- Prof. Leszek Ignatowicz, Principal Investigator
- Medical College of Georgia, Augusta, USA
- Origin and Allocation of Regulatory T cells upon Graft Rejection or Acceptance
A small subpopulation of T cells, called regulatory CD4+ cells, can induce dominant and long-term tolerance to grafted solid organs. The origin and role of individual regulatory T cell (Treg) clones that are involved in induction of tolerance to grafted tissues are currently unknown. Tregs may either differentiate either early in life in the thymus or later from non-regulatory, naive T cells. Whereas thymus-derived Tregs are long-lived and can exert their suppressive function during their lifespan, Tregs converted from naïve T cells as a part of response to graft may not be so long lived. Here we propose to determine where Tregs that defend a graft and fight effector T cells are made, and how to selectively expand or differentiate Tregs to improve their performance. Furthermore, we will also examine why Tregs have a very diverse repertoire of antigen receptors. Our experiments should reveal if future therapeutic approaches should be focused on selective expansion of pre-existing Tregs or rather de novo induction of such cells from non-regulatory CD4+ T cells.