Group leader: 

Lesley Forrester

Position: 

PhD Training Programme Co-ordinator

Contact: 

L [dot] Forrester [at] ed [dot] ac [dot] uk

Aims
Our primary research is focused on identifying and characterizing the molecular processes involved in the differentiation of haematopoietic cells from embryonic stem cells in vitro.

Background
Embryonic stem cells are derived from the inner cell mass of the mouse blastocyst and are able to give rise to all tissues of the developing embryo. They are also able to differentiate in vitro into many cell types and this system has been used as a model to study developmental and diseases processes as well as providing a source of cells for regenerative medicine. However, it has proven difficult to produce pure populations of mature cell type in high numbers. Our research is focused on optimizing the differentiation protocols for the production of haemotopoietic cells from ES cells in vitro using knowledge obtained from the study of these cell types in vivo.

Approaches and progress

Differentiation of haematopoietic lineages from ES cells
We are using a number of strategies to increase the production of haematopoietic progenitor cells from ES cells. We have shown that we can increase haematopoietic differentiation of ES cells by co-culturing them on stromal cell lines derived from the aorta-mesonephros-gonadal region of the developing embryo (Krassowska et al., 2006). We have also established a hormone-inducable expression system to over-express HOXB4 fusion proteins in ES cells because this transcription factor has been shown to enhance haematopoietic differentiation. Identification of HOXB4 target genes in subpopulations of differentiating ES cells will further our understanding about how this transcription factor functions.

In collaboration with Prof. Chris Gregory, Jeremy Hughes and David Kluth within the Centre for Inflammation Research the above approaches are being used to enhance the production of pure populations of macrophages from ES cells to be used to further understand the inflammatory process in a variety of models. Our induction systems are also being applied to the in vitro production of red blood cells.

Role of SCF/KIT pathway in ES cell differentiation
The SCF/KIT pathway plays a role in the many stem cell systems and, using a novel inducible pharmacological-induction strategy, we have shown that it is also critical for the survival of differentiating ES cells (Bashamboo et al, 2006). We are now combining this system with microarray and proteomics approaches to analyse the downstream signaling events in the differentiating ES cells.

Selected publications

• Jackson M, Axton RA, Taylor AH, Wilson JA, Gordon-Keylock SA, Kokkaliaris K, Brickman JM, Schulz H, Hummel O, Hubner N, Forrester LM. 2011.HOXB4 Can Enhance the Differentiation of Embryonic Stem Cells by Modulating the Haematopoietic Niche. Stem Cells, in print. doi: 10.1002/stem.782
• Gordon-Keylock SA, Jackson M, Huang C, Samuel K, Axton RA, Oostendorp RA, Taylor H, Wilson J, Forrester LM. 2010. Induction of hematopoietic differentiation of mouse embryonic stem cells by an AGM-derived stromal cell line is not further enhanced by overexpression of HOXB4. Stem Cells Dev. 19(11):1687-98. doi:10.1089/scd.2009.0467
• Tsakiridis A, Tzouanacou E, Rahman A, Colby D, Axton R, Chambers I, Wilson V, Forrester L, Brickman JM. 2009. Expression-independent gene trap vectors for random and targeted mutagenesis in embryonic stem cells. Nucleic Acids Res 37(19):e129.
• Schulz H, Kolde R, Adler P, Aksoy I, Anastassiadis K, Bader M, Billon N, Boeuf H, Bourillot PY, Buchholz F, et al. 2009. The FunGenES database: a genomics resource for mouse embryonic stem cell differentiation. PLoS One 4, e6804.
• Ledran MH, Krassowska A, Armstrong L, Dimmick I, Renstrom J, Lang R, Yung S, Santibanez-Coref M, Dzierzak E, Stojkovic M, et al. 2008. Efficient hematopoietic differentiation of human embryonic stem cells on stromal cells derived from hematopoietic niches. Cell Stem Cell 3:85-98.
• Axton R, Wallis JA, Taylor H, Hanks M, Forrester LM. 2008. Aminopeptidase O contains a functional nucleolar localization signal and is implicated in vascular biology. J Cell Biochem 103:1171-1182.
• Tsakiridis A, Tzouanakou E, Larralde O, Watts TM, Samuel K, Wilson V, Forrester LM, Brickman JM. 2007. A Novel Triple Fusion Reporter System for Use in Gene Trap Mutagenesis. Genesis 45:353-360.
• Krassowska A, Gordon-Keylock S, Samuel K, Gilchrist D, Dzierzak E, Oostendorp R, Forrester LM, Ansell JD. 2006. Promotion of haematopoietic activity in embryonic stem cells by the aorta-gonad-mesonephros microenvironment. Exp Cell Res 312:3595-3603.
• Jackson M, Watt AJ, Gautier P, Gilchrist D, Driehaus J, Graham GJ, Keebler J, Prugnolle F, Awadalla P, Forrester LM. 2006. A Murine Specific Expansion of the Rhox Cluster involved in Embryonic Stem Cell Biology. BMC Genomics 7:212.
• Bashamboo A, Taylor H, Samuel K, Panthier J-J, Whetton A, Forrester LM. 2006. The survival of differentiating embryonic stem cells is dependent on the SCF/KIT pathway. J. Cell Science. 119:3039-3046.

Funding

• Medical Research Council
• Wellcome Trust
• Scottish Funding Council