IL-7 is critical for homeostatic proliferation and survival of naive T cells.
In T cell-deficient conditions, naive T cells undergo spontaneous "homeostatic" proliferation in response to contact with self-MHC/peptide ligands. With the aid of an in vitro system, we show here that homeostatic proliferation is also cytokine-dependent. The cytokines IL-4, IL-7, and IL-15 enhanced homeostatic proliferation of naive T cells in vitro. Of these cytokines, only IL-7 was found to be critical; thus, naive T cells underwent homeostatic proliferation in IL-4(-) and IL-15(-) hosts but proliferated minimally in IL-7(-) hosts. In addition to homeostatic proliferation, the prolonged survival of naive T cells requires IL-7. Thus, naïve T cells disappeared gradually over a 1-month period upon adoptive transfer into IL-7(-) hosts. These findings indicate that naive T cells depend on IL-7 for survival and homeostatic proliferation.
Tan
J T
JT
Department of Immunology, The Scripps Research Institute, La Jolla, CA 92037, USA.
Dudl
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E
LeRoy
E
E
Murray
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R
Sprent
J
J
Weinberg
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KI
Surh
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CD
D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000166:cytology* / Q000378:metabolism; D018414:CD8-Positive T-Lymphocytes / Q000166:cytology* / Q000378:metabolism; D002455:Cell Division; D002470:Cell Survival; D006801:Humans; D015851:Interleukin-7 / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism
D015851:Interleukin-7; D019253:Proto-Oncogene Proteins c-bcl-2