Hematopoietic stem cells (HSCs) continuously replenish all blood cell lineages. Their hallmark property is the ability to maintain a balance between self-renewal and differentiation from embryogenesis to adult life. HSC transplantation whether from bone marrow, mobilized peripheral blood or cord blood is the best example of regenerative cell therapy. Transplantation of HSCs is a widely utilized therapy for a range of genetic and acquired disorders. Allogeneic transplantation depends on genetic matching to avoid graft versus host disease as well as graft rejection. To date, it has been very difficult to maintain and/or expand HSCs in vitro. Cultured HSCs proliferate but with a rapid loss of their stem cell properties. The production of HSCs from other patient cell-types would, in principle, yield genetically matched transplantable material. We have previously shown the generation of HSC-like cells by direct cell reprogramming of skin fibroblasts with expression of three transcription factors (TFs). Some TFs remain bound to chromosomes during mitosis, a process termed mitotic bookmarking. We hypothesize that HSC generation and maintenance through cell division rely on mitotic bookmarking.
In this project, we aim to elucidate the role of mitotic retention and bookmarking by the hematopoietic TF GATA2 during HSC specification and hematopoietic reprogramming. The main aim of the project is to address whether mutations in GATA2 associated with leukemia impact mitotic bookmarking. Key experimental approaches will include molecular cloning, flow cytometry, high-content automated image acquisition and analysis, gene expression profiling, cellular transplantation and Crispr/Cas9 gene editing. Overall, the project will provide new insights on how reprogramming factors impose and preserve HSC cell fate. Ultimately, these studies will allow designing improved TFs to generate patient tailored HSCs in sufficient numbers for autologous transplantation.
Cell Reprogramming in Hematopoiesis and Immunity lab
Cellular reprogramming can be achieved experimentally in different ways, including nuclear transfer, cell fusion or expression of transcription factors. We aim to uncover how hematopoietic stem cell and effector cell identity is established employing cellular reprogramming logic. Ultimately our work may allow the generation of patient-specific hematopoietic cells for regenerative medicine and immunotherapy.
- Gomes, A. et al. Human Hemogenic Reprogramming is Mediated by Cooperative Transcription Factor Induction. Cell Reports 2018, 1-15.
- Pereira, C.F.** et al. Hematopoietic Reprogramming In Vitro Informs In Vivo Identification of Hemogenic Precursors to Definitive Hematopoietic Stem Cells. Developmental Cell 2016, 36 (5), 525-39. **corresponding author.
- Pereira, C. F. ** et al. Induction of a hemogenic program in mouse fibroblasts. Cell Stem Cell 2013, 13 (2), 205-18. **corresponding author.