SMaRT Technology Enables Gene Expression Repair in Skin Gene Therapy

In this issue, Wally et al. (2008) report successful gene expression repair by spliceosome-mediated RNA trans-splicing (SMaRT), a novel achievement in molecular medicine. In their model, SMaRT was able to replace a mutation of the plectin gene in epidermolysis bullosa simplex with muscular dystrophy. This approach is particularly attractive for skin gene therapy of dominant-negative mutations present in a number of blistering genodermatoses

Interaction of Adenovirus E1A with the HHV8 Promoter of Latent Genes: E1A Proteins are Able to Activate the HHV-8 LANAp in MV3 Reporter Cells

Human herpesvirus 8 (HHV-8) is associated with Kaposi’s sarcoma, body cavity-based lymphoma, and Castleman’s disease. Adenoviral (Ad) E1A proteins regulate the activity of cellular and viral promoters/enhancers and transcription factors and can suppress tumorigenicity of human cancers. As (i) HHV-8 and Ad may co-exist in immunocompromised patients and (ii) E1A might be considered as therapeutic transgene for HHV-8-associated neoplasms we investigated whether the promoter of the latency-associated nuclear antigen (LANAp) controlling expression of vCyclin, vFLIP, and LANA proteins required for latent type infection is regulated by E1A. Transfection experiments in MV3 melanoma cells revealed activation of the LANAp by Ad5 E1A constructs containing an intact N terminus (aa 1-119). In particular, an Ad12 E1A mutant, Spm2, lacking six consecutive alanine residues in the “spacer” region activated the HHV-8 promoter about 15-fold compared to vector controls. In summary, we report the activation of the LANAp by E1A as a novel interaction of E1A with a viral promoter. These data may have relevance for the management of viral infections in immunocompromised patients. A role for E1A as a therapeutic in this context remains to be defined

Efficient Expression of Naked Plasmid DNA in Mucosal Epithelium: Prospective for the Treatment of Skin Lesions

Mucocutaneous gene therapy offers exciting new treatment modalities for skin lesions. Transient expression of naked plasmid DNA could be used as a local treatment of various skin lesions where the corresponding gene product (protein) has therapeutic or immunization potential. We analyzed the time course, magnitude, and histologic expression of the indicator plasmid DNA (pCMV:β-Gal) in mucosal epithelium and papilloma lesions. Upon direct injection of naked plasmid DNA (20 μg) into oral mucosa, expression occurred at high local concentrations, up to 35-fold higher than in comparable injections into the epidermis. Due to the accelerated turnover of mucosal epithelium β-galactosidase positive epithelial cells were detected in the basal and suprabasal layers as early as 3 h after injection, whereas only the most superficial mucosal layers demonstrated β-galactosidase staining at 24 h post-injection. These biologic characteristics need to be taken into consideration when clinical applications of expressing naked plasmid DNA in epithelial tissues are considered

Visualization of plasmid delivery to keratinocytes in mouse and human epidermis

The accessibility of skin makes it an ideal target organ for nucleic acid-based therapeutics; however, effective patient-friendly delivery remains a major obstacle to clinical utility. A variety of limited and inefficient methods of delivering nucleic acids to keratinocytes have been demonstrated; further advances will require well-characterized reagents, rapid noninvasive assays of delivery, and well-developed skin model systems. Using intravital fluorescence and bioluminescence imaging and a standard set of reporter plasmids we demonstrate transfection of cells in mouse and human xenograft skin using intradermal injection and two microneedle array delivery systems. Reporter gene expression could be detected in individual keratinocytes, in real-time, in both mouse skin as well as human skin xenografts. These studies revealed that non-invasive intravital imaging can be used as a guide for developing gene delivery tools, establishing a benchmark for comparative testing of nucleic acid skin delivery technologies

Prevalence and incidence of head lice

[Extract] Head lice are cosmopolitan insects, and infestations are prevalent throughout the world. Prevalence varies considerably among populations, gender, age groups and according to behavioural factors within a population. In general, head lice are more common at younger age and in females. It is commonly accepted that girls have a higher prevalence of infestation due to playing with each other more closely than age-matched boys. Independent of socio-cultural settings, prevalence of infestation may be high. During recent years, anecdotal evidence suggested that the prevalence has increased worldwide, mainly in resource-rich countries