Project Summary/Abstract
T cells play a central role in immunity and are of great therapeutic importance. Studies on T cell
development provide direct insights into the pathophysiology of a wide variety of diseases and can
facilitate adoptive T cell immunotherapies. Though a large effort has been made to identify pathways
that regulate T cell differentiation, these studies have mostly focused on secreted proteins, cell
surface receptors, and transcription factors known to directly drive developmental processes.
Recently, we discovered that manipulation of an epigenetic regulator of lymphoid potential promotes
the generation of mature, functional T cells from human induced pluripotent stem cells (iPSCs),
demonstrating an important role for epigenetic modulators in T cell development and function. To
date, the epigenetic regulation of T cell development remains elusive. In this application, we propose
to test the hypothesis that iPSCs provide a platform to identify novel mechanisms regulating T cell
development, and new insights into epigenetic regulations of T cell differentiation can be used to
facilitate the generation of more robust iPSC-T cells for adoptive T cell immunotherapy. Previously,
we have established a stroma-free differentiation system that faithfully recapitulates T cell
development in culture. In Aim 1, we will perform small molecule screens at different stages of iPSC-
T cell differentiation to discover new epigenetic regulators that can affect lymphoid specification and T
cell maturation. We have provided a proof-of-concept by conducting a pilot screen using a library of
small molecules that modulate the activity of epigenetic modification enzymes. The screen identified
several epigenetic modulators, such as histone methyltransferase G9a, that promote T cell fate
commitment. In Aim 2, we will transition our study to mechanistically examine how epigenetic
regulations govern lymphocyte fate decisions via modulating chromatin structure. The impact of
epigenetic modulators, including G9a, on lymphopoiesis will be probed in both iPSC-derived blood
cells and zebrafish models. Lastly, Aim 3 will focus on using small molecule-mediate epigenetic
modulation to facilitate the production of mature iPSC-T cells with enhanced function. Success in the
proposed study will not only improve our understanding of the molecular mechanisms underlying the
formation of immune cells but also open new avenues for stem cell-based immunotherapies. The
career development award will allow me to develop new skills necessary to fulfill the proposed goals
and foster my development into an independent investigator.