Skin-specific promoters for genetic immunisation by DNA electroporation

This study aimed at restricting expression of DNA vaccine to specific cell types by using skin-specific promoters (i) to contribute to the understanding of the mechanism of intradermal DNA vaccines and (ii) to address safety concerns associated with DNA vaccines. The expression and immune response after delivery of plasmids encoding luciferase by intradermal DNA electroporation were assessed. Two ubiquitous promoters, CMV and CAG, and three tissue specific promoters were studied. Keratin14 promoter restricts gene expression to keratinocytes of the epidermal basal layer, CD11c promoter to dendritic cells and fascin promoter only to mature dendritic cells. The use of plasmids with tissue specific promoter resulted in significant, but very low protein expression, as compared to that obtained with ubiquitous promoter plasmids. Immunisation with both ubiquitous promoter plasmids elicited humoral and cellular anti-luciferase immune response. No immune response was observed after delivery of CD11c plasmid while fascin and keratin14 plasmids induced IFN-gamma response suggesting that the targeting of skin-specific cells could be a suitable approach but only for the treatment of pathologies or pathogens requiring mainly cellular and not humoral immune response

Correlated gene expression supports synchronous activity in brain networks

During rest, brain activity is synchronized between different regions widely distributed throughout the brain, forming functional networks. However, the molecular mechanisms supporting functional connectivity remain undefined. We show that functional brain networks defined with resting-state functional magnetic resonance imaging can be recapitulated by using measures of correlated gene expression in a post mortem brain tissue data set. The set of 136 genes we identify is significantly enriched for ion channels. Polymorphisms in this set of genes significantly affect resting-state functional connectivity in a large sample of healthy adolescents. Expression levels of these genes are also significantly associated with axonal connectivity in the mouse. The results provide convergent, multimodal evidence that resting-state functional networks correlate with the orchestrated activity of dozens of genes linked to ion channel activity and synaptic function

Effect of tape stripping and adjuvants on immune response after intradermal DNA electroporation

PURPOSE: DNA vaccines require both efficient delivery methods and appropriate adjuvants. Based on their mechanisms of action, we hypothesised that some adjuvants could enhance vaccine immunogenicity or direct the response towards Th1 profile after intradermal DNA electroporation. METHODS: After intradermal electroporation of plasmid DNA encoding luciferase, mice received hyaluronidase, imiquimod, monophosphoryl lipid A or were tape stripped in order to modulate the immune response against the encoded protein. We measured total immunoglobulin G, IgG1, IgG2a titres and the cytokines produced by splenocyte cultures to assess both humoral and cellular response. The effect of tape stripping on the response against intradermally delivered ovalbumin protein was also assessed. RESULTS: Neither hyaluronidase nor imiquimod improved the immune response against the encoded luciferase. Monophosphoryl lipid A did not modify the cytokines production but increased the anti-luciferase IgG2a titres. Tape stripping significantly increased anti-luciferase IgG2a and IFN-gamma responses. It also enhanced the humoral response after intradermal injection of the ovalbumin protein. CONCLUSIONS: Tape stripping is able to increase the Th1 immune response against both DNA and protein vaccines. Therefore, tape stripping appears to have interesting adjuvant effect on intradermal vaccination