| First Author | Dooms H | Year | 2007 |
| Journal | J Exp Med | Volume | 204 |
| Issue | 3 | Pages | 547-57 |
| PubMed ID | 17312008 | Mgi Jnum | J:125364 |
| Mgi Id | MGI:3758377 | Doi | 10.1084/jem.20062381 |
| Citation | Dooms H, et al. (2007) Interleukin-2 enhances CD4+ T cell memory by promoting the generation of IL-7R alpha-expressing cells. J Exp Med 204(3):547-57 |
| abstractText | The common gamma chain cytokines interleukin (IL)-2 and IL-7 are important regulators of T cell homeostasis. Although IL-2 is implicated in the acute phase of the T cell response, IL-7 is important for memory T cell survival. We asked whether regulated responsiveness to these growth factors is determined by temporal expression of the cytokine-specific IL-2 receptor (R) alpha and IL-7Ralpha chains. We demonstrate that IL-2Ralpha is expressed early after priming in T cell receptor-transgenic CD4(+) T cells, whereas IL-7Ralpha expression is lost. In the later stage of the response, IL-7Ralpha is reexpressed while IL-2Ralpha expression is silenced. This reciprocal pattern of IL-2Ralpha/IL-7Ralpha expression is disturbed when CD4(+) T cells are primed in the absence of IL-2 signals. Primed IL-2(-/-) or CD25(-/-) (IL-2Ralpha(-/-)) CD4(+) T cells, despite showing normal induction of activation markers and cell division, fail to reexpress IL-7Ralpha late in the response. Because the generation of CD4(+) memory T cells is dependent on IL-7-IL-7Ralpha interactions, primed IL-2(-/-) or CD25(-/-) CD4(+) T cells develop poorly into long-lived memory cells. Retrovirus-mediated expression of IL-7Ralpha in IL-2(-/-) T cells restores their capacity for long-term survival. These results identify IL-2 as a factor regulating IL-7Ralpha expression and, consequently, memory T cell homeostasis in vivo. |
