Clonal Culture Models of T Cell Senescence

Abstract

The ability to culture T cells long-term first became a reality after the discovery of T cell growth factor in the late 1970s. Using interleukin 2 (IL 2), as it is now known, normal human T lymphocytes can now be cultured for extended periods allowing for them to be cloned and monoclonal populations to be grown up to usable amounts for experimentation. This still cannot be achieved with other normal immune cells such as B cells or macrophages, which can only be cultured long term after transformation. This chapter considers clonal T cell populations as models of immune aging. T cell clones may be derived from younger or older, healthy or frail subjects, centenarians, T cell precursors, and a variety of other sources. Their lifespan in culture can be determined under different conditions and progressive changes occurring over time can be investigated. Analogous to the large body of work on fibroblast senescence in vitro, T cell clones may provide models for events occurring in vivo and provide a test bed for certain interventions to restore appropriate immune function.