PROJECT SUMMARY
Allogeneic hematopoietic stem cell transplantation (HSCT) plays a vital role in treating high-risk hematologic
malignancies and some non-malignant conditions. However, many patients undergoing HSCT develop acute
graft-versus-host disease (GVHD), and current prevention strategies that globally immunosuppress or
selectively deplete T cells are associated with higher risks of cancer relapse, delayed immune reconstitution,
increased infections, and other toxicities. Identifying the best way to suppress donor T cells to prevent GVHD
while not losing their beneficial functions remains a critically unmet need. The adoptive transfer of murine
invariant natural killer T (iNKT) cells significantly reduces GVHD, and a number of human studies support a role
for iNKT cells in GVHD suppression. Several immunophenotypically and functionally distinct iNKT subsets have
been defined in mice, and only certain subsets have the capacity to suppress GVHD. Despite these advances
in understanding murine iNKT cells, the heterogeneity of human iNKT cells remains largely unexplored, and the
subset best suited to prevent GVHD is unknown. The overall goal of this proposal is to define human iNKT cell
heterogeneity and to develop strategies for the targeted selection and generation of immunosuppressive iNKT
cells. To achieve this goal, similar approaches to those used in mice, as well as novel techniques, will be used
to define the phenotypic, molecular, and functional characteristics of human iNKT subsets to delineate an
immunosuppressive population with the potential to prevent GVHD. In addition, a gene-engineering strategy will
be employed to enhance immunosuppressive function. These experiments will contribute substantially by
providing the scientific basis for the isolation of immunoregulatory iNKT cells which will enable the design of a
future clinical trial of iNKT cell adoptive transfer for GVHD prevention. Importantly, this work is broadly applicable
beyond control of GVHD, as understanding human iNKT heterogeneity will provide a framework for future studies
of iNKT cells and iNKT-based therapies in other disease states, including autoimmunity, cancer, and infection.
The proposed project is part of a comprehensive career development plan for the applicant to build upon her
substantial prior research experience in cellular immunology and hematopoietic stem cell transplantation. In
particular, she plans to acquire new skillsets including high throughput proteomic and transcriptomic analyses
and genetic engineering of cells. This training will occur under the guidance of her primary mentor, Dr. Robert
Negrin, and her research advisory committee, including Drs. Maria Grazia Roncarolo, Matthew Porteus, Samuel
Strober, and Holden Maecker. Their guidance and expertise, combined with that of her collaborators Drs. Ken
Weinberg, Kara Davis, Nima Aghaeepour, and Everett Meyer, will ensure that the applicant completes the
proposed studies and acquires the expertise necessary to fulfill her career goal of becoming an independent
physician scientist with a research program focusing on immune regulation of GVHD in HSCT.