Prolonged exposure of naïve CD8+T cells to interleukin-7 or interleukin-15 stimulates proliferation without differentiation or loss of telomere length

Autor: Janine Oldham, Diana L. Wallace, Marion Bérard, Joanne E. Cook, Arne N. Akbar, Peter C. L. Beverley, David F. Tough, Maria V. D. Soares
Rok vydání: 2006
Předmět:
Zdroj: Immunology. 119:243-253
ISSN: 0019-2805
DOI: 10.1111/j.1365-2567.2006.02429.x
Popis: Interleukin (IL)-7 and IL-15 are cytokines implicated in homeostatic control of the peripheral CD8 T-cell pool. We compared the effects of IL-7 and IL-15 on survival and proliferation of purified human CD8+ T-cell subsets. Low concentrations of either cytokine reduced the spontaneous apoptosis of all subsets, and enhancement of survival corresponded to the extent of Bcl-2 up-regulation. Surprisingly, although minimal proliferation of naive CD8+ T cells was observed during the first week of culture with cytokines, a marked expansion of these cells occurred at later time points, particularly in response to IL-15. This occurred largely without phenotypic change or acquisition of effector function, indicating a dissociation of differentiation from proliferation. Notably, progression of naive CD8+ T cells through several cell divisions resulted in up-regulation of telomerase and the maintenance of telomere length. These data show that IL-7 and IL-15 induce cell proliferation and rescue from apoptosis in a concentration, time and subset-dependent manner, and have implications for the homeostatic expansion of the naive CD8+ T-cell pool.
Databáze: OpenAIRE