Background
Small non-coding micro-RNAs (miRNA) are important post-transcriptional regulators of mammalian gene expression. More recently, miRNAs have been described that regulate key elements of the adaptive immune response, such as T-cell development and activation (miR-181) and antigen presentation and development in B-cells (miR-155. miR-150), and various aspects of innate immunity (miR-146). We examined whether DNA vaccine vectors co-expressing miRNA with Env antigen could influence the magnitude or quality of the immune responses to Env in mice.