Chemokine receptor CCR5 expression in in vitro differentiating human fetal neural stem/progenitor and glioblastoma cells.

We have studied the expression of CC-chemokine receptor 5 (CCR5) at the protein level in human fetal neural stem/progenitor and glioblastoma cells in differentiation, using immunocytochemistry, routine fluorescence microscopy and confocal laser microscopy analysis. Neural stem/progenitor cells were isolated from the brain of 18-21 weeks old fetuses aborted due to medical indications, and propagated in vitro as neurospheres. Glioblastoma cells were isolated from tumour biopsies and propagated in vitro as spheres according to the same methods as fetal neural cells. Two stem/progenitor cell neurosphere and two glioblastoma spheroid cultures were initiated to differentiate using RA and cAMP. The cells were fixed and analyzed immunocytochemically on the 1st, 3rd, and 8th days of the differentiation. The expression of CCR5 was localized mainly in the cell nuclei, and was usually much weaker, if at all, in cytoplasm. Confocal laser microscopy analysis confirmed the same location. The expression of CCR5 was the highest one on the 3rd day of differentiation in all cultures, but showed also distinct differences between cultures, and in normal fetal differentiated stem/progenitor cells the expression of CCR5 was much weaker than in differentiated glioblastoma spheric cells.