Expression Pattern of Tumor Necrosis Factor-α–Induced Protein 8-Like 2 in Acute Rejection of Cardiac Allograft

Tumor necrosis factor-α–induced protein-8 like-2 (TIPE2) is a negative regulator of innate immunity and cellular immunity, yet the expression pattern of TIPE2 in acute rejection of cardiac allograft remain enigmatic. We developed cardiac transplantation models and divided into 3 groups: a naive group, a syngeneic group, and an allogeneic group. Then, we detected the messenger RNA and protein of TIPE2 in cardiac allografts. Real-time polymerase chain reaction showed expression of CD4 and CD8 in the donor heart, and immunofluorescence assay revealed the association between T cells and TIPE2. In our study, we first found that the expression of TIPE2 in cardiac allografts is upregulated compared with the syngeneic control, and increases in a time-dependent manner. The immunocytochemistry of heart grafts revealed a strong expression of TIPE2 in the inflammatory cells, but not in the cardiomyocytes. Finally, we proved that CD4+ and CD8+ T cells infiltrated cardiac allografts abundantly, which express ample TIPE2. The upregulated expression of TIPE2 in cardiac allografts, mainly came from T cells, which infiltrated the donor heart. This finding indicates that there may be an association between TIPE2 and acute cardiac allograft rejection. •We first found the expression of tumor necrosis factor-α–induced protein 8-like 2 (TIPE2) increased in cardiac allografts in a time-dependent manner.•TIPE2 is abundant in inflammatory cells infiltrated in cardiac allografts, but not in myocardial cells.•CD4+ and CD8+ T cells were upregulated in cardiac allografts, which expressed ample TIPE2.