PHILADELPHIA — Invitrogen is developing human embryonic stem-cell lines that can be used as a high-throughput platform for drug screening, the company said this week.
The project is currently in the proof-of-concept stage. If the work is successful, Invitrogen could begin offering services based on the platform toward the end of this year or the beginning of next year, said Jonathan Chesnut, Invitrogen’s director of stem cells and regenerative medicine.
The cell lines have a phage integrase-specific locus that determines where multi-gene-expression constructs are inserted into a cell, according to Chesnut.
Inserting these expression constructs from what Chesnut referred to as Invitrogen’s Gateway Element Tool Box creates engineered hESC lines.
Possible applications for the engineered hESCs include using ESC lineage reporters for basic research and drug discovery services; perturbing cells to analyze signaling pathways; and for transgenic animal research, Chesnut said.
Chesnut presented Invitrogen’s technology at the World Pharmaceutical Congress, held here this week.
Components of the Gateway Toolbox include constitutive and inducible promoters, lineage and pathway-specific promoters, and reporters such as β-lactamase and GFP, said Chesnut.
The expression constructs could include special components such as miRNA and mRNA overexpression or knockdown, IRES sequences, insulators, and Tet repressors.
Chesnut told CBA News that he and his colleagues are still trying to determine where in the genome the construct will be inserted.
“Possible applications include the use of ESC lineage reporters for basic research and drug discovery services, cell perturbation for signaling pathway analysis, and the rapid production of engineered ESCs for transgenic animal research.”
“We are looking for a location that is transcriptionally active but stable, that isn’t interrupting other genes, and that doesn’t get silenced when the cells differentiate,” he explained.
He said Invitrogen wants to identify good loci that researchers can retarget again and again, and have their assay be in exactly the same location in every cell each time. Chestnut said his team believes that this will ensure a very reliable and homogeneous assay system in which every cell in a well is expressing exactly the same amount of protein.
Chesnut said that Invitrogen scientists know they can target sites and that they have several cell lines with a target site at specific loci. They also know they can retarget that site.
Now they are looking at these different clones and different loci to see how they behave when the cells differentiate, he said.
Invitrogen already has an undisclosed number of collaborations to develop assays based on the hESC platform, Chesnut said.
Another project Invitrogen is developing is engineered transgenic “platform” mice, and Chesnut said the same ESC system is as applicable in mice as in humans.
Chesnut said that the ready-engineered adult stem and progenitor cells harvested from these mice could be used for basic research or for drug screening and ADME/Tox testing.
“In the long run, our plan is to learn, along with the rest of the field, how [stem] cells behave, and how we may best be able to use them 10 or 15 years in the future,” Chesnut said.