[Effect of intravenous injection of interleukin-8 on mouse hematopoietic progenitor cell mobilization].

OBJECTIVE

To study the mobilization effects of recombinant human IL-8(rhIL-8) on mouse peripheral blood hematopoietic progenitors (HPCs).

METHODS

A daily single dose of rhIL-8 was intravenously injected into normal or G-CSF-treated mice for two days. The number of colony-forming unit-Mix (CFU-Mix) in peripheral blood was analyzed by colony assay, while the number of c-kit+ Sca-1+ HPCs was examined by immunofluorescence staining. In addition, colony forming unit of spleen (CFU-S) and marrow repopulating ability (MRA) cells were examined by transplanting lethally irradiated mice.

RESULTS

Single dose of rhIL-8 (30 micrograms) significantly increased the numbers of CFU-Mix[(194 +/- 61) x 10(3)/L] and c-kit+ Sca-1+ cells [(3186 +/- 517) x 10(3)/L] in the peripheral blood as compared with that of normal saline controls [(7 +/- 3) x 10(3)/L and (644 +/- 341) x 10(3)/L] at 15 minutes after intravenous injection. G-CSF could also increase peripheral CFU-Mix and c-kit+ Sca-1+ cells to (790 +/- 48) x 10(3)/L and (10,729 +/- 2339) x 10(3)/L, respectively, after subcutaneously injection for two days, this increase was further augmented by rhIL-8 injection. IL-8 alone or in combination with G-CSF could significantly increase the number of CFU-S and MRA cells in circulating blood.

CONCLUSION

IL-8 alone or in combination with G-CSF could significantly mobilize circulating HPCs.