Elimination of contaminating cap genes in AAV vector virions reduces immune responses and improves transgene expression in a canine gene therapy model.

Animal and human gene therapy studies utilizing AAV vectors have shown that immune responses to AAV capsid proteins can severely limit transgene expression. The main source of capsid antigen is that associated with the AAV vectors, which can be reduced by stringent vector purification. A second source of AAV capsid proteins is that expressed from cap genes aberrantly packaged into AAV virions during vector production. This antigen source can be eliminated by the use of a cap gene that is too large to be incorporated into an AAV capsid, such as a cap gene containing a large intron (captron gene). Here, we investigated the effects of elimination of cap gene transfer and of vector purification by CsCl gradient centrifugation on AAV vector immunogenicity and expression following intramuscular injection in dogs. We found that both approaches reduced vector immunogenicity and that combining the two produced the lowest immune responses and highest transgene expression. This combined approach enabled the use of a relatively mild immunosuppressive regimen to promote robust micro-dystrophin gene expression in Duchenne muscular dystrophy-affected dogs. Our study shows the importance of minimizing AAV cap gene impurities and indicates that this improvement in AAV vector production may benefit human applications.

Comprehensive survey of developmental genes in the pea aphid, Acyrthosiphon pisum: frequent lineage-specific duplications and losses of developmental genes.

Aphids exhibit unique attributes, such as polyphenisms and specialized cells to house endosymbionts, that make them an interesting system for studies at the interface of ecology, evolution and development. Here we present a comprehensive characterization of the developmental genes in the pea aphid, Acyrthosiphon pisum, and compare our results to other sequenced insects. We investigated genes involved in fundamental developmental processes such as establishment of the body plan and organogenesis, focusing on transcription factors and components of signalling pathways. We found that most developmental genes were well conserved in the pea aphid, although many lineage-specific gene duplications and gene losses have occurred in several gene families. In particular, genetic components of transforming growth factor beta (TGFbeta) Wnt, JAK/STAT (Janus kinase/signal transducer and activator of transcription) and EGF (Epidermal Growth Factor) pathways appear to have been significantly modified in the pea aphid.

Frailty, family, and church support among urban African American elderly.

A community-based survey of 507 African Americans aged 60 and older from South Central Los Angeles was conducted to estimate the prevalence of frailty and describe the correlation between frailty, social support from family and church, and use of community services. Persons were considered frail if they met criteria for any of four conditions: functional impairment, depression, urinary incontinence, falls. Sixty-seven percent met criteria for frailty. Analyses revealed that frail elderly were significantly less likely to report feeling very close to family. Family contact, feeling that church was important, and receiving church support were similar for the frail and nonfrail. Frail elderly were more likely to use community services. These findings suggest that frail elderly in this population may not receive more support from family and church than nonfrail elderly. There is a need for caution when assuming families and churches in urban African American communities are able to support the most vulnerable elderly.

Early soft tissue ingrowth into porous block hydroxyapatite.

A dog model was used to determine the rate of soft tissue infiltration into porous block hydroxyapatite (PBHA) in order to provide a scientific basis for treatment of exposed implants. Ten mongrel dogs underwent alveolar ridge augmentation with PBHA and were killed at various times up to 21 days. Significant soft tissue ingrowth had occurred by 14 days and was complete by day 21. Bone formation was also seen as early as 14 days.