The Open Cancer Immunology Journal, 2009, 2, 1-13

Jing Ni1, Britta Nolte1, Vandermeulen Gaëlle2, Veronique Preat2, Daniel Scherman3, Volker
Schirrmacher1 and Philippe Fournier 1*
1 Division of Cellular Immunology, German Cancer Research Center, Heidelberg, Germany
2 Université catholique de Louvain, Department of Pharmaceutics, UCL73.20, 1200 Brussels, Belgium
3 Inserm, U640, Paris, F-75006 France; CNRS, UMR8151, Paris, F-75006 France; Université Paris Descartes, Faculté
de Pharmacie, Chemical and Genetic Pharmacology Laboratory, Paris, F-75270 France; Ecole Nationale Supérieure
de Chimie de Paris, Paris, F-75005 France

Abstract: DNA vaccination appears a very attractive approach for inducing immune responses towards the encoded antigen,
but studies in large animals and in humans revealed weaknesses of such responses. In this study, we evaluated a new
approach based on a new device combining DNA vaccination with electroporation (EP) at the ear pinna site. Under optimal
EP conditions, the expression of the DNA encoded antigen and the induced immune responses were considerably increased.
Very interestingly, DNA vaccination using EP at the ear pinna induced much stronger cellular immune responses
than at the flank skin although antigen expression was similar at both sites. As compared to vaccination at the ear pinna
without EP, IFN-.. but not IL-4 production by splenocytes from immunized mice was significantly enhanced. In contrast,
IL-4 but not IFN-.. production was increased by EP at the flank skin. The vaccination site of the ear pinna combined with
EP route even provided therapeutic effects in a mouse tumor model.
In conclusion, this study highlights the ear pinna as a privileged site for the induction of strong Th1 polarized cellular immunity
against a defined antigen when combining DNA vaccination with EP.