Cellular expression of functional chemokine receptor CCR5 and CXCR4 in human embryonic neurons

In the present study we analysed expression of the chemokine receptors CCR5 and CXCR4 in human embryonic neurons. Both receptors were detected in neur ons from primary cultures by immunofluorescence and confocal laser microsco py analysis. Both CCR5 and CXCR4 were mainly located inside the cell in the neuronal cell body and processes. In addition, neurons synthesised CCR5 an d CXCR4 transcripts, as demonstrated by reverse transcription-polymerase ch ain reaction. Stimulation with the CCR5 and the CXCR4 agonists increased [C a2+](i) in embryonic neurons, indicating that CXCR4 and CCR5 were functiona l at the neuronal surface. The inhibitory effect of pertussis toxin demonst rated that G(i alpha) protein is involved in chemokine receptor activation. The fact that chemokine receptors are expressed at embryonic stage in neur ons reinforces the idea that chemokines might be cues for neuron pathfindin g during brain ontogeny. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.