Granulocyte-colony stimulating factor mobilizes T helper 2-inducing dendritic cells.
Peripheral blood stem cells (PBSC) obtained from granulocyte-colony stimulating factor (G-CSF)-mobilized donors are increasingly used for allogeneic transplantation. Despite a 10-fold higher dose of transplanted T cells, acute graft-versus-host disease (GVHD) does not develop in higher proportion in recipients of PBSC than in recipients of marrow. T cells from G-CSF-treated experimental animals preferentially produce IL-4 and IL-10, cytokines characteristic of Th2 responses, which are associated with diminished GVHD-inducing ability. We hypothesized that G-CSF-mobilized PBSC contain antigen-presenting cells, which prime T-lymphocytes to produce Th2 cytokines. Two distinct lineages of dendritic cells (DC) have been described in humans, DC1 and DC2, according to their ability to induce naive T-cell differentiation to Th1 and Th2 effector cells, respectively. We have used multicolor microfluorometry to enumerate DC1 and DC2 in the peripheral blood of normal donors. G-CSF treatment with 10 to 16 microg/kg per day for 5 days increased peripheral blood DC2 counts from a median of 4.9 x 10(6)/L to 24.8 x 10(6)/L (P =.0009), whereas DC1 counts did not change. Purified DC1, from either untreated or G-CSF treated donors, induced the proliferation of allogeneic naive T cells, but fresh DC2 were poor stimulators. Tumor necrosis factor-alpha (TNF-alpha)-activated DC1 induced allogeneic naive T cells to produce IFN-gamma, which is typical of Th1 responses, whereas TNF-alpha-activated DC2 induced allogeneic naive T cells to produce IL-4 and IL-10, which are typical of Th2 responses. PBSC transplants contained higher doses of DC2 than marrow transplants (median, 2.4 x 10(6)/kg versus 0.5 x 10(6)/kg) (P =.006), whereas the dose of DC1 was comparable. Thus, it is conceivable that transplantation of G-CSF-stimulated PBSC does not result in overwhelming acute GVHD because the graft contains predominantly Th2-inducing DC. Adoptive transfer of purified DC2 may be exploited to induce immune deviation after transplantation of hematopoietic stem cells or organ allografts. (Blood. 2000;95:2484-2490)
Arpinati
M
M
Division of Clinical Research, Fred Hutchinson Cancer Research Center, University of Washington, Seattle, WA, USA.
Green
C L
CL
Heimfeld
S
S
Heuser
J E
JE
Anasetti
C
C
D019264:Adoptive Transfer; D017951:Antigen Presentation; D003713:Dendritic Cells / Q000276:immunology*; D006086:Graft vs Host Disease / Q000276:immunology / Q000517:prevention & control; D016179:Granulocyte Colony-Stimulating Factor / Q000494:pharmacology*; D019650:Hematopoietic Stem Cell Mobilization; D018380:Hematopoietic Stem Cell Transplantation; D006801:Humans; D018418:Th2 Cells / Q000276:immunology*; D014181:Transplantation Immunology; D014184:Transplantation, Homologous
D016179:Granulocyte Colony-Stimulating Factor