Study into the link between T cells and dendritic cells could lead to reduced rates of organ rejection in transplant patients.

A worldwide team lead by researchers at the University of Pittsburgh School of Medicine studied just how T cells work in the rejection of transplanted organs in the receiver’s body. When immunosuppressive drugs are not taken, the T cells in the body attack the new organ when activated. Researchers set out to study just how these cells become activated and found a way to stop the activation, which has the potential for researchers to develop a new method for preventing the rejection of donor organs.

When studying T cell activation in mice, the researchers concluded that dendritic cells become activated when come into contact with T cells. In mice with kidney and spleen transplants, the donor dendritic cells were being replaced by the organ recipient’s dendritic cells. This replacement of dendritic cells promoted the activation of T cells within the transplant and increased the rate of organ rejection.

"We demonstrated that dendritic cells not only exert a key role as antigen-presenting cells in graft-draining lymphoid organs, but also play a critical function within the transplanted organs," wrote co-author Adrian E. Morelli, MD, PhD, et al. "Our study indicates that eliminating transplant-infiltrating dendritic cells reduces proliferation and survival of T cells within the graft with the consequent prolongation of transplant survival."