpenAIRE |
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