Justin Killebrew

Department: Immunology
Year Entered: 2006
Prior Degrees: BS, Colorado State University, 2003

Research Synopsis:
The majority of T cells expressing autoreactive T cell receptors are eliminated in the thymus during negative selection. However, as the stringency of negative selection increases, the breadth of the T cell repertoire available to respond to pathogens becomes increasingly limited. Therefore, to maintain T cell receptor diversity, some T cells bearing self-reactive receptors are permitted to emerge into the periphery where their activation must be controlled. My research focuses on understanding the cell types and mechanisms responsible for preventing autoimmune disease by regulating these self-reactive T cells. Specifically, I am investigating how homing receptor expression by regulatory T cells affects their ability to migrate to distinct anatomical sites and maintain tolerance toward autoantigens. In the future, regulatory T cell-based therapies may be an effective tool in the treatment of transplant rejection and autoimmune disease.

Why I am participating in the Molecular Medicine Program:
As a student in the Molecular Medicine Training Program, I have gained an understanding of the necessity for collaboration between scientists and clinicians in addressing complex immunological problems. Additionally, the program has taught me the importance of asking clinically relevant questions in my own research.

Publications:
The transcription factor T-bet controls regulatory T cell homeostasis and function during type 1 inflammation. Koch MA, Tucker-Heard G, Perdue NR, Killebrew JR, Urdahl KB, Campbell DJ.
Nat Immunol. 2009 Jun;10(6):595-602. Epub 2009 May 3.