@Article{ecn.2011.0273,
AUTHOR = {Astrid Stienen, Oliver Feyen, Tim Niehues},
TITLE = {Effect of age on homeostasis of lymphocytes in an interleukin-7-deficient mouse model},
JOURNAL = {European Cytokine Network},
VOLUME = {22},
YEAR = {2011},
NUMBER = {1},
PAGES = {63--72},
URL = {http://www.techscience.com/ECN/v22n1/65837},
ISSN = {1952-4005},
ABSTRACT = {Interleukin (IL)-7 is thought to be a non-redundant cytokine for lymphopoiesis as there is a reduction
of T and B cells in peripheral blood (PB) and a loss of TCRγδ<sup>+</sup> cells in PB and bone marrow (BM) in IL-7<sup>-/-</sup> mice. To
investigate whether the absence of IL-7 influences the organ-dependent distribution of the lymphocytes, we analyzed
single cell suspensions of several organs (BM, lung, liver, small intestine, and spleen) at different ages (three and 12
months) of IL-7<sup>+/+</sup> and IL-7<sup>-/-</sup> mice using flow cytometry; immunohistochemical staining was performed on frozen
sections of various organs. We observed lymphocytopenia in almost all organs of IL-7<sup>-/-</sup> mice, but normal counts in
the liver and the lung of three-month-old IL-7<sup>-/-</sup> mice. CD4<sup>+</sup> and CD8<sup>+</sup> cell numbers were decreased in the spleen
and the BM. With aging, we found a greater increase in CD4<sup>+</sup> and CD8<sup>+</sup> cells in the BM of IL-7<sup>-/-</sup> than in IL-7<sup>+/+</sup>
mice, particularly of memory cells. The spleen of IL-7<sup>-/-</sup> mice was characterized by lymphocytopenia. We challenge
the view that IL-7 is a non-redundant cytokine for lymphocyte development. Some of the changes observed, e.g.
partial absence of TCRγδ<sup>+</sup> T cells in the PB, BM and small intestine and complete loss in liver, lung and spleen, may
be due to the altered organ distribution instead of a defect in γδ<sup>+</sup> T cell lymphopoiesis. In this model, aging leads
to a significantly altered composition of lymphocyte subsets, and the lack of IL-7 seems to accelerate this process.},
DOI = {10.1684/ecn.2011.0273}
}