title: Telomerase is involved in IL-7-mediated differential survival of naive and memory CD4+ T cells.
abstract: IL-7 plays an essential role in T cell maintenance and survival. The survival effect of IL-7 is thought to be mediated through regulation of Bcl2 family proteins. After a comparative analysis of IL-7-induced growth and cell death of human naive and memory CD4(+) T cells, we observed that more memory CD4(+) T cells underwent cell division and proceeded to apoptosis than naive cells in response to IL-7. However, IL-7-induced expressions of Bcl2 family members (Bcl2, Bcl-x(L), Bax, and Bad) were similar between naive and memory cells. Instead, we found that IL-7 induced higher levels of telomerase activity in naive cells than in memory cells, and the levels of IL-7-induced telomerase activity had a significant inverse correlation with cell death in CD4(+) T cells. Furthermore, we showed that reducing expression of telomerase reverse transcriptase and telomerase activity significantly increased cell death of IL-7-cultured CD4(+) T cells. Together, these findings demonstrate that telomerase is involved in IL-7-mediated differential survival of naive and memory CD4(+) T cells.
authors.affiliation: Laboratory of Immunology, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA.
authors.forename: Yinhua
authors.initials: Y
authors.lastname: Yang
authors.forename: Jie
authors.initials: J
authors.lastname: An
authors.forename: Nan-ping
authors.initials: NP
authors.lastname: Weng
mesh_terms: D000328:Adult; D015496:CD4-Positive T-Lymphocytes / Q000166:cytology / Q000201:enzymology* / Q000276:immunology*; D016923:Cell Death / Q000276:immunology; D049109:Cell Proliferation; D002470:Cell Survival / Q000276:immunology; D002478:Cells, Cultured; D006801:Humans; D007156:Immunologic Memory; D015851:Interleukin-7 / Q000502:physiology*; D016192:Resting Phase, Cell Cycle / Q000276:immunology; D016176:T-Lymphocyte Subsets / Q000166:cytology / Q000201:enzymology* / Q000276:immunology*; D019098:Telomerase / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*
chemical_list: D015851:Interleukin-7; D019098:Telomerase