Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA 02115, USA.
Proc Natl Acad Sci U S A. 2010 Jul 20;107(29):12895-900. doi: 10.1073/pnas.0914878107. Epub 2010 Jul 6.
It is well established that CD4(+) CD8(+) thymocytes are more sensitive to myriad death stimuli than CD4(+) or CD8(+) single positive (SP) thymocytes. The mechanism behind this hypersensitivity to apoptosis of CD4(+) CD8(+) thymocytes is not understood. To test whether the difference lay in the apoptotic preset of mitochondria, established by the BCL-2 family of proteins, we developed a method, FACS-based BH3 profiling. Using this tool, we could discriminate thymocyte subpopulations and demonstrate that mitochondria in double positive (DP) thymocytes are more primed for death than those in single positive counterparts. Loss of proapoptotic BIM, known to cause autoimmunity, also causes loss of "priming." Priming is a phenotype with physiologic consequences, which can be measured at the single-cell level in complex samples using FACS-based BH3 profiling.
已经证实，CD4(+) CD8(+) 胸腺细胞比 CD4(+) 或 CD8(+) 单阳性 (SP) 胸腺细胞对多种死亡刺激更为敏感。这种 CD4(+) CD8(+) 胸腺细胞对细胞凋亡的超敏感性的机制尚不清楚。为了测试差异是否在于由 BCL-2 蛋白家族决定的线粒体凋亡预设，我们开发了一种方法，基于流式细胞术的 BH3 分析。使用此工具，我们可以区分胸腺细胞亚群，并证明双阳性 (DP) 胸腺细胞中的线粒体比单阳性对应物更容易引发细胞死亡。已知促凋亡 BIM 的缺失会导致自身免疫，也会导致“引发”的缺失。引发是一种具有生理后果的表型，可以使用基于流式细胞术的 BH3 分析在复杂样本中在单细胞水平上进行测量。
