Methods are provided for modulating expression of claudin-1 and/or claudin-23, for purposes of regulating formation of tight junctions in keratinocytes or other types of cells such as antigen presenting cells (e.g., dendritic cells and Langertians cells), by either increasing or decreasing expression of claudin-1 and/or claudin-23. Also provided are transdermal formulations that decrease expression of claudin-1 and/or claudin-23, thereby diminishing tight junction formation in cells expressing claudin-1 and/or claudin-23, as well as a transdermal patch for delivering the same.
