| First Author | Turnquist HR | Year | 2011 |
| Journal | J Immunol | Volume | 187 |
| Issue | 9 | Pages | 4598-610 |
| PubMed ID | 21949025 | Mgi Jnum | J:179437 |
| Mgi Id | MGI:5302431 | Doi | 10.4049/jimmunol.1100519 |
| Citation | Turnquist HR, et al. (2011) IL-33 expands suppressive CD11b+ Gr-1 int and regulatory T cells, including ST2L+ Foxp3+ cells, and mediates regulatory T cell-dependent promotion of cardiac allograft survival. J Immunol 187(9):4598-610 |
| abstractText | IL-33 administration is associated with facilitation of Th2 responses and cardioprotective properties in rodent models. However, in heart transplantation, the mechanism by which IL-33, signaling through ST2L (the membrane-bound form of ST2), promotes transplant survival is unclear. We report that IL-33 administration, while facilitating Th2 responses, also increases immunoregulatory myeloid cells and CD4(+) Foxp3(+) regulatory T cells (Tregs) in mice. IL-33 expands functional myeloid-derived suppressor cells, CD11b(+) cells that exhibit intermediate (int) levels of Gr-1 and potent T cell suppressive function. Furthermore, IL-33 administration causes an St2-dependent expansion of suppressive CD4(+) Foxp3(+) Tregs, including an ST2L(+) population. IL-33 monotherapy after fully allogeneic mouse heart transplantation resulted in significant graft prolongation associated with increased Th2-type responses and decreased systemic CD8(+) IFN-gamma(+) cells. Also, despite reducing overall CD3(+) cell infiltration of the graft, IL-33 administration markedly increased intragraft Foxp3(+) cells. Whereas control graft recipients displayed increases in systemic CD11b(+) Gr-1(hi) cells, IL-33-treated recipients exhibited increased CD11b(+) Gr-1(int) cells. Enhanced ST2 expression was observed in the myocardium and endothelium of rejecting allografts, however the therapeutic effect of IL-33 required recipient St2 expression and was dependent on Tregs. These findings reveal a new immunoregulatory property of IL-33. Specifically, in addition to supporting Th2 responses, IL-33 facilitates regulatory cells, particularly functional CD4(+) Foxp3(+) Tregs that underlie IL-33-mediated cardiac allograft survival. |
