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Geron mit News Geron Corporation Announces Publication on the Production of Hematopoietic Cells from Human Embryonic Stem Cells Thursday May 22, 7:30 am ET MENLO PARK, Calif.--(BUSINESS WIRE)--May 22, 2003--Geron Corporation (Nasdaq:GERN - News) announced today publication of research data that further demonstrate the potential of human embryonic stem cells (hESCs) for cell-based therapies. In research funded by Geron and currently available as a "first edition" article online (www.bloodjournal.org), Dr. Mickie Bhatia and his colleagues at the Robarts Research Institute in London, Ontario show that hematopoietic cells, which generate the cellular components of blood, can be produced from hESCs using a scalable process suitable for production of therapeutic cells. Such hESC-derived hematopoietic cells have potential applications in bone marrow transplantation procedures and also in generating immunological tolerance to other hESC-derived transplanted cells. ADVERTISEMENT In this research, which will also be published in the August 1 issue of Blood, Dr. Bhatia and his colleagues found that hematopoietic cells could be derived from hESCs using defined combinations of growth factors. This development provides a significant improvement over previously reported methods to derive hematopoietic cells from hESCs that had employed co-cultivation with mouse stromal support cells to trigger differentiation. Dr. Bhatia reported that as many as 8% of the differentiated cells expressed the CD34 and CD45 cell surface markers which define them as hematopoietic progenitor cells. This percentage is comparable to that typically found in normal hematopoietic tissue such as bone marrow, peripheral blood and cord blood. "Being able to use defined reagents to differentiate hESCs into hematopoietic cells is an important step toward scalably producing standardized, well-characterized cells that meet the high standards of quality required for a therapeutic product," stated Thomas B. Okarma Ph.D., M.D., Geron`s president and chief executive officer. "The efficient production of large quantities of high-quality cells is key to the commercialization of any cell therapy, including hESC-based therapies. Not only is this critical for the production of hematopoietic cells for bone marrow transplantation procedures, it is also essential for the use of these cells to achieve immunologic tolerance to other hESC-derived transplanted cells, such as cardiomyocytes for heart failure or islet cells for diabetes. In this approach to achieve tolerance, a low-dose of hESC-derived hematopoietic cells is administered, followed later by the transplanted therapeutic cells derived from the identical hESC line. The hematopoietic cells prevent the rejection of the therapeutic cells because they share identical tissue types, having both been derived from an identical hESC "parental" line. This approach avoids the use of long-term, potentially toxic immunosuppressive drugs." Geron has previously announced the acquisition of license rights to intellectual property from the Robarts Research Institute and the Wisconsin Alumni Research Foundation to produce and use hESC-derived hematopoietic stem cells for these therapeutic applications. Background When cells, tissues or organs are transplanted into the human body, the immune system generally recognizes the tissue as foreign, and mounts an immune response which can lead to the rejection of the transplant. Currently, this rejection response is controlled by the long-term administration of immunosuppressive drugs that suppress the patient`s entire immune system. These drugs often have severe side effects and are costly. Similar, but possibly less severe rejection responses may be encountered in certain instances following transplantation of cells made from hESCs. In conjunction with its collaborators, Geron has been studying various ways by which the immune response against transplanted hESC-derived cells could be reduced or eliminated. In earlier clinical organ transplantation studies, patients who first received a bone marrow transplant (BMT) and then later received an organ transplant from a donor with identical tissue type to that of the prior BMT donor were less likely to reject the organ than patients who had not received such prior BMT. The patients were said to have been "tolerized" to the tissue of the organ donor by virtue of receiving the prior BMT. Specifically, hematopoietic cells from the donated bone marrow combined permanently with the immune system of the BMT recipients such that their immune system no longer recognized tissues from the organ donor as foreign. In this way, the patient`s immune system was taught to tolerate the transplanted organ. This "tolerizing" approach has subsequently been validated with solid organ transplants. It represents an attractive alternative to immunosuppressive drugs because the patient`s immune system remains available to fight off infection and disease. The method could be applied to hESC transplantation by using hematopoietic cells derived from a particular hESC line to "tolerize" a patient to any other transplanted tissue derived from the same hESC line. gruss meislo |
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| aus der Diskussion: | Geron mit Hammernews!! |
| Autor (Datum des Eintrages): | meislo (22.05.03 13:47:32) |
| Beitrag: | 122 von 3,090 (ID:9528259) |
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