The long-term goal of this project is to develop an autologous cell-based therapy to reconstitute the injured lung epithelium utilizing induced pluripotent stem cells (iPSCs), a novel cell population generated by reprogramming fibroblasts into cells virtually indistinguishable from embryonic stem cells (ESCs). The remarkable developmental and differentiation potential of iPSCs makes them attractive candidates for cell-based therapies. Before the full potential of iPSCs can be realized, however, it is first necessary to precisely direct their differentiation in culture and to develop the methodologies needed to sort these cells to purity without contamination by undifferentiated pluripotent cells. This proposal presents three specific aims designed to further advance iPSC research in order to direct the differentiation of these cells into lung epithelial progenitors with a defined cell surfce phenotype. Approaches for utilizing the resulting cells for regeneration of alveolar tissue are presented, and discoveries made in the mouse ESC system in the previous funding cycle are applied to human cells in order to prepare patient-specific lung progenitors from iPSCs.
Aim 1 develops methodologies for the isolation of mouse iPSC-derived lung progenitors, using novel cell surface markers that identify Nkx2.1+ endoderm.
Aim 2 tests the functional roles of a subset of these surface proteins, and Aim 3 utilizes human iPSCs to establish the surface phenotype of primordial human NKX2.1+ endodermal lung progenitors.

Public Health Relevance

This renewal application proposes to develop novel approaches for the regeneration of injured or diseased lung tissue. Completion of these goals would significantly advance the goal of achieving future stem cell-based treatment approaches applicable to any end-stage lung disease, such as cystic fibrosis and emphysema. Herein we propose to develop the methodologies necessary for the derivation and purification of lung progenitors from reprogrammed patient-specific cells, called induced pluripotent stem cells (iPSCs). We propose to utilize iPSCs we have derived from mice and humans, and we will engineer these cells in order to be able to accomplish: a) the purification of lung progenitors based on newly identified cell surface protein markers, and b) the directed differentiation of patient-derived iPSCs into lung epithelial progenitors and endothelial cells.

National Institute of Health (NIH)
National Heart, Lung, and Blood Institute (NHLBI)
Research Project (R01)
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Lung Injury, Repair, and Remodeling Study Section (LIRR)
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Blaisdell, Carol J
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Boston University
Internal Medicine/Medicine
Schools of Medicine
United States
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Longmire, Tyler A; Ikonomou, Laertis; Hawkins, Finn et al. (2012) Efficient derivation of purified lung and thyroid progenitors from embryonic stem cells. Cell Stem Cell 10:398-411
Christodoulou, Constantina; Longmire, Tyler A; Shen, Steven S et al. (2011) Mouse ES and iPS cells can form similar definitive endoderm despite differences in imprinted genes. J Clin Invest 121:2313-25
Somers, Aba; Jean, Jyh-Chang; Sommer, Cesar A et al. (2010) Generation of transgene-free lung disease-specific human induced pluripotent stem cells using a single excisable lentiviral stem cell cassette. Stem Cells 28:1728-40