Upregulation of intragraft interleukin-10 by infusion of granulocyte colony-stimulating factor-mobilized donor leukocytes

We examined the effects of granulocyte colony-stimulating factor (G-CSF)-mobilized donor leukocyte infusion (G-DLI) on facilitation of allograft survival using heart transplantation from DA to Lewis rats that were transiently treated with tacrolimus (2 mg/kg i.m. on day 0). Other DA rats were given G-CSF (250 mug/kg/day s.c. from days -5 to 0), and isolated leukocytes were infused into Lewis recipients after surgery. Cytokine mRNA levels were quantified by reverse transcription and real-time polymerase chain reaction. After G-CSF treatment, leukocytes in circulation increased by 7.6 times and secreted in-vitro 6.0-times-higher levels of IL-10 after lipopolysaccharide stimulation than did untreated leukocytes. G-DLI facilitated graft survival dose-dependently. Significant IL-10 mRNA upregulation was detected in grafts 24 h after surgery but not in the recipient's heart, spleen, or liver. On day 6, IFN-gamma and IL-2 mRNA levels were approximately half those of the control levels. Allograft-restricted IL-10 upregulation followed by type-1 cytokine downregulation can be achieved by the use of G-DLI.