Preoperative application of combination of portal venous injection of donor spleen cells and intraperitoneal injection of rapamycin prolongs the survival of cardiac allografts in mice.

Objective: To investigate the effects of preoperative portal venous injection of donor spleen cells (PVIDSC) and intraperitoneal injection of rapamycin in the acute rejection of cardiac allograft in mice and the underlying mechanisms.

Methods: Homogenous female B6 mice and BALB/c mice were used as recipients and donors of heart transplantation. These mice were randomly divided into different groups and received PVIDSC alone, rapamycin alone, or PVIDSC and rapamycin combined therapy.

The recall alloresponse following retransplantation is more intense compared with the T cell memory-transfer model.

The presence of alloreactive memory T cells in recipient is a critical handicap to achieving transplantation tolerance. To make a mouse model that can as closely as possible mimic the presensitized transplant patient is important for research on this subject. Thus, we developed a novel retransplant model and compared the alloresponse in this model with that in the memory T cells-transfer model (transfer control).

Rapamycin or tacrolimus alone fails to resist cardiac allograft accelerated rejection mediated by alloreactive CD4(+) memory T cells in mice.

Donor-reactive memory T (Tm) cells undermine transplanted organs more readily than naive T cells. Rapamycin (RAPA) and tacrolimus (FK-506) are current mainstay immunosuppressants used for preventing acute allograft rejection. Although their efficacy in suppressing naive T cell is established, their suppressing effect on memory T cells is undefined.