Multi-cellular and multi-molecular immune interactions in the transplantation tolerance and rejection

Transplantation tolerance remains the paramount goal for achieving long-term allograft survival.  Several chemotherapeutic drugs are in use to prolong allograft survival, but its side effects and toxicity limits its clinic application. Transplantation tolerance requires complex cellular and molecular interaction between immune cells and stromal cells in the secondary lymphoid tissues. Early interaction of these cells decides the fate of generation and maintenance of tolerance. The role of adaptive immunity (T cells and B cells) in the inflammation and tolerance are well established, and new cellular and molecular interactions are evolving with time. In this review, we discussed the importance of innate and adaptive immune cells and how their interactions contribute to transplantation tolerance or rejection. We also discussed how these cellular and molecular interactions had been explored to control the inflammatory reactions and promote the survival of allogenic grafts in the various transplantation setting.