Granulocyte colony-stimulating factor-induced comobilization of CD4- CD8- T cells and hematopoietic progenitor cells (CD34+) in the blood of normal donors.

The feasibility of transplantation of HLA-matched hematopoietic progenitor cells from the blood of normal donors given granulocyte colony-stimulating factor (G-CSF) has been reported recently. In the current study, the changes in T-cell subsets as well as CD34+ cells were determined in one blood volume leukapheresis products of six normal individuals given G-CSF. Examination of the T-cell subsets in the leukapheresis products showed three different patterns: one in which a discrete population of CD4- CD8- alphabeta T cells was found in addition to the typical CD4+ and CD8+ T cells in the unfractionated as well as in high- and low-density cells; a second in which the discrete population of CD4- CD8- alphabeta T cells was predominant only in the low-density fractions; and a third in which a discrete population of CD4- CD8- T cells was not observed. The median yield of CD4- CD8- T cells was about fourfold to fivefold higher than the calculated number present in one blood volume (5L) from normal individuals. The ratios of CD34+ cells to CD4+ and CD8+ T cells, and of CD4- CD8- T cells to CD4+ and CD8+ T cells, were highest in the low-density fractions. These fractions suppressed the mixed leukocyte, and may ameliorate graft-versus-host disease as compared with unfractionated cells.