| First Author | McKarns SC | Year | 2004 |
| Journal | J Immunol | Volume | 172 |
| Issue | 7 | Pages | 4275-84 |
| PubMed ID | 15034041 | Mgi Jnum | J:88727 |
| Mgi Id | MGI:3036962 | Doi | 10.4049/jimmunol.172.7.4275 |
| Citation | McKarns SC, et al. (2004) Smad3 is essential for TGF-beta 1 to suppress IL-2 production and TCR-induced proliferation, but not IL-2-induced proliferation. J Immunol 172(7):4275-84 |
| abstractText | Transforming growth factor-beta1 is essential to maintain T cell homeostasis, as illustrated by multiorgan inflammation in mice deficient in TGF-beta1 signaling. Despite the physiological importance, the mechanisms that TGF-beta1 uses to regulate T cell expansion remain poorly understood. TGF-beta1 signals through transmembrane receptor serine/threonine kinases to activate multiple intracellular effector molecules, including the cytosolic signaling transducers of the Smad protein family. We used Smad3(-/-) mice to investigate a role for Smad3 in IL-2 production and proliferation in T cells. Targeted disruption of Smad3 abrogated TGF-beta1-mediated inhibition of anti-CD3 plus anti-CD28-induced steady state IL-2 mRNA and IL-2 protein production. CFSE labeling demonstrated that TGF-beta1 inhibited entry of wild-type anti-CD3 plus anti-CD28-stimulated cells into cycle cell, and this inhibition was greatly attenuated in Smad3(-/-) T cells. In contrast, disruption of Smad3 did not affect TGF-beta1-mediated inhibition of IL-2-induced proliferation. These results demonstrate that TGF-beta1 signals through Smad3-dependent and -independent pathways to inhibit T cell proliferation. The inability of TGF-beta1 to inhibit TCR-induced proliferation of Smad3(-/-) T cells suggests that IL-2 is not the primary stimulus driving expansion of anti-CD3 plus anti-CD28-stimulated T cells. Thus, we establish that TGF-beta1 signals through multiple pathways to suppress T cell proliferation. |
