Improved transduction efficiency of a lentiviral vector for neuron-specific retrograde gene transfer by optimizing the junction of fusion envelope glycoprotein.

BACKGROUND

The vector for neuron-specific retrograde gene transfer (NeuRet) is a pseudotype of human immunodeficiency virus type 1 (HIV-1)-based vector with fusion glycoprotein type C (FuG-C), which consists of the N-terminal region of the extracellular domain of rabies virus glycoprotein (RVG) and the membrane-proximal region of the extracellular domain and the transmembrane/cytoplasmic domains of vesicular stomatitis virus glycoprotein (VSVG). The NeuRet vector shows a high efficiency of gene transfer through retrograde axonal transport and transduces selectively neuronal cells around the injection site.

NEW METHOD: We aimed to improve the efficiency of retrograde gene transfer of the NeuRet vector by optimizing the junction of RVG and VSVG segments in fusion glycoproteins in their membrane-proximal region.

RESULTS

We produced various types of fusion glycoproteins, in which the junction of the two glycoprotein segments diverged in the membrane-proximal region and used for pseudotyping of HIV-1-based vector to evaluate the in vivo gene transfer efficiency after intrastriatal injection. We found a novel type of fusion glycoprotein termed type E (FuG-E) that yielded enhanced efficiency of retrograde gene delivery, showing neuron-specific transduction surrounding the injection site.

COMPARISON WITH EXISTING

METHODS

The NeuRet vector pseudotyped with FuG-E displayed the improved efficiency of retrograde gene transfer into different neural pathways compared with the original vector pseudotyped with FuG-C.

CONCLUSIONS

Our vector system with FuG-E provides a powerful tool for gene therapeutic trials of neurological and neurodegenerative diseases and for the study of the mechanisms of neural networks underlying various brain functions.