| Autor: |
Wilkins, R. C., Kutzner, B. C., Truong, M., McLean, J. R. N. |
| Předmět: |
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| Zdroj: |
International Journal of Radiation Biology; Aug2002, Vol. 78 Issue 8, p681-688, 8p |
| Abstrakt: |
Purpose: Apoptosis occurs spontaneously in cultured human peripheral blood lymphocytes but is enhanced by exposure to ionizing radiation. Subpopulations of lymphocytes are known to have varying radiosensitivities to radiation-induced apoptosis. The purpose of this study was to examine the radiation-induced apoptotic response of CD4[sup +] and CD8[sup +] T-cells incubated as a complete lymphocyte population. Materials and Methods: Using a four-colour flow-cytometry method, which measures annexin-V binding to phosphatidyl serine and propidium iodide, spontaneous and radiation-induced apoptosis was measured in the total lymphocyte fraction and in CD4[sup +] and CD8[sup +] T-cell subpopulations. Results: It was found that CD8[sup +] T-cells were more sensitive to radiation-induced apoptosis than CD4[sup +] T-cells at doses up to 2 Gy. The yield of radiation-induced apoptosis in the total lymphocyte fraction decreased with increasing ratios of CD4[sup +] to CD8[sup +] T-cells (CD4/CD8 ratio). By manipulating the CD4/CD8 ratio within lymphocyte cultures, it was found that the CD4/CD8 ratio had a dramatic effect on the yield of spontaneous apoptosis of total lymphocytes fraction and CD4[sup +] T-cells but not CD8[sup +] T-cells. Conclusion: The CD4/CD8 ratio affects the apoptotic response of human lymphocytes and CD4[sup +] T-cells. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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