In vitro differentiated cell and human embryonic stem cell population
This invention provides a system for producing differentiated cells from a stem cell population for use wherever a relatively homogenous cell population is desirable. The cells contain an effector gene under control of a transcriptional control element (such as the TERT promoter) that causes the gene to be expressed in relatively undifferentiated cells in the population. Expression of the effector gene results in depletion of undifferentiated cells, or expression of a marker that can be used to remove them later. Suitable effector sequences encode a toxin, a protein that induces apoptosis; a cell-surface antigen, or an enzyme (such as thymidine kinase) that converts a prodrug into a substance that is lethal to the cell. The differentiated cell populations produced according to this disclosure are suitable for use in tissue regeneration, and non-therapeutic applications such as drug screening.
1. An isolated in vitro cell population comprising differentiated cells and less than 1% human embryonic stem (hES) cells, wherein the differentiated cells are the progeny of the hES cells, and wherein the differentiated cells and the hES cells comprise a nucleic acid molecule comprising the structure P-X,
wherein X is a nucleic acid sequence encoding a product that is lethal to a cell in which it is expressed or renders a cell in which it is expressed susceptible to a lethal effect of an external agent, and
wherein P is a transcriptional control element that is expressed in the hES cells and down regulated when the hES cells are induced to differentiate.
2. The cell population of claim 1 , wherein X encodes a toxin, or a protein that induces or mediates apoptosis.
3. The cell population of claim 1 , wherein X encodes an enzyme that converts a prodrug to a compound that is lethal to a cell in which X is expressed.
4. The cell of population claim 3 , wherein X encodes a thymidine kinase.
5. The cell population of claim 1 , wherein P-X is an introduced heterologous molecule.
6. The cell population of claim 1 , wherein P is an endogenous transcriptional control element.
7. The cell population of claim 1 , wherein P is an OCT 4 promoter or a promoter of telomerase reverse transcriptase (TERT).
8. The cell population of claim 1 , wherein the differentiated cells are at least one of neurons, hepatocytes, and cardiomyocytes.
9. The cell population of claim 8 , wherein the differentiated cells are neurons.
10. The cell population of claim 8 , wherein the differentiated cells are hepatocytes.
11. The cell population of claim 8 , wherein the differentiated cells are cardiomyocytes.