TY - JOUR
T1 - IL-15 is required for sustained lymphopenia-driven proliferation and accumulation of CD8 T cells
AU - Sandau, Michelle M.
AU - Winstead, Colleen J.
AU - Jameson, Stephen C.
PY - 2007/7/1
Y1 - 2007/7/1
N2 - Naive T cells undergo slow homeostatic proliferation in response to T cell lymphopenia, which is also called lymphopenia-induced proliferation (LIP). IL-7 is critically required for this process, but previous studies suggested IL-15 was expendable for LIP of naive CD8 T cells. In contrast, we show that IL-15 is important for sustained CD8 T cell proliferation and accumulation in a lymphopenic setting, as revealed by truncated LIP in IL-15-/- hosts. At the same time, we find that IL-12 enhances LIP by acting directly on the CD8 T cells and independently of IL-15, suggesting distinct pathways by which cytokines can regulate homeostatic proliferation. Interestingly, the memory-phenotype CD8 T cell generated by LIP in IL-15-/- hosts are phenotypically distinct from the rare endogenous memory-phenotype cells found in IL-15-/- animals, suggesting these cells are generated by different means. These findings demonstrate that cytokine requirements for LIP change during the process itself, illustrating the need to identify factors that regulate successive stages of lymphopenia-driven proliferation.
AB - Naive T cells undergo slow homeostatic proliferation in response to T cell lymphopenia, which is also called lymphopenia-induced proliferation (LIP). IL-7 is critically required for this process, but previous studies suggested IL-15 was expendable for LIP of naive CD8 T cells. In contrast, we show that IL-15 is important for sustained CD8 T cell proliferation and accumulation in a lymphopenic setting, as revealed by truncated LIP in IL-15-/- hosts. At the same time, we find that IL-12 enhances LIP by acting directly on the CD8 T cells and independently of IL-15, suggesting distinct pathways by which cytokines can regulate homeostatic proliferation. Interestingly, the memory-phenotype CD8 T cell generated by LIP in IL-15-/- hosts are phenotypically distinct from the rare endogenous memory-phenotype cells found in IL-15-/- animals, suggesting these cells are generated by different means. These findings demonstrate that cytokine requirements for LIP change during the process itself, illustrating the need to identify factors that regulate successive stages of lymphopenia-driven proliferation.
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U2 - 10.4049/jimmunol.179.1.120
DO - 10.4049/jimmunol.179.1.120
M3 - Article
C2 - 17579029
AN - SCOPUS:34250890678
SN - 0022-1767
VL - 179
SP - 120
EP - 125
JO - Journal of Immunology
JF - Journal of Immunology
IS - 1
ER -