BackgroundSuppressor of cytokine signaling 3 (SOCS3) is the main negative feedback regulator of cytokine signals. We investigated the hypothesis that overexpression of SOCS3 in a murine cardiac allograft transplantation model may result in a survival advantage of the allograft by attenuating alloreactive T-cell responses. MethodsWith the use of BALB/c (H-2(d)) donor mice and C57Bl/6j (H-2(b)) recipient mice, the murine cardiac transplantation model was established. Recipient mice received a tail intravenous injection with eukaryotic expression plasmid pEF-FLAG-I/mSOCS3 before and after transplantation. The heart beat of the grafts and immune responses were monitored. ResultsOverexpression of SOCS3 within grafts and spleens can prolong the survival time of cardiac allografts by attenuating infiltration of inflammatory cells such as T cells and macrophages in the grafts, decreasing the number of CD4(+)IL-17(+) cells and CD8(+)IL-17(+) cells in spleens, as well as reducing the expression of STAT3 in grafts and phosphorylation of STAT3 in both grafts and spleens. ConclusionsOverexpression of SOCS3 significantly delays cardiac allograft acute rejection, which is associated with reduced allograft proinflammatory leukocyte infiltration and impaired alloreactive IL-17(+) T cell immunity. Copyright (c) 2014 John Wiley & Sons, Ltd.