Pseudotype-dependent lentiviral transduction of astrocytes or neurons in the rat substantia nigra

Gene transfer to the central nervous system provides powerful methodology for the study of gene function and gene–environment interactions in vivo, in addition to a vehicle for the delivery of therapeutic transgenes for gene therapy. The aim of the present study was to determine patterns of tropism exhibited by pseudotyped lentiviral vectors in the rat substantia nigra, in order to evaluate their utility for gene transfer in experimental models of Parkinson's disease. Isogenic lentiviral vector particles encoding a GFP reporter were pseudotyped with envelope glycoproteins derived from vesicular stomatitis virus (VSV), Mokola virus (MV), lymphocytic choriomeningitis virus (LCMV), or Moloney murine leukemia virus (MuLV). Adult male Lewis rats received unilateral stereotactic infusions of vector into the substantia nigra; three weeks later, patterns of viral transduction were determined by immunohistological detection of GFP. Different pseudotypes gave rise to transgene expression in restricted and distinct cellular populations. VSV and MV pseudotypes transduced midbrain neurons, including a subset of nigral dopaminergic neurons. In contrast, LCMV- and MuLV-pseudotyped lentivirus produced transgene expression exclusively in astrocytes; the restricted transduction of astroglial cells was not explained by the cellular distribution of receptors previously shown to mediate entry of LCMV or MuLV. These data suggest that pseudotyped lentiviral vectors will be useful for experimental gene transfer to the rat substantia nigra. In particular, the availability of neuronal and astrocytic-targeting vectors will allow dissociation of cell autonomous and cell non-autonomous functions of key gene products in vivo.

Research Highlights
► Lentiviral tropism in the rat substantia nigra is pseudotype-dependent.
► VSV- and Mokola-pseudotyped lentiviruses selectively transduce midbrain neurons, including nigral dopamine neurons.
► Neither pseudotype induces signs of toxicity in the nigrostriatal system.
► LCMV- and MuLV-pseudotyped lentiviruses selectively transduce midbrain astrocytes rather than neurons.
► Astrocytic tropism of LCMV- and MuLV-pseudotyped vectors is not explained by the cellular distribution of receptors known to mediate entry of native LCMV or MuLV.