title: Dual roles of autologous CD8+ T cells in hematopoietic progenitor cell mobilization and engraftment.
abstract: BACKGROUND
  Poor marrow cellularity alone cannot explain poor hematopoietic progenitor cell (HPC) mobilization. This study assessed the role of CD8+ T cells in HPC cell mobilization and engraftment.
  
  
  METHODS
  Mobilization and engraftment were assessed in 192 autologous HPC donors. CD34+, CD4+, and CD8+ T-cell contents in apheresis products were evaluated. Using a chemotaxis assay, we assessed the effect of purified autologous CD8+ T cells from low and high mobilizers on HPC migration from high to low stromal cell-derived factor (SDF-1α) concentration gradients. We also assessed CD8+ T-cell content association with days to neutrophil engraftment.
  
  
  RESULTS
  The median number of CD34+ cells/kg was 4.7 × 10(6) . Patients were categorized according to their total CD34+ cell collection quartile distribution into low, moderate, and high mobilizers. We found that HPC products from low mobilizers contained more CD8+ T cells than HPC products from moderate and high mobilizers. Chemotaxis assays showed depletion of CD8+ T cells enhances HPC mobilization independent of SDF-1α concentration. Neutrophil engraftment analysis showed that the higher the CD8+ T-cell content per unit CD34+ cell, the faster the rate of engraftment.
  
  
  CONCLUSIONS
  Our findings suggest CD8+ T cells inhibit HPC mobilization and facilitate homing and engraftment.
authors.affiliation: Transfusion Medicine, Department of Pathology, Jacksonville, Florida.
authors.forename: Athena
authors.initials: A
authors.lastname: Russell
authors.affiliation: Transfusion Medicine, Department of Pathology, Jacksonville, Florida.
authors.forename: Sunita
authors.initials: S
authors.lastname: Malik
authors.affiliation: Division of Hematology/Oncology, Mayo Clinic, Rochester, Minnesota.
authors.forename: Mark
authors.initials: M
authors.lastname: Litzow
authors.affiliation: Division of Hematology/Oncology, Mayo Clinic, Rochester, Minnesota.
authors.forename: Dennis
authors.initials: D
authors.lastname: Gastineau
authors.affiliation: Division of Hematology/Oncology, Mayo Clinic, Jacksonville, Florida.
authors.forename: Vivek
authors.initials: V
authors.lastname: Roy
authors.affiliation: Transfusion Medicine, Department of Pathology, Jacksonville, Florida.
authors.forename: Abba C
authors.initials: AC
authors.lastname: Zubair
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D064592:Autografts; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D054377:Chemokine CXCL12 / Q000187:drug effects; D002633:Chemotaxis / Q000187:drug effects / Q000276:immunology*; D005260:Female; D006085:Graft Survival / Q000276:immunology*; D019650:Hematopoietic Stem Cell Mobilization; D018380:Hematopoietic Stem Cell Transplantation; D006801:Humans; D007937:Leukapheresis; D008297:Male; D008875:Middle Aged
chemical_list: C515255:CXCL12 protein, human; D054377:Chemokine CXCL12