Retrograde Transgene Expression via Neuron-Specific Lentiviral Vector Depends on Both Species and Input Projections

Abstract

For achieving retrograde gene transfer, we have so far developed two types of lentiviral vectors pseudotyped with fusion envelope glycoprotein, termed HiRet vector and NeuRet vector, consisting of distinct combinations of rabies virus and vesicular stomatitis virus glycoproteins. In the present study, we compared the patterns of retrograde transgene expression for the HiRet vs. NeuRet vectors by testing the cortical input system. These vectors were injected into the motor cortex in rats, marmosets, and macaques, and the distributions of retrograde labels were investigated in the cortex and thalamus. Our histological analysis revealed that the NeuRet vector generally exhibits a higher efficiency of retrograde gene transfer than the HiRet vector, though its capacity of retrograde transgene expression in the macaque brain is unexpectedly low, especially in terms of the intracortical connections, as compared to the rat and marmoset brains. It was also demonstrated that the NeuRet but not the HiRet vector displays sufficiently high neuron specificity and causes no marked inflammatory/immune responses at the vector injection sites in the primate (marmoset and macaque) brains. The present results indicate that the retrograde transgene efficiency of the NeuRet vector varies depending not only on the species but also on the input projections.

Dissecting the Prefrontal Network With Pathway-Selective Manipulation in the Macaque Brain—A Review

“…For more efficient retrograde transduction, lentivirus-based HiRet and NeuRet vectors have been developed. These vectors are pseudotyped with fusion glycoproteins composed of rabies virus glycoproteins and vesicular stomatitis virus glycoprotein segments ( Kato et al, 2011a , b , 2014 , 2019 ; Hirano et al, 2013 ; Otsuka et al, 2021 ). The HiRet vector is particularly suited for retrograde transduction from the axon terminals of motor neurons on muscle fibers, whereas the NeuRet vector is suited for retrograde transduction between the subcortical regions.…”

“…The HiRet vector is particularly suited for retrograde transduction from the axon terminals of motor neurons on muscle fibers, whereas the NeuRet vector is suited for retrograde transduction between the subcortical regions. HiRet is less neuron-selective and causes inflammation characterized by microglial and lymphocytic infiltration at the injection site, whereas the NeuRet vector is more neuron-selective and less likely to cause an inflammatory response ( Tanabe et al, 2019 ; Otsuka et al, 2021 ). Recently, rAAV2.retro, which has been proven to infect retrogradely in the rodent brains, has been tested in macaque monkeys.…”

Special Issue “Lentiviral Vectors”

“…Pseudotyping of LV with various non-lentiviral envelopes for gene transfer purposes [ 6 ] and serological studies and testing [ 7 ] was reviewed. Such versatility of LV is exemplified in the research paper testing chimeric envelope proteins between two different viruses on gene transfer to neuronal cells [ 8 ]. Another review on pseudotyping using various envelope proteins focused on gene transfer into hematopoietic cells, an important gene therapy target cell type [ 9 ].…”