A Partial Structural and Functional Rescue of a Retinitis Pigmentosa Model with Compacted DNA Nanoparticles

Previously we have shown that compacted DNA nanoparticles can drive high levels of transgene expression after subretinal injection in the mouse eye. Here we delivered compacted DNA nanoparticles containing a therapeutic gene to the retinas of a mouse model of retinitis pigmentosa. Nanoparticles containing the wild-type retinal degeneration slow (Rds) gene were injected into the subretinal space of rds+/− mice on postnatal day 5. Gene expression was sustained for up to four months at levels up to four times higher than in controls injected with saline or naked DNA. The nanoparticles were taken up into virtually all photoreceptors and mediated significant structural and biochemical rescue of the disease without histological or functional evidence of toxicity. Electroretinogram recordings showed that nanoparticle-mediated gene transfer restored cone function to a near-normal level in contrast to transfer of naked plasmid DNA. Rod function was also improved. These findings demonstrate that compacted DNA nanoparticles represent a viable option for development of gene-based interventions for ocular diseases and obviate major barriers commonly encountered with non-viral based therapies

Encephalomyocarditis virus may use different pathways to initiateinfection of primary human cardiomyocytes

Encephalomyocarditis virus (EMCV) caninfect a wide range of vertebrate species including swineand non-human primates, but few data are available forhumans. We therefore wanted to gain further insight intothe mechanisms involved in EMCV infection of humancells. For this purpose, we analyzed the permissiveness ofprimary human cardiomyocytes towards two strains ofEMCV; a pig myocardial strain (B279/95) and a rat strain(1086C). In this study, we show that both strains productivelyinfect primary human cardiomyocytes and inducecomplete cytolysis. Binding and infection inhibitionexperiments indicated that attachment and infection areindependent of sialic acid and heparan sulfate for B279/95and dependent for 1086C. Sequence comparison betweenthe two strains and three-dimensional analysis of the capsidrevealed that six of the seven variable residues are surfaceexposed,suggesting a role for these amino acids in binding.Moreover, analysis of variants isolated from the 1086Cstrain revealed the importance of lysine 231 of VP1 in theattachment of EMCV to cell-surface sialic acid residues.Together, these results show a potential for EMCV strainsto use at least two different binding possibilities to initiateinfection and provide new insights into the mechanismsinvolved in primary human cell recognition by EMCV