Wolfraim Lawrence A, Letterio John J
Laboratory of Cell Regulation and Carcinogenesis, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA.
J Immunol. 2005 Mar 1;174(5):2481-4. doi: 10.4049/jimmunol.174.5.2481.
Cell cycle re-entry of quiescent T cells is dependent upon cyclin-dependent kinase 2. Inhibition of cyclin-dependent kinase 2 by p27(Kip1) is believed to be the principal constraint on S-phase entry in T cells. We report that deficiency for p27(Kip1) has a more pronounced effect on the expansion of murine naive CD8(+) T cells and that this disparity is due to a reduced requirement for CD28-mediated costimulation in CD8(+) but not CD4(+) T cells lacking p27(Kip1). These data highlight a previously unappreciated difference in the way CD28 signaling is coupled to the core cell cycle machinery in these two T cell subsets.
静止T细胞重新进入细胞周期依赖于细胞周期蛋白依赖性激酶2。p27（Kip1）对细胞周期蛋白依赖性激酶2的抑制被认为是T细胞进入S期的主要限制因素。我们报告称，p27（Kip1）缺陷对小鼠幼稚CD8⁺T细胞的扩增有更显著的影响，这种差异是由于缺乏p27（Kip1）的CD8⁺而非CD4⁺T细胞对CD28介导的共刺激的需求降低。这些数据突出了这两个T细胞亚群中CD28信号与核心细胞周期机制耦合方式上一个以前未被认识到的差异。
