| First Author | Ostiguy V | Year | 2007 |
| Journal | J Leukoc Biol | Volume | 82 |
| Issue | 3 | Pages | 645-56 |
| PubMed ID | 17554014 | Mgi Jnum | J:124239 |
| Mgi Id | MGI:3721164 | Doi | 10.1189/jlb.0806494 |
| Citation | Ostiguy V, et al. (2007) IL-21 promotes T lymphocyte survival by activating the phosphatidylinositol-3 kinase signaling cascade. J Leukoc Biol 82(3):645-656 |
| abstractText | IL-21 is a Type I cytokine, which uses the common gamma chain (gamma(c)) in its receptor. As members of the gamma(c) cytokine/cytokine receptors family play crucial role in the differentiation, activation, and survival of lymphocytes, we have investigated if IL-21 could promote T cell survival and thus, contribute to T cell homeostasis and expansion. Unlike most gamma(c) cytokine receptors, we report that IL-21R is constitutively expressed by all mature T lymphocytes and that stromal cells of lymphoid organs are a constitutive source of IL-21. These observations are reminiscent of what is observed for IL-7/IL-7R, which control T cell survival and homeostasis and suggest a role for IL-21 in T cell homeostasis. Indeed, our results show that IL-21 is a survival factor for resting and activated T cells. Moreover, the ability of IL-21 to costimulate T cell proliferation is mediated by enhancing T cell viability. Further investigation of how IL-21R signaling induces T cell survival shows for the first time that IL-21 binding to its receptor activates the PI-3K signaling pathway and induces Bcl-2 expression. Moreover, the activation of the PI-3K signaling pathway is essential for IL-21-mediated T cell survival. Our data provide a new role for IL-21 in the immune system, which might be used to improve T cell homeostasis in immunocompromised patients. |
