Chemical based reprogramming of human cells to pluripotency

Principal Supervisor: Pascale Guillot

Subsidiary Supervisor: Paolo De Coppi

Project Summary:

The reprogramming of somatic cells to pluripotency was originally pioneered by forced expression of transcription factors (TFs) using retroviral transduction¹. Cellular reprogramming to pluripotency using chemicals alone in replacement of ectopically expressed genes (induced pluripotent stem cells, iPS cells) has not yet been achieved in human cells. We previously demonstrated for the first time that human amniocytes cultivated with valproic acid (VPA_AFS cells) formed well-differentiated teratomas containing derivates of the three germ layers when transplanted into immunodeficient mice, indicating they acquired functional pluripotency^2-4. However, the cells only share 84% transcriptional identity with human embryonic stem (hES) cells.

This internationally competitive 3-year PhD project aims at deriving and characterising translatable human chemically-induced pluripotent stem (hCiPS) cells.

Specifically, the following questions will be addressed: (i) What is the chromatin organisation status within the pluripotency network of CiPSCs? (ii) How does this translate into functional differences in the way these cells perform in various functional assays? (iii) What is the pathway involved into chemical reactivation of the pluripotent network? (iv) Is it possible to revert the cells to naïve pluripotency using a cocktail of small molecule inhibitors?

The techniques used will include deriving iPS cells using small molecules and episomes, transcriptome, epigenome and secretome analysis, culture and characterisation of pluripotent stem cells, imaging.

References:

1. Cell 131, 861-72 (2007)
2. Mol. Ther. 20, 1953-67 (2012)
3. Curr Stem Cell Res Ther 8, 73-81 (2013)
4. Stem Cells Dev 22, 444-58 (2013)