Impaired responsiveness of IL-2 receptor-expressing T lymphocytes from aged mice.
IL-2 receptor-bearing splenic T lymphocytes derived from aged C57BL6/J mice (22-24 months) display a relative inability to respond to IL-2 when compared to similar cells from young (2-3 months) animals. As a population the aged cells incorporate less [3H]thymidine and fewer are able to undergo vigorous clonal growth. Both the CD4+ and CD8+ subsets display these defects. The clonal assay indicates that aged T cells, in addition to having longer cell cycle transit time, also have a higher frequency of cell cycle arrest than similarly activated young T cells. This defect in IL-2 responsiveness is distinct from those in early signal transduction which limit aged T lymphocyte entry into cycle and cannot be corrected by phorbol myristate acetate or ionomycin.
Thoman
M L
ML
Department of Immunology, Research Institute of Scripps Clinic, La Jolla, California 92037.
D000375:Aging / Q000276:immunology*; D000818:Animals; D002453:Cell Cycle; D004247:DNA / Q000096:biosynthesis; D007376:Interleukin-2 / Q000494:pharmacology; D015759:Ionomycin / Q000494:pharmacology; D008213:Lymphocyte Activation; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D015375:Receptors, Interleukin-2 / Q000032:analysis*; D015398:Signal Transduction; D013601:T-Lymphocytes / Q000276:immunology*; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology; D050378:T-Lymphocytes, Regulatory / Q000276:immunology; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
D007376:Interleukin-2; D015375:Receptors, Interleukin-2; D015759:Ionomycin; D004247:DNA; D013755:Tetradecanoylphorbol Acetate