Potent skin allograft survival prolongation using a committed progenitor fraction of bone marrow in mice.
BACKGROUND
The infusion of donor bone marrow (BM) into mice conditioned with antilymphocyte serum (ALS) and sirolimus (Sir) prolongs skin allograft survival and produces chimerism. This study identifies the BM cell(s) responsible for this effect and determines whether enrichment for these cells will improve efficacy.


METHODS
Skin grafts from BALB/C mice were transplanted into C57BL/6 or C57BL/10 recipients by using ALS, Sir, and BM (or fractions). BM was fractionated by using immunomagnetic beads. Flow cytometry was used for phenotyping and detecting chimerism.


RESULTS
The median graft survival in mice receiving 25 million BM cells was 61 days. Infusion of BM depleted of cells expressing CD19, CD3, CD11c, and c-kit had no effect on median graft survival, whereas infusion of fractions enriched for those cells resulted in median graft survival of 38, 48, 28, and 83 days, respectively. The administration of higher doses (4 x 10(6) and 8x10(6)) of fractions enriched for c-kit resulted in median graft survival of 124 and 197 days, respectively, without chimerism. This favorably compared with mice receiving 150 million BM cells that demonstrated transient mixed chimerism and a median graft survival of 190 days. The majority of cells in the c-kit+-enriched fraction expressed lineage markers. Removal of lineage positive cells from BM before infusion shortened median graft survival (90 days), indicating that the c-kit+ lin+ population is largely responsible for prolongation of graft survival.


CONCLUSIONS
Cells enriched for C-kit+lin+ constitute approximately 5% of murine BM cells and are more potent than whole BM at prolonging skin allograft survival in mice treated with ALS and Sir.
Akpinar
Edip
E
Transplantation Branch, National Institute of Diabetes, Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, USA.
Craighead
Nancy
N
Smoot
Douglas
D
Hale
Douglas A
DA
D000818:Animals; D000961:Antilymphocyte Serum / Q000627:therapeutic use*; D001854:Bone Marrow Cells / Q000166:cytology; D003114:Colony-Forming Units Assay; D006085:Graft Survival / Q000187:drug effects / Q000276:immunology / Q000502:physiology*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D011817:Rabbits; D011956:Receptors, Cell Surface / Q000276:immunology; D016038:Skin Transplantation / Q000276:immunology / Q000502:physiology*; D033581:Stem Cell Transplantation / Q000379:methods*; D013997:Time Factors; D018183:Transplantation Chimera; D014184:Transplantation, Homologous
D000961:Antilymphocyte Serum; D011956:Receptors, Cell Surface