Toll-like receptor-9 expression induced by tape-stripping triggers on effective immune response with CpG-oligodeoxynucleotides

Recently, there has been a lot of interest in the potential of non-invasive routes, such as via the skin, for vaccine delivery. CpG-oligodeoxynucleotides (ODN) are an effective adjuvant for the induction of cellular and humoral immunities when administered with an antigen. We demonstrated here that tape-stripping induces the expression of toll-like receptor (TLR)-9 in the skin, and enhances the Th1-type immune response triggered by CpG-ODN administered through the tape-stripped skin. Tape-stripping induces expression of TLR-9 and tumor necrosis factor (TNF)-α in the skin, and CpG-ODN treatment through the tape-stripped skin enhances the migration of antigen presenting cells (APCs) to the draining lymph nodes. On the other hand, TLR-9 mRNA and TNF-α mRNA were not observed in the skin when CpG-ODN was injected intradermally in a volume of 10 μL, or in a Th1-type immune response. The transdermal application of CpG-ODN with an antigen through the tape-stripped skin is an effective way to induce a Th1-type immune response, and is also a simple, cost-effective and needle-free vaccination system.