Raf-1 Protein Kinase Activity in T Cells from Aged Mice

Most of our models of signal transduction through the T-cell receptor (TCR) involve components and pathways first described in T-cell clones and T-cell lymphomas such as the Jurkat cell line (1 ). These studies, while providing valuable insights, are not always reliable guides to the analogous biochemical events in cells freshly isolated from live donors (2 ). Thus, studies of the effects of aging on T-cell activation must frequently begin with a detailed study of the responses of cells from young individuals. Studies of aging effects involve additional challenges, including the difficulty of purifying sufficient numbers of cells from specific subsets, and allowing for the inherent variability among donors of any age.