Abstract: Based on previous evidence suggesting positive effects of fever on in vivo hematopoiesis, the effect of hyperthermia on the expansion and differentiation of megakaryocytes (MKs) in ex vivo cultures of CB CD34-enriched cells has now been tested. Cells were cultured at 37° C. or 39° C. for 14 days in cytokine conditions optimized for MK development, and analyzed periodically by microscopy, flow cytometry and colony assays. Compared to 37° C., cultures maintained at 39° C. produced much more total cells (5×), MK progenitors (9×) and total MKs (7×), and showed accelerated (3-4 days) and enhanced MK maturation with increased yields of proplatelets and platelets (11.7×). The increased number of CD34+ cells and myeloid progenitors in the 39° C. cultures also suggested a general stimulatory effect of hyperthermia on the expansion of more primitive stem/progenitor cells and of cells of other lineages.

Abstract: Based on previous evidence suggesting positive effects of fever on in vivo hematopoiesis, the effect of hyperthermia on the expansion and differentiation of megakaryocytes (MKs) in ex vivo cultures of CB CD34-enriched cells has now been tested. Cells were cultured at 37° C. or 39° C. for 14 days in cytokine conditions optimized for MK development, and analyzed periodically by microscopy, flow cytometry and colony assays. Compared to 37°?C., cultures maintained at 39° C. produced much more total cells (5X), MK progenitors (9X) and total MKs (7X), and showed accelerated (3-4 days) and enhanced MK maturation with increased yields of proplatelets and platelets (11.7X). The increased number of CD34+ cells and myeloid progenitors in the 39° C. cultures also suggested a general stimulatory effect of hyperthermia on the expansion of more primitive stem/progenitor cells and of cells of other lineages.

Abstract: The present invention relates to a novel method for producing human natural interferon-&agr; using ex vivo expanded cord blood hematopoietic cells infected with sendaivirus, on a large scale.