Ex vivo manipulation of hematopoietic stem and progenitor cells

Approaches to manipulate peripheral blood progenitor cells (PBPC) ex vivo currently include the selection of CD34+ cells as a means to purge contaminating tumor cells from leukapheresis preparations or to provide a homogeneous starting population for the expansion of hematopoietic progenitor cells as well as the induction of postprogenitor cells of either the myeloid or megakaryocytic lineage. The latter cell populations might be used for an additional transplantation together with PBPC to possibly shorten the period of aplasia. In addition, ex vivo expansion of CD34+ cells can be used to generate autologous tumor-antigen-presenting dendritic cells for immunotherapeutic approaches aiming to treat minimal residual disease following high-dose chemotherapy.