| First Author | Allard EL | Year | 2007 |
| Journal | Eur J Immunol | Volume | 37 |
| Issue | 11 | Pages | 3069-77 |
| PubMed ID | 17918202 | Mgi Jnum | J:126318 |
| Mgi Id | MGI:3761028 | Doi | 10.1002/eji.200637017 |
| Citation | Allard EL, et al. (2007) Overexpression of IL-21 promotes massive CD8(+) memory T cell accumulation. Eur J Immunol 37(11):3069-77 |
| abstractText | The ability of IL-21 to promote in vitro T cell survival led us to investigate its biological activity in vivo. We report that overexpression of IL-21 in transgenic mice drives CD8(+) memory T cell accumulation with a concomitant reduction in naive T cell numbers. These memory T cells are functional, given their ability to rapidly produce IFN-gamma and proliferate following stimulation. Since the homeostasis of naive and memory T cells is controlled by cytokines, we evaluated whether IL-21 influences cytokine receptor expression. We show that IL-21 inhibits IL-7R expression on naive T cells in vitro, suggesting impaired IL-7-mediated naive T cell survival in IL-21-transgenic mice. In contrast, IL-7R expression on CD4(+) memory T cells is not affected, allowing their IL-7-dependent survival in IL-21-transgenic mice. Although IL-21 decreases IL-7R expression on CD8(+) memory T cells, this has no impact on their survival since their maintenance in the T cell pool is IL-7-independent. Rather, we demonstrate that CD8(+) memory T cells are receptive to IL-21 survival signals allowing for their accumulation in IL-21-transgenic mice. This study identifies new roles for IL-21 in T cell homeostasis and in the regulation of T cell responses to cytokines. |
