title: Local and systemic responses following intravitreous injection of AAV2-encoded modified Volvox channelrhodopsin-1 in a genetically blind rat model.
abstract: We previously designed a modified channelrhodopsin-1 (mVChR1) protein chimera with a broader action than that of Chlamydomonas channelrhodopsin-2 and reported that its transduction into retinal ganglion cells can restore visual function in genetically blind, dystrophic Royal College of Surgeons (RCS) rats, with photostimuli ranging from 486 to 640 nm. In the current study, we sought to investigate the safety and influence of mVChR1 transgene expression. Adeno-associated virus type 2 encoding mVChR1 was administered by intravitreous injection into dystrophic RCS rats. Reverse-transcription PCR was used to monitor virus and transgene dissemination and the results demonstrated that their expression was restricted specifically within the eye tissues, and not in non-target organs. Moreover, examination of the blood, plasma and serum revealed that no excess immunoreactivity was present, as determined using standard clinical hematological parameters. Serum antibodies targeting the recombinant adeno-associated virus (rAAV) capsid increased after the injection; however, no increase in mVChR1 antibody was detected during the observation period. In addition, retinal histological examination showed no signs of inflammation in rAAV-injected rats. In conclusion, our results demonstrate that mVChR1 can be exogenously expressed without harmful immunological reactions in vivo. These findings will aid in studies of AAV gene transfer to restore vision in late-stage retinitis pigmentosa.
authors.affiliation: Laboratory of Visual Neuroscience, Department of Chemistry and Bioengineering, Iwate University Graduate School of Engineering, Morioka, Iwate, Japan.
authors.forename: E
authors.initials: E
authors.lastname: Sugano
authors.affiliation: Laboratory of Visual Neuroscience, Department of Chemistry and Bioengineering, Iwate University Graduate School of Engineering, Morioka, Iwate, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Tabata
authors.affiliation: Laboratory of Visual Neuroscience, Department of Chemistry and Bioengineering, Iwate University Graduate School of Engineering, Morioka, Iwate, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Takahashi
authors.affiliation: Laboratory of Visual Neuroscience, Department of Chemistry and Bioengineering, Iwate University Graduate School of Engineering, Morioka, Iwate, Japan.
authors.forename: F
authors.initials: F
authors.lastname: Nishiyama
authors.affiliation: Laboratory of Visual Neuroscience, Department of Chemistry and Bioengineering, Iwate University Graduate School of Engineering, Morioka, Iwate, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Shimizu
authors.affiliation: Laboratory of Visual Neuroscience, Department of Chemistry and Bioengineering, Iwate University Graduate School of Engineering, Morioka, Iwate, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Sato
authors.affiliation: Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Tamai
authors.affiliation: Laboratory of Visual Neuroscience, Department of Chemistry and Bioengineering, Iwate University Graduate School of Engineering, Morioka, Iwate, Japan.|Clinical Research, Innovation and Education Center, Tohoku University Hospital, Sendai, Miyagi, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Tomita
mesh_terms: D000818:Animals; D001766:Blindness / Q000235:genetics / Q000628:therapy; D000229:Dependovirus / Q000235:genetics / Q000276:immunology*; D004195:Disease Models, Animal; D005074:Evoked Potentials, Visual; D005240:Feasibility Studies; D015316:Genetic Therapy; D005822:Genetic Vectors / Q000276:immunology*; D056724:Immunity, Humoral; D058449:Intravitreal Injections; D051381:Rats; D012160:Retina / Q000378:metabolism / Q000473:pathology; D012174:Retinitis Pigmentosa / Q000628:therapy*; D025604:Rhodopsins, Microbial / Q000235:genetics / Q000276:immunology* / Q000627:therapeutic use; D014018:Tissue Distribution; D014161:Transduction, Genetic; D044446:Volvox / Q000235:genetics / Q000276:immunology*
chemical_list: D025604:Rhodopsins, Microbial