Granulocyte-colony stimulating factor facilitates the restoration of resistance to opportunistic fungi in leukopenic mice.
Administration of recombinant human granulocyte-colony stimulating factor (G-CSF), which induces hemopoietic precursor cells to proliferate and differentiate into neutrophils, protected leukopenic mice infected with opportunistic fungi. Mice were injected with cyclophosphamide and were then subcutaneously (s.c.) or intravenously (i.v.) administered 15-120 micrograms G-CSF kg-1 day-1 for 3 days. The number of peripheral blood neutrophils in the G-CSF treated mice was significantly increased 48 h after G-CSF administration. All leukopenic mice infected with either Candida albicans, Cryptococcus neoformans or Aspergillus fumigatus were significantly protected by treatment with the G-CSF. Moreover, G-CSF treatment caused a decrease in the number of viable yeasts in kidneys of Candida infected mice. These data suggest that prophylactic therapy with G-CSF may be useful against fungal infections in an immunocompromised host.