Differential modulation of IL-12 family cytokines in autoimmune islet graft failure in mice
The relative contribution of T helper (Th)1 and Th17 cells in graft rejection is inconclusive, on the basis of evidence provided by different T cell-related cytokine-deficient animal models and graft types.
We used novel antigen-presenting-cell-specific Il-12p35 (also known as Il12a)-knockout (KO), IL-23p19-knockdown (KD) and IL-27p28-KD strategies to investigate T cell differentiation in islet graft rejection.
In vitro dendritic cell–T cell coculture experiments revealed that dendritic cells from Il-12p35-KO and IL-23p19-KD mice showed reduced ability to stimulate IFN-γ and IL-17 production in T cells, respectively. To further explore the T cell responses in islet graft rejection, we transplanted islets into streptozotocin-induced diabetic NOD/severe combined immunodeficiency (SCID) recipient mice with IL-12-, IL-23-, or IL-27-deficient backgrounds and then challenged them with NOD.BDC2.5 T cells. The survival of islet grafts was significantly prolonged in Il-12p35-KO and IL-23p19-KD recipients compared with the control recipients. T cell infiltrations and Th1 cell populations were also decreased in the grafts, correlating with prolonged graft survival.
Our results suggest that IL-12 and IL-23 promote and/or maintain Th1 cell-mediated islet graft rejection. Thus, blockade of IL-12 and IL-23 might act as therapeutic strategies for reducing rejection responses.
KeywordsGraft rejection IL-12 IL-23 Islet transplantation Th1 Th17
Bone-marrow-derived dendritic cell
Pancreatic lymph node
Severe combined immunodeficiency
- 24.Judkowski V, Pinilla C, Schroder K, Tucker L, Sarvetnick N, Wilson DB (2001) Identification of MHC class II-restricted peptide ligands, including a glutamic acid decarboxylase 65 sequence, that stimulate diabetogenic T cells from transgenic BDC2.5 nonobese diabetic mice. J Immunol 166:908–917CrossRefPubMedGoogle Scholar
- 32.Zhang GX, Gran B, Yu S et al (2003) Induction of experimental autoimmune encephalomyelitis in IL-12 receptor-beta 2-deficient mice: IL-12 responsiveness is not required in the pathogenesis of inflammatory demyelination in the central nervous system. J Immunol 170:2153–2160CrossRefPubMedGoogle Scholar
- 36.Alegre ML, Chong A (2009) Toll-like receptors (TLRs) in transplantation. Front Biosci 1:36–43Google Scholar