Research Group

  • Dr. Sheri M. Krams, Principal Investigator
  • Hideaki Obara, Research Associate
  • Christine Hsieh, Research Associate


  • Stanford University, Stanford, USA


  • NK Cells in Transplantation

Although there have been great advances in the field of organ transplantation, most transplant recipients are still dependent upon immunosuppressive drugs for long-term graft survival. The goal of having the immune system simply “ignore” the foreign graft has yet to be achieved. In recent studies, our group has determined that NK cells of host origin infiltrate liver allografts very early after transplantation. These NK cells are a source of both proinflammatory cytokines and death-inducing molecules.

Currently, little is known about the activation of NK cells, especially within the context of transplantation. We have cloned a novel NK cell activation receptor, rat NKp30 (rNKp30), from infiltrating lymphocytes of a rejecting rat liver allograft. The goal of this research is to examine the role of NK cells and the receptors that activate NK cells in solid organ transplantation. Knowledge of NK cell activation receptors and effector pathways will clarify the role of NK cells in the innate immune system and in solid organ transplantation. Successful completion of these studies may lead to novel strategies to induce tolerance to foreign grafts.