Retinal cell type expression specificity of HIV-1-derived gene transfer vectors upon subretinal injection in the adult rat: influence of pseudotyping and promoter.
BACKGROUND
Gene therapy, and particularly gene restoration, is currently a great hope for non-curable hereditary retinal degeneration. Clinical applications require a gene transfer vector capable of accurately targeting particular cell types in the retina. To develop such a vector, we compared the expression of a reporter gene after subretinal injections of lentiviral constructs of various pseudotypes and with the transgene expression driven by various promoters.


METHODS
Lentiviral vectors expressing the green fluorescent protein (GFP) under the transcriptional control of cytomegalovirus (CMV), mouse phosphoglycerate kinase (PGK), human elongation factor 1-alpha (EF1alpha), or human rhodopsin (RHO) promoters were pseudotyped by vesicular stomatitis virus (VSV) or Mokola virus envelope proteins. These constructs were injected into the subretinal space of adult rdy rats. GFP expression was analyzed in vivo 1 and 4 weeks after injection by fundus examination. The precise location of transgene expression was then determined by immunohistochemistry and in situ hybridization.


RESULTS
Constructs of both vesicular stomatitis virus and Mokola pseudotypes with ubiquitous promoters led to a strong expression of GFP in vivo. Histological studies confirmed the production of GFP in the retinal pigment epithelium (RPE) in most cases. However, only the combination of the VSV pseudotype with the RHO promoter led to GFP production in photoreceptors, and did so in a sporadic manner.


CONCLUSIONS
Mokola-pseudotyped lentiviral vectors are effective for specific gene transfer to the RPE. Neither VSV- nor Mokola-pseudotyped lentiviral vectors are adequate for efficient gene transfer to photoreceptors of adult rats.
Bemelmans
Alexis-Pierre
AP
BioVectys, c/o laboratoire LGN, Hôpital de la Pitié-Salpêtrière, Paris, France.
Bonnel
Sébastien
S
Houhou
Leïla
L
Dufour
Noëlle
N
Nandrot
Emeline
E
Helmlinger
Dominique
D
Sarkis
Chamsy
C
Abitbol
Marc
M
Mallet
Jacques
J
D000818:Animals; D005822:Genetic Vectors; D049452:Green Fluorescent Proteins / Q000096:biosynthesis / Q000235:genetics; D015497:HIV-1 / Q000235:genetics*; D007267:Injections; D018114:Lyssavirus / Q000235:genetics; D020419:Photoreceptor Cells, Vertebrate / Q000378:metabolism; D010857:Pigment Epithelium of Eye / Q000378:metabolism; D011401:Promoter Regions, Genetic; D051381:Rats; D012160:Retina / Q000378:metabolism*; D014721:Vesicular stomatitis Indiana virus / Q000235:genetics; D014759:Viral Envelope Proteins / Q000235:genetics
D014759:Viral Envelope Proteins; D049452:Green Fluorescent Proteins