Granulocyte colony-stimulating factor (G-CSF) is a growth factor that plays an essential role in the modulation of hematopoiesis through direct effects on proliferation, survival, and mobilization of bone marrow (BM) and peripheral blood (PB) derived stem cells (SCs).

Evaluate the influence of G-CSF administration on cytokine production by SCs derived from BM and PB in primary culture.

SCs were isolated from BM and PB from 27 BALB/c mice pre-treated for 4 consecutive days with intraperitoneal (i.p.) injections of phosphate-buffered saline (PBS) solution (160 μl/i.p.) or G-CSF (200 μg/kg) at 24-hours intervals. On day 5 (D5), mice were also injected with PBS or G-CSF again. SCs were obtained through BM mononuclear cell isolation by Ficoll-Hypaque™gradient and then stimulated or not with G-CSF in cell culture. Cytokines in the supernatant were quantified by flow cytometry - Cytometric Bead Array (CBA) using the BD™Mouse TH1/TH2/TH17 Cytokine Kit according to manufacturer's instructions. The cytokines measured were IL-2, IL-4, IL-6, IL-10, TNF-α, IFN-γ and IL-17. The kinetics of these cytokines were monitored on days 3, 6, 9, 12 and 15 of culture. FCAP array software (v3.0.1) was used to calculate the concentrations of each cytokine and the mean fluorescence intensity.

An increase in IL-2 and IL-4 was observed between days 9 and 12 of BM-derived SCs culture in groups stimulated with G-CSF. In the culture of PB-derived SCs, the increase in IL-2 and IL-4 occurred between days 3 and 9 in cultures stimulated with G-CSF. The production of IL-6 occurred between days 3 and 9 of culture, both in BM- and PB-derived SCs cultures and reduced until day 15 of culture. In non-G-CSF-stimulated BM-derived SCs cultures, IL-6 levels are elevated in relation to cultures that received G-CSF as a stimulus, on days 6 and 9. IL-10 increased in BM- and PB-derived SCs cultures stimulated with G-CSF on day 3, reducing its concentration until day 15. The same event was observed in BM-derived SCs cultures for IFN-γ and TNF-α, which, like IL-10, were elevated in BM-derived SCs cultures. In PB, an increase in TNF-α is observed on day 3, decreasing progressively until day 15. IL-17 increased on day 12 of BM-derived SCs culture, remaining stable on different days in both BM- and PB-derived SCs cultures.

G-CSF can modulate or induce the production of different cytokines by SCs derived from BM and PB, contributing to better regulation of immune responses in pathological and therapeutical different contexts.

FAPEAM, CAPES and CNPq.