Targeted delivery of proteins into the central nervous system mediated by rabies virus glycoprotein-derived peptide.

PURPOSE: Delivery of therapeutic proteins across the blood-brain barrier (BBB) is severely limited by their size and biochemical properties. Here we showed that a 39-amino acid peptide derived from the rabies virus glycoprotein (RDP) was exploited as an efficient protein carrier for brain-targeting delivery.

METHODS: Three proteins with different molecular weight and pI, β-galactosidase (β-Gal), luciferase (Luc) and brain-derived neurotrophic factor (BDNF), were fused to RDP and intravenously injected into the mice respectively. The slices of different tissues with X-Gal staining were used to examine whether RDP could deliver β-Gal targeted into the CNS. The time-course relationship of RDP-Luc was studied to confirm the transport efficiency of RDP. The neuroprotective function of RDP-BDNF was examined in mouse experimental stroke to explore the pharmacological effect of RDP fusion protein.

RESULTS: The results showed that the fusion proteins rapidly and specific entered the nerve cells in 15 min, and the t(1/2) was about 1 hr. Furthermore, RDP-BDNF fusion protein showed the neuroprotective properties in mouse experimental stroke including reduction of stroke volume and neural deficit.

CONCLUSIONS: RDP provides an effective approach for the targeted delivery of biological active proteins into the central nervous system.