Development of Suspension Adaptation, Scale-up cGMP Banking and Cell Characterization Technologies for hESC Lines
Tools and Technologies I
Statement of Benefit to California:
The goal of this proposal is to develop human embryonic stem cell (hESC) lines that are compatible with suspension-based growth for scaled up culture and banking with cGMP compliance. Initially, the applicants will adapt 3 hESC lines for adherent-free growth with the objectives of eliminating use of feeder cells, more precisely defining media and matrix components, and minimizing the need for mechanical manipulation. The cells will be extensively evaluated throughout these procedures to ensure retention of pluripotency and stability of the genome. In the next phase of this effort, the applicants propose to optimize large-scale expansion technologies for establishing master cell banks of hESC. In addition to evaluation of several scale-up technologies for adaptation of adherent ES Cultures to suspension, the applicants will perform number of assays to demonstrate that the suspension-grown cells are comparable to the parental, adherent lines. The applicants propose to additionally test the cells using novel genetic and epigenetic fingerprinting assays, which will be evaluated as potential tools for final product release and in-culture monitoring. They also will attempt to correlate these fingerprints with the capacity for teratoma and pluripotency. The reviewers were very impressed with the scope, breadth, and potential impact of this proposal. The research plan was well conceived, clearly conveyed, and extremely comprehensive. The collaborating team of investigators is excellent and well suited to this effort. The reviewers expressed some concerns about the choice of cell lines to be used and felt that more attention should have been devoted to providing alternative strategies for potential pitfalls. Despite these concerns, the reviewers agreed that the potential impact and utility of the resulting technology would more than adequately justify the risk of this approach. The impact that the proposed technology offers is potentially very high and directly addresses a roadblock in stem cell biology; the inability to effectively scale and maintain functional, stable hESC lines. Such tools would be of tremendous value for regenerative medicine and could accelerate the translation of these studies into the clinic. Several reviewers expressed concern about the cell lines that are to be used in this study. It appears that one, or perhaps two of the three proposed lines were maintained on murine feeder cells. As these would not be optimal for clinical use, the impact of this effort would be lower. However, if the culturing techniques, assays and other proposed tools could be applied to other cell lines, the impact would remain significant. Despite the complex and ambitious scope of this proposal, the reviewers were generally optimistic of its feasibility due to the logical, thorough research plan and the supreme qualifications of the applicants. The proposal was well conceived and clearly written, although the reviewers were disappointed in the paucity of details that were provided for alternative strategies in the event of failure. Other concerns that were raised alluded mainly to the general risk of the endeavor. The success of the proposal rests on the completion of the first aim, which is expected to take 9 months to 1 year to complete. In addition, the applicants offered too few details on several assays to judge their merit such as sensitivity of the assays. The reviewers found the principal investigator and collaborators to have extensive experience and relevant expertise in all aspects of this proposal. The co-investigators have excellent track records in the areas in which they will contribute. The private/public partnership was considered one of the major assets in this proposal. The research environments were also judged to be outstanding. The budget for this effort was judged to be reasonable, although some reviewers felt that the distribution of funds was too heavily weighted towards investigators with overlapping responsibilities. Overall, this is an ambitious but highly interesting proposal that addresses a key roadblock in the field. The comprehensive approach and strong research team were deemed sound and more than adequate to justify the risk.